query: The heaviest precipitation events will become more frequent and more extreme.

positive: 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 .

positive: Supercell A supercell is a thunderstorm characterized by the presence of a mesocyclone : a deep , persistently rotating updraft . For this reason , these storms are sometimes referred to as rotating thunderstorms . Of the four classifications of thunderstorms ( supercell , squall line , multi-cell , and single-cell ) , supercells are the overall least common and have the potential to be the most severe . Supercells are often isolated from other thunderstorms , and can dominate the local weather up to 32 km away .   Supercells are often put into three classification types : Classic , Low-precipitation ( LP ) , and High-precipitation ( HP ) . LP supercells are usually found in climates that are more arid , such as the high plains of the United States , and HP supercells are most often found in moist climates . Supercells can occur anywhere in the world under the right pre-existing weather conditions , but they are most common in the Great Plains of the United States in an area known as Tornado Alley and in the Tornado Corridor of Argentina , Uruguay and southern Brazil .

positive: 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 .

positive: Climate of India The climate of India comprises a wide range of weather conditions across a vast geographic scale and varied topography , making generalisations difficult . Based on the Köppen system , India hosts six major climatic subtypes , ranging from arid desert in the west , alpine tundra and glaciers in the north , and humid tropical regions supporting rainforests in the southwest and the island territories . Many regions have starkly different microclimates . The nation has four seasons : winter ( December , January and February ) , summer ( March , April and May ) , a monsoon rainy season ( June to September ) , and a post-monsoon period ( October to November ) .   India 's geography and geology are climatically pivotal : the Thar Desert in the northwest and the Himalayas in the north work in tandem to effect a culturally and economically important monsoonal regime . As Earth 's highest and most massive mountain range , the Himalayas bar the influx of frigid katabatic winds from the icy Tibetan Plateau and northerly Central Asia . Most of North India is thus kept warm or is only mildly chilly or cold during winter ; the same thermal dam keeps most regions in India hot in summer .   Though the Tropic of Cancer -- the boundary between the tropics and subtropics -- passes through the middle of India , the bulk of the country can be regarded as climatically tropical . As in much of the tropics , monsoonal and other weather patterns in India can be wildly unstable : epochal droughts , floods , cyclones , and other natural disasters are sporadic , but have displaced or ended millions of human lives . There is one scientific opinion which states that in South Asia such climatic events are likely to change in unpredictability , frequency , and severity . Ongoing and future vegetative changes and current sea level rises and the attendant inundation of India 's low-lying coastal areas are other impacts , current or predicted , that are attributable to global warming .

positive: Uruguay Uruguay ( -LSB- ˈjʊərəɡwaɪ -RSB- -LSB- uɾuˈɣwai̯ -RSB- ) , officially the Oriental Republic of Uruguay ( República Oriental del Uruguay ) , is a sovereign State in the southeastern region of South America . It borders Argentina to its west and Brazil to its north and east , with the Río de la Plata ( River of Silver ) to the south and the Atlantic Ocean to the southeast . Uruguay is home to an estimated 3.42 million people , of whom 1.8 million live in the metropolitan area of its capital and largest city , Montevideo . With an area of approximately 176000 km2 , Uruguay is geographically the second-smallest nation in South America , only larger in size than Suriname .   Uruguay was inhabited by the Charrúa people for approximately 4000 years before the Portuguese established Colonia del Sacramento , one of the oldest European settlements in the region , in 1680 . Montevideo was founded as a military stronghold by the Spanish in the early 18th century , signifying the competing claims over the region . Uruguay won its independence between 1811 and 1828 , following a four-way struggle between Spain , Portugal , Argentina and Brazil . It remained subject to foreign influence and intervention throughout the 19th century , with the military playing a recurring role in domestic politics until the late 20th century . Modern Uruguay is a democratic constitutional republic , with a president who serves as both head of state and head of government .   Uruguay is ranked first in Latin America in democracy , peace , lack of corruption , e-government , and is first in South America when it comes to press freedom , size of the middle class and prosperity . On a per-capita basis , Uruguay contributes more troops to United Nations peace-keeping missions than any other country . It ranks second in the region on economic freedom , income equality , per-capita income and inflows of FDI . Uruguay is the third-best country on the continent in terms of HDI , GDP growth , innovation and infrastructure . It is regarded as a high-income country ( top group ) by the UN . Uruguay is also the third-best ranked in the world in e-Participation .  Uruguay is an important global exporter of combed wool , rice , soybeans , frozen beef , malt and milk . Nearly 95 % of Uruguay 's electricity comes from renewable energy , mostly hydroelectric facilities and wind parks .   The Economist named Uruguay `` country of the year '' in 2013 , acknowledging the innovative policy of legalizing the production , sale and consumption of cannabis . Same-sex marriage and abortion are also legal , leading Uruguay to be regarded as one of the most progressive nations in the world , and one of the most socially developed , outstanding regionally , and ranking highly on global measures of personal rights , tolerance , and inclusion issues .

negative: European Severe Storms Laboratory The European Severe Storms Laboratory ( ESSL ) started as an informal network of European scientists with the goal to advance research on severe convective storms and extreme weather events on a European level and can be seen as the European equivalent to the National Severe Storms Laboratory . Severe weather includes extreme local meteorological events like tornados , heavy precipitation events and avalanches .  The ESSL focuses on research questions concerning convective storms and other extreme weather phenomena which can be treated more efficiently on a pan-European scale .

negative: Extreme value theory Extreme value theory or extreme value analysis ( EVA ) is a branch of statistics dealing with the extreme deviations from the median of probability distributions . It seeks to assess , from a given ordered sample of a given random variable , the probability of events that are more extreme than any previously observed . Extreme value analysis is widely used in many disciplines , such as structural engineering , finance , earth sciences , traffic prediction , and geological engineering . For example , EVA might be used in the field of hydrology to estimate the probability of an unusually large flooding event , such as the 100-year flood . Similarly , for the design of a breakwater , a coastal engineer would seek to estimate the 50-year wave and design the structure accordingly .

negative: Proarrhythmia Proarrhythmia is a new or more frequent occurrence of pre-existing arrhythmias , paradoxically precipitated by antiarrhythmic therapy , which means it is a side effect associated with the administration of some existing antiarrhythmic drugs , as well as drugs for other indications . In other words , it is a tendency of antiarrhythmic drugs to facilitate emergence of new arrhythmias .

negative: Tropical savanna climate Tropical savanna climate or tropical wet and dry climate is a type of climate that corresponds to the Köppen climate classification categories `` Aw '' and `` As '' .  Tropical savanna climates have monthly mean temperatures above 18 ° C in every month of the year and typically a pronounced dry season , with the driest month having precipitation less than 60 mm and also less than 100 -- -LSB- total annual precipitation -LCB- mm -RCB- / 25 -RSB- of precipitation . This latter fact is in direct contrast to a tropical monsoon climate , whose driest month sees less than 60 mm of precipitation but has more than 100 -- -LSB- total annual precipitation -LCB- mm -RCB- / 25 -RSB- of precipitation . In essence , a tropical savanna climate tends to either see less rainfall than a tropical monsoon climate or have more pronounced dry seasons .   There are generally four types of tropical savanna climate :   1 . Distinct wet and dry seasons of relatively equal duration . Most of the region 's annual rainfall is experienced during the wet season and very little precipitation falls during the dry season .  2 . A lengthy dry season and a relatively short wet season . This version features seven or more dry season months and five or less wet season months . There are variations within this version :  On one extreme , the region receives just enough precipitation during the short wet season to preclude it from a semi-arid climate classification . This drier variation of the tropical savanna climate is typically found adjacent to regions with semi-arid climates .  On the other extreme , the climate features a lengthy dry season followed by a short but extremely rainy wet season . However , regions with this variation of the climate do not experience enough rainfall during the wet season to qualify as a tropical monsoon climate .  3 . A lengthy wet season and a relatively short dry season . This version features seven or more wet season months and five or less dry season months . This version 's precipitation pattern is similar to precipitation patterns observed in some tropical monsoon climates , but does not experience enough rainfall during the wet season to be classified as such .  4 . A dry season with a noticeable amount of rainfall followed by a rainy wet season . In essence , this version mimics the precipitation patterns more commonly found in a tropical monsoon climate , but do not receive enough precipitation during either the dry season or the year to be classified as such .

negative: Palindromic rheumatism Palindromic rheumatism ( PR ) consists of sudden and rapidly developing attacks of arthritis . There is acute pain , redness , swelling , and disability of one ( usually ) or multiple joints . The interval between recurrent attacks is extremely variable and how long the attack lasts is also variable . Attacks may last from few hours to days . Attacks may become more frequent with time . There is no joint damage after attacks .

negative: Ossifying fibromyxoid tumour An ossifying fibromyxoid tumour is a type of myxoma . It presents in the extremities more frequently than the trunk . It is derived from mesenchyme . Appearance in the head and neck is rare , but has been reported . Their malignancy has been characterized as `` intermediate '' .

negative: Warming center A warming center is a short-term emergency shelter that operates when temperatures or a combination of precipitation , wind chill , wind and temperature become dangerously inclement . Their paramount purpose is the prevention of death and injury from exposure to the elements . This may include acute trauma from falling objects such as trees , or injury to extremities due to frostbite . A more prevalent emergency which warming centers seek to prevent is hypothermia , the risk for which is aggravated by factors such as age , alcohol consumption , and homelessness .

negative: Climate of south-west England The climate of south-west England is classed as oceanic ( Cfb ) according to the Köppen climate classification . The oceanic climate is typified by cool winters with warmer summers and precipitation all year round , with more experienced in winter . Annual rainfall is about 1000 mm and up to 2000 mm on higher ground . Summer maxima averages range from 18 ° C to 22 ° C and winter minima averages range from 1 ° C to 4 ° C across the south-west . It is the second windiest area of the United Kingdom , the majority of winds coming from the south-west and north-east . Government organisations predict the area will experience a rise in temperature and become the hottest region in the United Kingdom .   Inland areas of low altitude experience the least amount of precipitation . They have the highest summer maxima temperatures , but winter minima are lower than those of the coast . Snowfalls are more frequent in comparison to the coast , but less so in comparison to higher ground . They experience the lowest wind speeds and the total sunshine hours are between those of the coast and the moors . This typical climate of inland areas is more noticeable the further north-east into the region .   In comparison to inland areas , the coast experiences high minimum temperatures , especially in winter , and slightly lower maximum temperatures during the summer . Rainfall is lowest at the coast and snowfall there is rarer than the rest of the region . Coastal areas are the windiest parts of the peninsula and they receive the most sunshine . The general coastal climate becomes more prevalent further south-west into the region .   The south-west has areas of moorland inland such as Bodmin Moor , Dartmoor and Exmoor . Because of their high altitude they experience lower temperatures and more precipitation than the rest of the south west ( approximately twice as much rainfall as lowland areas ) . Both of these factors also result in the highest levels of snowfall and the lowest levels of sunshine . Exposed areas of the moors are windier than the lowlands and can be almost as windy as the coast .

negative: Precipitated silica Precipitated silica is a silica ( SiO2 ) produced by precipitation from a solution containing silicate salts . In 1999 , more than 1M tons/y were produced , mainly for use in tires and shoe soles .

negative: Polycoria Polycoria is a pathological condition of the eye characterized by more than one pupillary opening in the iris . It may be congenital or result from a disease affecting the iris .   Polycoria is extremely rare , and other conditions are frequently mistaken for it .

negative: Boiling chip A boiling chip , boiling stone , or anti-bumping granule is a tiny , unevenly shaped piece of substance added to liquids to make them boil more calmly . Boiling chips are frequently employed in distillation and heating . When a liquid becomes superheated , a particle of dust or a stirring rod can cause flash boiling . This very rapid boiling can be extremely violent and cause reagents to splatter , possibly causing severe burns , ruining experiments , and damaging equipment . Boiling chips work by providing nucleation sites so the liquid boils smoothly without becoming superheated or bumping .

negative: Absolute democracy Absolute democracy is an extreme form of a collective perception of order .   It should not to be confused with `` power democracy '' as found in the Swiss political system ( in which elective activities for the adjustment of social/political matters are more frequent than in other democracies ) .

negative: Protein precipitation Protein Precipitation is widely used in downstream processing of biological products in order to concentrate proteins and purify them from various contaminants . For example , in the biotechnology industry protein precipitation is used to eliminate contaminants commonly contained in blood . The underlying mechanism of precipitation is to alter the solvation potential of the solvent , more specifically , by lowering the solubility of the solute by addition of a reagent .

negative: Optical rogue waves Optical rogue waves are rare pulses of light analogous to rogue or freak ocean waves . The term optical rogue waves was coined to describe rare pulses of broadband light arising during the process of supercontinuum generation -- a noise-sensitive nonlinear process in which extremely broadband radiation is generated from a narrowband input waveform -- in nonlinear optical fiber . In this context , optical rogue waves are characterized by an anomalous surplus in energy at particular wavelengths ( e.g. , those shifted to the red of the input waveform ) and/or an unexpected peak power . These anomalous events have been shown to follow heavy-tailed statistics , also known as L-shaped statistics , fat-tailed statistics , or extreme-value statistics . These probability distributions are characterized by long tails : large outliers occur rarely , yet much more frequently than expected from Gaussian statistics and intuition . Such distributions also describe the probabilities of freak ocean waves and various phenomena in both the man-made and natural worlds . Despite their infrequency , rare events wield significant influence in many systems . Aside from the statistical similarities , light waves traveling in optical fibers are known to obey the similar mathematics as water waves traveling in the open ocean ( the nonlinear Schrödinger equation ) , supporting the analogy between oceanic rogue waves and their optical counterparts . More generally , research has exposed a number of different analogies between extreme events in optics and hydrodynamic systems . A key practical difference is that most optical experiments can be done with a table-top apparatus , offer a high degree of experimental control , and allow data to be acquired extremely rapidly . Consequently , optical rogue waves are attractive for experimental and theoretical research and have become a highly studied phenomenon . The particulars of the analogy between extreme waves in optics and hydrodynamics may vary depending on the context , but the existence of rare events and extreme statistics in wave-related phenomena are common ground .

negative: Historic desertification Historic desertification is the study of the desert-forming process from a historic perspective . It was presumed in the past that the main causes of desertification lay in overuse of the land resulting in impoverishment of the soil , reduced vegetation cover , increased risk of drought and the resulting wind erosion . However recent projects to regreen deserts have not met with the success envisaged , and cast doubts on this theory . Research suggests that it is extreme events rather than drought caused by low annual prcipitation , that do the most damage . Heavy downpours resulting in flash floods wash away sediment and there seems to have been an increased number of extreme events in the Levant at the end of the Byzantine period . The decline of settlements in the desert belt at this time may have been caused by these extreme events rather than a reduction in annual precipitation .

negative: Mountains of Tlemcen The mountains of Tlemcen are a mountain range of Algeria located in the north-west of the country in the wilaya of Tlemcen .   The Tlemcen Mountains are a chain of the Tellian Atlas situated at its western extremity to the south of the Tlemcen basin . The massif is relatively well watered with precipitation greater than 600 mm / year . It is more forested than the Trara massif , especially in the south-western part . The northern part of the mountains is included in the Tlemcen National Park which overlooks the town of Tlemcen .

negative: Peptization Peptization is the process responsible for the formation of stable dispersion of colloidal particles in dispersion medium . In other words it may be defined as a process of converting a precipitate into colloidal sol by shaking it with dispersion medium in the presence of small amount of electrolyte . The electrolyte used in this process is called as peptizing agent .   This is particularly important in colloid chemistry or for precipitation reactions in an aqueous solution . When colloidal particles bear a same sign electric charge , they mutually repel each other and can not aggregate together . Freshly precipitated aluminium or iron hydroxide is extremely difficult to filter because the very fine colloidal particles directly pass through a paper filter . To facilitate the filtration , the colloidal suspension must be first flocculated by adding a concentrated solution of salt to the system . Multivalent cations are more efficient flocculants than monovalent cations : AlCl3 > CaCl2 > NaCl . The electrical charges present at the surface of the particles are so `` neutralised '' and disappear . More correctly speaking , the electrical double layer existing at the surface of the particles is compressed by the added electrolyte and collapses at high ionic strength . The electrical repulsion no longer hinders the aggregation of particles and they can then coalesce to form a flocculent precipitate that is easy to filter . If the precipitate is washed with an excessive volume of deionised water , the electrical double layer present at the surface of the particles expands again and the electrical repulsion reappears : the precipitate peptizes and the particles pass again through the filter .   Peptization is also used in nanoparticle synthesis to make a large grouping of particles split into many primary particles . This is done by changing the surface properties , applying a charge , or by adding a surfactant .   In the synthesis of titania ( titanium dioxide ) nanoparticles , peptization involves adsorption of quaternary ammonium cation on the titania surface . This causes the surface to become positively charged . Electrostatic repulsion of the primary particles in the agglomerated titania breaks up the agglomerate into primary particles .

negative: Prostatic congestion Prostatic congestion is a medical condition of the prostate gland ( prostatosis ) that happens when the prostate becomes swollen by excess fluid . The condition often results in a sufferer feeling the urge to urinate frequently .   Some physicians recommend reducing congestion in the prostate by ejaculating more frequently or by massaging the prostate regularly .

negative: Partisan sorting Partisan sorting or geographic sorting is an effect in politics in which voters with specific viewpoints migrate to specific areas , becoming much more concentrated in them than in the wider electorate . This effect may create or contribute to an effect of polarisation , in which separate areas become dominated by political movements much more extreme than might be expected given the `` average '' political views of voters .   In 2008 , The Economist commented that in American politics sorting was making `` the culture war more bitter and politics harder . ''   A 2016 study finds no evidence that partisans move to more politically compatible communities .

negative: Cortes (surname) Cortés ( Castilian , Galician , Valencian ) , Cortês ( Portuguese ) , Cortès ( Catalan ) is a surname of Spanish and Portuguese origin , respectively . The surname derived from the Old French corteis or curteis , meaning `` courteous '' or `` polite '' and is related to the English Curtis , although the English form has become more widely used as a given name .   The surname has become more frequent among Romani people in Spain than among the general Spanish population .

negative: Iterative aspect The iterative aspect ( abbreviated ) , also called `` semelfactive '' , `` event-internal pluractionality '' , or `` multiplicative '' , is a grammatical aspect that expresses the repetition of an event observable on one single occasion , as in ` he knocked on the door ' , ` he coughed ' , ` she is drumming ' , etc. . It is not to be confused with frequentative aspect and habitual aspect , which both signal repetition over more than one occasion .   Other authors have reserve the term `` semelfactive '' for this mono-occasional repetition , and defined iterative aspect as denoting ` several ' repetitions over more than one occasion , as opposed to the ` frequent ' repetitions conveyed by frequentative aspect .

negative: Boxing at the 1964 Summer Olympics – Heavyweight The heavyweight class in the boxing at the 1964 Summer Olympics competition was the heaviest class . Heavyweights included all boxers weighing in at more than 81 kilograms .

negative: Climate change in Wyoming On a per-person basis , Wyoming emits more carbon dioxide than any other state or any other country : 276000 lb of it per capita a year , because of burning coal , which provides nearly all of the state 's electrical power .   Over the last century , the average temperature in Laramie , Wyoming , has increased 1.5 ° F ( 0.8 ° C ) , and precipitation has decreased by up to 20 % in many parts of the state .   Over the next century , climate in Wyoming may change even more . For example , based on projections made by the Intergovernmental Panel on Climate Change and results from the United Kingdom Hadley Centre 's climate model ( HadCM2 ) , a model that accounts for both greenhouse gases and aerosols , by 2100 temperatures in Wyoming could increase by 4 ° F ( 2 ° C ) in spring and fall ( with a range of 2-7 ° F ) , 5 ° F ( 2.5 ° C ) in summer ( with a range of 2-8 ° F ) , and 6 ° F ( 3 ° C ) in winter ( with a range of 3-11 ° F ) . Precipitation is estimated to decrease slightly in summer ( with a range of 0-10 % ) , increase by 10 % in spring and fall ( with a range of 5-20 % ) , and increase by 30 % in winter ( with a range of 10-50 % ) . Other climate models may show different results , especially regarding estimated changes in precipitation . The amount of precipitation on extreme wet or snowy days in winter is likely to increase . The frequency of extreme hot days in summer would increase because of the general warming trend . It is not clear how the severity of storms might be affected , although an increase in the frequency and intensity of winter storms is possible .

negative: Foothill woodland Foothill woodland is a California vegetation type characterized by an overstory of broadleaf and coniferous trees , generally found in areas of higher elevations and more precipitation than grasslands and oak savannah , and at lower elevations and less precipitation than mixed coniferous .

negative: Travertine Travertine is a form of limestone deposited by mineral springs , especially hot springs . Travertine often has a fibrous or concentric appearance and exists in white , tan , cream-colored , and even rusty varieties . It is formed by a process of rapid precipitation of calcium carbonate , often at the mouth of a hot spring or in a limestone cave . In the latter , it can form stalactites , stalagmites , and other speleothems . It is frequently used in Italy and elsewhere as a building material .   Travertine is a terrestrial sedimentary rock , formed by the precipitation of carbonate minerals from solution in ground and surface waters , and/or geothermally heated hot-springs . Similar ( but softer and extremely porous ) deposits formed from ambient-temperature water are known as tufa .

negative: Computers in the classroom Computers in the classroom include any digital technology used to enhance , supplement , or replace a traditional educational curriculum . As computers have become more accessible , inexpensive , and powerful , the demand for this technology has increased , leading to more frequent use of computer resources within classes , and a decrease in the student-to-computer ratio within schools .

negative: Young Gods (film) Young Gods ( Finnish title : Hymypoika ) , is a 2003 film from Finland . The film centres on a group of Finnish teenagers who begin to make videos of themselves and others having sex . Their adventures become more and more extreme , eventually leading to tragic consequences .   It was directed by Jukka-Pekka Siili and stars Jussi Nikkilä .   The movie is available in the USA from Picture This ! Entertainment .

negative: The Weather of the Future The Weather of the Future : Heat Waves , Extreme Storms , and Other Scenes From a Climate-Changed Planet ( ISBN 978-0-06-172688-0 ) is a 2010 book by climatologist Heidi Cullen . Cullen takes as her starting point the `` clear and present dangers '' posed by the greenhouse gases which result from the burning fossil fuels . She offers a vision of what life might be like in a warmer world . Cullen predicts `` more frequent and more violent storms , more hot spells , cold spells , droughts , famines and huge waves of desperate refugees '' .

negative: Woodwardia unigemmata Woodwardia unigemmata is a species of fern native to Eastern Asia and provides a large area of undergrowth , requiring more than average precipitation .

negative: Nitrofural Nitrofural ( INN , trade name Furacin ) is a bactericidal compound used as an antibiotic most commonly in the form of ointments . Its use in medicine has become less frequent as safer and more effective products have become available , and it has been discontinued in the US . The substance is pale yellow and crystalline .   Other names include nitrofurazone and furacilin .

negative: Extreme sport Extreme sports are recreational activities perceived as involving a high degree of risk . These activities often involve speed , height , a high level of physical exertion , and highly specialized gear .   The definition of an extreme sport is not exact and the origin of the term is unclear , but it gained popularity in the 1990s when it was picked up by marketing companies to promote the X Games and when the Extreme Sports Channel and Extreme.com launched . More recently , the commonly used definition from research is `` a competitive ( comparison or self-evaluative ) activity within which the participant is subjected to natural or unusual physical and mental challenges such as speed , height , depth or natural forces and where fast and accurate cognitive perceptual processing may be required for a successful outcome '' by Dr. Rhonda Cohen ( 2012 ) .   While use of the term `` extreme sport '' has spread far and wide to describe a multitude of different activities , exactly which sports are considered ` extreme ' is debatable . There are , however , several characteristics common to most extreme sports . While not the exclusive domain of youth , extreme sports tend to have a younger-than-average target demographic . Extreme sports are rarely sanctioned by schools . Extreme sports tend to be more solitary than traditional sports ( rafting and paintballing are notable exceptions , as they are done in teams ) . In addition , beginning extreme athletes tend to work on their craft without the guidance of a coach ( though some may hire a coach later ) .   Activities categorized by media as extreme sports differ from traditional sports due to the higher number of inherently uncontrollable variables . These environmental variables are frequently weather and terrain related , including wind , snow , water and mountains . Because these natural phenomena can not be controlled , they inevitably affect the outcome of the given activity or event .   In a traditional sporting event , athletes compete against each other under controlled circumstances . While it is possible to create a controlled sporting event such as X Games , there are environmental variables that can not be held constant for all athletes . Examples include changing snow conditions for snowboarders , rock and ice quality for climbers , and wave height and shape for surfers .   Whilst traditional sporting judgment criteria may be adopted when assessing performance ( distance , time , score , etc. ) , extreme sports performers are often evaluated on more subjective and aesthetic criteria . This results in a tendency to reject unified judging methods , with different sports employing their own ideals and indeed having the ability to evolve their assessment standards with new trends or developments in the sports .

negative: Climatic regions of Argentina Due to its vast size and range of altitudes , Argentina possesses a wide variety of climatic regions , ranging from the hot subtropical region in the north to the cold subantarctic in the far south . Lying between those is the Pampas region , featuring a mild and humid climate . Many regions have different , often contrasting , microclimates . In general , Argentina has four main climate types : warm , moderate , arid , and cold in which the relief features , and the latitudinal extent of the country , determine the different varieties within the main climate types .   Northern parts of the country are characterized by hot , humid summers with mild , drier winters , and highly seasonal precipitation . Mesopotamia , located in northeast Argentina , has a subtropical climate with no dry season and is characterized by high temperatures and abundant rainfall because of exposure to moist easterly winds from the Atlantic Ocean throughout the year . The Chaco region in the center-north , despite being relatively homogeneous in terms of precipitation and temperature , is the warmest region in Argentina , and one of the few natural areas in the world located between tropical and temperate latitudes that is not a desert . Precipitation decreases from east to west in the Chaco region because eastern areas are more influenced by moist air from the Atlantic Ocean than the west , resulting in the vegetation transitioning from forests and marshes to shrubs . Northwest Argentina is predominantly dry , hot , and subtropical although its rugged topography results in a diverse climate .   Central Argentina , which includes the Pampas to the east , and the Cuyo region to the west , has a temperate climate with hot summers and cool , drier winters . In the Cuyo region , the Andes obstruct the path of rain-bearing clouds from the Pacific Ocean ; moreover , its latitude coincides with the subtropical high . Both factors render the region dry . With a wide range of altitudes , the Cuyo region is climatically diverse , with icy conditions persisting at altitudes higher than 4,000 m . The Pampas is mostly flat and receives more precipitation , averaging 500 mm in the western parts to 1200 mm in the eastern parts . The weather in the Pampas is variable due to the contrasting air masses and frontal storms that impact the region . These can generate thunderstorms with intense hailstorms and precipitation , and are known to have the most frequent lightning , and highest convective cloud tops , in the world .   Patagonia , in the south , is mostly arid or semi -- arid except in the extreme west where abundant precipitation supports dense forest coverage , glaciers , and permanent snowfields . Its climate is classified as temperate to cool temperate with the surrounding oceans moderating temperatures on the coast . Away from the coast , areas on the plateaus have large daily and annual temperature ranges . The influence of the Andes , in conjunction with general circulation patterns , generates one of the strongest precipitation gradients ( rate of change in mean annual precipitation in relation to a particular location ) in the world , decreasing rapidly to the east . In much of Patagonia precipitation is concentrated in winter with snowfall occurring occasionally , particularly in the mountainous west and south ; precipitation is more evenly distributed in the east and south . One defining characteristic is the strong winds from the west which blow year-round , lowering the perception of temperature ( wind chill ) , while being a factor in keeping the region arid by favouring evaporation .


query: Greenhouse gases have been the main contributor of warming since 1970.

positive: 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.

positive: 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 .

positive: 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 .

negative: Greenhouse gas emissions by the United Kingdom According to official statistics , there has been a reduction in domestic greenhouse gas emissions in the United Kingdom . These emissions are caused primarily by primary energy consumption . If indirect emissions are accounted for , however , research suggests that UK emissions may have increased since 1990 , due largely to manufacture of short-term consumer items overseas .   Carbon dioxide and other greenhouse gases continue to drive global warming and ocean acidification . Under the Kyoto protocol the UK Government committed to reducing the levels of and five other greenhouse gases by 12.5 % below 1990 levels by 2008 to 2012 . These commitments have been surpassed and new targets set .

negative: Regional effects of global warming Regional effects of global warming are long-term significant changes in the expected patterns of average weather of a specific region due to global warming . The world average temperature is rising due to the greenhouse effect caused by increasing levels of greenhouse gases , especially carbon dioxide . When the global temperature changes , the changes in climate are not expected to be uniform across the Earth . In particular , land areas change more quickly than oceans , and northern high latitudes change more quickly than the tropics , and the margins of biome regions change faster than do their cores .   Regional effects of global warming vary in nature . Some are the result of a generalised global change , such as rising temperature , resulting in local effects , such as melting ice . In other cases , a change may be related to a change in a particular ocean current or weather system . In such cases , the regional effect may be disproportionate and will not necessarily follow the global trend . The increasing temperatures from greenhouse gases have been causing sea levels to rise for many years .   There are three major ways in which global warming will make changes to regional climate : melting or forming ice , changing the hydrological cycle ( of evaporation and precipitation ) and changing currents in the oceans and air flows in the atmosphere . The coast can also be considered a region , and will suffer severe impacts from sea level rise .

negative: Deforestation and climate change Deforestation is one of the main contributors to climate change . It is the second largest anthropogenic source of carbon dioxide to the atmosphere , after fossil fuel combustion . Deforestation and forest degradation contribute to atmospheric greenhouse gas emissions through combustion of forest biomass and decomposition of remaining plant material and soil carbon . It used to account for more than 20 % of carbon dioxide emissions , but it 's currently somewhere around the 10 % mark . By 2008 , deforestation was 12 % of total , or 15 % if peatlands are included . These proportions are likely to have fallen since given the continued rise of fossil fuel use .   Averaged over all land and ocean surfaces , temperatures warmed roughly 1.53 ° F ( 0.85 ° C ) between 1880 and 2012 , according to the Intergovernmental Panel on Climate Change . In the Northern Hemisphere , 1983 to 2012 were the warmest 30-year period of the last 1400 years .

negative: Global dimming Global dimming is the gradual reduction in the amount of global direct irradiance at the Earth 's surface that was observed for several decades after the start of systematic measurements in the 1950s . The effect varies by location , but worldwide it has been estimated to be of the order of a 4 % reduction over the three decades from 1960 -- 1990 . However , after discounting an anomaly caused by the eruption of Mount Pinatubo in 1991 , a very slight reversal in the overall trend has been observed .   Global dimming is thought to have been caused by an increase in particulates such as sulfate aerosols in the atmosphere due to human action .   It has interfered with the hydrological cycle by reducing evaporation and may have reduced rainfall in some areas . Global dimming also creates a cooling effect that may have partially counteracted the effect of greenhouse gases on global warming .

negative: Low-carbon economy A low-carbon economy ( LCE ) , low-fossil-fuel economy ( LFFE ) , or decarbonised economy is an economy based on low carbon power sources that therefore has a minimal output of greenhouse gas ( GHG ) emissions into the biosphere , but specifically refers to the greenhouse gas carbon dioxide . GHG emissions due to anthropogenic ( human ) activity are the dominant cause of observed global warming ( climate change ) since the mid-20th century . Continued emission of greenhouse gases will cause further warming and long-lasting changes around the world , increasing the likelihood of severe , pervasive and irreversible impacts for people and ecosystems .   Many countries around the world are designing and implementing low emission development strategies ( LEDS ) . These strategies seek to achieve social , economic and environmental development goals while reducing long-term greenhouse gas emissions and increasing resilience to climate change impacts .   Globally implemented low-carbon economies are therefore proposed by those having drawn this conclusion , as a means to avoid catastrophic climate change , and as a precursor to the more advanced , zero-carbon economy .

negative: Migration of marine species in the Northern Atlantic Ocean The world 's oceans are warming due to climate change . Climate change is caused by three major factors which are the greenhouse effect , variation in the sun 's energy that reaches Earth , and changes in reflectivity within Earth 's atmosphere and its surface . The greenhouse effect is caused by greenhouse gases that absorb sunlight . Energy from the sun that reaches Earth is either retained or sent into space . Greenhouse gases in Earth 's atmosphere such as carbon dioxide , methane , and water vapor absorb energy which cause a blanketing effect that warms the earth . Aerosols such as black carbon also catalyze the warming effect as they are unreflective and absorb energy from the sun supplementing greenhouse gases in the warming effect .   These combined factors are warming the Earth 's land as well as the oceans . Many fish species possess a certain range of water temperature that they are able to tolerate which is causing species to migrate to different areas where the water temperature is livable . The warming of the Atlantic Ocean is causing many fish species to shift north towards once cooler waters so they can live within their temperature range . Tropical species are being found outside their normal range and into more northern waters causing an array of ecological , economic , and fishery management problems .

negative: GHG footprint The GHG footprint , or greenhouse gas footprint , refers to the amount of GHG that are emitted during the creation of products or services . It is more comprehensive than the commonly used carbon footprint , which measures only carbon dioxide , one of many greenhouse gases .   The GHG footprint differs from the ecological footprint in that the former is expressed in units of GHG warming potential ( GGWP ) and is generated by products or services , whereas the latter is expressed in units of land area and is generated by whole societies .

negative: Runaway greenhouse effect A runaway greenhouse effect is a process in which a net positive feedback between surface temperature and atmospheric opacity increases the strength of the greenhouse effect on a planet until its oceans boil away . An example of this is believed to have happened in the early history of Venus . On the Earth , the IPCC states that `` a ` runaway greenhouse effect ' -- analogous to -LSB- that of -RSB- Venus -- appears to have virtually no chance of being induced by anthropogenic activities . ''   Other large-scale climate changes are sometimes loosely called a `` runaway greenhouse effect '' although it is not an appropriate description . For example , it has been hypothesized that large releases of greenhouse gases may have occurred concurrently with the Permian -- Triassic extinction event or Paleocene -- Eocene Thermal Maximum . Other terms , such as `` abrupt climate change '' , or tipping points could be used when describing such scenarios .

negative: Landfill gas Landfill gas is a complex mix of different gases created by the action of microorganisms within a landfill . Landfill gas is approximately forty to sixty percent methane , with the remainder being mostly carbon dioxide . Trace amounts of other volatile organic compounds comprise the remainder ( < 1 % ) . These trace gases include a large array of species , mainly simple hydrocarbons .   Landfill gases have an influence on climate change . The major components are CO2 and methane , both of which are greenhouse gas . In terms of global warming potential , methane is over 25 times more detrimental to the atmosphere than carbon dioxide . Landfills are the third largest source of methane in the US .

negative: Greenhouse gas removal Greenhouse gas removal projects are a type of climate engineering that seek to remove greenhouse gases from the atmosphere , and thus they tackle the root cause of global warming . These techniques either directly remove greenhouse gases , or alternatively seek to influence natural processes to remove greenhouse gases indirectly . The discipline overlaps with carbon capture and storage and carbon sequestration , and some projects listed may not be considered to be geoengineering by all commentators , instead being described as mitigation .

negative: Radiative forcing Radiative forcing or climate forcing is the difference between insolation ( sunlight ) absorbed by the Earth and energy radiated back to space . Typically , radiative forcing is quantified at the tropopause in units of watts per square meter of the Earth 's surface . Positive forcing ( incoming energy exceeding outgoing energy ) warms the system , while negative forcing ( outgoing energy exceeding incoming energy ) cools it . Causes of radiative forcing include changes in insolation and the concentrations of radiatively active gases , commonly known as greenhouse gases and aerosols .

negative: Emission Reduction Unit The emission reduction unit ( ERU ) is an emissions unit issued under a Joint Implementation project in terms of the Kyoto Protocol . An ERU represents a reduction of greenhouse gases under the Joint Implementation mechanism , where it represents one tonne of equivalent reduced .   To allow comparison between the different effects of gases on the environment , scientists have defined multipliers for gases that compare their greenhouse potency ( global warming potential ) relative to that of carbon dioxide .   One example of a Joint Implementation project resulting in an emission reduction unit , is the production of biogases by landfill sites . These gases consist of mainly methane which escapes to the atmosphere if it is not collected . The main reason for dealing with methane is that it has a 100-year global warming potential multiplier of 25 compared to carbon dioxide ( i.e. has 25 times the greenhouse potency ) . Collection of methane is usually accompanied by its combustion . Burning one tonne of methane produces nearly 3 tonnes of , thus reducing its greenhouse effect by ( 25-3 = 22 ) ERU .   In December 2012 , ERU prices crashed to a low of 15 euro cents before recovering to 23c after news that EU 's Climate Change Committee was to vote on a ban of ERUs from countries that have not signed up to a second commitment period under the Kyoto Protocol .   In January 2013 , Bloomberg reported that emission reduction unit prices declined 89 percent in 2012

negative: GWG GWG is a three letter acronym that can stand for :   Girls with guns  Girls with glasses  Game-winning goal , in sports  Global warming gases ( greenhouse gases )  Games with Gold , an Xbox Live promotion  Goodwill Gang

negative: Simon Tett Simon Tett is a climatologist working at the University of Edinburgh . He used to work at the Hadley Centre .   His most-cited paper , is , and of it he says :   All attempts at detecting and attributing climate change signals need a reliable observed data set and simulations with mechanisms that drive climate change included . In a nutshell , this paper is important because it was the first study to investigate the effect of sulphate aerosols in a general circulation model of the climate system . The experiments simulate the climate back to 1860 ( which is when the global records of surface temperature became reliable ) ... After 1970 our model with greenhouse gases alone begins to depart significantly from the observations . However , when we included sulphate aerosols , which have a cooling effect , the model agreed with the data from the 1930s and onwards . The rapid warming that has taken place since 1970 is , according to the model , attributable to a heating effect from greenhouse gases and a cooling effect from sulphate aerosols .

negative: Criticism of the IPCC Fourth Assessment Report The IPCC Fourth Assessment Report ( AR4 ) is a report on climate change created with the help of a large number of contributors , both scientists and governmental representatives . There has been considerable political controversy over a small number of errors found in the report , and there have been calls for review of the process used to formulate the report . The overwhelming majority view of scientists with expertise in climate change is that errors , when found , are corrected , and the issues as identified do not undermine the conclusions of the report that the climate system is warming in response to increased levels of greenhouse gases , largely due to human activities .

negative: Economics of global warming The economics of global warming concerns the economic aspects of global warming ; this can inform policies that governments might consider in response . A number of factors make this a difficult problem from both economic and political perspectives : it is a long-term , intergenerational problem ; benefits and costs are distributed unequally both within and across countries ; and scientific and public opinions may diverge .   One of the most important greenhouse gases is carbon dioxide . Around 20 % of carbon dioxide which is emitted due to human activities can remain in the atmosphere for many thousands of years . The long time scales and uncertainty associated with global warming have led analysts to develop `` scenarios '' of future environmental , social and economic changes . These scenarios can help governments understand the potential consequences of their decisions .   The impacts of climate change include the loss of biodiversity , sea level rise , increased frequency and severity of some extreme weather events , and acidification of the oceans . Economists have attempted to quantify these impacts in monetary terms , but these assessments can be controversial .   The two main policy responses to global warming are to reduce greenhouse gas emissions ( climate change mitigation ) and to adapt to the impacts of global warming ( e.g. , by building levees in response to sea level rise ) . Another policy response which has recently received greater attention is geoengineering of the climate system ( e.g. injecting aerosols into the atmosphere to reflect sunlight away from the Earth 's surface ) .   One of the responses to the uncertainties of global warming is to adopt a strategy of sequential decision making . This strategy recognizes that decisions on global warming need to be made with incomplete information , and that decisions in the near term will have potentially long-term impacts . Governments might choose to use risk management as part of their policy response to global warming . For instance , a risk-based approach can be applied to climate impacts which are difficult to quantify in economic terms , e.g. , the impacts of global warming on indigenous peoples .   Analysts have assessed global warming in relation to sustainable development . Sustainable development considers how future generations might be affected by the actions of the current generation . In some areas , policies designed to address global warming may contribute positively towards other development objectives . In other areas , the cost of global warming policies may divert resources away from other socially and environmentally beneficial investments ( the opportunity costs of climate change policy ) .

negative: Total equivalent warming impact Total equivalent warming impact or TEWI is besides global warming potential measure used to express contributions to global warming .   It is defined as sum of the direct emissions ( chemical ) and indirect emissions ( energy use ) of greenhouse gases .

negative: Atmospheric carbon cycle The atmosphere is one of the Earth 's major carbon reservoirs and an important component of the global carbon cycle , holding approximately 720 gigatons of carbon . Atmospheric carbon plays an important role in the greenhouse effect . The most important carbon compound in this respect is the gas carbon dioxide . Although it is a small percentage of the atmosphere ( approximately 0.04 % on a molar basis ) , it plays a vital role in retaining heat in the atmosphere and thus in the greenhouse effect . Other gases with effects on the climate containing carbon in the atmosphere are methane and chlorofluorocarbons ( the latter is entirely anthropogenic ) . Emissions by humans in the past 200 years have almost doubled the amount carbon dioxide in the atmosphere .

negative: Ozone depletion and climate change Ozone depletion and climate change , or Ozone hole and global warming in more popular terms , are environmental challenges whose connections have been explored and which have been compared and contrasted , for example in terms of global regulation , in various studies and books .   There is widespread scientific interest in better regulation of climate change , ozone depletion and air pollution , as in general the human relationship with the biosphere is deemed of major historiographical and political significance . Already by 1994 the legal debates about respective regulation regimes on climate change , ozone depletion and air pollution were being dubbed `` monumental '' and a combined synopsis provided .   There are some parallels between atmospheric chemistry and anthropogenic emissions in the discussions which have taken place and the regulatory attempts which have been made . Most important is that the gases causing both problems have long lifetimes after emission to the atmosphere , thus causing problems which are difficult to reverse . However , the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol that amended it are seen as success stories , while the Kyoto Protocol on anthropogenic climate change has largely failed . Currently efforts are being undertaken to assess the reasons and to use synergies , for example with regard to data reporting and policy design and further exchanging of information . While the general public tends to see global warming as a subset of ozone depletion , in fact ozone and chemicals such as chlorofluorocarbons ( CFCs ) and other halocarbons , which are held responsible for ozone depletion , are important greenhouse gasses . Furthermore , natural levels of ozone in both the stratosphere and troposphere have a warming effect .

negative: IPCC list of greenhouse gases This is a list of LLGHG ( long-lived greenhouse gases ) greenhouse gases as used by the IPCC TAR .

negative: Global temperature record The global temperature record shows the fluctuations of the temperature of the atmosphere and the oceans through various spans of time.  The most detailed information exists since 1850, when methodical thermometer-based records began.  There are numerous estimates of temperatures since the end of the Pleistocene glaciation, particularly during the current Holocene epoch.  Older time periods are studied by paleoclimatology.

negative: Advisory Group on Greenhouse Gases The Advisory Group on Greenhouse Gases , created in 1985 , was an advisory body for the review of studies into the greenhouse effect . The group was created by the International Council of Scientific Unions , the United Nations Environment Programme , and the World Meteorological Organization to follow up on the recommendations of the International conference of the Assessment of the role of carbon dioxide and of other greenhouse gases in climate variations and associated impacts , held at Villach , Austria , in October 1985 .   The seven-member panel included Swedish meteorologist Bert Bolin and Canadian climatologist Kenneth Hare .   The group held its last meeting in 1990 . It was gradually replaced by the Intergovernmental Panel on Climate Change .

negative: Mitigation of global warming in Australia Mitigation of global warming involves taking actions to reduce greenhouse gas emissions and to enhance sinks aimed at reducing the extent of global warming . This is in distinction to adaptation to global warming , which involves taking action to minimise the effects of global warming . Scientific consensus on global warming , together with the precautionary principle and the fear of non-linear climate transitions , is leading to increased effort to develop new technologies and sciences and carefully manage others in an attempt to mitigate global warming .   Carbon capture and storage ( CCS ) for coal-fired power stations has been put forward as a solution to rising greenhouse gas emissions . However , CCS can not deliver in time to avoid dangerous increases in temperatures , as widespread commercial use of CCS is not expected before 2030 .   Following the introduction of government mandatory renewable energy targets , more opportunities have opened up for renewable energy technologies such as wind power , photovoltaics , and solar thermal technologies . The deployment of these technologies provides opportunities for mitigating greenhouse gases .   A carbon price was introduced on 1 July 2012 by the government of Julia Gillard with the purpose of reducing Australia 's carbon emissions . It requires large businesses ( defined as those with annual carbon dioxide equivalent emissions over 25,000 tonnes annually ) to pay a price for emissions permits . The tax was scrapped by the Abbott government in July 2014 in what was a widely criticised and highly publicised move .

negative: Regulation of greenhouse gases under the Clean Air Act The United States Environmental Protection Agency ( EPA ) began regulating greenhouse gases ( GHGs ) under the Clean Air Act ( `` CAA '' or `` Act '' ) from mobile and stationary sources of air pollution for the first time on January 2 , 2011 . Standards for mobile sources have been established pursuant to Section 202 of the CAA , and GHGs from stationary sources are currently controlled under the authority of Part C of Title I of the Act . The basis for regulations was upheld in the United States Court of Appeals for the District of Columbia in June 2012 .

negative: Carbon sequestration Carbon sequestration is the process involved in carbon capture and the long-term storage of atmospheric carbon dioxide . Carbon sequestration involves long-term storage of carbon dioxide or other forms of carbon to mitigate or defer global warming . It has been proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases , which are released by burning fossil fuels .   Carbon dioxide is naturally captured from the atmosphere through biological , chemical , and physical processes . Artificial processes have been devised to produce similar effects , including large-scale , artificial capture and sequestration of industrially produced using subsurface saline aquifers , reservoirs , ocean water , aging oil fields , or other carbon sinks .

negative: 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 .

negative: Methane Methane ( -LSB- ˈmɛθeɪn -RSB- or -LSB- ˈmiːθeɪn -RSB- ) is a chemical compound with the chemical formula ( one atom of carbon and four atoms of hydrogen ) . It is a group 14 hydride and the simplest alkane , and is the main constituent of natural gas . The relative abundance of methane on Earth makes it an attractive fuel , though capturing and storing it poses challenges due to its gaseous state under normal conditions for temperature and pressure .   Natural methane is found both below ground and under the sea floor . When it reaches the surface and the atmosphere , it is known as atmospheric methane . The Earth 's atmospheric methane concentration has increased by about 150 % since 1750 , and it accounts for 20 % of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases ( these gases do n't include water vapor which is by far the largest component of the greenhouse effect ) .

negative: Global warming potential Global warming potential ( GWP ) is a relative measure of how much heat a greenhouse gas traps in the atmosphere . It compares the amount of heat trapped by a certain mass of the gas in question to the amount of heat trapped by a similar mass of carbon dioxide . A GWP is calculated over a specific time interval , commonly 20 , 100 , or 500 years . GWP is expressed as a factor of carbon dioxide ( whose GWP is standardized to 1 ) . In the Fifth Assessment Report of the Intergovernmental Panel on Climate Change , methane has a lifetime of 12.4 years and with climate-carbon feedbacks a global warming potential of 86 over 20 years and 34 over 100 years in response to emissions . User related choices such as the time horizon can greatly affect the numerical values obtained for carbon dioxide equivalents . For a change in time horizon from 20 to 100 years , the GWP for methane decreases by a factor of approximately 2.5 .  The substances subject to restrictions under the Kyoto protocol either are rapidly increasing their concentrations in Earth 's atmosphere or have a large GWP .   The GWP depends on the following factors :  the absorption of infrared radiation by a given species  the spectral location of its absorbing wavelengths  the atmospheric lifetime of the species  Thus , a high GWP correlates with a large infrared absorption and a long atmospheric lifetime . The dependence of GWP on the wavelength of absorption is more complicated . Even if a gas absorbs radiation efficiently at a certain wavelength , this may not affect its GWP much if the atmosphere already absorbs most radiation at that wavelength . A gas has the most effect if it absorbs in a `` window '' of wavelengths where the atmosphere is fairly transparent . The dependence of GWP as a function of wavelength has been found empirically and published as a graph .   Because the GWP of a greenhouse gas depends directly on its infrared spectrum , the use of infrared spectroscopy to study greenhouse gases is centrally important in the effort to understand the impact of human activities on global climate change .

negative: Atmospheric methane Atmospheric methane is the methane present in Earth 's atmosphere . Atmospheric methane concentrations are of interest because it is one of the most potent greenhouse gases in Earth 's atmosphere . The 100-year global warming potential of methane is 28 . That is , over a 100-year period , it traps 28 times more heat per mass unit than carbon dioxide and 32 times the effect when accounted for aerosol interactions . Global methane levels , had risen to 1800 parts per billion ( ppb ) by 2011 , an increase by a factor of 2.5 since pre-industrial times , from 722 ppb , the highest value in at least 800,000 years . Its concentration is higher in the Northern Hemisphere since most sources ( both natural and human ) are located on land and the Northern Hemisphere has more land mass . The concentrations vary seasonally , with , for example , a minimum in the northern tropics during April − May mainly due to removal by the hydroxyl radical .   Early in the Earth 's history carbon dioxide and methane likely produced a greenhouse effect . The carbon dioxide would have been produced by volcanoes and the methane by early microbes . During this time , Earth 's earliest life appeared . These first , ancient bacteria added to the methane concentration by converting hydrogen and carbon dioxide into methane and water . Oxygen did not become a major part of the atmosphere until photosynthetic organisms evolved later in Earth 's history . With no oxygen , methane stayed in the atmosphere longer and at higher concentrations than it does today .   Methane is created near the surface , and it is carried into the stratosphere by rising air in the tropics . Uncontrolled build-up of methane in Earth 's atmosphere is naturally checked -- although human influence can upset this natural regulation -- by methane 's reaction with hydroxyl radicals formed from singlet oxygen atoms and with water vapor .

negative: 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.

negative: ExxonMobil climate change controversy The ExxonMobil climate change controversy is the controversy around ExxonMobil 's activities related to climate change , especially their promotion of climate change denial . Since the 1970s , ExxonMobil engaged in research , lobbying , advertising , and grant making , some of which were conducted with the purpose of delaying widespread acceptance and action on global warming .   From the late 1970s and through the 1980s , Exxon funded internal and university collaborations , broadly in line with the developing public scientific approach . After the 1980s , the company was a leader in climate change denial , opposing regulations to curtail global warming . ExxonMobil funded organizations critical of the Kyoto Protocol and seeking to undermine public opinion about the scientific consensus that global warming is caused by the burning of fossil fuels . Exxon helped to found and lead the Global Climate Coalition of businesses opposed to the regulation of greenhouse gas emissions .

negative: Avoiding Dangerous Climate Change Avoiding Dangerous Climate Change : A Scientific Symposium on Stabilisation of Greenhouse Gases was a 2005 international conference that examined the link between atmospheric greenhouse gas concentration , and the 2 ° C ( 3.6 ° F ) ceiling on global warming thought necessary to avoid the most serious effects of global warming . Previously this had generally been accepted as being 550 ppm .   The conference took place under the United Kingdom 's presidency of the G8 , with the participation of around 200 ` internationally renowned ' scientists from 30 countries . It was chaired by Dennis Tirpak and hosted by the Hadley Centre for Climate Prediction and Research in Exeter , from 1 February to 3 February .