query_id
stringlengths 1
41
| doc_id
stringlengths 1
109
| query
stringlengths 2
5.5k
| document
stringlengths 0
122k
|
|---|---|---|---|
1606 | Renewable_energy | Renewable energy investment kills jobs. | Renewable energy Renewable energy is energy that is collected from renewable resources , which are naturally replenished on a human timescale , such as sunlight , wind , rain , tides , waves , and geothermal heat . Renewable energy often provides energy in four important areas : electricity generation , air and water heating/cooling , transportation , and rural ( off-grid ) energy services . Based on REN21 's 2016 report , renewables contributed 19.2 % to humans ' global energy consumption and 23.7 % to their generation of electricity in 2014 and 2015 , respectively . This energy consumption is divided as 8.9 % coming from traditional biomass , 4.2 % as heat energy ( modern biomass , geothermal and solar heat ) , 3.9 % hydro electricity and 2.2 % is electricity from wind , solar , geothermal , and biomass . Worldwide investments in renewable technologies amounted to more than US$ 286 billion in 2015 , with countries like China and the United States heavily investing in wind , hydro , solar and biofuels . Globally , there are an estimated 7.7 million jobs associated with the renewable energy industries , with solar photovoltaics being the largest renewable employer . As of 2015 worldwide , more than half of all new electricity capacity installed was renewable . Renewable energy resources exist over wide geographical areas , in contrast to other energy sources , which are concentrated in a limited number of countries . Rapid deployment of renewable energy and energy efficiency is resulting in significant energy security , climate change mitigation , and economic benefits . The results of a recent review of the literature concluded that as greenhouse gas ( GHG ) emitters begin to be held liable for damages resulting from GHG emissions resulting in climate change , a high value for liability mitigation would provide powerful incentives for deployment of renewable energy technologies . In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power . At the national level , at least 30 nations around the world already have renewable energy contributing more than 20 percent of energy supply . National renewable energy markets are projected to continue to grow strongly in the coming decade and beyond . Some places and at least two countries , Iceland and Norway generate all their electricity using renewable energy already , and many other countries have the set a goal to reach 100 % renewable energy in the future . For example , in Denmark the government decided to switch the total energy supply ( electricity , mobility and heating/cooling ) to 100 % renewable energy by 2050 . While many renewable energy projects are large-scale , renewable technologies are also suited to rural and remote areas and developing countries , where energy is often crucial in human development . United Nations ' Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity . As most of renewables provide electricity , renewable energy deployment is often applied in conjunction with further electrification , which has several benefits : Electricity can be converted to heat ( where necessary generating higher temperatures than fossil fuels ) , can be converted into mechanical energy with high efficiency and is clean at the point of consumption . In addition to that electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements , because most renewables do n't have a steam cycle with high losses ( fossil power plants usually have losses of 40 to 65 % ) . Renewable energy systems are rapidly becoming more efficient and cheaper . Their share of total energy consumption is increasing . Growth in consumption of coal and oil could end by 2020 due to increased uptake of renewables and natural gas . |
1048 | Little_Ice_Age | While transient weather variability is playing a key role here, the widespread record warmth across the U.S. so far this year is part of a long-term trend toward more warm temperature records versus cold ones. | Little Ice Age The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions . The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period . Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population . |
812 | Saudi_Arabia | The human contribution can be up to 30 percent or so of the total rainfall coming out of the storm | Saudi Arabia Saudi Arabia ( -LSB- saʊ - -RSB- ) , officially the Kingdom of Saudi Arabia ( KSA ) , is an Arab sovereign state in Western Asia constituting the bulk of the Arabian Peninsula . With a land area of approximately , Saudi Arabia is geographically the fifth-largest state in Asia and second-largest state in the Arab world after Algeria . Saudi Arabia is bordered by Jordan and Iraq to the north , Kuwait to the northeast , Qatar , Bahrain and the United Arab Emirates to the east , Oman to the southeast and Yemen to the south . It is separated from Israel and Egypt by the Gulf of Aqaba . It is the only nation with both a Red Sea coast and a Persian Gulf coast and most of its terrain consists of arid desert and mountains . The area of modern-day Saudi Arabia formerly consisted of four distinct regions : Hejaz , Najd and parts of Eastern Arabia ( Al-Ahsa ) and Southern Arabia ( ` Asir ) . The Kingdom of Saudi Arabia was founded in 1932 by Ibn Saud . He united the four regions into a single state through a series of conquests beginning in 1902 with the capture of Riyadh , the ancestral home of his family , the House of Saud . Saudi Arabia has since been an absolute monarchy , effectively a hereditary dictatorship governed along Islamic lines . The ultraconservative Wahhabi religious movement within Sunni Islam has been called `` the predominant feature of Saudi culture '' , with its global spread largely financed by the oil and gas trade . Saudi Arabia is sometimes called `` the Land of the Two Holy Mosques '' in reference to Al-Masjid al-Haram ( in Mecca ) and Al-Masjid an-Nabawi ( in Medina ) , the two holiest places in Islam . The state has a total population of 28.7 million , of which 20 million are Saudi nationals and 8 million are foreigners . The state 's official language is Arabic . Petroleum was discovered on 3 March 1938 and followed up by several other finds in the Eastern Province . Saudi Arabia has since become the world 's largest oil producer and exporter , controlling the world 's second largest oil reserves and the sixth largest gas reserves . The kingdom is categorized as a World Bank high-income economy with a high Human Development Index and is the only Arab country to be part of the G-20 major economies . However , the economy of Saudi Arabia is the least diversified in the Gulf Cooperation Council , lacking any significant service or production sector ( apart from the extraction of resources ) . The state has attracted criticism for its treatment of women and use of capital punishment . Saudi Arabia is a monarchical autocracy , has the fourth highest military expenditure in the world and SIPRI found that Saudi Arabia was the world 's second largest arms importer in 2010 -- 2014 . Saudi Arabia is considered a regional and middle power . In addition to the GCC , it is an active member of the Organisation of Islamic Cooperation and OPEC . |
3119 | Greenhouse_gas | CO2 constitutes 80% of the non-condensing greenhouse gas forcing. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
2516 | Global_warming | The long term warming trend indicates the total energy in the Earth's climate system is increasing due to an energy imbalance. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1052 | Anoxic_event | But as that upper layer warms up, the oxygen-rich waters are less likely to mix down into cooler layers of the ocean because the warm waters are less dense and do not sink as readily. | Anoxic event Oceanic anoxic events or anoxic events ( anoxia conditions ) refer to intervals in the Earth 's past where portions of oceans become depleted in oxygen ( O2 ) at depths over a large geographic area . During some of these events , euxinia , waters that contained hydrogen sulfide , developed . Although anoxic events have not happened for millions of years , the geological record shows that they happened many times in the past . Anoxic events coincided with several mass extinctions and may have contributed to them . These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating . Many geologists believe oceanic anoxic events are strongly linked to slowing of ocean circulation , climatic warming , and elevated levels of greenhouse gases . Researchers have proposed enhanced volcanism ( the release of CO2 ) as the `` central external trigger for euxinia '' . |
2575 | Coral_bleaching | Over the last 30-40 years 80% of coral in the Caribbean have been destroyed and 50% in Indonesia and the Pacific. | Coral bleaching Coral bleaching occurs when coral polyps expel algae that lives inside their tissues . Normally , coral polyps live in an endosymbiotic relationship with the algae and that relationship is crucial for the coral and hence for the health of the whole reef . Bleached corals continue to live . But as the algae provide the coral with 90 % of its energy , after expelling the algae the coral begins to starve . Above-average sea water temperatures caused by global warming have been identified as a leading cause for coral bleaching worldwide . Between 2014 and 2016 , the longest global bleaching events ever were recorded . According to the United Nations Environment Programme , these bleaching events killed coral on an unprecedented scale . In 2016 , bleaching hit 90 percent of coral on the Great Barrier Reef and killed 29 percent of the reef 's coral . In 2017 , the bleaching further expanded to areas of the park that were previously spared , such as the central one . __ TOC __ |
2068 | Attribution_of_recent_climate_change | Global warming responsible for record 2019 July warmth in Alaska. | Attribution of recent climate change Attribution of recent climate change is the effort to scientifically ascertain mechanisms responsible for recent climate changes on Earth , commonly known as ` global warming ' . The effort has focused on changes observed during the period of instrumental temperature record , when records are most reliable ; particularly in the last 50 years , when human activity has grown fastest and observations of the troposphere have become available . The dominant mechanisms are anthropogenic , i.e. , the result of human activity . They are : increasing atmospheric concentrations of greenhouse gases global changes to land surface , such as deforestation increasing atmospheric concentrations of aerosols . There are also natural mechanisms for variation including climate oscillations , changes in solar activity , and volcanic activity . According to the Intergovernmental Panel on Climate Change ( IPCC ) , it is `` extremely likely '' that human influence was the dominant cause of global warming between 1951 and 2010 . The IPCC defines `` extremely likely '' as indicating a probability of 95 to 100 % , based on an expert assessment of all the available evidence . Multiple lines of evidence support attribution of recent climate change to human activities : A basic physical understanding of the climate system : greenhouse gas concentrations have increased and their warming properties are well-established . Historical estimates of past climate changes suggest that the recent changes in global surface temperature are unusual . Computer-based climate models are unable to replicate the observed warming unless human greenhouse gas emissions are included . Natural forces alone ( such as solar and volcanic activity ) can not explain the observed warming . The IPCC 's attribution of recent global warming to human activities is a view shared by the scientific community , and is also supported by 196 other scientific organizations worldwide ( see also : scientific opinion on climate change ) . |
993 | Sea_level_rise | While there has been a mean rise of a little more than 3mm per year worldwide since the 1990s, in the last decade, the NOAA Virginia Key tide gauge just south of Miami Beach has measured a 9mm rise annually." | Sea level rise A sea level rise is an increase in the volume of water in the world 's oceans , resulting in an increase in global mean sea level . Sea level rise is usually attributed to global climate change by thermal expansion of the water in the oceans and by melting of Ice sheets and glaciers on land . Melting of floating ice shelves or icebergs at sea raises sea levels only slightly . Sea level rise at specific locations may be more or less than the global average . Local factors might include tectonic effects , subsidence of the land , tides , currents , storms , etc. . Sea level rise is expected to continue for centuries . Because of the slow inertia , long response time for parts of the climate system , it has been estimated that we are already committed to a sea-level rise of approximately 2.3 m for each degree Celsius of temperature rise within the next 2,000 years . IPCC Summary for Policymakers , AR5 , 2014 , indicated that the global mean sea level rise will continue during the 21st century , very likely at a faster rate than observed from 1971 to 2010 . Projected rates and amounts vary . A January 2017 NOAA report suggests a range of GMSL rise of 0.3 -- 2.5 m possible during the 21st century . Sea level rises can considerably influence human populations in coastal and island regions and natural environments like marine ecosystems . |
1079 | Instrumental_temperature_record | " NASA concurred with NOAA, also declaring 2016 the warmest year on record in its own data set that tracks the temperatures at the surface of the planet's land and oceans, and expressing 'greater than 95 percent certainty' in that conclusion. | Instrumental temperature record The instrumental temperature record provides the temperature of Earth 's climate system from the historical network of in situ measurements of surface air temperatures and ocean surface temperatures . Data are collected at thousands of meteorological stations , buoys and ships around the globe . The longest-running temperature record is the Central England temperature data series , that starts in 1659 . The longest-running quasi-global record starts in 1850 . In recent decades more extensive sampling of ocean temperatures at various depths have begun allowing estimates of ocean heat content but these do not form part of the global surface temperature datasets . |
698 | Nuclear_winter | A recent study led by Lawrence Livermore National Laboratory climate scientist Ben Santer found that while the models ran hot, the 'overestimation' was 'partly due to systematic deficiencies in some of the post-2000 external forcings used in the model simulations.' | Nuclear winter Nuclear winter is the severe global-climatic-cooling-effect , hypothesized to occur after the ignition of a number of firestorms , from nuclear bomb detonations , or wide spread bombardments . Such fires , which can inject soot into the stratosphere , have historically occurred in a number of cities , with nuclear winter researchers using both Hamburg and the less ferocious Hiroshima firestorms as the principal examples . However , as firestorms are most frequently encountered in much larger area wildfires , these latter fires are the most significant today in assessing both the initial and present-day `` nuclear winter '' computer models . |
2295 | 2000s_(decade) | As a result, "The warmest year on US record is now 1934. | 2000s (decade) The 2000s ( pronounced `` two-thousands '' or `` twenty-hundreds '' ) was a decade of the Gregorian calendar that began on January 1 , 2000 , and ended on December 31 , 2009 . The growth of the Internet contributed to globalization during the decade , which allowed faster communication among people around the world . The economic growth of the 2000s had considerable social , environmental and mass extinction consequences , raised demand for diminishing energy resources , and was still vulnerable , as demonstrated by the financial crisis of 2007 -- 08 . |
3004 | Orbital_resonance | "The solar system oscillates with a 60-year cycle due to the Jupiter/Saturn three-synodic cycle and to a Jupiter/Saturn beat tidal cycle... | Orbital resonance In celestial mechanics , an orbital resonance occurs when orbiting bodies exert a regular , periodic gravitational influence on each other , usually because their orbital periods are related by a ratio of small integers . Most commonly this relationship is found for a pair of objects . The physics principle behind orbital resonance is similar in concept to pushing a child on a swing , where the orbit and the swing both have a natural frequency , and the other body doing the `` pushing '' will act in periodic repetition to have a cumulative effect on the motion . Orbital resonances greatly enhance the mutual gravitational influence of the bodies , i.e. , their ability to alter or constrain each other 's orbits . In most cases , this results in an unstable interaction , in which the bodies exchange momentum and shift orbits until the resonance no longer exists . Under some circumstances , a resonant system can be stable and self-correcting , so that the bodies remain in resonance . Examples are the 1:2:4 resonance of Jupiter 's moons Ganymede , Europa and Io , and the 2:3 resonance between Pluto and Neptune . Unstable resonances with Saturn 's inner moons give rise to gaps in the rings of Saturn . The special case of 1:1 resonance ( between bodies with similar orbital radii ) causes large Solar System bodies to eject most other bodies sharing their orbits ; this is part of the much more extensive process of clearing the neighbourhood , an effect that is used in the current definition of a planet . A binary resonance ratio in this article should be interpreted as the completed in the same time interval , rather than as the , which would be the inverse ratio . Thus the 2:3 ratio above means Pluto completes two orbits in the time it takes Neptune to complete three . In the case of resonance relationships between three or more bodies , either type of ratio may be used ( in such cases the smallest whole-integer ratio sequences are not necessarily reversals of each other ) and the type of ratio will be specified . |
2692 | Global_cooling | Volcanoes, solar variations, clouds, methane, aerosols - these all change the way energy enters and/or leaves our climate. | Global cooling Global cooling was a conjecture during the 1970s of imminent cooling of the Earth 's surface and atmosphere culminating in a period of extensive glaciation . This hypothesis had little support in the scientific community , but gained temporary popular attention due to a combination of a slight downward trend of temperatures from the 1940s to the early 1970s and press reports that did not accurately reflect the full scope of the scientific climate literature , which showed a larger and faster-growing body of literature projecting future warming due to greenhouse gas emissions . The current scientific opinion on climate change is that the Earth has not durably cooled , but underwent global warming throughout the 20th century . |
2841 | Antarctic_sea_ice | The exception to this ice loss is Antarctic sea ice which has been growing despite the warming Southern Ocean. | Antarctic sea ice Antarctic sea ice is the sea ice of the Southern Ocean . It extends far north in winter and retreats almost to the coastline each summer . Sea ice is frozen seawater that is usually less than a few meters thick . This is in contrast to ice shelves , which are formed by glaciers , float in the sea , and are up to a kilometer thick . There are two subdivisions of sea ice : fast ice , which is attached to land ; and ice floes , which are not . Sea ice in the Southern Ocean melts from the bottom instead of from the surface like Arctic ice because it is covered in snow . As a result , melt ponds are rarely observed . On average , Antarctic sea ice is younger , thinner , warmer , saltier , and more mobile than Arctic sea ice . Due to its inaccessibility , it is not as well-studied as Arctic ice . |
3038 | Carbon_cycle | Clearly, other factors besides atmospheric carbon influence earth temperatures and global warming." | Carbon cycle The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere , pedosphere , geosphere , hydrosphere , and atmosphere of the Earth . Carbon is the main component of biological compounds as well as a major component of many minerals such as limestone . Along with the nitrogen cycle and the water cycle , the carbon cycle comprises a sequence of events that are key to make Earth capable of sustaining life . It describes the movement of carbon as it is recycled and reused throughout the biosphere , as well as long-term processes of carbon sequestration to and release from carbon sinks . The global carbon budget is the balance of the exchanges ( incomes and losses ) of carbon between the carbon reservoirs or between one specific loop ( e.g. , atmosphere and biosphere ) of the carbon cycle . An examination of the carbon budget of a pool or reservoir can provide information about whether the pool or reservoir is functioning as a source or sink for carbon dioxide . The carbon cycle was initially discovered by Joseph Priestley and Antoine Lavoisier , and popularized by Humphry Davy . |
2084 | Tropical_cyclone | Hurricanes aren't linked to global warming | Tropical cyclone A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center , a closed low-level atmospheric circulation , strong winds , and a spiral arrangement of thunderstorms that produce heavy rain . Depending on its location and strength , a tropical cyclone is referred to by names such as hurricane ( -LSB- ˈhʌrᵻkən -RSB- or -LSB- ˈhʌrᵻkeɪn -RSB- ) , typhoon -LSB- taɪ ` fuːn -RSB- , tropical storm , cyclonic storm , tropical depression , and simply cyclone . A hurricane is a storm that occurs in the Atlantic Ocean and northeastern Pacific Ocean , a typhoon occurs in the northwestern Pacific Ocean , and a cyclone occurs in the south Pacific or Indian Ocean . Tropical cyclones typically form over large bodies of relatively warm water . They derive their energy through the evaporation of water from the ocean surface , which ultimately recondenses into clouds and rain when moist air rises and cools to saturation . This energy source differs from that of mid-latitude cyclonic storms , such as nor'easter s and European windstorms , which are fueled primarily by horizontal temperature contrasts . The strong rotating winds of a tropical cyclone are a result of the conservation of angular momentum imparted by the Earth 's rotation as air flows inwards toward the axis of rotation . As a result , they rarely form within 5 ° of the equator . Tropical cyclones are typically between 100 and in diameter . Tropical refers to the geographical origin of these systems , which form almost exclusively over tropical seas . Cyclone refers to their cyclonic nature , with wind blowing counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere . The opposite direction of circulation is due to the Coriolis effect . In addition to strong winds and rain , tropical cyclones are capable of generating high waves , damaging storm surge , and tornadoes . They typically weaken rapidly over land where they are cut off from their primary energy source . For this reason , coastal regions are particularly vulnerable to damage from a tropical cyclone as compared to inland regions . Heavy rains , however , can cause significant flooding inland , and storm surges can produce extensive coastal flooding up to 40 km from the coastline . Though their effects on human populations are often devastating , tropical cyclones can relieve drought conditions . They also carry heat energy away from the tropics and transport it toward temperate latitudes , which may play an important role in modulating regional and global climate . |
1150 | Arctic_Ocean | To make matters worse, the water temperatures in the Arctic Ocean are several degrees above average, which is an expected result of having less sea ice. | Arctic Ocean The Arctic Ocean is the smallest and shallowest of the world 's five major oceans . The International Hydrographic Organization ( IHO ) recognizes it as an ocean , although some oceanographers call it the Arctic Mediterranean Sea or simply the Arctic Sea , classifying it a mediterranean sea or an estuary of the Atlantic Ocean . Alternatively , the Arctic Ocean can be seen as the northernmost part of the all-encompassing World Ocean . Located mostly in the Arctic north polar region in the middle of the Northern Hemisphere , the Arctic Ocean is almost completely surrounded by Eurasia and North America . It is partly covered by sea ice throughout the year and almost completely in winter . The Arctic Ocean 's surface temperature and salinity vary seasonally as the ice cover melts and freezes ; its salinity is the lowest on average of the five major oceans , due to low evaporation , heavy fresh water inflow from rivers and streams , and limited connection and outflow to surrounding oceanic waters with higher salinities . The summer shrinking of the ice has been quoted at 50 % . The US National Snow and Ice Data Center ( NSIDC ) uses satellite data to provide a daily record of Arctic sea ice cover and the rate of melting compared to an average period and specific past years . |
1377 | Effects_of_global_warming_on_humans | there has been no increase in frequency or intensity of storms, floods or droughts, while deaths attributed to such natural disasters have never been fewer | Effects of global warming on humans Climate change has brought about possibly permanent alterations to Earth 's geological , biological and ecological systems . These changes have led to the emergence of large-scale environmental hazards to human health , such as extreme weather , ozone depletion , increased danger of wildland fires , loss of biodiversity , stresses to food-producing systems and the global spread of infectious diseases . The World Health Organization ( WHO ) estimates that 160,000 deaths , since 1950 , are directly attributable to climate change . Many believe this to be a conservative estimate . To date , a neglected aspect of the climate change debate , much less research has been conducted on the impacts of climate change on health , food supply , economic growth , migration , security , societal change , and public goods , such as drinking water , than on the geophysical changes related to global warming . Human impacts can be both negative and positive . Climatic changes in Siberia , for instance , are expected to improve food production and local economic activity , at least in the short to medium term . Numerous studies suggest , however , that the current and future impacts of climate change on human society are and will continue to be overwhelmingly negative . The majority of the adverse effects of climate change are experienced by poor and low-income communities around the world , who have much higher levels of vulnerability to environmental determinants of health , wealth and other factors , and much lower levels of capacity available for coping with environmental change . A report on the global human impact of climate change published by the Global Humanitarian Forum in 2009 , estimated more than 300,000 deaths and about $ 125 billion in economic losses each year , and indicating that most climate change induced mortality is due to worsening floods and droughts in developing countries . |
1923 | Americans | More than 260,000 Americans are employed by the domestic solar industry — three times as many workers as employed by the entire coal mining industry. | Americans Americans are citizens of the United States of America . The country is home to people of many different national origins . As a result , Americans do not equate their nationality with ethnicity , but with citizenship and allegiance . Although citizens make up the majority of Americans , non-citizen residents , dual citizens , and expatriates may also claim an American identity . The use in English of the term `` American '' to exclusively mean people of the United States developed from its original use to differentiate English people of the American colonies from English people of England despite its linguistic ambiguity in other senses of the word `` American '' , which can also refer to people from the Americas in general . See Names for United States citizens . |
1784 | Carbon_dioxide_in_Earth's_atmosphere | Many lines of evidence, including simple accounting, demonstrate beyond a shadow of a doubt that the increase in atmospheric CO2 is due to human fossil fuel burning. | Carbon dioxide in Earth's atmosphere Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years . Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds . The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification . |
2869 | Intergovernmental_Panel_on_Climate_Change | Claims that the IPCC does not accurately represent the views and findings of the scientists, on whose work the IPCC reports are based, are not supported by the facts. | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
2242 | Anoxic_event | The warming causes the oceans to release CO2. | Anoxic event Oceanic anoxic events or anoxic events ( anoxia conditions ) refer to intervals in the Earth 's past where portions of oceans become depleted in oxygen ( O2 ) at depths over a large geographic area . During some of these events , euxinia , waters that contained hydrogen sulfide , developed . Although anoxic events have not happened for millions of years , the geological record shows that they happened many times in the past . Anoxic events coincided with several mass extinctions and may have contributed to them . These mass extinctions include some that geobiologists use as time markers in biostratigraphic dating . Many geologists believe oceanic anoxic events are strongly linked to slowing of ocean circulation , climatic warming , and elevated levels of greenhouse gases . Researchers have proposed enhanced volcanism ( the release of CO2 ) as the `` central external trigger for euxinia '' . |
3007 | Gale_(crater) | There seems to be evidence for a link between solar activity and water levels. | Gale (crater) Gale is a crater , and probable dry lake on Mars near the northwestern part of the Aeolis quadrangle at . It is 154 km in diameter and estimated to be about 3.5-3 .8 billion years old . The crater was named after Walter Frederick Gale , an amateur astronomer from Sydney , Australia , who observed Mars in the late 19th century . Aeolis Mons is a mountain in the center of Gale and rises 5.5 km high . Aeolis Palus is the plain between the northern wall of Gale and the northern foothills of Aeolis Mons . Peace Vallis , a nearby outflow channel , ` flows ' down from the Gale crater hills to the Aeolis Palus below and seems to have been carved by flowing water . The NASA Mars rover , Curiosity , of the Mars Science Laboratory ( MSL ) mission , landed in `` Yellowknife '' Quad 51 of Aeolis Palus in Gale at 05:32 UTC August 6 , 2012 . NASA named the landing location Bradbury Landing on August 22 , 2012 . Curiosity is exploring Aeolis Mons and surrounding areas . |
568 | Regime_shift | The research also revealed how large areas of the polar ice caps could collapse and significant changes to ecosystems could see the Sahara Desert become green and the edges of tropical forests turn into fire-dominated savanna. | Regime shift In ecology , regime shifts are large , abrupt , persistent changes in the structure and function of a system . A regime is a characteristic behaviour of a system which is maintained by mutually reinforced processes or feedbacks . Regimes are considered persistent relative to the time period over which the shift occurs . The change of regimes , or the shift , usually occurs when a smooth change in an internal process ( feedback ) or a single disturbance ( external shocks ) triggers a completely different system behavior . Although such non-linear changes have been widely studied in different disciplines ranging from atoms to climate dynamics , regime shifts have gained importance in ecology because they can substantially affect the flow of ecosystem services that societies rely upon , such as provision of food , clean water or climate regulation . Moreover , regime shift occurrence is expected to increase as human influence on the planet increases -- the Anthropocene -- including current trends on human induced climate change and biodiversity loss . |
905 | Greenhouse_gas | "Some experts, such as UN climate scientist Dr. Indur Goklany, have defended rising CO2 levels as a good thing for humanity. | Greenhouse gas A greenhouse gas ( abbrev . GHG ) is a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range . This process is the fundamental cause of the greenhouse effect . The primary greenhouse gases in Earth 's atmosphere are water vapor , carbon dioxide , methane , nitrous oxide , and ozone . Without greenhouse gases , the average temperature of Earth 's surface would be about -18 ° C , rather than the present average of 15 ° C . In the Solar System , the atmospheres of Venus , Mars and Titan also contain gases that cause a greenhouse effect . Human activities since the beginning of the Industrial Revolution ( taken as the year 1750 ) have produced a 40 % increase in the atmospheric concentration of carbon dioxide , from 280 ppm in 1750 to 406 ppm in early 2017 . This increase has occurred despite the uptake of a large portion of the emissions by various natural `` sinks '' involved in the carbon cycle . Anthropogenic carbon dioxide emissions ( i.e. , emissions produced by human activities ) come from combustion of fossil fuels , principally coal , oil , and natural gas , along with deforestation , soil erosion and animal agriculture . It has been estimated that if greenhouse gas emissions continue at the present rate , Earth 's surface temperature could exceed historical values as early as 2047 , with potentially harmful effects on ecosystems , biodiversity and the livelihoods of people worldwide . Recent estimates suggest that on the current emissions trajectory the Earth could pass a threshold of 2 ° C global warming , which the United Nations ' IPCC designated as the upper limit to avoid `` dangerous '' global warming , by 2036 . |
2369 | Passive_solar_building_design | The public understand it, in that if you get a fall evening or spring evening and the sky is clear the heat will escape and the temperature will drop and you get frost. | Passive solar building design In passive solar building design , windows , walls , and floors are made to collect , store , and distribute solar energy in the form of heat in the winter and reject solar heat in the summer . This is called passive solar design because , unlike active solar heating systems , it does not involve the use of mechanical and electrical devices . The key to design a passive solar building is to best take advantage of the local climate performing an accurate site analysis . Elements to be considered include window placement and size , and glazing type , thermal insulation , thermal mass , and shading . Passive solar design techniques can be applied most easily to new buildings , but existing buildings can be adapted or `` retrofitted '' . |
1591 | Geysers_on_Mars | Murry Salby finds CO2 rise is natural. | Geysers on Mars Martian geysers (or CO2 jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Martian geysers are distinct from geysers on Earth, which are typically associated with hydrothermal activity. These are unlike any terrestrial geological phenomenon. The reflectance (albedo), shapes and unusual spider appearance of these features have stimulated a variety of hypotheses about their origin, ranging from differences in frosting reflectance, to explanations involving biological processes. However, all current geophysical models assume some sort of jet or geyser-like activity on Mars. Their characteristics, and the process of their formation, are still a matter of debate. These features are unique to the south polar region of Mars in an area informally called the 'cryptic region', at latitudes 60° to 80° south and longitudes 150°W to 310°W; this 1 meter deep carbon dioxide (CO2) ice transition area—between the scarps of the thick polar ice layer and the permafrost—is where clusters of the apparent geyser systems are located. The seasonal frosting and defrosting of carbon dioxide ice results in the appearance of a number of features, such dark dune spots with spider-like rilles or channels below the ice, where spider-like radial channels are carved between the ground and the carbon dioxide ice, giving it an appearance of spider webs, then, pressure accumulating in their interior ejects gas and dark basaltic sand or dust, which is deposited on the ice surface and thus, forming dark dune spots. This process is rapid, observed happening in the space of a few days, weeks or months, a growth rate rather unusual in geology – especially for Mars. However, it would seem that multiple years would be required to carve the larger spider-like channels. There is no direct data on these features other than images taken in the visible and infrared spectra. |
803 | Intergovernmental_Panel_on_Climate_Change | The team of climate scientists notes that in failing to predict the warming 'hiatus' in the beginning of the 21st century, the Intergovernmental Panel on Climate Change (IPCC) models overestimated temperature increases… | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
1169 | Sea_level_rise | "Sea level rise, which was occurring long before humans could be blamed, has not accelerated and still amounts to only 1 inch every ten years. | Sea level rise A sea level rise is an increase in the volume of water in the world 's oceans , resulting in an increase in global mean sea level . Sea level rise is usually attributed to global climate change by thermal expansion of the water in the oceans and by melting of Ice sheets and glaciers on land . Melting of floating ice shelves or icebergs at sea raises sea levels only slightly . Sea level rise at specific locations may be more or less than the global average . Local factors might include tectonic effects , subsidence of the land , tides , currents , storms , etc. . Sea level rise is expected to continue for centuries . Because of the slow inertia , long response time for parts of the climate system , it has been estimated that we are already committed to a sea-level rise of approximately 2.3 m for each degree Celsius of temperature rise within the next 2,000 years . IPCC Summary for Policymakers , AR5 , 2014 , indicated that the global mean sea level rise will continue during the 21st century , very likely at a faster rate than observed from 1971 to 2010 . Projected rates and amounts vary . A January 2017 NOAA report suggests a range of GMSL rise of 0.3 -- 2.5 m possible during the 21st century . Sea level rises can considerably influence human populations in coastal and island regions and natural environments like marine ecosystems . |
2616 | Humidity | To claim that humidity is decreasing requires you ignore a multitude of independent reanalyses that all show increasing humidity. | Humidity Humidity is the amount of water vapor present in the air . Water vapor is the gaseous state of water and is invisible to the human eye . Humidity indicates the likelihood of precipitation , dew , or fog . Higher humidity reduces the effectiveness of sweating in cooling the body by reducing the rate of evaporation of moisture from the skin . This effect is calculated in a heat index table or humidex . The amount of water vapor that is needed to achieve saturation increases as the temperature increases . As the temperature of a parcel of water becomes lower it will eventually reach the point of saturation without adding or losing water mass . The differences in the amount of water vapor in a parcel of air can be quite large . For example , a parcel of air that is near saturation may contain 28 grams of water per cubic meter of air at 30 ° C , but only 8 grams of water per cubic meter of air at 8 ° C. There are three main measurements of humidity : absolute , relative and specific . Absolute humidity is the water content of air expressed in gram per cubic meter . Relative humidity , expressed as a percent , measures the current absolute humidity relative to the maximum ( highest point ) for that temperature . Specific humidity is the ratio of the mass of water vapor to the total mass of the moist air parcel . |
1995 | Solar_power_in_the_United_States | There are about 120,000 solar energy jobs in the United States, but only 1,700 of them are in Georgia. | Solar power in the United States Solar power in the United States includes utility-scale solar power plants as well as local distributed generation , mostly from rooftop photovoltaics . As of the end of 2016 , the U.S. had 40 gigawatts ( GW ) of installed photovoltaic capacity , having almost doubled in capacity from the previous year . In the twelve months through March 2017 , utility scale solar power generated 38.3 terawatt-hours ( TWh ) , 0.94 % of total U.S. electricity . During the same time period total solar generation , including estimated distributed solar photovoltaic generation , was 59.8 TWh , 1.47 % of total U.S. electricity . In terms of total installed capacity , by year end 2015 the USA ranked 4th in the world behind China , Germany , and Japan . In 2016 , 39 % of all new electricity generation capacity in the country came from solar , more than any other source and ahead of natural gas ( 29 % ) . By 2015 , solar employment had overtaken oil and gas as well as coal employment in the U.S. The United States conducted much early research in photovoltaics and concentrated solar power . The U.S. is among the top countries in the world in electricity generated by the Sun and several of the world 's largest utility-scale installations are located in the desert Southwest . The oldest solar power plant in the world is the 354-megawatt ( MW ) SEGS thermal power plant , in California . The Ivanpah Solar Electric Generating System is a solar thermal power project in the California Mojave Desert , 40 miles ( 64 km ) southwest of Las Vegas , with a gross capacity of 392 MW . The 280 MW Solana Generating Station is a solar power plant near Gila Bend , Arizona , about 70 mi southwest of Phoenix , completed in 2013 . When commissioned it was the largest parabolic trough plant in the world and the first U.S. solar plant with molten salt thermal energy storage . There are plans to build many other large solar plants in the United States . Many states have set individual renewable energy goals with solar power being included in various proportions . Governor Jerry Brown has signed legislation requiring California 's utilities to obtain 50 percent of their electricity from renewable energy sources by the end of 2030 . |
1744 | Sea-level_curve | The claim sea level isn't rising is based on blatantly doctored graphs contradicted by observations. | Sea-level curve The sea-level curve is the representation of the changes of the sea level throughout the geological history . The first such curve is the Vail curve or Exxon curve . The names of the curve refer to the fact that in 1977 a team of Exxon geologists from Esso Production Research headed by Peter Vail published a monograph on global eustatic sea-level changes . Their sea-level curve was based on seismic and biostratigraphic data accumulated during petroleum exploration . The Vail curve ( and the monograph itself ) was the subject of debate among geologists , because it was based on undisclosed commercially confidential stratigraphic data , and hence not independently verifiable . Because of this , there were later efforts to establish a sea-level curve based on non-commercial data . In 1987 -- 1988 a revised eustatic sea-level curve for the Mesozoic and Cenozoic eras was published , now known as the Haq sea-level curve , in reference to the Pakistani-American Oceanographer Bilal Haq . |
849 | Permafrost | The most notorious was 252 million years ago; it began when carbon warmed the planet by five degrees, accelerated when that warming triggered the release of methane in the Arctic, and ended with 97 percent of all life on Earth dead." | Permafrost In geology , permafrost is ground , including rock or ( cryotic ) soil , at or below the freezing point of water 0 C for two or more years . Most permafrost is located in high latitudes ( in and around the Arctic and Antarctic regions ) , but alpine permafrost may exist at high altitudes in much lower latitudes . Ground ice is not always present , as may be in the case of nonporous bedrock , but it frequently occurs and it may be in amounts exceeding the potential hydraulic saturation of the ground material . Permafrost accounts for 0.022 % of total water on earth and exists in 24 % of exposed land in the Northern Hemisphere . It also occurs subsea on the continental shelves of the continents surrounding the Arctic Ocean , portions of which were exposed during the last glacial period , with global weather implications . A global temperature rise of 1.5 C-change above current levels would be enough to start the thawing of permafrost in Siberia , according to one group of scientists . |
1109 | Arctic_sea_ice_decline | "The chain of events that links the melting Arctic with weather to the south begins with rising global temperatures causing more sea ice to melt. | Arctic sea ice decline Arctic sea ice decline is the sea ice loss observed in recent decades in the Arctic Ocean . The Intergovernmental Panel on Climate Change ( IPCC ) Fourth Assessment Report states that greenhouse gas forcing is largely , but not wholly , responsible for the decline in Arctic sea ice extent . A study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades . A study from 2007 found the decline to be `` faster than forecasted '' by model simulations . The IPCC Fifth Assessment Report concluded with high confidence that sea ice continues to decrease in extent , and that there is robust evidence for the downward trend in Arctic summer sea ice extent since 1979 . It has been established that the region is at its warmest for at least 40,000 years and the Arctic-wide melt season has lengthened at a rate of 5 days per decade ( from 1979 to 2013 ) , dominated by a later autumn freezeup . Sea ice changes have been identified as a mechanism for polar amplification . |
2193 | Solar_activity_and_climate | In the last 35 years of global warming, the sun has shown a slight cooling trend. | Solar activity and climate Solar irradiance variation has been a main driver of climate change over geologic time , but its role in the recent warming has been found to be insignificant . |
717 | Climatology | Scientists used to think that ice sheets could take millennia to respond to changing climates | Climatology Climatology ( from Greek κλίμα , klima , `` place , zone '' ; and - λογία , - logia ) or climate science is the study of climate , scientifically defined as weather conditions averaged over a period of time . This modern field of study is regarded as a branch of the atmospheric sciences and a subfield of physical geography , which is one of the Earth sciences . Climatology now includes aspects of oceanography and biogeochemistry . Basic knowledge of climate can be used within shorter term weather forecasting using analog techniques such as the El Niño -- Southern Oscillation ( ENSO ) , the Madden -- Julian oscillation ( MJO ) , the North Atlantic oscillation ( NAO ) , the Northern Annular Mode ( NAM ) which is also known as the Arctic oscillation ( AO ) , the Northern Pacific ( NP ) Index , the Pacific decadal oscillation ( PDO ) , and the Interdecadal Pacific Oscillation ( IPO ) . Climate models are used for a variety of purposes from study of the dynamics of the weather and climate system to projections of future climate . Weather is known as the condition of the atmosphere over a period of time . While Climate has to do with the atmospheric condition over an extended to indefinite period of time . |
281 | Climatic_Research_Unit_email_controversy | In an interview with the BBC after the scandal broke, Dr Jones admitted there had been no statistically significant global warming since 1995 | Climatic Research Unit email controversy The Climatic Research Unit email controversy ( also known as `` Climategate '' ) began in November 2009 with the hacking of a server at the Climatic Research Unit ( CRU ) at the University of East Anglia ( UEA ) by an external attacker , copying thousands of emails and computer files , the Climatic Research Unit documents , to various internet locations several weeks before the Copenhagen Summit on climate change . The story was first broken by climate change denialists with columnist James Delingpole popularising the term `` Climategate '' to describe the controversy . Several people considered climate change `` skeptics '' argued that the emails showed global warming was a scientific conspiracy , that scientists manipulated climate data and attempted to suppress critics . The CRU rejected this , saying the emails had been taken out of context and merely reflected an honest exchange of ideas . The mainstream media picked up the story as negotiations over climate change mitigation began in Copenhagen on 7 December 2009 . Because of the timing , scientists , policy makers and public relations experts said that the release of emails was a smear campaign intended to undermine the climate conference . In response to the controversy , the American Association for the Advancement of Science ( AAAS ) , the American Meteorological Society ( AMS ) and the Union of Concerned Scientists ( UCS ) released statements supporting the scientific consensus that the Earth 's mean surface temperature had been rising for decades , with the AAAS concluding , `` based on multiple lines of scientific evidence that global climate change caused by human activities is now underway ... it is a growing threat to society . '' Eight committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . However , the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work , for example by opening up access to their supporting data , processing methods and software , and by promptly honouring freedom of information requests . The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations . |
1944 | Air_pollution | Over the past eight years, the United States has reduced our total carbon pollution more than any other nation on Earth. | Air pollution Air pollution occurs when harmful substances including particulates and biological molecules are introduced into Earth 's atmosphere . It may cause diseases , allergies or death in humans ; it may also cause harm to other living organisms such as animals and food crops , and may damage the natural or built environment . Human activity and natural processes can both generate air pollution . Indoor air pollution and poor urban air quality are listed as two of the world 's worst toxic pollution problems in the 2008 Blacksmith Institute World 's Worst Polluted Places report . According to the 2014 WHO report , air pollution in 2012 caused the deaths of around 7 million people worldwide , an estimate roughly matched by the International Energy Agency . |
821 | World_War_I | Societies do fall apart from war, disease or chaos. | World War I World War I ( WWI or WW1 ) , also known as the First World War , the Great War , or the War to End All Wars , was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918 . More than 70 million military personnel , including 60 million Europeans , were mobilised in one of the largest wars in history . Over nine million combatants and seven million civilians died as a result of the war ( including the victims of a number of genocides ) , a casualty rate exacerbated by the belligerents ' technological and industrial sophistication , and the tactical stalemate caused by gruelling trench warfare . It was one of the deadliest conflicts in history , and paved the way for major political changes , including revolutions in many of the nations involved and to WWII twenty-one years later . The war drew in all the world 's economic great powers , assembled in two opposing alliances : the Allies ( based on the Triple Entente of the Russian Empire , the French Third Republic , and the United Kingdom of Great Britain and Ireland ) versus the Central Powers of Germany and Austria-Hungary . Although Italy was a member of the Triple Alliance alongside Germany and Austria-Hungary , it did not join the Central Powers , as Austria-Hungary had taken the offensive against the terms of the alliance . These alliances were reorganised and expanded as more nations entered the war : Italy , Japan and the United States joined the Allies , while the Ottoman Empire and Bulgaria joined the Central Powers . The trigger for the war was the assassination of Archduke Franz Ferdinand of Austria , heir to the throne of Austria-Hungary , by Yugoslav nationalist Gavrilo Princip in Sarajevo on 28 June 1914 . This set off a diplomatic crisis when Austria-Hungary delivered an ultimatum to the Kingdom of Serbia , and entangled international alliances formed over the previous decades were invoked . Within weeks , the major powers were at war and the conflict soon spread around the world . On 25 July Russia began mobilisation and on 28 July , the Austro-Hungarians declared war on Serbia . Germany presented an ultimatum to Russia to demobilise , and when this was refused , declared war on Russia on 1 August . Being outnumbered on the eastern front , Russia urged its Triple Entente ally France to open up a second front in the west . Back in 1870 , the Franco-Prussian war had ended the Second French Empire and ceded the provinces of Alsace-Lorraine to a unified Germany . Bitterness over their defeat and the determinance to retake Alsace-Lorraine made the acceptance of Russia 's plea for help an easy choice so France began full mobilisation on 1 August and on 3 August , Germany declared war on France . The border between France and Germany was heavily fortified on both sides so according to the Schlieffen Plan , Germany then invaded neutral Belgium and Luxembourg before moving towards France from the north , leading the United Kingdom to declare war on Germany on 4 August due to their violation of Belgian neutrality . After the German march on Paris was halted in the Battle of the Marne , what became known as the Western Front settled into a battle of attrition , with a trench line that changed little until 1917 . On the Eastern Front , the Russian army led a successful campaign against the Austro-Hungarians , but the Germans stopped its invasion of East Prussia in the battles of Tannenberg and the Masurian Lakes . In November 1914 , the Ottoman Empire joined the Central Powers , opening fronts in the Caucasus , Mesopotamia and the Sinai . In 1915 , Italy joined the Allies and Bulgaria joined the Central Powers ; Romania joined the Allies in 1916 , as did the United States in 1917 . The Russian government collapsed in March 1917 , and a revolution in November followed by a further military defeat brought the Russians to terms with the Central Powers via the Treaty of Brest Litovsk , which granted the Germans a significant victory . After a stunning German offensive along the Western Front in the spring of 1918 , the Allies rallied and drove back the Germans in a series of successful offensives . On 4 November 1918 , the Austro-Hungarian empire agreed to an armistice , and Germany , which had its own trouble with revolutionaries , agreed to an armistice on 11 November 1918 , ending the war in victory for the Allies . By the end of the war or soon after , the German Empire , Russian Empire , Austro-Hungarian Empire and the Ottoman Empire ceased to exist . National borders were redrawn , with several independent nations restored or created , and Germany 's colonies were parceled out among the victors . During the Paris Peace Conference of 1919 , the Big Four ( Britain , France , the United States and Italy ) imposed their terms in a series of treaties . The League of Nations was formed with the aim of preventing any repetition of such a conflict . This effort failed , and economic depression , renewed nationalism , weakened successor states , and feelings of humiliation ( particularly in Germany ) eventually contributed to the start of World War II . |
708 | Ice_age | Before human burning of fossil fuels triggered global warming, the continent's ice was in relative balance | Ice age An ice age is a period of long-term reduction in the temperature of Earth 's surface and atmosphere , resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers . Within a long-term ice age , individual pulses of cold climate are termed `` glacial periods '' ( or alternatively `` glacials '' or `` glaciations '' or colloquially as `` ice age '' ) , and intermittent warm periods are called `` interglacials '' . In the terminology of glaciology , ice age implies the presence of extensive ice sheets in both northern and southern hemispheres . By this definition , we are in an interglacial period -- the Holocene -- of the ice age . The ice age began 2.6 million years ago at the start of the Pleistocene epoch , because the Greenland , Arctic , and Antarctic ice sheets still exist . |
366 | Cold_War | Armed conflicts over resources may become a reality, and have the potential to escalate into nuclear war. | Cold War The Cold War was a state of geopolitical tension after World War II between powers in the Eastern Bloc ( the Soviet Union and its satellite states ) and powers in the Western Bloc ( the United States , its NATO allies and others ) . Historians do not fully agree on the dates , but a common timeframe is the period between 1947 , the year the Truman Doctrine ( a U.S. foreign policy pledging to aid nations threatened by Soviet expansionism ) was announced , and 1991 , the year the Soviet Union collapsed . The term `` cold '' is used because there was no large-scale fighting directly between the two sides involved in the conflict , although there were major regional wars , known as proxy wars , supported by the two sides . The Cold War split the temporary wartime alliance against Nazi Germany , leaving the Soviet Union and the United States as two superpowers with profound economic and political differences . The USSR was a Marxist -- Leninist state led by its Communist Party of the Soviet Union , who in turn were led by a leader , with different titles over time , and a small committee called the Politburo . The Party controlled the press , the military , the economy and many organization . It also controlled the other states in the Eastern Bloc , and funded Communist parties around the world , sometimes in competition with Communist China , particularly following the Sino-Soviet split of the 1960s . In opposition stood the West , staunchly democratic and capitalist with a free press and independent organizations . A small neutral bloc arose with the Non-Aligned Movement ; it sought good relations with both sides . The two superpowers never engaged directly in full-scale armed combat , but they were heavily armed in preparation for a possible all-out nuclear world war . Each side had a nuclear strategy that discouraged an attack by the other side , on the basis that such an attack would lead to the total destruction of the attacker : the doctrine of mutually assured destruction ( MAD ) . Aside from the development of the two sides ' nuclear arsenals , and their deployment of conventional military forces , the struggle for dominance was expressed via proxy wars around the globe , psychological warfare , massive propaganda campaigns and espionage , rivalry at sports events , and technological competitions such as the Space Race . The first phase of the Cold War began in the first two years after the end of the Second World War in 1945 . The USSR consolidated its control over the states of the Eastern Bloc , while the United States began a strategy of global containment to challenge Soviet power , extending military and financial aid to the countries of Western Europe ( for example , supporting the anti-communist side in the Greek Civil War ) and creating the NATO alliance . The Berlin Blockade ( 1948 -- 49 ) was the first major crisis of the Cold War . With the victory of the communist side in the Chinese Civil War and the outbreak of the Korean War ( 1950 -- 53 ) , the conflict expanded . The USSR and USA competed for influence in Latin America , and the decolonizing states of Africa and Asia . Meanwhile , the Hungarian Revolution of 1956 was stopped by the Soviets . The expansion and escalation sparked more crises , such as the Suez Crisis ( 1956 ) , the Berlin Crisis of 1961 , and the Cuban Missile Crisis of 1962 . Following the Cuban Missile Crisis , a new phase began that saw the Sino-Soviet split complicate relations within the communist sphere , while US allies , particularly France , demonstrated greater independence of action . The USSR crushed the 1968 Prague Spring liberalization program in Czechoslovakia , and the Vietnam War ( 1955 -- 75 ) ended with the defeat of the US-backed Republic of Vietnam , prompting further adjustments . By the 1970s , both sides had become interested in making accommodations in order to create a more stable and predictable international system , inaugurating a period of détente that saw Strategic Arms Limitation Talks and the US opening relations with the People 's Republic of China as a strategic counterweight to the Soviet Union . Détente collapsed at the end of the decade with the beginning of the Soviet -- Afghan War in 1979 . The early 1980s were another period of elevated tension , with the Soviet downing of Korean Air Lines Flight 007 ( 1983 ) , and the `` Able Archer '' NATO military exercises ( 1983 ) . The United States increased diplomatic , military , and economic pressures on the Soviet Union , at a time when the communist state was already suffering from economic stagnation . In the mid-1980s , the new Soviet leader Mikhail Gorbachev introduced the liberalizing reforms of perestroika ( `` reorganization '' , 1987 ) and glasnost ( `` openness '' , c. 1985 ) and ended Soviet involvement in Afghanistan . Pressures for national independence grew stronger in Eastern Europe , especially Poland . Gorbachev meanwhile refused to use Soviet troops to bolster the faltering Warsaw Pact regimes as had occurred in the past . The result in 1989 was a wave of revolutions that peacefully ( with the exception of the Romanian Revolution ) overthrew all of the communist regimes of Central and Eastern Europe . The Communist Party of the Soviet Union itself lost control and was banned following an abortive coup attempt in August 1991 . This in turn led to the formal dissolution of the USSR in December 1991 and the collapse of communist regimes in other countries such as Mongolia , Cambodia and South Yemen . The United States remained as the world 's only superpower . The Cold War and its events have left a significant legacy . It is often referred to in popular culture , especially in media featuring themes of espionage ( e.g. the internationally successful James Bond movie franchise ) and the threat of nuclear warfare . |
377 | Atmosphere_of_Mars | If we halve the carbon dioxide content of the atmosphere, all life dies. | Atmosphere of Mars The atmosphere of Mars is the layer of gases surrounding Mars . It is composed mostly of carbon dioxide . The atmospheric pressure on the Martian surface averages 600 Pa , about 0.6 % of Earth 's mean sea level pressure of 101.3 kPa . It ranges from a low of 30 Pa on Olympus Mons 's peak to over 1155 Pa in the depths of Hellas Planitia . This pressure is well below the Armstrong limit for the unprotected human body . Mars 's atmospheric mass of 25 teratonnes compares to Earth 's 5148 teratonnes with a scale height of about 11 km versus Earth 's 7 km . The Martian atmosphere consists of approximately 96 % carbon dioxide , 1.9 % argon , 1.9 % nitrogen , and traces of free oxygen , carbon monoxide , water and methane , among other gases , for a mean molar mass of 43.34 g/mol . There has been renewed interest in its composition since the detection of traces of methane in 2003 that may indicate life but may also be produced by a geochemical process , volcanic or hydrothermal activity . The atmosphere is quite dusty , giving the Martian sky a light brown or orange-red color when seen from the surface ; data from the Mars Exploration Rovers indicate suspended particles of roughly 1.5 micrometres in diameter . On 16 December 2014 , NASA reported detecting an unusual increase , then decrease , in the amounts of methane in the atmosphere of the planet Mars . Organic chemicals have been detected in powder drilled from a rock by the Curiosity rover . Based on deuterium to hydrogen ratio studies , much of the water at Gale Crater on Mars was found to have been lost during ancient times , before the lakebed in the crater was formed ; afterwards , large amounts of water continued to be lost . On 18 March 2015 , NASA reported the detection of an aurora that is not fully understood and an unexplained dust cloud in the atmosphere of Mars . On 4 April 2015 , NASA reported studies , based on measurements by the Sample Analysis at Mars ( SAM ) instrument on the Curiosity rover , of the Martian atmosphere using xenon and argon isotopes . Results provided support for a `` vigorous '' loss of atmosphere early in the history of Mars and were consistent with an atmospheric signature found in bits of atmosphere captured in some Martian meteorites found on Earth . This was further supported by results from the MAVEN orbiter circling Mars , that the solar wind is responsible for stripping away the atmosphere of Mars over the years . |
1484 | Intergovernmental_Panel_on_Climate_Change | the Intergovernmental Panel on Climate Change is misleading humanity about climate change and sea levels, and that in fact a new solar-driven cooling period is not far off. | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
2267 | Climate_change_denial | Focusing on a few suggestive emails, taken out of context, merely serves to distract from the wealth of empirical evidence for man-made global warming. | Climate change denial Climate change denial , or global warming denial , is part of the global warming controversy . It involves denial , dismissal , unwarranted doubt or contrarian views which strongly depart from the scientific opinion on climate change , including the extent to which it is caused by humans , its impacts on nature and human society , or the potential of adaptation to global warming by human actions . Some deniers do endorse the term , but others often prefer the term climate change skepticism , although this is a misnomer for those who deny anthropogenic global warming . In effect , the two terms form a continuous , overlapping range of views , and generally have the same characteristics : both reject , to a greater or lesser extent , mainstream scientific opinion on climate change . Climate change denial can also be implicit , when individuals or social groups accept the science but fail to come to terms with it or to translate their acceptance into action . Several social science studies have analyzed these positions as forms of denialism . Campaigning to undermine public trust in climate science has been described as a `` denial machine '' of industrial , political and ideological interests , supported by conservative media and skeptical bloggers in manufacturing uncertainty about global warming . In the public debate , phrases such as climate skepticism have frequently been used with the same meaning as climate denialism . The labels are contested : those actively challenging climate science commonly describe themselves as `` skeptics '' , but many do not comply with common standards of scientific skepticism and , regardless of evidence , persistently deny the validity of human caused global warming . Although scientific opinion on climate change is that human activity is extremely likely to be the primary driver of climate change , the politics of global warming have been affected by climate change denial , hindering efforts to prevent climate change and adapt to the warming climate . Those promoting denial commonly use rhetorical tactics to give the appearance of a scientific controversy where there is none . Of the world 's countries , the climate change denial industry is most powerful in the United States . Since January 2015 , the United States Senate Committee on Environment and Public Works has been chaired by oil lobbyist and climate change denier Jim Inhofe . Inhofe is notorious for having called climate change `` the greatest hoax ever perpetrated against the American people '' and for having claimed to have debunked the alleged hoax in February 2015 when he brought a snowball with him in the Senate chamber and tossed it across the floor . Organised campaigning to undermine public trust in climate science is associated with conservative economic policies and backed by industrial interests opposed to the regulation of emissions . Climate change denial has been associated with the fossil fuels lobby , the Koch brothers , industry advocates and libertarian think tanks , often in the United States . More than 90 % of papers sceptical on climate change originate from right-wing think tanks . The total annual income of these climate change counter-movement-organizations is roughly $ 900 million . Between 2002 and 2010 , nearly $ 120 million ( # 77 million ) was anonymously donated via the Donors Trust and Donors Capital Fund to more than 100 organisations seeking to undermine the public perception of the science on climate change . In 2013 the Center for Media and Democracy reported that the State Policy Network ( SPN ) , an umbrella group of 64 U.S. think tanks , had been lobbying on behalf of major corporations and conservative donors to oppose climate change regulation . Since the late 1970s , oil companies have published research broadly in line with the standard views on global warming . Despite this , oil companies organized a climate change denial campaign to disseminate public disinformation for several decades , a strategy that has been compared to the organized denial of the hazards of tobacco smoking by tobacco companies . |
2282 | Himalayas | While there are isolated cases of growing glaciers, the overwhelming trend in glaciers worldwide is retreat. | Himalayas The Himalayas , or Himalaya , ( -LSB- ˌhɪməˈleɪ.ə -RSB- or -LSB- hɪˈmɑːləjə -RSB- ) form a mountain range in Asia separating the plains of the Indian subcontinent from the Tibetan Plateau . The Himalayan range has many of the Earth 's highest peaks , including the highest , Mount Everest . The Himalayas include over fifty mountains exceeding 7200 m in elevation , including ten of the fourteen 8000m peaks . By contrast , the highest peak outside Asia -- Aconcagua , in the Andes -- is 6961 m tall . The Himalayan range is bordered on the northwest by the Karakoram and Hindu Kush ranges , on the north by the Tibetan Plateau , and on the south by the Indo-Gangetic Plain . The Himalayas are distinct from the other great ranges of central Asia , although sometimes the term Himalaya is loosely used to include the Karakoram and some of the other ranges . The Himalayas are spread across five countries : Nepal , India , Bhutan , China and Pakistan , with the first three countries having sovereignty over most of the range . Some of the world 's major rivers , the Indus , the Ganges , and the Tsangpo-Brahmaputra , rise in the Himalayas , and their combined drainage basin is home to roughly 600 million people . The Himalayas have profoundly shaped the cultures of South Asia ; many Himalayan peaks are sacred in Hinduism and Buddhism . Lifted by the subduction of the Indian tectonic plate under the Eurasian Plate , the Himalayan Mountain range runs , west-northwest to east-southeast , in an arc 2400 km long . Its western anchor , Nanga Parbat , lies just south of the northernmost bend of Indus river . Its eastern anchor , Namcha Barwa , is just west of the great bend of the Tsangpo river . The range varies in width from 400 km in the west to 150 km in the east . |
316 | Deforestation | the models predicted seven times as much warming as has been observed | Deforestation Deforestation , clearance or clearing is the removal of a forest or stand of trees where the land is thereafter converted to a non-forest use . Examples of deforestation include conversion of forestland to farms , ranches , or urban use . The most concentrated deforestation occurs in tropical rainforests . About 30 % of Earth 's land surface is covered by forests . Deforestation occurs for multiple reasons : trees are cut down to be used for building or sold as fuel , ( sometimes in the form of charcoal or timber ) , while cleared land is used as pasture for livestock and plantation . The removal of trees without sufficient reforestation has resulted in damage to habitat , biodiversity loss and aridity . It has adverse impacts on biosequestration of atmospheric carbon dioxide . Deforestation has also been used in war to deprive the enemy of vital resources and cover for its forces . Modern examples of this were the use of Agent Orange by the British military in Malaya during the Malayan Emergency and the United States military in Vietnam during the Vietnam War . As of 2005 , net deforestation rates have ceased to increase in countries with a per capita GDP of at least US$ 4,600 . Deforested regions typically incur significant adverse soil erosion and frequently degrade into wasteland . Disregard of ascribed value , lax forest management and deficient environmental laws are some of the factors that allow deforestation to occur on a large scale . In many countries , deforestation , both naturally occurring and human-induced , is an ongoing issue . Deforestation causes extinction , changes to climatic conditions , desertification , and displacement of populations as observed by current conditions and in the past through the fossil record . More than half of all plant and land animal species in the world live in tropical forests . Between 2000 and 2012 , 2.3 e6sqkm of forests around the world were cut down . As a result of deforestation , only 6.2 e6km2 remain of the original 16 e6km2 of forest that formerly covered the Earth . |
1743 | Arctic_sea_ice_decline | Arctic sea ice has shrunk by an area equal to Western Australia, and summer or multi-year sea ice might be all gone within a decade. | Arctic sea ice decline Arctic sea ice decline is the sea ice loss observed in recent decades in the Arctic Ocean . The Intergovernmental Panel on Climate Change ( IPCC ) Fourth Assessment Report states that greenhouse gas forcing is largely , but not wholly , responsible for the decline in Arctic sea ice extent . A study from 2011 suggested that internal variability enhanced the greenhouse gas forced sea ice decline over the last decades . A study from 2007 found the decline to be `` faster than forecasted '' by model simulations . The IPCC Fifth Assessment Report concluded with high confidence that sea ice continues to decrease in extent , and that there is robust evidence for the downward trend in Arctic summer sea ice extent since 1979 . It has been established that the region is at its warmest for at least 40,000 years and the Arctic-wide melt season has lengthened at a rate of 5 days per decade ( from 1979 to 2013 ) , dominated by a later autumn freezeup . Sea ice changes have been identified as a mechanism for polar amplification . |
904 | Carbon_dioxide_in_Earth's_atmosphere | Without human intervention, the concentration of CO2 has climbed as high as 7,000 parts per million (ppm) in prior eras, whereas at present the concentration is just over 400 ppm. | Carbon dioxide in Earth's atmosphere Carbon dioxide is an important trace gas in Earth 's atmosphere . Currently it constitutes about 0.041 % ( equal to 410 parts per million ; ppm ) by volume of the atmosphere . Despite its relatively small concentration is a potent greenhouse gas and plays a vital role in regulating Earth 's surface temperature through radiative forcing and the greenhouse effect . Reconstructions show that concentrations of in the atmosphere have varied , ranging from as high as 7,000 ppm during the Cambrian period about 500 million years ago to as low as 180 ppm during the Quaternary glaciation of the last two million years . Carbon dioxide is an integral part of the carbon cycle , a biogeochemical cycle in which carbon is exchanged between the Earth 's oceans , soil , rocks and the biosphere . Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis . Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds . The current episode of global warming is attributed to increasing emissions of and other greenhouse gases into Earth 's atmosphere . The global annual mean concentration of in the atmosphere has increased by more than 40 % since the start of the Industrial Revolution , from 280 ppm , the level it had for the last 10,000 years leading up to the mid-18th century , to 399 ppm as of 2015 . The present concentration is the highest in at least the past 800,000 years and likely the highest in the past 20 million years . The increase has been caused by anthropogenic sources , particularly the burning of fossil fuels and deforestation . The daily average concentration of atmospheric CO2 at Mauna Loa Observatory first exceeded 400 ppm on 10 May 2013 . It is currently rising at a rate of approximately 2 ppm/year and accelerating . An estimated 30 -- 40 % of the released by humans into the atmosphere dissolves into oceans , rivers and lakes , which contributes to ocean acidification . |
2805 | Global_warming | Arctic sea ice loss is three times greater than Antarctic sea ice gain, and the amount of solar energy absorbed by the Earth is increasing as a result. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1872 | Climate_change_denial | Donald Trump claims Global Warming is a hoax | Climate change denial Climate change denial , or global warming denial , is part of the global warming controversy . It involves denial , dismissal , unwarranted doubt or contrarian views which strongly depart from the scientific opinion on climate change , including the extent to which it is caused by humans , its impacts on nature and human society , or the potential of adaptation to global warming by human actions . Some deniers do endorse the term , but others often prefer the term climate change skepticism , although this is a misnomer for those who deny anthropogenic global warming . In effect , the two terms form a continuous , overlapping range of views , and generally have the same characteristics : both reject , to a greater or lesser extent , mainstream scientific opinion on climate change . Climate change denial can also be implicit , when individuals or social groups accept the science but fail to come to terms with it or to translate their acceptance into action . Several social science studies have analyzed these positions as forms of denialism . Campaigning to undermine public trust in climate science has been described as a `` denial machine '' of industrial , political and ideological interests , supported by conservative media and skeptical bloggers in manufacturing uncertainty about global warming . In the public debate , phrases such as climate skepticism have frequently been used with the same meaning as climate denialism . The labels are contested : those actively challenging climate science commonly describe themselves as `` skeptics '' , but many do not comply with common standards of scientific skepticism and , regardless of evidence , persistently deny the validity of human caused global warming . Although scientific opinion on climate change is that human activity is extremely likely to be the primary driver of climate change , the politics of global warming have been affected by climate change denial , hindering efforts to prevent climate change and adapt to the warming climate . Those promoting denial commonly use rhetorical tactics to give the appearance of a scientific controversy where there is none . Of the world 's countries , the climate change denial industry is most powerful in the United States . Since January 2015 , the United States Senate Committee on Environment and Public Works has been chaired by oil lobbyist and climate change denier Jim Inhofe . Inhofe is notorious for having called climate change `` the greatest hoax ever perpetrated against the American people '' and for having claimed to have debunked the alleged hoax in February 2015 when he brought a snowball with him in the Senate chamber and tossed it across the floor . Organised campaigning to undermine public trust in climate science is associated with conservative economic policies and backed by industrial interests opposed to the regulation of emissions . Climate change denial has been associated with the fossil fuels lobby , the Koch brothers , industry advocates and libertarian think tanks , often in the United States . More than 90 % of papers sceptical on climate change originate from right-wing think tanks . The total annual income of these climate change counter-movement-organizations is roughly $ 900 million . Between 2002 and 2010 , nearly $ 120 million ( # 77 million ) was anonymously donated via the Donors Trust and Donors Capital Fund to more than 100 organisations seeking to undermine the public perception of the science on climate change . In 2013 the Center for Media and Democracy reported that the State Policy Network ( SPN ) , an umbrella group of 64 U.S. think tanks , had been lobbying on behalf of major corporations and conservative donors to oppose climate change regulation . Since the late 1970s , oil companies have published research broadly in line with the standard views on global warming . Despite this , oil companies organized a climate change denial campaign to disseminate public disinformation for several decades , a strategy that has been compared to the organized denial of the hazards of tobacco smoking by tobacco companies . |
1453 | January | Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months. | January January is the first month of the year in the Julian and Gregorian calendars and the first month to have the length of 31 days . The first day of the month is known as New Year 's Day . It is , on average , the coldest month of the year within most of the Northern Hemisphere ( where it is the second month of winter ) and the warmest month of the year within most of the Southern Hemisphere ( where it is the second month of summer ) . In the Southern hemisphere , January is the seasonal equivalent of July in the Northern hemisphere and vice versa . Ancient Roman observances during this month include Cervula , and Juvenalia ; celebrated January 1 , as well as one of three Agonalia , celebrated January 9 , and Carmentalia , celebrated January 11 . These dates do not correspond to the modern Gregorian calendar . |
1547 | Water_vapor | Water vapor is the most powerful greenhouse gas. | Water vapor Water vapor , water vapour or aqueous vapor is the gaseous phase of water . It is one state of water within the hydrosphere . Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice . Unlike other forms of water , water vapor is invisible . Under typical atmospheric conditions , water vapor is continuously generated by evaporation and removed by condensation . It is lighter than air and triggers convection currents that can lead to clouds . Being a component of Earth 's hydrosphere and hydrologic cycle , it is particularly abundant in Earth 's atmosphere where it is also a potent greenhouse gas along with other gases such as carbon dioxide and methane . Use of water vapor , as steam , has been important to humans for cooking and as a major component in energy production and transport systems since the industrial revolution . Water vapor is a relatively common atmospheric constituent , present even in the solar atmosphere as well as every planet in the Solar System and many astronomical objects including natural satellites , comets and even large asteroids . Likewise the detection of extrasolar water vapor would indicate a similar distribution in other planetary systems . Water vapor is significant in that it can be indirect evidence supporting the presence of extraterrestrial liquid water in the case of some planetary mass objects . |
1458 | Retreat_of_glaciers_since_1850 | Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa. | Retreat of glaciers since 1850 The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use , mountain recreation , animals and plants that depend on glacier-melt , and , in the longer term , the level of the oceans . Studied by glaciologists , the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of global warming . Mid-latitude mountain ranges such as the Himalayas , Alps , Rocky Mountains , Cascade Range , and the southern Andes , as well as isolated tropical summits such as Mount Kilimanjaro in Africa , are showing some of the largest proportionate glacial losses . Glacier mass balance is the key determinant of the health of a glacier . If the amount of frozen precipitation in the accumulation zone exceeds the quantity of glacial ice lost due to melting or in the ablation zone a glacier will advance ; if the accumulation is less than the ablation , the glacier will retreat . Glaciers in retreat will have negative mass balances , and if they do not find an equilibrium between accumulation and ablation , will eventually disappear . The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the present . Subsequently , until about 1940 , glaciers around the world retreated as the climate warmed substantially . Glacial retreat slowed and even reversed temporarily , in many cases , between 1950 and 1980 as global temperatures cooled slightly . Since 1980 , a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous , so much so that some glaciers have disappeared altogether , and the existences of many of the remaining glaciers are threatened . In locations such as the Andes of South America and Himalayas in Asia , the demise of glaciers in these regions has the potential to affect water supplies in those areas . The retreat of mountain glaciers , notably in western North America , Asia , the Alps and tropical and subtropical regions of South America , Africa and Indonesia , provide evidence for the rise in global temperatures since the late 19th century . The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level , which would affect coastal regions . |
1421 | Climate_change_in_the_Arctic | The melting in the polar ice caps and in high altitude plains can lead to the dangerous release of methane gas | Climate change in the Arctic The effects of global warming in the Arctic , or climate change in the Arctic include rising temperatures , loss of sea ice , and melting of the Greenland ice sheet with a related cold temperature anomaly , observed in recent years . Potential methane release from the region , especially through the thawing of permafrost and methane clathrates , is also a concern . The Arctic warms twice as fast compared to the rest of the world . The pronounced warming signal , the amplified response of the Arctic to global warming , it is often seen as a leading indicator of global warming . The melting of Greenland 's ice sheet is linked to polar amplification . According to a study published in 2016 , about 0.5 ◦ C of the warming in the Arctic has been attributed to reductions in sulfate aerosols in Europe since 1980 . |
2844 | Science | The claim sea level isn't rising is based on blatantly doctored graphs and conspiracy theories that are contradicted by empirical observational data. | Science Science is a systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe . Contemporary science is typically subdivided into the natural sciences , which study the material universe ; the social sciences , which study people and societies ; and the formal sciences , which study logic and mathematics . The formal sciences are often excluded as they do not depend on empirical observations . Disciplines which use science , like engineering and medicine , may also be considered to be applied sciences . From classical antiquity through the 19th century , science as a type of knowledge was more closely linked to philosophy than it is now , and in the Western world the term `` natural philosophy '' once encompassed fields of study that are today associated with science , such as astronomy , medicine , and physics . However , during the Islamic Golden Age foundations for the scientific method were laid by Ibn al-Haytham in his Book of Optics . While the classification of the material world by the ancient Indians and Greeks into air , earth , fire and water was more philosophical , medieval Middle Easterns used practical and experimental observation to classify materials . In the 17th and 18th centuries , scientists increasingly sought to formulate knowledge in terms of physical laws . Over the course of the 19th century , the word `` science '' became increasingly associated with the scientific method itself as a disciplined way to study the natural world . It was during this time that scientific disciplines such as biology , chemistry , and physics reached their modern shapes . That same time period also included the origin of the terms `` scientist '' and `` scientific community '' , the founding of scientific institutions , and the increasing significance of their interactions with society and other aspects of culture . |
1829 | Tipping_points_in_the_climate_system | "the cascading effects" of climate change contributed to the rise of ISIS. | Tipping points in the climate system A tipping point in the climate system is a threshold that, when exceeded, can lead to large changes in the state of the system. Potential tipping points have been identified in the physical climate system, in impacted ecosystems, and sometimes in both. For instance, feedback from the global carbon cycle is a driver for the transition between glacial and interglacial periods, with orbital forcing providing the initial trigger. Earth's geologic temperature record includes many more examples of geologically rapid transitions between different climate states.Climate tipping points are of particular interest in reference to concerns about global warming in the modern era. Possible tipping point behaviour has been identified for the global mean surface temperature by studying self-reinforcing feedbacks and the past behavior of Earth's climate system. Self-reinforcing feedbacks in the carbon cycle and planetary reflectivity could trigger a cascading set of tipping points that lead the world into a hothouse climate state.Large-scale components of the Earth system that may pass a tipping point have been referred to as tipping elements. Tipping elements are found in the Greenland and Antarctic ice sheets, possibly causing tens of meters of sea level rise. These tipping points are not always abrupt. For example, at some level of temperature rise the melt of a large part of the Greenland ice sheet and/or West Antarctic Ice Sheet will become inevitable; but the ice sheet itself may persist for many centuries. Some tipping elements, like the collapse of ecosystems, are irreversible. |
2400 | Climate_change_mitigation | 'To suddenly label CO2 as a "pollutant" is a disservice to a gas that has played an enormous role in the development and sustainability of all life on this wonderful Earth. | Climate change mitigation Climate change mitigation consists of actions to limit the magnitude or rate of long-term climate change . Climate change mitigation generally involves reductions in human ( anthropogenic ) emissions of greenhouse gases ( GHGs ) . Mitigation may also be achieved by increasing the capacity of carbon sinks , e.g. , through reforestation . Mitigation policies can substantially reduce the risks associated with human-induced global warming . According to the IPCC 's 2014 assessment report , `` Mitigation is a public good ; climate change is a case of the ` tragedy of the commons . Effective climate change mitigation will not be achieved if each agent ( individual , institution or country ) acts independently in its own selfish interest ( see international cooperation and emissions trading ) , suggesting the need for collective action . Some adaptation actions , on the other hand , have characteristics of a private good as benefits of actions may accrue more directly to the individuals , regions , or countries that undertake them , at least in the short term . Nevertheless , financing such adaptive activities remains an issue , particularly for poor individuals and countries . '' Examples of mitigation include phasing out fossil fuels by switching to low-carbon energy sources , such as renewable and nuclear energy , and expanding forests and other `` sinks '' to remove greater amounts of carbon dioxide from the atmosphere . Energy efficiency may also play a role , for example , through improving the insulation of buildings . Another approach to climate change mitigation is climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) . The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference of the climate system . Scientific analysis can provide information on the impacts of climate change , but deciding which impacts are dangerous requires value judgments . In 2010 , Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . With the Paris Agreement of 2015 this was confirmed , but was revised with a new target laying down `` parties will do the best '' to achieve warming below 1.5 ° C . The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 ° C . Other mitigation policies have been proposed , some of which are more stringent or modest than the 2 ° C limit . |
554 | Rain | The heaviest precipitation events will become more frequent and more extreme. | Rain Rain is liquid water in the form of droplets that have condensed from atmospheric water vapor and then precipitated -- that is , become heavy enough to fall under gravity . Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Earth . It provides suitable conditions for many types of ecosystems , as well as water for hydroelectric power plants and crop irrigation . The major cause of rain production is moisture moving along three-dimensional zones of temperature and moisture contrasts known as weather fronts . If enough moisture and upward motion is present , precipitation falls from convective clouds ( those with strong upward vertical motion ) such as cumulonimbus ( thunder clouds ) which can organize into narrow rainbands . In mountainous areas , heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation which forces moist air to condense and fall out as rainfall along the sides of mountains . On the leeward side of mountains , desert climates can exist due to the dry air caused by downslope flow which causes heating and drying of the air mass . The movement of the monsoon trough , or intertropical convergence zone , brings rainy seasons to savannah climes . The urban heat island effect leads to increased rainfall , both in amounts and intensity , downwind of cities . Global warming is also causing changes in the precipitation pattern globally , including wetter conditions across eastern North America and drier conditions in the tropics . Antarctica is the driest continent . The globally averaged annual precipitation over land is 715 mm , but over the whole Earth it is much higher at 990 mm . Climate classification systems such as the Köppen classification system use average annual rainfall to help differentiate between differing climate regimes . Rainfall is measured using rain gauges . Rainfall amounts can be estimated by weather radar . Rain is also known or suspected on other planets , where it may be composed of methane , neon , sulfuric acid , or even iron rather than water . |
2702 | Kyoto_Protocol | While it's true that any single country's CO2 emissions reductions will make little difference, only if every nation agrees to limit CO2 emissions can we achieve significant cuts on a global scale. | Kyoto Protocol The Kyoto Protocol is an international treaty which extends the 1992 United Nations Framework Convention on Climate Change ( UNFCCC ) that commits State Parties to reduce greenhouse gas emissions , based on the fact that ( a ) global warming exists and ( b ) human-made CO2 emissions have caused it . The Kyoto Protocol was adopted in Kyoto , Japan , on 11 December 1997 and entered into force on 16 February 2005 . There are currently 192 parties ( Canada withdrew effective December 2012 ) to the Protocol . The Kyoto Protocol implemented the objective of the UNFCCC to fight global warming by reducing greenhouse gas concentrations in the atmosphere to `` a level that would prevent dangerous anthropogenic interference with the climate system '' ( Art. 2 ) . The Protocol is based on the principle of common but differentiated responsibilities : it puts the obligation to reduce current emissions on developed countries on the basis that they are historically responsible for the current levels of greenhouse gases in the atmosphere . The Protocol 's first commitment period started in 2008 and ended in 2012 . A second commitment period was agreed on in 2012 , known as the Doha Amendment to the protocol , in which 37 countries have binding targets : Australia , the European Union ( and its 28 member states ) , Belarus , Iceland , Kazakhstan , Liechtenstein , Norway , Switzerland , and Ukraine . Belarus , Kazakhstan and Ukraine have stated that they may withdraw from the Protocol or not put into legal force the Amendment with second round targets . Japan , New Zealand and Russia have participated in Kyoto 's first-round but have not taken on new targets in the second commitment period . Other developed countries without second-round targets are Canada ( which withdrew from the Kyoto Protocol in 2012 ) and the United States ( which has not ratified the Protocol ) . As of July 2016 , 66 states have accepted the Doha Amendment , while entry into force requires the acceptances of 144 states . Of the 37 countries with binding commitments , 7 have ratified . Negotiations were held in the framework of the yearly UNFCCC Climate Change Conferences on measures to be taken after the second commitment period ends in 2020 . This resulted in the 2015 adoption of the Paris Agreement , which is a separate instrument under the UNFCCC rather than an amendment of the Kyoto protocol . |
1586 | Retreat_of_glaciers_since_1850 | Ice Sheet losses are overestimated. | Retreat of glaciers since 1850 The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use , mountain recreation , animals and plants that depend on glacier-melt , and , in the longer term , the level of the oceans . Studied by glaciologists , the temporal coincidence of glacier retreat with the measured increase of atmospheric greenhouse gases is often cited as an evidentiary underpinning of global warming . Mid-latitude mountain ranges such as the Himalayas , Alps , Rocky Mountains , Cascade Range , and the southern Andes , as well as isolated tropical summits such as Mount Kilimanjaro in Africa , are showing some of the largest proportionate glacial losses . Glacier mass balance is the key determinant of the health of a glacier . If the amount of frozen precipitation in the accumulation zone exceeds the quantity of glacial ice lost due to melting or in the ablation zone a glacier will advance ; if the accumulation is less than the ablation , the glacier will retreat . Glaciers in retreat will have negative mass balances , and if they do not find an equilibrium between accumulation and ablation , will eventually disappear . The Little Ice Age was a period from about 1550 to 1850 when the world experienced relatively cooler temperatures compared to the present . Subsequently , until about 1940 , glaciers around the world retreated as the climate warmed substantially . Glacial retreat slowed and even reversed temporarily , in many cases , between 1950 and 1980 as global temperatures cooled slightly . Since 1980 , a significant global warming has led to glacier retreat becoming increasingly rapid and ubiquitous , so much so that some glaciers have disappeared altogether , and the existences of many of the remaining glaciers are threatened . In locations such as the Andes of South America and Himalayas in Asia , the demise of glaciers in these regions has the potential to affect water supplies in those areas . The retreat of mountain glaciers , notably in western North America , Asia , the Alps and tropical and subtropical regions of South America , Africa and Indonesia , provide evidence for the rise in global temperatures since the late 19th century . The acceleration of the rate of retreat since 1995 of key outlet glaciers of the Greenland and West Antarctic ice sheets may foreshadow a rise in sea level , which would affect coastal regions . |
1944 | Climate_change_in_the_United_States | Over the past eight years, the United States has reduced our total carbon pollution more than any other nation on Earth. | Climate change in the United States Because of global warming , there has been concern in the United States and internationally , that the country should reduce total greenhouse gas which is relatively high per capita . In 2012 , the United States experienced its warmest year on record . , the thirteen warmest years for the entire planet have all occurred since 1998 , transcending those from 1880 . From 1950 to 2009 , the American government 's surface temperature record shows an increase by 1 F-change , approximately . Global warming has caused many changes in the U.S. . According to a 2009 statement by the National Oceanic and Atmospheric Administration ( NOAA ) , trends include lake and river ice melting earlier in the spring , plants blooming earlier , multiple animal species shifting their habitat ranges northward , and reductions in the size of glaciers . Predicting future climate changes are fraught with difficulty . Some research has warned against possible problems due to American climate changes such as the spread of invasive species and possibilities of floods as well as droughts . Changes in climate in the regions of the United States appear significant . Drought conditions appear to be worsening in the southwest while improving in the northeast for example . President Barack Obama committed in the December 2009 Copenhagen Climate Change Summit to reduce carbon dioxide emissions in the range of 17 % below 2005 levels by 2020 , 42 % below 2005 levels by 2030 , and 83 % below 2005 levels by 2050 . In an address towards the U.S. Congress in June 2013 , Obama detailed a specific action plan to achieve the 17 % carbon emissions cut from 2005 by 2020 . He included such measures as shifting from coal-based power generation to solar and natural gas production . Climate change is seen as a national security threat to the United States . In 2015 , according to The New York Times and others , oil companies knew that burning oil and gas could cause global warming since the 1970s but , nonetheless , funded deniers for years . 2016 was an historic year for billion-dollar weather and climate disasters in U.S. |
1919 | Climate_change_in_the_Arctic | Measurements indicating that 2017 had relatively more sea ice in the Arctic and less melting of glacial ice in Greenland casts scientific doubt on the reality of global warming. | Climate change in the Arctic The effects of global warming in the Arctic , or climate change in the Arctic include rising temperatures , loss of sea ice , and melting of the Greenland ice sheet with a related cold temperature anomaly , observed in recent years . Potential methane release from the region , especially through the thawing of permafrost and methane clathrates , is also a concern . The Arctic warms twice as fast compared to the rest of the world . The pronounced warming signal , the amplified response of the Arctic to global warming , it is often seen as a leading indicator of global warming . The melting of Greenland 's ice sheet is linked to polar amplification . According to a study published in 2016 , about 0.5 ◦ C of the warming in the Arctic has been attributed to reductions in sulfate aerosols in Europe since 1980 . |
2902 | Climatic_Research_Unit_documents | "So recently the media picked up on the fact that CRU deleted the raw data for this important global temperature set long ago. | Climatic Research Unit documents Climatic Research Unit documents including thousands of e-mails and other computer files were stolen from a server at the Climatic Research Unit of the University of East Anglia in a hacking incident in November 2009 . The documents were redistributed first through several blogs of global warming skeptics , and allegations were made that they indicated misconduct by leading climate scientists . A series of investigations rejected these allegations , while concluding that CRU scientists should have been more open with distributing data and methods on request . Precisely six committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . The scientific consensus that global warming is occurring as a result of human activity remained unchanged by the end of the investigations . The incident occurred shortly before the opening December 2009 Copenhagen global climate summit . It has prompted general discussion about increasing the openness of scientific data ( though the majority of climate data have always been freely available ) . Scientists , scientific organisations , and government officials have stated that the incident does not affect the overall scientific case for climate change . Andrew Revkin reported in the New York Times that `` The evidence pointing to a growing human contribution to global warming is so widely accepted that the hacked material is unlikely to erode the overall argument . '' |
1239 | United_States | Through decades of research, it has become clear that human civilization, roughly 6,000 years old, developed during an unusually stable period for global sea levels. | United States The United States of America ( USA ) , commonly known as the United States ( U.S. ) or America , is a constitutional federal republic composed of 50 states , a federal district , five major self-governing territories , and various possessions . Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico . The state of Alaska is in the northwest corner of North America , bordered by Canada to the east and across the Bering Strait from Russia to the west . The state of Hawaii is an archipelago in the mid-Pacific Ocean . The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea . Nine time zones are covered . The geography , climate and wildlife of the country are extremely diverse . At 3.8 million square miles ( 9.8 million km2 ) and with over 324 million people , the United States is the world 's third - or fourth-largest country by total area , third-largest by land area , and the third-most populous . It is one of the world 's most ethnically diverse and multicultural nations , and is home to the world 's largest immigrant population . The capital is Washington , D.C. , and the largest city is New York City ; nine other major metropolitan areas -- each with at least 4.5 million inhabitants and the largest having more than 13 million people -- are Los Angeles , Chicago , Dallas , Houston , Philadelphia , Miami , Atlanta , Boston , and San Francisco . Paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago . European colonization began in the 16th century . The United States emerged from 13 British colonies along the East Coast . Numerous disputes between Great Britain and the colonies following the Seven Years ' War led to the American Revolution , which began in 1775 . On July 4 , 1776 , during the course of the American Revolutionary War , the colonies unanimously adopted the Declaration of Independence . The war ended in 1783 with recognition of the independence of the United States by Great Britain , representing the first successful war of independence against a European power . The current constitution was adopted in 1788 , after the Articles of Confederation , adopted in 1781 , were felt to have provided inadequate federal powers . The first ten amendments , collectively named the Bill of Rights , were ratified in 1791 and designed to guarantee many fundamental civil liberties . The United States embarked on a vigorous expansion across North America throughout the 19th century , displacing Native American tribes , acquiring new territories , and gradually admitting new states until it spanned the continent by 1848 . During the second half of the 19th century , the American Civil War led to the end of legal slavery in the country . By the end of that century , the United States extended into the Pacific Ocean , and its economy , driven in large part by the Industrial Revolution , began to soar . The Spanish -- American War and confirmed the country 's status as a global military power . The United States emerged from as a global superpower , the first country to develop nuclear weapons , the only country to use them in warfare , and a permanent member of the United Nations Security Council . The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the world 's sole superpower . The U.S. is a founding member of the United Nations , World Bank , International Monetary Fund , Organization of American States ( OAS ) , and other international organizations . The United States is a highly developed country , with the world 's largest economy by nominal GDP and second-largest economy by PPP . Though its population is only 4.3 % of the world total , Americans hold nearly 40 % of the total wealth in the world . The United States ranks among the highest in several measures of socioeconomic performance , including average wage , human development , per capita GDP , and productivity per person . While the U.S. economy is considered post-industrial , characterized by the dominance of services and knowledge economy , the manufacturing sector remains the second-largest in the world . Accounting for approximately a quarter of global GDP and a third of global military spending , the United States is the world 's foremost economic and military power . The United States is a prominent political and cultural force internationally , and a leader in scientific research and technological innovations . |
442 | Global_warming | There is no empirical evidence that increasing greenhouse gases are the primary cause of Global Warming | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
398 | Natural_environment | nothing we can do to stop the Earth's naturally occurring climate cycles. | Natural environment The natural environment encompasses all living and non-living things occurring naturally , meaning in this case not artificial . The term is most often applied to the Earth or some parts of Earth . This environment encompasses the interaction of all living species , climate , weather , and natural resources that affect human survival and economic activity . The concept of the natural environment can be distinguished by components : Complete ecological units that function as natural systems without massive civilized human intervention , including all vegetation , microorganisms , soil , rocks , atmosphere , and natural phenomena that occur within their boundaries and their nature Universal natural resources and physical phenomena that lack clear-cut boundaries , such as air , water , and climate , as well as energy , radiation , electric charge , and magnetism , not originating from civilized human activity In contrast to the natural environment is the built environment . In such areas where man has fundamentally transformed landscapes such as urban settings and agricultural land conversion , the natural environment is greatly modified into a simplified human environment . Even acts which seem less extreme , such as building a mud hut or a photovoltaic system in the desert , modify the natural environment into an artificial one . Though many animals build things to provide a better environment for themselves , they are not human , hence beaver dams and the works of Mound-building termites are thought of as natural . People seldom find absolutely natural environments on Earth , and naturalness usually varies in a continuum , from 100 % natural in one extreme to 0 % natural in the other . More precisely , we can consider the different aspects or components of an environment , and see that their degree of naturalness is not uniform . If , for instance , in an agricultural field , the mineralogic composition and the structure of its soil are similar to those of an undisturbed forest soil , but the structure is quite different . Natural environment is often used as a synonym for habitat . For instance , when we say that the natural environment of giraffes is the savanna . |
463 | 20th_century | "So now we're able to explain from natural factors how we've had the 20th Century warming. | 20th century The 20th century was a century that began on January 1 , 1901 and ended on December 31 , 2000 . It was the tenth and final century of the 2nd millennium . It is distinct from the century known as the 1900s which began on January 1 , 1900 , and ended on December 31 , 1999 . The 20th century was dominated by a chain of events that heralded significant changes in world history as to redefine the era : World War I and World War II , nuclear power and space exploration , nationalism and decolonization , the Cold War and post-Cold War conflicts ; intergovernmental organizations and cultural homogenization through developments in emerging transportation and communications technology ; poverty reduction and world population growth , awareness of environmental degradation , ecological extinction ; and the birth of the Digital Revolution . It saw great advances in communication and medical technology that by the late 1980s allowed for near-instantaneous worldwide computer communication and genetic modification of life . The term `` short twentieth century '' was coined to represent the events from 1914 to 1991 . Global total fertility rates , sea level rise and ecological collapses increased ; the resulting competition for land and dwindling resources accelerated deforestation , water depletion . and the mass extinction of half the world 's estimated nine million unique species and wildlife population ; consequences which are now being dealt with . It took all of human history up to 1804 for the world 's population to reach 1 billion ; world population reached an estimated 2 billion in 1927 ; by late 1999 , the global population reached 6 billion . Global literacy averaged 80 % ; global lifespan-averages exceeded 40 + years for the first time in history , with over half achieving 70 + years ( three decades longer than it was a century ago ) . |
688 | Wallace_Smith_Broecker | "The arc of global warming will be variously steep and less steep,' said Richard Seager, a climate scientist at the Lamont-Doherty Earth Observatory of Columbia University. | Wallace Smith Broecker Wallace Smith Broecker ( born November 29 , 1931 in Chicago ) is the Newberry Professor in the Department of Earth and Environmental Sciences at Columbia University , a scientist at Columbia 's Lamont-Doherty Earth Observatory and a sustainability fellow at Arizona State University . He developed the idea of a global `` conveyor belt '' linking the circulation of the global ocean and made major contributions to the science of the carbon cycle and the use of chemical tracers and isotope dating in oceanography . Broecker has received the Crafoord Prize and the Vetlesen Prize . |
0 | Global_warming | Global warming is driving polar bears toward extinction | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
880 | Global_warming | The peer-reviewed study by two scientists and a veteran statistician looked at the global average temperature datasets[…] | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
1077 | Earth | Antarctic ice fluctuates wildly year to year, and the link to man-made global warming there is not clear, NASA ice expert Walt Meier said. | Earth Earth ( from Eorðe -LSB- Γαῖα , Gaia -RSB- Terra ) , otherwise known as the World or the Globe , is the third planet from the Sun and the only object in the Universe known to harbor life . It is the densest planet in the Solar System and the largest of the four terrestrial planets . According to radiometric dating and other sources of evidence , Earth formed about 4.54 billion years ago . Earth 's gravity interacts with other objects in space , especially the Sun and the Moon , Earth 's only natural satellite . During one orbit around the Sun , Earth rotates about its axis over 365 times ; thus , an Earth year is about 365.26 days long . Earth 's axis of rotation is tilted , producing seasonal variations on the planet 's surface . The gravitational interaction between the Earth and Moon causes ocean tides , stabilizes the Earth 's orientation on its axis , and gradually slows its rotation . Earth 's lithosphere is divided into several rigid tectonic plates that migrate across the surface over periods of many millions of years . About 71 % of Earth 's surface is covered with water , mostly by its oceans . The remaining 29 % is land consisting of continents and islands that together have many lakes , rivers and other sources of water that contribute to the hydrosphere . The majority of Earth 's polar regions are covered in ice , including the Antarctic ice sheet and the sea ice of the Arctic ice pack . Earth 's interior remains active with a solid iron inner core , a liquid outer core that generates the Earth 's magnetic field , and a convecting mantle that drives plate tectonics . Within the first billion years of Earth 's history , life appeared in the oceans and began to affect the Earth 's atmosphere and surface , leading to the proliferation of aerobic and anaerobic organisms . Some geological evidence indicates that life may have arisen as much as 4.1 billion years ago . Since then , the combination of Earth 's distance from the Sun , physical properties , and geological history have allowed life to evolve and thrive . In the history of the Earth , biodiversity has gone through long periods of expansion , occasionally punctuated by mass extinction events . Over 99 % of all species that ever lived on Earth are extinct . Estimates of the number of species on Earth today vary widely ; most species have not been described . Over 7.4 billion humans live on Earth and depend on its biosphere and minerals for their survival . Humans have developed diverse societies and cultures ; politically , the world has about 200 sovereign states . |
1772 | Climate_change_mitigation | Preventing global warming is relatively cheap; business-as-usual will cause accelerating climate damage costs that economists struggle to even estimate. | Climate change mitigation Climate change mitigation consists of actions to limit the magnitude or rate of long-term climate change . Climate change mitigation generally involves reductions in human ( anthropogenic ) emissions of greenhouse gases ( GHGs ) . Mitigation may also be achieved by increasing the capacity of carbon sinks , e.g. , through reforestation . Mitigation policies can substantially reduce the risks associated with human-induced global warming . According to the IPCC 's 2014 assessment report , `` Mitigation is a public good ; climate change is a case of the ` tragedy of the commons . Effective climate change mitigation will not be achieved if each agent ( individual , institution or country ) acts independently in its own selfish interest ( see international cooperation and emissions trading ) , suggesting the need for collective action . Some adaptation actions , on the other hand , have characteristics of a private good as benefits of actions may accrue more directly to the individuals , regions , or countries that undertake them , at least in the short term . Nevertheless , financing such adaptive activities remains an issue , particularly for poor individuals and countries . '' Examples of mitigation include phasing out fossil fuels by switching to low-carbon energy sources , such as renewable and nuclear energy , and expanding forests and other `` sinks '' to remove greater amounts of carbon dioxide from the atmosphere . Energy efficiency may also play a role , for example , through improving the insulation of buildings . Another approach to climate change mitigation is climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) . The ultimate objective of the UNFCCC is to stabilize atmospheric concentrations of GHGs at a level that would prevent dangerous human interference of the climate system . Scientific analysis can provide information on the impacts of climate change , but deciding which impacts are dangerous requires value judgments . In 2010 , Parties to the UNFCCC agreed that future global warming should be limited to below 2.0 ° C ( 3.6 ° F ) relative to the pre-industrial level . With the Paris Agreement of 2015 this was confirmed , but was revised with a new target laying down `` parties will do the best '' to achieve warming below 1.5 ° C . The current trajectory of global greenhouse gas emissions does not appear to be consistent with limiting global warming to below 1.5 or 2 ° C . Other mitigation policies have been proposed , some of which are more stringent or modest than the 2 ° C limit . |
551 | Climate | Gone are the days when scientists drew a bright line dividing weather and climate. | Climate Climate is the statistics of weather , usually over a 30-year interval . It is measured by assessing the patterns of variation in temperature , humidity , atmospheric pressure , wind , precipitation , atmospheric particle count and other meteorological variables in a given region over long periods of time . Climate differs from weather , in that weather only describes the short-term conditions of these variables in a given region . A region 's climate is generated by the climate system , which has five components : atmosphere , hydrosphere , cryosphere , lithosphere , and biosphere . The climate of a location is affected by its latitude , terrain , and altitude , as well as nearby water bodies and their currents . Climates can be classified according to the average and the typical ranges of different variables , most commonly temperature and precipitation . The most commonly used classification scheme was the Köppen climate classification . The Thornthwaite system , in use since 1948 , incorporates evapotranspiration along with temperature and precipitation information and is used in studying biological diversity and how climate change affects it . The Bergeron and Spatial Synoptic Classification systems focus on the origin of air masses that define the climate of a region . Paleoclimatology is the study of ancient climates . Since direct observations of climate are not available before the 19th century , paleoclimates are inferred from proxy variables that include non-biotic evidence such as sediments found in lake beds and ice cores , and biotic evidence such as tree rings and coral . Climate models are mathematical models of past , present and future climates . Climate change may occur over long and short timescales from a variety of factors ; recent warming is discussed in global warming . Global warming results in redistributions . For example , `` a 3 ° C change in mean annual temperature corresponds to a shift in isotherms of approximately 300 -- 400 km in latitude ( in the temperate zone ) or 500 m in elevation . Therefore , species are expected to move upwards in elevation or towards the poles in latitude in response to shifting climate zones '' . |
2487 | El_Niño–Southern_Oscillation | The El Nino Southern Oscillation shows close correlation to global temperatures over the short term. | El Niño–Southern Oscillation El Niño -- Southern Oscillation ( ENSO ) is an irregularly periodical variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean , affecting much of the tropics and subtropics . The warming phase is known as El Niño and the cooling phase as La Niña . Southern Oscillation is the accompanying atmospheric component , coupled with the sea temperature change : El Niño is accompanied with high , and La Niña with low air surface pressure in the tropical western Pacific . The two periods last several months each ( typically occur every few years ) and their effects vary in intensity . The two phases relate to the Walker circulation , discovered by Gilbert Walker during the early twentieth century . The Walker circulation is caused by the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean , and a low pressure system over Indonesia . When the Walker circulation weakens or reverses , an El Niño results , causing the ocean surface to be warmer than average , as upwelling of cold water occurs less or not at all . An especially strong Walker circulation causes a La Niña , resulting in cooler ocean temperatures due to increased upwelling . Mechanisms that cause the oscillation remain under study . The extremes of this climate pattern 's oscillations cause extreme weather ( such as floods and droughts ) in many regions of the world . Developing countries dependent upon agriculture and fishing , particularly those bordering the Pacific Ocean , are the most affected . |
243 | Global_warming | In its 5th assessment report in 2013, the IPCC estimated that human emissions are probably responsible for more than half of the observed increase in global average temperature from 1951 to 2010. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
2862 | Climatic_Research_Unit_email_controversy | The Independent Climate Change Email Review found the CRU scientists were unhelpful and unsympathetic to information requesters and at times broke FoI laws. | Climatic Research Unit email controversy The Climatic Research Unit email controversy ( also known as `` Climategate '' ) began in November 2009 with the hacking of a server at the Climatic Research Unit ( CRU ) at the University of East Anglia ( UEA ) by an external attacker , copying thousands of emails and computer files , the Climatic Research Unit documents , to various internet locations several weeks before the Copenhagen Summit on climate change . The story was first broken by climate change denialists with columnist James Delingpole popularising the term `` Climategate '' to describe the controversy . Several people considered climate change `` skeptics '' argued that the emails showed global warming was a scientific conspiracy , that scientists manipulated climate data and attempted to suppress critics . The CRU rejected this , saying the emails had been taken out of context and merely reflected an honest exchange of ideas . The mainstream media picked up the story as negotiations over climate change mitigation began in Copenhagen on 7 December 2009 . Because of the timing , scientists , policy makers and public relations experts said that the release of emails was a smear campaign intended to undermine the climate conference . In response to the controversy , the American Association for the Advancement of Science ( AAAS ) , the American Meteorological Society ( AMS ) and the Union of Concerned Scientists ( UCS ) released statements supporting the scientific consensus that the Earth 's mean surface temperature had been rising for decades , with the AAAS concluding , `` based on multiple lines of scientific evidence that global climate change caused by human activities is now underway ... it is a growing threat to society . '' Eight committees investigated the allegations and published reports , finding no evidence of fraud or scientific misconduct . However , the reports called on the scientists to avoid any such allegations in the future by taking steps to regain public confidence in their work , for example by opening up access to their supporting data , processing methods and software , and by promptly honouring freedom of information requests . The scientific consensus that global warming is occurring as a result of human activity remained unchanged throughout the investigations . |
2608 | Natural_gas | And their wind and manure emit more than one third of emissions of another, methane, which warms the world 20 times faster than carbon dioxide. | Natural gas Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane , but commonly including varying amounts of other higher alkanes , and sometimes a small percentage of carbon dioxide , nitrogen , hydrogen sulfide , or helium . It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years . The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas . Natural gas is a fossil fuel used as a source of energy for heating , cooking , and electricity generation . It is also used as fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals . Fossil fuel based natural gas is a non-renewable resource . Natural gas is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates . Petroleum is another resource and fossil fuel found in close proximity to and with natural gas . Most natural gas was created over time by two mechanisms : biogenic and thermogenic . Biogenic gas is created by methanogenic organisms in marshes , bogs , landfills , and shallow sediments . Deeper in the earth , at greater temperature and pressure , thermogenic gas is created from buried organic material . In petroleum production gas is often burnt as flare gas . The World Bank estimates that over 150 cubic kilometers of natural gas are flared or vented annually . Before natural gas can be used as a fuel , most , but not all , must be processed to remove impurities , including water , to meet the specifications of marketable natural gas . The by-products of this processing include : ethane , propane , butanes , pentanes , and higher molecular weight hydrocarbons , hydrogen sulfide ( which may be converted into pure sulfur ) , carbon dioxide , water vapor , and sometimes helium and nitrogen . Natural gas is often informally referred to simply as `` gas '' , especially when compared to other energy sources such as oil or coal . However , it is not to be confused with gasoline , especially in North America , where the term gasoline is often shortened in colloquial usage to gas . Natural gas was used by the Chinese in about 500 BCE ( possibly even 1000 BCE ) . They discovered a way to transport gas seeping from the ground in crude pipelines of bamboo to where it was used to boil salt water to extract the salt , in the Ziliujing District of Sichuan . The world 's first industrial extraction of natural gas started at Fredonia , New York , United States in 1825 . By 2009 , 66 000 km ³ ( or 8 % ) had been used out of the total 850 000 km ³ of estimated remaining recoverable reserves of natural gas . Based on an estimated 2015 world consumption rate of about 3400 km ³ of gas per year , the total estimated remaining economically recoverable reserves of natural gas would last 250 years at current consumption rates . An annual increase in usage of 2 -- 3 % could result in currently recoverable reserves lasting significantly less , perhaps as few as 80 to 100 years . |
2420 | Little_Ice_Age | The sun has shown no long term trend since 1950 and in fact has shown a slight cooling trend in recent decades. | Little Ice Age The Little Ice Age ( LIA ) was a period of cooling that occurred after the Medieval Warm Period . Although it was not a true ice age , the term was introduced into scientific literature by François E. Matthes in 1939 . It has been conventionally defined as a period extending from the 16th to the 19th centuries , but some experts prefer an alternative timespan from about 1300 to about 1850 . Climatologists and historians working with local records no longer expect to agree on either the start or end dates of the period , which varied according to local conditions . The NASA Earth Observatory notes three particularly cold intervals : one beginning about 1650 , another about 1770 , and the last in 1850 , all separated by intervals of slight warming . The Intergovernmental Panel on Climate Change Third Assessment Report considered the timing and areas affected by the Little Ice Age suggested largely-independent regional climate changes rather than a globally-synchronous increased glaciation . At most , there was modest cooling of the Northern Hemisphere during the period . Several causes have been proposed : cyclical lows in solar radiation , heightened volcanic activity , changes in the ocean circulation , variations in Earth 's orbit and axial tilt ( orbital forcing ) , inherent variability in global climate , and decreases in the human population . |
2077 | Agriculture | The increase in damage in recent years is due to population growth in vulnerable areas and poor forest management. | Agriculture Agriculture or farming is the cultivation and breeding of animals , plants and fungi for food , fiber , biofuel , medicinal plants and other products used to sustain and enhance human life . Agriculture was the key development in the rise of sedentary human civilization , whereby farming of domesticated species created food surpluses that nurtured the development of civilization . The study of agriculture is known as agricultural science . The history of agriculture dates back thousands of years , and its development has been driven and defined by greatly different climates , cultures , and technologies . Industrial agriculture based on large-scale monoculture farming has become the dominant agricultural methodology . Modern agronomy , plant breeding , agrochemicals such as pesticides and fertilizers , and technological developments have in many cases sharply increased yields from cultivation , but at the same time have caused widespread ecological damage and negative human health effects . Selective breeding and modern practices in animal husbandry have similarly increased the output of meat , but have raised concerns about animal welfare and the health effects of the antibiotics , growth hormones , and other chemicals commonly used in industrial meat production . Genetically modified organisms are an increasing component of agriculture , although they are banned in several countries . Agricultural food production and water management are increasingly becoming global issues that are fostering debate on a number of fronts . Significant degradation of land and water resources , including the depletion of aquifers , has been observed in recent decades , and the effects of global warming on agriculture and of agriculture on global warming are still not fully understood . The major agricultural products can be broadly grouped into foods , fibers , fuels , and raw materials . Specific foods include cereals ( grains ) , vegetables , fruits , oils , meats and spices . Fibers include cotton , wool , hemp , silk and flax . Raw materials include lumber and bamboo . Other useful materials are also produced by plants , such as resins , dyes , drugs , perfumes , biofuels and ornamental products such as cut flowers and nursery plants . Over one third of the world 's workers are employed in agriculture , second only to the service sector , although the percentages of agricultural workers in developed countries has decreased significantly over the past several centuries . |
645 | Nitrogen_fixation | Scientists just discovered a massive, heretofore unknown, source of nitrogen | Nitrogen fixation Nitrogen fixation is a process by which nitrogen in the Earth 's atmosphere is converted into ammonia ( NH3 ) or other molecules available to living organisms . Atmospheric nitrogen or molecular dinitrogen ( N2 ) is relatively inert : it does not easily react with other chemicals to form new compounds . The fixation process frees nitrogen atoms from their triply bonded diatomic form , N ≡ N , to be used in other ways . Nitrogen fixation is essential for all forms of life because inorganic nitrogen compounds are required for the biosynthesis of the basic building blocks of plants , animals and other life forms , e.g. , nucleotides for DNA and RNA , the coenzyme nicotinamide adenine dinucleotide for its role in metabolism ( transferring electrons between molecules ) , and amino acids for proteins . Therefore , as part of the nitrogen cycle , it is essential for agriculture and the manufacture of fertilizer . It is also , indirectly , relevant to the manufacture of all chemical compounds that contain nitrogen , which includes explosives , most pharmaceuticals , dyes , etc. . Nitrogen fixation is carried out naturally in the soil by nitrogen fixing bacteria such as Azotobacter . Some nitrogen-fixing bacteria have symbiotic relationships with some plant groups , especially legumes . Looser relationships between nitrogen-fixing bacteria and plants are often referred to as associative or non-symbiotic , as seen in nitrogen fixation occurring on rice roots . It also occurs naturally in the air by means of NOx production by lightning . All biological nitrogen fixation is done by way of metalloenzymes called nitrogenases . These enzymes contain iron , often with a second metal , usually molybdenum but sometimes vanadium . Microorganisms that can fix nitrogen are prokaryotes ( both bacteria and archaea , distributed throughout their respective Domains ) called diazotrophs . Some higher plants , and some animals ( termites ) , have formed associations ( symbiosis ) with diazotrophs . |
2461 | Global_warming | Early 20th century warming was in large part due to rising solar activity and relatively quiet volcanic activity. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
3051 | Global_warming | Once natural influences, in particular the impact of El Niño and La Niña, are removed from the recent termperature record, there is no evidence of a significant change in the human contribution to climate change. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
97 | 2000s_(decade) | according, again, to the official figures—during this past 10 years, if anything, mean global temperature, average world temperature, has slightly declined | 2000s (decade) The 2000s ( pronounced `` two-thousands '' or `` twenty-hundreds '' ) was a decade of the Gregorian calendar that began on January 1 , 2000 , and ended on December 31 , 2009 . The growth of the Internet contributed to globalization during the decade , which allowed faster communication among people around the world . The economic growth of the 2000s had considerable social , environmental and mass extinction consequences , raised demand for diminishing energy resources , and was still vulnerable , as demonstrated by the financial crisis of 2007 -- 08 . |
353 | Scientific_consensus_on_climate_change | The bottom line is there's no solid connection between climate change and the major indicators of extreme weather | Scientific consensus on climate change There is currently a strong scientific consensus that the Earth is warming and that this warming is mainly caused by human activities. This consensus is supported by various studies of scientists' opinions and by position statements of scientific organizations, many of which explicitly agree with the Intergovernmental Panel on Climate Change (IPCC) synthesis reports. Nearly all actively publishing climate scientists (97–98%) support the consensus on anthropogenic climate change, and the remaining 2% of contrarian studies either cannot be replicated or contain errors. |
350 | New_York_City | Since 1965, more parts of the U.S. have seen a decrease in flooding than have seen an increase. | New York City The City of New York , often called New York City or simply New York , is the most populous city in the United States . With an estimated 2016 population of 8,537,673 distributed over a land area of about 302.6 sqmi , New York City is also the most densely populated major city in the United States . Located at the southern tip of the state of New York , the city is the center of the New York metropolitan area , one of the most populous urban agglomerations in the world . A global power city , New York City exerts a significant impact upon commerce , finance , media , art , fashion , research , technology , education , and entertainment , its fast pace defining the term New York minute . Home to the headquarters of the United Nations , New York is an important center for international diplomacy and has been described as the cultural , financial , and media capital of the world . Situated on one of the world 's largest natural harbors , New York City consists of five boroughs , each of which is a separate county of New York State . The five boroughs -- Brooklyn , Queens , Manhattan , The Bronx , and Staten Island -- were consolidated into a single city in 1898 . The city and its metropolitan area constitute the premier gateway for legal immigration to the United States , and as many as 800 languages are spoken in New York , making it the most linguistically diverse city in the world . New York City is home to more than 3.2 million residents born outside the United States , the world 's largest foreign-born population of any city . By 2016 estimates , the New York City metropolitan region remains by a significant margin the most populous in the United States , as defined by both the Metropolitan Statistical Area ( MSA ) , 20.2 million residents , and the Combined Statistical Area ( CSA ) , 23.7 million residents . In 2013 , the MSA produced a gross metropolitan product ( GMP ) of nearly US$ 1.39 trillion . In 2012 , the CSA generated a GMP of over US$ 1.55 trillion . NYC 's MSA and CSA GDP are higher than the GDPs of all but 11 and 12 countries , respectively . New York City traces its origin to its 1624 founding in Lower Manhattan as a trading post by colonists of the Dutch Republic and was named New Amsterdam in 1626 . The city and its surroundings came under English control in 1664 and were renamed New York after King Charles II of England granted the lands to his brother , the Duke of York . New York served as the capital of the United States from 1785 until 1790 . It has been the country 's largest city since 1790 . The Statue of Liberty greeted millions of immigrants as they came to the Americas by ship in the late 19th and early 20th centuries and is a symbol of the United States and its democracy . In the 21st century , New York has emerged as a global node of creativity and entrepreneurship , social tolerance , and environmental sustainability . Many districts and landmarks in New York City have become well known , and the city received a record of nearly 60 million tourists in 2015 , hosting three of the world 's ten most visited tourist attractions in 2013 . Several sources have ranked New York the most photographed city in the world . Times Square , iconic as the world 's `` heart '' and its `` Crossroads '' , is the brightly illuminated hub of the Broadway Theater District , one of the world 's busiest pedestrian intersections , and a major center of the world 's entertainment industry . The names of many of the city 's bridges , tapered skyscrapers , and parks are known around the world . Anchored by Wall Street in the Financial District of Lower Manhattan , New York City has been called both the most economically powerful city and the leading financial center of the world , and the city is home to the world 's two largest stock exchanges by total market capitalization , the New York Stock Exchange and NASDAQ . Manhattan 's real estate market is among the most expensive in the world . Manhattan 's Chinatown incorporates the highest concentration of Chinese people in the Western Hemisphere , with multiple signature Chinatowns developing across the city . Providing continuous 24/7 service , the New York City Subway is one of the most extensive metro systems worldwide , with stations in operation . Over 120 colleges and universities are located in New York City , including Columbia University , New York University , and Rockefeller University , which have been ranked among the top 35 in the world . |
1395 | Severe_weather | Severe storms, floods and agricultural losses may cost a great deal of money, but such extreme weather events—and their resulting costs—are dramatically declining as the Earth modestly warms. | Severe weather Severe weather refers to any dangerous meteorological phenomena with the potential to cause damage , serious social disruption , or loss of human life . Types of severe weather phenomena vary , depending on the latitude , altitude , topography , and atmospheric conditions . High winds , hail , excessive precipitation , and wildfires are forms and effects of severe weather , as are thunderstorms , downbursts , lightning , tornadoes , waterspouts , tropical cyclones , and extratropical cyclones . Regional and seasonal severe weather phenomena include blizzards , snowstorms , ice storms , and duststorms . |
1488 | Electric_vehicle | New Study Confirms EVs Considerably Worse For Climate Than Diesel Cars. | Electric vehicle An electric vehicle , also called an electric drive vehicle , uses one or more electric motors or traction motors for propulsion . An electric vehicle may be powered through a collector system by electricity from off-vehicle sources , or may be self-contained with a battery , solar panels or a generator to convert fuel to electricity . EVs include road and rail vehicles , surface and underwater vessels , electric aircraft and electric spacecraft . EVs first came into existence in the mid-19th century , when electricity was among the preferred methods for motor vehicle propulsion , providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time . The internal combustion engine has been the dominant propulsion method for motor vehicles for almost 100 years , but electric power has remained commonplace in other vehicle types , such as trains and smaller vehicles of all types . In the 21st century , EVs saw a resurgence due to technological developments and an increased focus on renewable energy . Government incentives to increase adoptions were introduced , including in the United States and the European Union . |
1665 | Sustainability | The effects of enhanced CO2 on terrestrial plants are variable and complex and dependent on numerous factors. | Sustainability In ecology , sustainability ( from sustain and ability ) is the property of biological systems to remain diverse and productive indefinite #Adjective . Long-lived and healthy wetlands and forests are examples of sustainable biological systems . In more general terms , sustainability is the endurance of systems and processes . The organizing principle for sustainability is sustainable development , which includes the four interconnected domains : ecology , economics , politics and culture . Sustainability science is the study of sustainable development and environmental science . Sustainability can also be defined as a socio-ecological process characterized by the pursuit of a common ideal . An ideal is by definition unattainable in a given time and space . However , by persistently and dynamically approaching it , the process results in a sustainable system . Healthy ecosystems and environments are necessary to the survival of humans and other organisms . Ways of reducing negative human impact are environmentally-friendly chemical engineering , environmental resources management and environmental protection . Information is gained from green chemistry , earth science , environmental science and conservation biology . Ecological economics studies the fields of academic research that aim to address human economies and natural ecosystems . Moving towards sustainability is also a social challenge that entails international and national law , urban planning and transport , local and individual lifestyles and ethical consumerism . Ways of living more sustainably can take many forms from reorganizing living conditions ( e.g. , ecovillages , eco-municipalities and sustainable cities ) , reappraising economic sectors ( permaculture , green building , sustainable agriculture ) , or work practices ( sustainable architecture ) , using science to develop new technologies ( green technologies , renewable energy and sustainable fission and fusion power ) , or designing systems in a flexible and reversible manner , and adjusting individual lifestyles that conserve natural resources . `` The term ` sustainability ' should be viewed as humanity 's target goal of human-ecosystem equilibrium ( homeostasis ) , while ` sustainable development ' refers to the holistic approach and temporal processes that lead us to the end point of sustainability . '' ( 305 ) Despite the increased popularity of the use of the term `` sustainability '' , the possibility that human societies will achieve environmental sustainability has been , and continues to be , questioned -- in light of environmental degradation , climate change , overconsumption , population growth and societies ' pursuit of unlimited economic growth in a closed system . |
1601 | Sun | Water levels correlate with sunspots. | Sun The Sun is the star at the center of the Solar System . It is a nearly perfect sphere of hot plasma , with internal convective motion that generates a magnetic field via a dynamo process . It is by far the most important source of energy for life on Earth . Its diameter is about 109 times that of Earth , and its mass is about 330,000 times that of Earth , accounting for about 99.86 % of the total mass of the Solar System . About three quarters of the Sun 's mass consists of hydrogen ( ~ 73 % ) ; the rest is mostly helium ( ~ 25 % ) , with much smaller quantities of heavier elements , including oxygen , carbon , neon , and iron . The Sun is a G-type main-sequence star ( G2V ) based on its spectral class . As such , it is informally referred to as a yellow dwarf . It formed approximately 4.6 billionAll numbers in this article are short scale . One billion is 109 , or 1,000,000,000 . years ago from the gravitational collapse of matter within a region of a large molecular cloud . Most of this matter gathered in the center , whereas the rest flattened into an orbiting disk that became the Solar System . The central mass became so hot and dense that it eventually initiated nuclear fusion in its core . It is thought that almost all stars form by this process . The Sun is roughly middle-aged ; it has not changed dramatically for more than four billion years , and will remain fairly stable for more than another five billion years . After hydrogen fusion in its core has diminished to the point at which it is no longer in hydrostatic equilibrium , the core of the Sun will experience a marked increase in density and temperature while its outer layers expand to eventually become a red giant . It is calculated that the Sun will become sufficiently large to engulf the current orbits of Mercury and Venus , and render Earth uninhabitable . The enormous effect of the Sun on Earth has been recognized since prehistoric times , and the Sun has been regarded by some cultures as a deity . The synodic rotation of Earth and its orbit around the Sun are the basis of the solar calendar , which is the predominant calendar in use today . |
2426 | Global_warming | "Twentieth century global warming did not start until 1910. | Global warming Global warming , also referred to as climate change , is the observed century-scale rise in the average temperature of the Earth 's climate system and its related effects . Multiple lines of scientific evidence show that the climate system is warming . Many of the observed changes since the 1950s are unprecedented in the instrumental temperature record which extends back to the mid 19th century , and in paleoclimate proxy records over thousands of years . In 2013 , the Intergovernmental Panel on Climate Change ( IPCC ) Fifth Assessment Report concluded that `` It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century . '' The largest human influence has been emission of greenhouse gases such as carbon dioxide , methane and nitrous oxide . Climate model projections summarized in the report indicated that during the 21st century the global surface temperature is likely to rise a further 0.3 to for their lowest emissions scenario and 2.6 to for the highest emissions scenario . These findings have been recognized by the national science academies of the major industrialized nations and are not disputed by any scientific body of national or international standing . Future climate change and associated impacts will differ from region to region around the globe . Anticipated effects include warming global temperature , rising sea levels , changing precipitation , and expansion of deserts in the subtropics . Warming is expected to be greater over land than over the oceans and greatest in the Arctic , with the continuing retreat of glaciers , permafrost and sea ice . Other likely changes include more frequent extreme weather events including heat waves , droughts , heavy rainfall with floods and heavy snowfall ; ocean acidification ; and species extinctions due to shifting temperature regimes . Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels . Because the climate system has a large `` inertia '' and greenhouse gases will stay in the atmosphere for a long time , many of these effects will not only exist for decades or centuries , but will persist for tens of thousands of years . Possible societal responses to global warming include mitigation by emissions reduction , adaptation to its effects , building systems resilient to its effects , and possible future climate engineering . Most countries are parties to the United Nations Framework Convention on Climate Change ( UNFCCC ) , whose ultimate objective is to prevent dangerous anthropogenic climate change . Parties to the UNFCCC have agreed that deep cuts in emissions are required and that global warming should be limited to well below 2.0 C-change relative to pre-industrial levels , with efforts made to limit warming to 1.5 C-change . Public reactions to global warming and concern about its effects are also increasing . A global 2015 Pew Research Center report showed a median of 54 % consider it `` a very serious problem '' . There are significant regional differences , with Americans and Chinese ( whose economies are responsible for the greatest annual CO2 emissions ) among the least concerned . |
593 | Equator | It shows that ECS is probably between two and 4.5 degrees, possibly as low as 1.5 but not lower, and possibly as high as nine degrees. | Equator An equator is the intersection of the surface of a rotating spheroid ( such as a planet ) with the plane perpendicular to the axis of rotation and midway between its poles . On Earth , the Equator is an imaginary line on the surface , equidistant from the North and South Poles , dividing the Earth into Northern and Southern Hemispheres . It is about 40,075 km long , of which 78.7 % lies across water and 21.3 % over land . |
2213 | Urban_heat_island | The warming trend is the same in rural and urban areas, measured by thermometers and satellites, and by natural thermometers. | Urban heat island An urban heat island ( UHI ) is an urban area or metropolitan area that is significantly warmer than its surrounding rural areas due to human activities . The temperature difference usually is larger at night than during the day , and is most apparent when winds are weak . UHI is most noticeable during the summer and winter . The main cause of the urban heat island effect is from the modification of land surfaces . Waste heat generated by energy usage is a secondary contributor . As a population center grows , it tends to expand its area and increase its average temperature . The less-used term heat island refers to any area , populated or not , which is consistently hotter than the surrounding area . Monthly rainfall is greater downwind of cities , partially due to the UHI . Increases in heat within urban centers increases the length of growing seasons , and decreases the occurrence of weak tornadoes . The UHI decreases air quality by increasing the production of pollutants such as ozone , and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems . Not all cities have a distinct urban heat island . Mitigation of the urban heat island effect can be accomplished through the use of green roofs and the use of lighter-colored surfaces in urban areas , which reflect more sunlight and absorb less heat . There are concerns raised about possible contribution from urban heat islands to global warming . Research on China and India indicates that urban heat island effect contributes to climate warming by about 30 % . On the other hand , one 1999 comparison between urban and rural areas proposed that the urban heat island effects have little influence on global mean temperature trends . Many studies reveal increases in the severity of the effect with the progress of climate change . |
917 | Sea_level_rise | Because the collapse of vulnerable parts of the ice sheet could raise the sea level dramatically, the continued existence of the world's great coastal cities — Miami, New York, Shanghai and many more — is tied to Antarctica's fate. | Sea level rise A sea level rise is an increase in the volume of water in the world 's oceans , resulting in an increase in global mean sea level . Sea level rise is usually attributed to global climate change by thermal expansion of the water in the oceans and by melting of Ice sheets and glaciers on land . Melting of floating ice shelves or icebergs at sea raises sea levels only slightly . Sea level rise at specific locations may be more or less than the global average . Local factors might include tectonic effects , subsidence of the land , tides , currents , storms , etc. . Sea level rise is expected to continue for centuries . Because of the slow inertia , long response time for parts of the climate system , it has been estimated that we are already committed to a sea-level rise of approximately 2.3 m for each degree Celsius of temperature rise within the next 2,000 years . IPCC Summary for Policymakers , AR5 , 2014 , indicated that the global mean sea level rise will continue during the 21st century , very likely at a faster rate than observed from 1971 to 2010 . Projected rates and amounts vary . A January 2017 NOAA report suggests a range of GMSL rise of 0.3 -- 2.5 m possible during the 21st century . Sea level rises can considerably influence human populations in coastal and island regions and natural environments like marine ecosystems . |
2994 | Greenhouse_effect | 'Mauna Loa has been producing a readout which supports Manning's predetermined goal by showing steady growth in atmospheric CO2 concentrations since 1959. | Greenhouse effect The greenhouse effect is the process by which radiation from a planet 's atmosphere warms the planet 's surface to a temperature above what it would be without its atmosphere . If a planet 's atmosphere contains radiatively active gases ( i.e. , greenhouse gases ) the atmosphere will radiate energy in all directions . Part of this radiation is directed towards the surface , warming it . The downward component of this radiation -- that is , the strength of the greenhouse effect -- will depend on the atmosphere 's temperature and on the amount of greenhouse gases that the atmosphere contains . On Earth , the atmosphere is warmed by absorption of infrared thermal radiation from the underlying surface ( heated by the sun ) , absorption of shorter wavelength radiant energy from the sun , and convective heat fluxes from the surface . Greenhouse gases in the atmosphere radiate energy , some of which is directed to the surface and lower atmosphere . The mechanism that produces this difference between the actual surface temperature and the effective temperature is due to the atmosphere and is known as the greenhouse effect . Earth 's natural greenhouse effect is critical to supporting life . Human activities , primarily the burning of fossil fuels and clearing of forests , have intensified the natural greenhouse effect , causing global warming . The mechanism is named after a faulty analogy with the effect of solar radiation passing through glass and warming a greenhouse . The way a greenhouse retains heat is fundamentally different , as a greenhouse works by reducing airflow and retaining warm air inside the structure . |
2966 | Carbon_dioxide | Over the three years from 1979 to 1982 when CO2 emissions were decreasing due to the rapid increase in the price of oil that drastically reduced consumption, there was no change in the rate of increase in atmospheric concentration of CO2 proving that humans were not the primary source for the increase in concentration.' | Carbon dioxide Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas . As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product . Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas . It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting . Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid . |
337 | Berlin | temperatures were 6-10C above normal over most of France, Germany and northern Spain during the final days of the month, according to C3S. | Berlin Berlin ( -LSB- bəɹˈlɪn -RSB- , -LSB- bɛɐ̯ˈliːn -RSB- ) is the capital and the largest city of Germany as well as one of its 16 constituent states . With a population of approximately 3.7 million , Berlin is the second most populous city proper and the seventh most populous urban area in the European Union . Located in northeastern Germany on the banks of the rivers Spree and Havel , it is the centre of the Berlin-Brandenburg Metropolitan Region , which has roughly 6 million residents from more than 180 nations . Due to its location in the European Plain , Berlin is influenced by a temperate seasonal climate . Around one-third of the city 's area is composed of forests , parks , gardens , rivers , canals and lakes . First documented in the 13th century and situated at the crossing of two important historic trade routes , Berlin became the capital of the Margraviate of Brandenburg ( 14171701 ) , the Kingdom of Prussia ( 1701 -- 1918 ) , the German Empire ( 1871 -- 1918 ) , the Weimar Republic ( 1919 -- 1933 ) and the Third Reich ( 1933 -- 1945 ) . Berlin in the 1920s was the third largest municipality in the world . After World War II and its subsequent occupation by the victorious countries , the city was divided ; East Berlin was declared capital of East Germany , while West Berlin became a de facto West German exclave , surrounded by the Berlin Wall ( 1961 -- 1989 ) and East German territory . Following German reunification in 1990 , Berlin once again became the capital of all-Germany . Berlin is a world city of culture , politics , media and science . Its economy is based on high-tech firms and the service sector , encompassing a diverse range of creative industries , research facilities , media corporations and convention venues . Berlin serves as a continental hub for air and rail traffic and has a highly complex public transportation network . The metropolis is a popular tourist destination . Significant industries also include IT , pharmaceuticals , biomedical engineering , clean tech , biotechnology , construction and electronics . Modern Berlin is home to world renowned universities , orchestras , museums , entertainment venues and is host to many sporting events . Its urban setting has made it a sought-after location for international film productions . The city is well known for its festivals , diverse architecture , nightlife , contemporary arts and a high quality of living . Since the 2000s Berlin has seen the emergence of a cosmopolitan entrepreneurial scene . |
294 | Emergency_management | A global network of 500 scientists and professionals has prepared this urgent message. | Emergency management -RCB- -RCB- Disaster management ( or emergency management ) can be defined as the organization and management of resources and responsibilities for dealing with all humanitarian aspects of emergencies in particular preparedness , response and recovery in order to reduce the impact of disasters . |
103 | 20th_century | global warming ceased around the end of the twentieth century and was followed (since 1997) by 19 years of stable temperature | 20th century The 20th century was a century that began on January 1 , 1901 and ended on December 31 , 2000 . It was the tenth and final century of the 2nd millennium . It is distinct from the century known as the 1900s which began on January 1 , 1900 , and ended on December 31 , 1999 . The 20th century was dominated by a chain of events that heralded significant changes in world history as to redefine the era : World War I and World War II , nuclear power and space exploration , nationalism and decolonization , the Cold War and post-Cold War conflicts ; intergovernmental organizations and cultural homogenization through developments in emerging transportation and communications technology ; poverty reduction and world population growth , awareness of environmental degradation , ecological extinction ; and the birth of the Digital Revolution . It saw great advances in communication and medical technology that by the late 1980s allowed for near-instantaneous worldwide computer communication and genetic modification of life . The term `` short twentieth century '' was coined to represent the events from 1914 to 1991 . Global total fertility rates , sea level rise and ecological collapses increased ; the resulting competition for land and dwindling resources accelerated deforestation , water depletion . and the mass extinction of half the world 's estimated nine million unique species and wildlife population ; consequences which are now being dealt with . It took all of human history up to 1804 for the world 's population to reach 1 billion ; world population reached an estimated 2 billion in 1927 ; by late 1999 , the global population reached 6 billion . Global literacy averaged 80 % ; global lifespan-averages exceeded 40 + years for the first time in history , with over half achieving 70 + years ( three decades longer than it was a century ago ) . |
2100 | Intergovernmental_Panel_on_Climate_Change | IPCC were wrong about Himalayan glaciers | Intergovernmental Panel on Climate Change The Intergovernmental Panel on Climate Change ( IPCC ) is a scientific and intergovernmental body under the auspices of the United Nations , set up at the request of member governments , dedicated to the task of providing the world with an objective , scientific view of climate change and its political and economic impacts . It was first established in 1988 by two United Nations organizations , the World Meteorological Organization ( WMO ) and the United Nations Environment Programme ( UNEP ) , and later endorsed by the United Nations General Assembly through Resolution 43/53 . Membership of the IPCC is open to all members of the WMO and UNEP . The IPCC produces reports that support the United Nations Framework Convention on Climate Change ( UNFCCC ) , which is the main international treaty on climate change . The ultimate objective of the UNFCCC is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -LSB- i.e. , human-induced -RSB- interference with the climate system '' . IPCC reports cover `` the scientific , technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change , its potential impacts and options for adaptation and mitigation . '' The IPCC does not carry out its own original research , nor does it do the work of monitoring climate or related phenomena itself . The IPCC bases its assessment on the published literature , which includes peer-reviewed and non-peer-reviewed sources . Thousands of scientists and other experts contribute ( on a voluntary basis , without payment from the IPCC ) to writing and reviewing reports , which are then reviewed by governments . IPCC reports contain a `` Summary for Policymakers '' , which is subject to line-by-line approval by delegates from all participating governments . Typically this involves the governments of more than 120 countries . The IPCC provides an internationally accepted authority on climate change , producing reports which have the agreement of leading climate scientists and the consensus of participating governments . The 2007 Nobel Peace Prize was shared , in equal parts , between the IPCC and Al Gore . |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.