query: (2009) have demonstrated recently  – the upper troposphere (the only place where adding CO2 to the  atmosphere could make any difference to temperature) is considerably  drier than the models are tuned to expect."

positive: Sea surface temperature Sea surface temperature ( SST ) is the water temperature close to the ocean 's surface . The exact meaning of surface varies according to the measurement method used , but it is between 1 mm and 20 m below the sea surface . Air masses in the Earth 's atmosphere are highly modified by sea surface temperatures within a short distance of the shore . Localized areas of heavy snow can form in bands downwind of warm water bodies within an otherwise cold air mass . Warm sea surface temperatures are known to be a cause of tropical cyclogenesis over the Earth 's oceans . Tropical cyclones can also cause a cool wake , due to turbulent mixing of the upper 30 m of the ocean . SST changes diurnally , like the air above it , but to a lesser degree . There is less SST variation on breezy days than on calm days . In addition , ocean currents such as the Atlantic Multidecadal Oscillation ( AMO ) , can effect SST 's on multi-decadal time scales , a major impact results from the global thermohaline circulation , which affects average SST significantly throughout most of the world 's oceans .   Coastal SSTs can cause offshore winds to generate upwelling , which can significantly cool or warm nearby landmasses , but shallower waters over a continental shelf are often warmer . Onshore winds can cause a considerable warm-up even in areas where upwelling is fairly constant , such as the northwest coast of South America . Its values are important within numerical weather prediction as the SST influences the atmosphere above , such as in the formation of sea breezes and sea fog . It is also used to calibrate measurements from weather satellites .

positive: Troposphere The troposphere is the lowest portion of Earth 's atmosphere , and is also where nearly all weather takes place . It contains approximately 75 % of the atmosphere 's mass and 99 % of the total mass of water vapor and aerosols . The average depths of the troposphere are 20 km in the tropics , 17 km in the mid latitudes , and 7 km in the polar regions in winter . The lowest part of the troposphere , where friction with the Earth 's surface influences air flow , is the planetary boundary layer . This layer is typically a few hundred meters to 2 km deep depending on the landform and time of day . Atop the troposphere is the tropopause , which is the border between the troposphere and stratosphere . The tropopause is an inversion layer , where the air temperature ceases to decrease with height and remains constant through its thickness .   The word troposphere derives from the for `` turn , turn toward , trope '' and '' - sphere '' ( as in , the Earth ) , reflecting the fact that rotational turbulent mixing plays an important role in the troposphere 's structure and behaviour . Most of the phenomena associated with day-to-day weather occur in the troposphere .

positive: Uranus Uranus is the seventh planet from the Sun . It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System . Uranus is similar in composition to Neptune , and both have different bulk chemical composition from that of the larger gas giants Jupiter and Saturn . For this reason , scientists often classify Uranus and Neptune as `` ice giants '' to distinguish them from the gas giants . Uranus 's atmosphere is similar to Jupiter 's and Saturn 's in its primary composition of hydrogen and helium , but it contains more `` ices '' such as water , ammonia , and methane , along with traces of other hydrocarbons . It is the coldest planetary atmosphere in the Solar System , with a minimum temperature of 49 K , and has a complex , layered cloud structure with water thought to make up the lowest clouds and methane the uppermost layer of clouds . The interior of Uranus is mainly composed of ices and rock .   Uranus is the only planet whose name is derived from a figure from Greek mythology , from the Latinised version of the Greek god of the sky Ouranos . Like the other giant planets , Uranus has a ring system , a magnetosphere , and numerous moons . The Uranian system has a unique configuration among those of the planets because its axis of rotation is tilted sideways , nearly into the plane of its solar orbit . Its north and south poles , therefore , lie where most other planets have their equators . In 1986 , images from Voyager 2 showed Uranus as an almost featureless planet in visible light , without the cloud bands or storms associated with the other giant planets . Observations from Earth have shown seasonal change and increased weather activity as Uranus approached its equinox in 2007 . Wind speeds can reach 250 m/s .

positive: Atmosphere of Jupiter The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System . It is mostly made of molecular hydrogen and helium in roughly solar proportions ; other chemical compounds are present only in small amounts and include methane , ammonia , hydrogen sulfide and water . Although water is thought to reside deep in the atmosphere , its directly measured concentration is very low . The nitrogen , sulfur , and noble gas abundances in Jupiter 's atmosphere exceed solar values by a factor of about three .   The atmosphere of Jupiter lacks a clear lower boundary and gradually transitions into the liquid interior of the planet . From lowest to highest , the atmospheric layers are the troposphere , stratosphere , thermosphere and exosphere . Each layer has characteristic temperature gradients . The lowest layer , the troposphere , has a complicated system of clouds and hazes , comprising layers of ammonia , ammonium hydrosulfide and water . The upper ammonia clouds visible at Jupiter 's surface are organized in a dozen zonal bands parallel to the equator and are bounded by powerful zonal atmospheric flows ( winds ) known as jets . The bands alternate in color : the dark bands are called belts , while light ones are called zones . Zones , which are colder than belts , correspond to upwellings , while belts mark descending air . The zones ' lighter color is believed to result from ammonia ice ; what gives the belts their darker colors is uncertain . The origins of the banded structure and jets are not well understood , though a `` shallow model '' and a `` deep model '' exist .   The Jovian atmosphere shows a wide range of active phenomena , including band instabilities , vortices ( cyclones and anticyclones ) , storms and lightning . The vortices reveal themselves as large red , white or brown spots ( ovals ) . The largest two spots are the Great Red Spot ( GRS ) and Oval BA , which is also red . These two and most of the other large spots are anticyclonic . Smaller anticyclones tend to be white . Vortices are thought to be relatively shallow structures with depths not exceeding several hundred kilometers . Located in the southern hemisphere , the GRS is the largest known vortex in the Solar System . It could engulf two or three Earths and has existed for at least three hundred years . Oval BA , south of GRS , is a red spot a third the size of GRS that formed in 2000 from the merging of three white ovals .   Jupiter has powerful storms , often accompanied by lightning strikes . The storms are a result of moist convection in the atmosphere connected to the evaporation and condensation of water . They are sites of strong upward motion of the air , which leads to the formation of bright and dense clouds . The storms form mainly in belt regions . The lightning strikes on Jupiter are hundreds of times more powerful than those seen on Earth . However , there are so few , that the amount of lightning activity is comparable to Earth .

negative: Jet standard atmosphere Jet Standard Atmosphere is often used by jet manufactures . It assumes a mean sea level temperature of +15 C . The temperature then lapses 2 C per 1000 ft to infinity . There is no Tropopause in the jet standard atmosphere . In the standard atmosphere , the Tropopause is the height at which the temperature stops decreasing . It is also the end of the Troposphere and start of the Stratosphere .

negative: Idealized greenhouse model The surface of the Sun radiates light and heat at approximately 5,500 ° C . The Earth is much cooler and so radiates heat back away from itself at much longer wavelengths , mostly in the infrared range . The idealized greenhouse model is based on the fact that certain gases in the Earth 's atmosphere , including carbon dioxide and water vapour , are transparent to the high-frequency , high-energy solar radiation , but are much more opaque to the lower frequency infrared radiation leaving the surface of the earth . Thus heat is easily let in , but is partially trapped by these gases as it tries to leave . Rather than get hotter and hotter , Kirchhoff 's law of thermal radiation says that the gases of the atmosphere also have to re-emit the infrared energy that they absorb , and they do so , also at long infrared wavelengths , both upwards into space as well as downwards back towards the Earth 's surface . In the long-term , thermal equilibrium is reached when all the heat energy arriving on the planet is leaving again at the same rate . In this idealized model , the greenhouse gases cause the surface of the planet to be warmer than it would be without them , in order for the required amount of heat energy finally to be radiated out into space from the top of the atmosphere .   The greenhouse effect can be illustrated with an idealized planet . This is a common `` textbook model '' : the planet will have a constant surface temperature Ts and an atmosphere with constant temperature Ta . For diagrammatic clarity , a gap can be depicted between the atmosphere and the surface . Alternatively , Ts could be interpreted as a temperature representative of the surface and the lower atmosphere , and Ta could be interpreted as the temperature of the upper atmosphere . In order to justify that Ta and Ts remain constant over the planet , strong ocean and atmospheric currents can be imagined to provide plentiful lateral mixing . Furthermore , any daily or seasonal cycles in temperature are assumed to be insignificant .

negative: Walker circulation The Walker circulation , also known as the Walker cell , is a conceptual model of the air flow in the tropics in the lower atmosphere ( troposphere ) . According to this model , parcels of air follow a closed circulation in the zonal and vertical directions . This circulation , which is roughly consistent with observations , is caused by differences in heat distribution between ocean and land . It was discovered by Gilbert Walker . In addition to motions in the zonal and vertical direction the tropical atmosphere also has considerable motion in the meridional direction as part of , for example , the Hadley Circulation .   The term `` Walker circulation '' was coined in 1969 by the Norwegian-American meteorologist Jacob Bjerknes .

negative: Lime kiln A lime kiln is a kiln used for the calcination of limestone ( calcium carbonate ) to produce the form of lime called quicklime ( calcium oxide ) . The chemical equation for this reaction is   CaCO3 + heat → CaO + CO2   This reaction takes place at 900 ° C ( 1650 ° F ; at which temperature the partial pressure of CO2 is 1 atmosphere ) , but a temperature around 1000 ° C ( 1800 ° F ; at which temperature the partial pressure of CO2 is 3.8 atmospheres ) is usually used to make the reaction proceed quickly . Excessive temperature is avoided because it produces unreactive , `` dead-burned '' lime .   Slaked lime ( calcium hydroxide ) can be formed by mixing water with quicklime .

negative: Mesopause The mesopause is the temperature minimum at the boundary between the mesosphere and the thermosphere atmospheric regions . Due to the lack of solar heating and very strong radiative cooling from carbon dioxide , the mesosphere is the coldest region on Earth with temperatures as low as -100 ° C ( -148 ° F or 173 K ) . The altitude of the mesopause for many years was assumed to be at around 85 km ( 53 mi . ) , but observations to higher altitudes and modeling studies in the last 10 years have shown that in fact the mesopause consists of two minima - one at about 85 km and a stronger minimum at about 100 km . ( 62 mi . )   Another feature is that the summer mesopause is cooler than the winter ( sometimes referred to as the mesopause anomaly ) . It is due to a summer-to-winter circulation giving rise to upwelling at the summer pole and downwelling at the winter pole . Air rising will expand and cool resulting in a cold summer mesopause and conversely downwelling air results in compression and associated increase in temperature at the winter mesopause . In the mesosphere the summer-to-winter circulation is due to gravity wave dissipation , which deposits momentum against the mean east-west flow , resulting in a small north-south circulation .   In recent years the mesopause has also been the focus of studies on global climate change associated with increases in CO2 . Unlike the troposphere , where greenhouse gases result in the atmosphere heating up , increased CO2 in the mesosphere acts to cool the atmosphere due to increased radiative emission . This results in a measurable effect - the mesopause should become cooler with increased CO2 . Observations do show a decrease of temperature of the mesopause , though the magnitude of this decrease varies and is subject to further study . Modeling studies of this phenomenon have also been carried out .

negative: Stratosphere The stratosphere ( -LSB- ˈstrætəˌsfɪər , _ - toʊ - -RSB- ) is the second major layer of Earth 's atmosphere , just above the troposphere , and below the mesosphere . About 20 % of the atmosphere 's mass is contained in the stratosphere . The stratosphere is stratified in temperature , with warmer layers higher and cooler layers closer to the Earth . The increase of temperature with altitude is a result of the absorption of the Sun 's ultraviolet radiation by the ozone . This is in contrast to the troposphere , near the Earth 's surface , where temperatures decreases with altitude . The border between the troposphere and stratosphere , the tropopause , marks where this temperature inversion begins . Near the equator , the stratosphere starts at 18 km ; at mid latitudes , it starts at 10 - and ends at 50 km ; at the poles , it starts at about 8 km . Temperatures vary within the stratosphere with the seasons , in particular with the polar night ( winter ) . The greatest variation of temperature takes place over the poles in the lower stratosphere ; those variations are largely steady at lower latitudes and higher altitudes .

negative: Lifted index The lifted index ( LI ) is the temperature difference between the environment Te ( p ) and an air parcel lifted adiabatically Tp ( p ) at a given pressure height in the troposphere ( lowest layer where most weather occurs ) of the atmosphere , usually 500 hPa ( mb ) . The temperature is measured in Celsius . When the value is positive , the atmosphere ( at the respective height ) is stable and when the value is negative , the atmosphere is unstable .

negative: Atmospheric temperature Atmospheric temperature is a measure of temperature at different levels of the Earth 's atmosphere . It is governed by many factors , including incoming solar radiation , humidity and altitude . When discussing surface temperature , the annual atmospheric temperature range at any geographical location depends largely upon the type of biome , as measured by the Köppen climate classification .

negative: Atmosphere of Uranus The atmosphere of Uranus is composed primarily of hydrogen and helium . At depth it is significantly enriched in volatiles ( dubbed `` ices '' ) such as water , ammonia and methane . The opposite is true for the upper atmosphere , which contains very few gases heavier than hydrogen and helium due to its low temperature . Uranus 's atmosphere is the coldest of all the planets , with its temperature reaching as low as 49 K.   The Uranian atmosphere can be divided into three main layers : the troposphere , between altitudes of − 300 and 50 km and pressures from 100 to 0.1 bar ; the stratosphere , spanning altitudes between 50 and 4000 km and pressures of between and the hot thermosphere ( and exosphere ) extending from an altitude of 4,000 km to several Uranian radii from the nominal surface at 1 bar pressure . Unlike Earth 's , Uranus 's atmosphere has no mesosphere .   The troposphere hosts four cloud layers : methane clouds at about 1.2 bar , hydrogen sulfide and ammonia clouds at 3 -- 10 bar , ammonium hydrosulfide clouds at 20 -- 40 bar , and finally water clouds below 50 bar . Only the upper two cloud layers have been observed directly -- the deeper clouds remain speculative . Above the clouds lie several tenuous layers of photochemical haze . Discrete bright tropospheric clouds are rare on Uranus , probably due to sluggish convection in the planet 's interior . Nevertheless , observations of such clouds were used to measure the planet 's zonal winds , which are remarkably fast with speeds up to 240 m/s .   Little is known about the Uranian atmosphere as to date only one spacecraft , Voyager 2 , which passed by the planet in 1986 , has studied it in detail . No other missions to Uranus are currently scheduled .

negative: Climate sensitivity Climate sensitivity is the equilibrium temperature change in response to changes of the radiative forcing . Therefore , climate sensitivity depends on the initial climate state , but potentially can be accurately inferred from precise palaeoclimate data . Slow climate feedbacks , especially changes of ice sheet size and atmospheric CO2 , amplify the total Earth system sensitivity by an amount that depends on the time scale considered .   Although climate sensitivity is usually used in the context of radiative forcing by carbon dioxide ( CO2 ) , it is thought of as a general property of the climate system : the change in surface air temperature ( ΔTs ) following a unit change in radiative forcing ( RF ) , and thus is expressed in units of ° C / ( W/m2 ) . For this to be useful , the measure must be independent of the nature of the forcing ( e.g. from greenhouse gases or solar variation ) ; to first order this is indeed found to be so .   The climate sensitivity specifically due to is often expressed as the temperature change in ° C associated with a doubling of the concentration of carbon dioxide in Earth 's atmosphere .   For coupled atmosphere-ocean global climate models ( e.g. CMIP5 ) the climate sensitivity is an emergent property : it is not a model parameter , but rather a result of a combination of model physics and parameters . By contrast , simpler energy-balance models may have climate sensitivity as an explicit parameter .   The terms represented in the equation relate radiative forcing ( RF ) to linear changes in global surface temperature change ( ΔTs ) via the climate sensitivity λ .   It is also possible to estimate climate sensitivity from observations ; however , this is difficult due to uncertainties in the forcing and temperature histories .

negative: Microwave Sounding Unit temperature measurements Microwave Sounding Unit temperature measurements refers to temperature measurement using the Microwave Sounding Unit instrument and is one of several methods of measuring Earth atmospheric temperature from satellites. Microwave measurements have been obtained from the troposphere since 1979, when they were included within NOAA weather satellites, starting with TIROS-N.  By comparison, the usable balloon (radiosonde) record begins in 1958 but has less geographic coverage and is less uniform. Microwave brightness measurements do not directly measure temperature.  They measure radiances in various wavelength bands, which must then be mathematically inverted to obtain indirect inferences of temperature. The resulting temperature profiles depend on details of the methods that are used to obtain temperatures from radiances. As a result, different groups that have analyzed the satellite data  have obtained different temperature trends. Among these groups are Remote Sensing Systems (RSS) and the University of Alabama in Huntsville (UAH). The satellite series is not fully homogeneous – the record is constructed from a series of satellites with similar but not identical instrumentation. The sensors deteriorate over time, and corrections are necessary for satellite drift in orbit. Particularly large differences between reconstructed temperature series occur at the few times when there is little temporal overlap between successive satellites, making intercalibration difficult.

negative: Sprite (lightning) Sprites are large-scale electrical discharges that occur high above thunderstorm clouds , or cumulonimbus , giving rise to a quite varied range of visual shapes flickering in the night sky . They are triggered by the discharges of positive lightning between an underlying thundercloud and the ground .   Sprites appear as luminous reddish-orange flashes . They often occur in clusters within atmosphere above the troposphere at an altitude range of 50 - . Sporadic visual reports of sprites go back at least to 1886 , but they were first photographed on July 6 , 1989 by scientists from the University of Minnesota and have subsequently been captured in video recordings many thousands of times .   Sprites are sometimes inaccurately called upper-atmospheric lightning . However , sprites are cold plasma phenomena that lack the hot channel temperatures of tropospheric lightning , so they are more akin to fluorescent tube discharges than to lightning discharges .

negative: The Street Scene The Street Scene is a basic model for epic theater set forth by Bertolt Brecht . It makes use of a simple , `` natural '' incident , such as could be seen on any street corner : an eyewitness demonstrating to a collection of people how a traffic accident took place . `` The bystanders may not have observed what happened , or they may simply not agree with him , may ` see things a different way ' ; the point is that the demonstrator acts the behavior of driver or victim both in such a way that the bystanders are able to form an opinion about the incident . '' This model is set forth as the most primitive type of epic theater to be easily understood by the reader or listener .

negative: Atmospheric focusing Atmospheric focusing is a phenomenon occurring when a large shock wave is produced in the atmosphere , as in a nuclear explosion or large extraterrestrial object impact . The shock wave is refracted horizontally by density variations in the atmosphere so that it can have impacts in localized areas much further away than the theoretical extent of its blast effect . In large bombs , some effects may thus be found hundreds of kilometers from the blast site ( such as in the case of the Tsar Bomba test , where damage was caused up to approximately 1,000 km away ) .   This effect operates similarly to the patterns made by sunlight on the bottom of a pool , the difference is that the light is bent at the contact point with the water while the shock wave is distorted by density variations ( e.g. due to temperature variations ) in the atmosphere . Variations of wind can cause a similar effect . This will disperse the shock wave at some places and focus it at others . For powerful shock waves this can cause damage farther than expected ; the shock wave energy density will decrease beyond expected values based on uniform geometry falloff for weak shock or acoustic waves , as expected at large distances ) .   Category : Shock waves  Category : Nuclear weapons

negative: Anticyclogenesis Anticyclogenesis is the development or strengthening of anticyclonic circulation in the atmosphere . It is the opposite of anticyclolysis , and has a cyclonic equivalent -- cyclogenesis . Anticyclones are alternatively referred to as high pressure systems . High pressure areas form due to downward motion through the troposphere , the atmospheric layer where weather occurs . Preferred areas within a synoptic flow pattern in higher levels of the troposphere are beneath the western side of troughs . On weather maps , these areas show converging winds ( isotachs ) , also known as confluence , or converging height lines near or above the level of non-divergence , which is near the 500 hPa pressure surface about midway up through the troposphere . On weather maps , high pressure centers are associated with the letter H. On constant pressure upper level charts , it is located within the highest height line contour .

negative: Atmosphere of Venus The atmosphere of Venus is the layer of gases surrounding Venus . It is composed primarily of carbon dioxide and is much denser and hotter than that of Earth . The temperature at the surface is 740 K ( 467 ° C , 872 ° F ) , and the pressure is 93 bar ( 9.3 MPa ) , roughly the pressure found 900 m underwater on Earth . The Venusian atmosphere supports opaque clouds made of sulfuric acid , making optical Earth-based and orbital observation of the surface impossible . Information about the topography has been obtained exclusively by radar imaging . Aside from carbon dioxide , the other main component is nitrogen . Other chemical compounds are present only in trace amounts .   Mikhail Lomonosov was the first person to hypothesize the existence of an atmosphere on Venus based on his observation of the transit of Venus of 1761 in a small observatory near his house in Saint Petersburg , Russia .   Aside from the very surface layers , the atmosphere is in a state of vigorous circulation . The upper layer of troposphere exhibits a phenomenon of super-rotation , in which the atmosphere circles the planet in just four Earth days , much faster than the planet 's sidereal day of 243 days . The winds supporting super-rotation blow at a speed of 100 m/s ( ~ 360 km/h or 220 mph ) or more . Winds move at up to 60 times the speed of the planet 's rotation , while Earth 's fastest winds are only 10 % to 20 % rotation speed . On the other hand , the wind speed becomes increasingly slower as the elevation from the surface decreases , with the breeze barely reaching the speed of 10 km/h ( 2.8 m/s ) on the surface . Near the poles are anticyclonic structures called polar vortices . Each vortex is double-eyed and shows a characteristic S-shaped pattern of clouds . Above there is an intermediate layer of mesosphere which separates the troposphere from the thermosphere . The thermosphere is also characterized by strong circulation , but very different in its nature - the gases heated and partially ionized by sunlight in the sunlit hemisphere migrate to the dark hemisphere where they recombine and downwell .   Unlike Earth , Venus lacks a magnetic field . Its ionosphere separates the atmosphere from outer space and the solar wind . This ionised layer excludes the solar magnetic field , giving Venus a distinct magnetic environment . This is considered Venus 's induced magnetosphere . Lighter gases , including water vapour , are continuously blown away by the solar wind through the induced magnetotail . It is speculated that the atmosphere of Venus up to around 4 billion years ago was more like that of the Earth with liquid water on the surface . A runaway greenhouse effect may have been caused by the evaporation of the surface water and subsequent rise of the levels of other greenhouse gases .   Despite the harsh conditions on the surface , the atmospheric pressure and temperature at about 50 km to 65 km above the surface of the planet is nearly the same as that of the Earth , making its upper atmosphere the most Earth-like area in the Solar System , even more so than the surface of Mars . Due to the similarity in pressure and temperature and the fact that breathable air ( 21 % oxygen , 78 % nitrogen ) is a lifting gas on Venus in the same way that helium is a lifting gas on Earth , the upper atmosphere has been proposed as a location for both exploration and colonization .   On January 29 , 2013 , ESA scientists reported that the ionosphere of the planet Venus streams outwards in a manner similar to `` the ion tail seen streaming from a comet under similar conditions . ''

negative: Stratopause The stratopause ( formerly Mesopeak ) is the level of the atmosphere which is the boundary between two layers : the stratosphere and the mesosphere . In the stratosphere the temperature increases with altitude , and the stratopause is the region where a maximum in the temperature occurs .  This atmospheric feature is not only associated with Earth : it occurs on any other planet or moon that has an atmosphere as well .   On Earth , the stratopause is 50 to high above the Earth 's surface . The atmospheric pressure is around 1/1000 of the pressure at sea level . The temperature in the stratopause is -15 degrees Celsius ( 5 degrees Fahrenheit ) .

negative: Tropospheric propagation Tropospheric propagation describes electromagnetic propagation in relation to the troposphere .  The service area from a VHF or UHF radio transmitter extends to just beyond the optical horizon , at which point signals start to rapidly reduce in strength . Viewers living in such a `` deep fringe '' reception area will notice that during certain conditions , weak signals normally masked by noise increase in signal strength to allow quality reception . Such conditions are related to the current state of the troposphere .   Tropospheric propagated signals travel in the part of the atmosphere adjacent to the surface and extending to some 25,000 feet ( 7,620 m ) . Such signals are thus directly affected by weather conditions extending over some hundreds of miles . During very settled , warm anticyclonic weather ( i.e. , high pressure ) , usually weak signals from distant transmitters improve in strength . Another symptom during such conditions may be interference to the local transmitter resulting in co-channel interference , usually horizontal lines or an extra floating picture with analog broadcasts and break-up with digital broadcasts . A settled high-pressure system gives the characteristic conditions for enhanced tropospheric propagation , in particular favouring signals which travel along the prevailing isobar pattern ( rather than across it ) . Such weather conditions can occur at any time , but generally the summer and autumn months are the best periods . In certain favourable locations , enhanced tropospheric propagation may enable reception of ultra high frequency ( UHF ) TV signals up to 1,000 mi or more .   The observable characteristics of such high-pressure systems are usually clear , cloudless days with little or no wind . At sunset the upper air cools , as does the surface temperature , but at different rates . This produces a boundary or temperature gradient , which allows an inversion level to form -- a similar effect occurs at sunrise . The inversion is capable of allowing very high frequency ( VHF ) and UHF signal propagation well beyond the normal radio horizon distance .   The inversion effectively reduces sky wave radiation from a transmitter -- normally VHF and UHF signals travel on into space when they reach the horizon , the refractive index of the ionosphere preventing signal return . With temperature inversion , however , the signal is to a large extent refracted over the horizon rather than continuing along a direct path into outer space .   Fog also produces good tropospheric results , again due to inversion effects . Fog occurs during high-pressure weather , and if such conditions result in a large belt of fog with clear sky above , there will be heating of the upper fog level and thus an inversion . This situation often arises towards night fall , continues overnight and clears with the sunrise over a period of around 4 -- 5 hours .

negative: BluOnyx BluOnyx is a brand of Mobile Content Server introduced in December 2006 by LSI Inc ( formerly Agere Systems ) . The first prototype models of the BluOnyx were demonstrated at the 2007 Consumer Electronics Show in Las Vegas with mass distribution expected later in the year . The purpose of the device is to store digital media away from the computer , creating a single place where many users with different mobile devices can connect . The device utilizes software which is `` pushed '' directly onto the phones , rather than have the device connected to a computer .

negative: Weather Weather is the state of the atmosphere , to the degree that it is hot or cold , wet or dry , calm or stormy , clear or cloudy . Most weather phenomena occur in the lowest level of the atmosphere , the troposphere , just below the stratosphere . Weather refers to day-to-day temperature and precipitation activity , whereas climate is the term for the averaging of atmospheric conditions over longer periods of time . When used without qualification , `` weather '' is generally understood to mean the weather of Earth .   Weather is driven by air pressure , temperature and moisture differences between one place and another . These differences can occur due to the sun 's angle at any particular spot , which varies with latitude . The strong temperature contrast between polar and tropical air gives rise to the largest scale atmospheric circulations : the Hadley Cell , the Ferrel Cell , the Polar Cell , and the jet stream . Weather systems in the mid-latitudes , such as extratropical cyclones , are caused by instabilities of the jet stream flow . Because the Earth 's axis is tilted relative to its orbital plane , sunlight is incident at different angles at different times of the year . On Earth 's surface , temperatures usually range ± 40 ° C ( − 40 ° F to 100 ° F ) annually . Over thousands of years , changes in Earth 's orbit can affect the amount and distribution of solar energy received by the Earth , thus influencing long-term climate and global climate change .   Surface temperature differences in turn cause pressure differences . Higher altitudes are cooler than lower altitudes as most atmospheric heating is due to contact with the Earth 's surface while radiative losses to space are mostly constant . Weather forecasting is the application of science and technology to predict the state of the atmosphere for a future time and a given location . The Earth 's weather system is a chaotic system ; as a result , small changes to one part of the system can grow to have large effects on the system as a whole . Human attempts to control the weather have occurred throughout history , and there is evidence that human activities such as agriculture and industry have modified weather patterns .   Studying how the weather works on other planets has been helpful in understanding how weather works on Earth . A famous landmark in the Solar System , Jupiter 's Great Red Spot , is an anticyclonic storm known to have existed for at least 300 years . However , weather is not limited to planetary bodies . A star 's corona is constantly being lost to space , creating what is essentially a very thin atmosphere throughout the Solar System . The movement of mass ejected from the Sun is known as the solar wind .

negative: Low-pressure area A low-pressure area , low , or depression is a region where the topographic map is atmospheric pressure is lower than that of surrounding locations . Low-pressure systems form under areas of wind divergence that occur in the upper levels of the troposphere . The formation process of a low-pressure area is known as cyclogenesis . Within the field of meteorology , atmospheric divergence aloft occurs in two areas . The first area is on the east side of upper troughs , which form half of a Rossby wave within the Westerlies ( a trough with large wavelength that extends through the troposphere ) . A second area of wind divergence aloft occurs ahead of embedded shortwave troughs , which are of smaller wavelength . Diverging winds aloft ahead of these troughs cause atmospheric lift within the troposphere below , which lowers surface pressures as upward motion partially counteracts the force of gravity .   Thermal lows form due to localized heating caused by greater sunshine over deserts and other land masses . Since localized areas of warm air are less dense than their surroundings , this warmer air rises , which lowers atmospheric pressure near that portion of the Earth 's surface . Large-scale thermal lows over continents help drive monsoon circulations . Low-pressure areas can also form due to organized thunderstorm activity over warm water . When this occurs over the tropics in concert with the Intertropical Convergence Zone , it is known as a monsoon trough . Monsoon troughs reach their northerly extent in August and their southerly extent in February . When a convective low acquires a well-hot circulation in the tropics it is termed a tropical cyclone . Tropical cyclones can form during any month of the year globally , but can occur in either the northern or southern hemisphere during November .   Atmospheric lift will also generally produce cloud cover through adiabatic cooling once the air becomes saturated as it rises , although the low-pressure area typically brings cloudy skies , which act to minimize diurnal temperature extremes . Since clouds reflect sunlight , incoming shortwave solar radiation decreases , which causes lower temperatures during the day . At night the absorptive effect of clouds on outgoing longwave radiation , such as heat energy from the surface , allows for warmer diurnal low temperatures in all seasons . The stronger the area of low pressure , the stronger the winds experienced in its vicinity . Globally , low-pressure systems are most frequently located over the Tibetan Plateau and in the lee of the Rocky mountains . In Europe ( particularly in the United Kingdom ) , recurring low-pressure weather systems are typically known as `` depressions '' .

negative: Planetary equilibrium temperature The planetary equilibrium temperature is a theoretical temperature that a planet would be at when considered simply as if it were a black body being heated only by its parent star . In this model , the presence or absence of an atmosphere ( and therefore any greenhouse effect ) is not considered , and one treats the theoretical black body temperature as if it came from an idealized surface of the planet .   Other authors use different names for this concept , such as equivalent blackbody temperature of a planet , or the effective radiation emission temperature of the planet . Similar concepts include the global mean temperature , global radiative equilibrium , and global-mean surface air temperature , which includes the effects of global warming .

negative: Life on Venus The speculation of life currently existing on Venus decreased significantly since the early 1960s , when spacecraft began studying Venus and it became clear that the conditions on Venus are extreme compared to those on Earth .   The fact that Venus is located closer to the Sun than Earth , raising temperatures on the surface to nearly 735 K , the atmospheric pressure is 90 times that of Earth , and the extreme impact of the greenhouse effect , make water-based life as we know it unlikely on the surface of the planet . However , a few scientists have speculated that thermoacidophilic extremophile microorganisms might exist in the lower-temperature , acidic upper layers of the Venusian atmosphere .

negative: Satellite temperature measurements The temperature of the atmosphere at various altitudes as well as sea and land surface temperatures can be inferred from satellite measurements . These measurements can be used to locate weather fronts , monitor the El Niño-Southern Oscillation , determine the strength of tropical cyclones , study urban heat islands and monitor the global climate . Wildfires , volcanos , and industrial hot spots can also be found via thermal imaging from weather satellites .   Weather satellites do not measure temperature directly . They measure radiances in various wavelength bands . Since 1978 microwave sounding units ( MSUs ) on National Oceanic and Atmospheric Administration polar orbiting satellites have measured the intensity of upwelling microwave radiation from atmospheric oxygen , which is related to the temperature of broad vertical layers of the atmosphere . Measurements of infrared radiation pertaining to sea surface temperature have been collected since 1967 .   Satellite datasets show that over the past four decades the troposphere has warmed and the stratosphere has cooled . Both of these trends are consistent with the influence of increasing atmospheric concentrations of greenhouse gases .

negative: Upper-atmospheric lightning Upper-atmospheric lightning or ionospheric lightning are terms sometimes used by researchers to refer to a family of short-lived electrical-breakdown phenomena that occur well above the altitudes of normal lightning and storm clouds . Upper-atmospheric lightning is believed to be electrically induced forms of luminous plasma . The preferred usage is transient luminous event ( TLE ) , because the various types of electrical-discharge phenomena in the upper atmosphere lack several characteristics of the more familiar tropospheric lightning .

negative: Hubbard model The Hubbard model is an approximate model used , especially in solid state physics , to describe the transition between conducting and insulating systems . The Hubbard model , named after John Hubbard , is the simplest model of interacting particles in a lattice , with only two terms in the Hamiltonian ( see example below ) : a kinetic term allowing for tunneling ( ` hopping ' ) of particles between sites of the lattice and a potential term consisting of an on-site interaction . The particles can either be fermions , as in Hubbard 's original work , or bosons , when the model is referred to as either the ` Bose -- Hubbard model ' or the ` boson Hubbard model ' .   The Hubbard model is a good approximation for particles in a periodic potential at sufficiently low temperatures that all the particles are in the lowest Bloch band , as long as any long-range interactions between the particles can be ignored . If interactions between particles on different sites of the lattice are included , the model is often referred to as the ` extended Hubbard model ' .   The model was originally proposed ( in 1963 ) to describe electrons in solids and has since been the focus of particular interest as a model for high-temperature superconductivity . More recently , the Bose -- Hubbard model has been used to describe the behavior of ultracold atoms trapped in optical lattices . Recent ultracold atom experiments have also realised the original , fermionic Hubbard model in the hope that such experiments could yield its phase diagram .   For electrons in a solid , the Hubbard model can be considered as an improvement on the tight-binding model , which includes only the hopping term . For strong interactions , it can give qualitatively different behavior from the tight-binding model , and correctly predicts the existence of so-called Mott insulators , which are prevented from becoming conducting by the strong repulsion between the particles .

negative: Anticyclone An anticyclone ( that is , opposite to a cyclone ) is a weather phenomenon defined by the United States National Weather Service 's glossary as `` a large-scale circulation of winds around a central region of high atmospheric pressure , clockwise in the Northern Hemisphere , counterclockwise in the Southern Hemisphere '' . Effects of surface-based anticyclones include clearing skies as well as cooler , drier air . Fog can also form overnight within a region of higher pressure . Mid-tropospheric systems , such as the subtropical ridge , deflect tropical cyclones around their periphery and cause a temperature inversion inhibiting free convection near their center , building up surface-based haze under their base . Anticyclones aloft can form within warm core lows such as tropical cyclones , due to descending cool air from the backside of upper troughs such as polar highs , or from large scale sinking such as the subtropical ridge .

negative: Remote Sensing Systems Remote Sensing Systems ( RSS ) is a private research company founded in 1974 by Frank Wentz . It processes microwave data from a variety of NASA satellites . Most of their research is supported by the Earth Science Enterprise program . The company is based in Santa Rosa , California .   They are a widely cited source of data , on the satellite temperature record . Their data is one source of evidence for global warming . Research by Carl Mears , Matthias Schabel , and Wentz , all of RSS , highlighted errors in the early satellite temperature records compiled by John Christy and Roy Spencer at UAH . The UAH data had previously showed no significant temperature trend , bringing the derived satellite data into closer agreement with surface temperature trends , radiosonde data and computer models . The UAH data is now closer to the RSS data but differences remain , for example the Lower Troposphere global average trend since 1979 , RSS currently have +0.133 K/decade while UAH have 0.140 K/decade , while the mid troposphere difference is even more marked at 0.079 K/decade and 0.052 K/decade respectively . However , in a recent online YouTube video , Dr. Carl Mears , a senior scientist with the team behind the satellite data , explained how he believes his data set needed correction .  I would have to say that the surface data seems that it 's more accurate , because a number of groups analyze the surface data , including some who set out to prove the other ones wrong , and they all get more or less the same answer .

negative: Cloud In meteorology , a cloud is an aerosol comprising a visible mass of minute liquid droplets , frozen crystals , or particles suspended in the atmosphere above the surface of a planetary body . The droplets and crystals may be made of water or various chemicals . On Earth , clouds are formed as a result of saturation of the air when it is cooled to its dew point , or when it gains sufficient moisture ( usually in the form of water vapor ) from an adjacent source to raise the dew point to the ambient temperature . They are seen in the Earth 's homosphere ( which includes the troposphere , stratosphere , and mesosphere ) . Nephology is the science of clouds which is undertaken in the cloud physics branch of meteorology .   There are two systems of naming clouds in their respective layers of the atmosphere ; Latin in the troposphere and mostly alpha-numeric above the troposphere . Cloud types in the troposphere , the atmospheric layer closest to Earth 's surface , have Latin names due to the universal adaptation of Luke Howard 's nomenclature . Formally proposed in 1802 , it became the basis of a modern international system that classifies clouds into five physical forms and three altitude levels ( formerly known as étages ) . These physical types , in approximate ascending order of convective activity , include stratiform sheets , cirriform wisps and patches , stratocumuliform layers ( mainly structured as rolls , ripples , and patches ) , cumuliform heaps , and very large cumulonimbiform heaps that often show complex structure . The physical forms are cross-classified by the altitude levels to produce ten basic genus-types , most of which can be divided into species , and subdivided into varieties .   Two cirriform clouds that form higher up in the stratosphere and mesosphere have common names for their main types , but are sub-classified alpha-numerically . They are relatively uncommon and are mostly seen in the polar regions of Earth . Clouds have been observed in the atmospheres of other planets and moons in the Solar System and beyond . However , due to their different temperature characteristics , they are often composed of other substances such as methane , ammonia , and sulfuric acid as well as water .   Homospheric types determined by cross-classification of forms and levels .   '' Homospheric types include the ten tropospheric genera and two additional major types above the troposphere . The cumulus genus includes three variants as defined by vertical size .

negative: COSPAR international reference atmosphere The COSPAR International Reference Atmosphere ( CIRA ) is an empirical model of the atmosphere of Earth . It consists of a set of tables of average air pressures , altitudes and temperatures . The CIRA models are developed by the Committee on Space Research ( COSPAR ) and have been important for the planning of spaceflight .

negative: Thaw (weather) January thaw is a term applied to a thaw or rise in temperature in mid-winter found in mid-latitude North America .   Sinusoidal estimates of expected temperatures , for northern locales , usually place the lowest temperatures around January 23 and the highest around July 24 , and provide fairly accurate estimates of temperature expectations . Actual average temperatures in North America usually significantly differ twice over the course of the year :   Mid-autumn temperatures tend to be warmer than predicted by the sinusoidal model , creating the impression of extended summer warmth known as Indian summer .  For five days around January 25 , temperatures are usually significantly warmer than predicted by the sinusoidal estimate , and also warmer than neighboring temperatures on both sides .   During this `` thaw '' period , usually lasting for about a week , temperatures are generally about 6 ° C ( 10 ° F ) above normal . This varies from year to year , and temperatures fluctuate enough that such a rise in late-January temperature would be unremarkable ; what is remarkable ( and unexplained ) is the tendency for such rises to occur more commonly in late January than in mid-January or early February , which sinusoidal estimates have to be slightly warmer .   In some regions ( such as northern Canada ) this phenomenon will not be manifest as a `` thaw '' in the technical sense , since temperatures will remain below freezing .   The January thaw is believed to be a weather singularity . A possible physical mechanism for such phenomena was offered in the 1950s by E.G. Bowen : he suggested that some `` calendaricities '' ( as he called them ) might be explicable in terms of meteoric particles from cometary orbits acting as ice nuclei in terrestrial clouds ; his theory then received some support from several sources . However , Bowen 's ideas later fell out of favour with the development of atmospheric dynamic modelling techniques , although one of his rainfall peaks does seem to correspond with the date of the January thaw .   Data analysis has not found statistically significant support for the supposed January thaw . The authors of this study state that `` the effects of sampling in finite climate records are wholly adequate to account for the existence of January thaw ` features ' in northeastern U.S. temperature data . ''

negative: Lipid microdomain Lipid microdomains are formed when lipids undergo lateral phase separations yielding stable coexisting lamellar domains . These phase separations can be induced by changes in temperature , pressure , ionic strength or by the addition of divalent cations or proteins . The question of whether such lipid microdomains observed in model lipid systems also exist in biomembranes had motivated considerable research efforts . Lipid domains are not readily isolated and examined as unique species , in contrast to the examples of lateral heterogeneity .  One can disrupt the membrane and demonstrate a heterogeneous range of composition in the population of the resulting vesicles or fragments . Electron microscopy can also be used to demonstrate lateral inhomogeneities in biomembranes .   Often , lateral heterogeneity has been inferred from biophysical techniques where the observed signal indicates multiple populations rather than the expected homogenous population . An example of this is the measurement of the diffusion coefficient of a fluorescent lipid analogue in soybean protoplasts . Membrane microheterogeneity is sometimes inferred from the behavior of enzymes , where the enzymatic activity does not appear to be correlated with the average lipid physical state exhibited by the bulk of the membrane . Often , the methods suggest regions with different lipid fluidity , as would be expected of coexisting gel and liquid crystalline phases within the biomembrane . This is also the conclusion of a series of studies where differential effects of perturbation caused by cis and trans fatty acids are interpreted in terms of preferential partitioning of the two liquid crystalline and gel-like domains .


query: When accelerating ice loss from Greenland and Antarctica are factored into sea level projections, the estimated sea level rise by 2100 is between 75cm to 2 metres.

positive: 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 .

negative: Past sea level Global or eustatic sea level has fluctuated significantly over the Earth 's history . The main factors affecting sea level are the amount and volume of available water and the shape and volume of the ocean basins . The primary influences on water volume are the temperature of the seawater , which affects density , and the amounts of water retained in other reservoirs like rivers , aquifers , lakes , glaciers , polar ice caps and sea ice . Over geological timescales , changes in the shape of the oceanic basins and in land/sea distribution affect sea level . In addition to eustatic changes , local changes in sea level are caused by tectonic uplift and subsidence .   Over geologic time sea level has fluctuated by hundreds of meters . Today 's interglacial level is near historic highs and is 130 meters above the low level reached during the Last Glacial Maximum 19,000 -- 20,000 years ago .   Observational and modeling studies of mass loss from glaciers and ice caps indicate a contribution to sea-level rise of 0.2 to 0.4 mm/yr averaged over the 20th century . Over this last million years , whereas it was higher most of the time before then , sea level was lower than today .

negative: Last Glacial Maximum The Last Glacial Maximum ( LGM ) was the last period in the Earth 's climate history during the last glacial period when ice sheets were at their greatest extension . Growth of the ice sheets reached their maximum positions in about 24,500 BCE . Deglaciation commenced in the Northern Hemisphere between approximately 18,000 to 17,000 BCE and in Antarctica approximately 12,500 BCE , which is consistent with evidence that it was the primary source for an abrupt rise in the sea level in about 12,500 BCE .   Vast ice sheets covered much of North America , northern Europe , and Asia . The ice sheets profoundly affected Earth 's climate by causing drought , desertification , and a dramatic drop in sea levels . It was followed by the Late Glacial .

negative: Copenhagen Diagnosis The Copenhagen Diagnosis is a report written by twenty-six climate scientists from eight countries . It was published in 2009 and was a summary of the peer-reviewed literature to date .   The Copenhagen Diagnosis is a follow-up of the previous Intergovernmental Panel on Climate Change 's Working Group 1 Report . The studies summarized , which date back to the cutoff point of the Working Group 1 Report , are those that authors viewed most relevant to the discussions at the 2009 United Nations Climate Change Conference . The Copenhagen Diagnosis served as the midpoint between IPCC -- AR4 and IPCC-AR5 .   In total , the Copenhagen Diagnosis contains eight main sections , which are :   Surging Greenhouse gas emissions  Since 1990 , the combined global emission of carbon dioxide from various origins , such as cement production , deforestation , and fossil fuel burning , has increased 27 % .  Human-induced warming  Studies conducted by Lee and Rind show that only 10 % of global warming over the past century was due to the Sun .  Acceleration of melting ice caps  Glaciers and melting ice caps can contribute to about 8/10ths of a meter to global sea level rise .  Rapid Arctic sea-ice decline  According to simulations run by NCAR Climate System Model version 3 , the Arctic summer is expected to be ice-free by 2040 .  Underestimation of changing sea levels  In contrast to previous IPCC , the rate of sea level rise ( 3.4 mm/yr over the past 15 years ) has increased around 80 % faster than previously predicted .  Damage due to inaction  A region of permafrost , called the Yedoma , stores about 500 Gt of CO2 and , once released due to rising global temperatures , will increase global temperatures even more .  Turning point must come soon  The largest climate science conference , held in 2009 , has stated , `` Temperature rises above 2 ° C will be difficult for contemporary societies to cope with , and are likely to cause major societal and environmental disruptions through the rest of the century and beyond . ''  The Future  By 2100 , global mean air-temperature is projected to warm by 2 ° C -- 7 ° C above pre-industrial levels .

negative: Sea level Mean sea level ( MSL ) ( abbreviated simply sea level ) is an average level of the surface of one or more of Earth 's oceans from which heights such as elevations may be measured . MSL is a type of vertical datuma standardised geodetic reference pointthat is used , for example , as a chart datum in cartography and marine navigation , or , in aviation , as the standard sea level at which atmospheric pressure is measured in order to calibrate altitude and , consequently , aircraft flight levels . A common and relatively straightforward mean sea-level standard is the midpoint between a mean low and mean high tide at a particular location .   Sea levels can be affected by many factors and are known to have varied greatly over geological time scales . The careful measurement of variations in MSL can offer insights into ongoing climate change , and sea level rise has been widely quoted as evidence of ongoing global warming .   The term above sea level generally refers to above mean sea level ( AMSL ) .

negative: Deglaciation Deglaciation describes the transition from full glacial conditions during ice ages , to warm interglacials , characterized by global warming and sea level rise due to change in continental ice volume ( IPCC AR5 ) . Thus , it refers to the retreat of a glacier , an ice sheet or frozen surface layer , and the resulting exposure of the Earth 's surface . The decline of the cryosphere due to ablation can occur on any scale from global to localized to a particular glacier . After the Last Glacial Maximum ( ca. 21k years ago ) , the last deglaciation begun , which lasted until the early Holocene .   The previous deglaciation took place between approximately 22ka until 11.5 ka . This occurred when there was an annual mean atmospheric temperature on the earth that increased by roughly 5 ° C , which was also accompanied by regional high-latitude warming that exceeded 10 ° C . This was also followed by noteworthy deep-sea and tropical-se warming , between about 1-2 ° C ( deep-sea ) and 2-4 ° C ( tropical sea ) . Not only did this warming occur , but the global hydrological budget also experienced noticeable changes and regional precipitation patters changed . As a result of all of this , the worlds main ice sheets , including the ones located in Eurasia , North America and parts of the Antarctic Ice Sheets melted . As a consequence , sea levels rose roughly 120 metres ) . These processes did not occur steadily , and they also did not occur at the same time .

negative: Quaternary glaciation The Quaternary glaciation , also known as the Pleistocene glaciation or the current ice age , is a series of glacial events separated by interglacial events during the Quaternary period from 2.58 Ma ( million years ago ) to present . During this period , ice sheets expanded , notably from out of Antarctica and Greenland , and fluctuating ice sheets occurred elsewhere ( for example , the Laurentide ice sheet ) . The major effects of the ice age are erosion and deposition of material over large parts of the continents , modification of river systems , creation of millions of lakes , changes in sea level , development of pluvial lakes far from the ice margins , isostatic adjustment of the crust , and abnormal winds . It affected oceans , flooding , and biological communities . The ice sheets themselves , by raising the albedo , affect a major feedback on climate cooling .

negative: Marine transgression A marine transgression is a geologic event during which sea level rises relative to the land and the shoreline moves toward higher ground , resulting in flooding . Transgressions can be caused either by the land sinking or the ocean basins filling with water ( or decreasing in capacity ) . Transgressions and regressions may be caused by tectonic events such as orogenies , severe climate change such as ice ages or isostatic adjustments following removal of ice or sediment load .   During the Cretaceous , seafloor spreading created a relatively shallow Atlantic basin at the expense of deeper Pacific basin . This reduced the world 's ocean basin capacity and caused a rise in sea level worldwide . As a result of this sea level rise , the oceans transgressed completely across the central portion of North America and created the Western Interior Seaway from the Gulf of Mexico to the Arctic Ocean .   The opposite of transgression is regression , in which the sea level falls relative to the land and exposes former sea bottom . During the Pleistocene Ice Ages , so much water was removed from the oceans and stored on land as year-round glaciers that the ocean regressed 120 m , exposing the Bering land bridge between Alaska and Asia .

negative: Konrad Steffen Konrad `` Koni '' Steffen ( born 1952 ) is a glaciologist and the former director of the Cooperative Institute for Research in Environmental Sciences at the University of Colorado Boulder , a position he held from 2005 until he took office as the director of the Swiss Federal Institute for Forest , Snow and Landscape Research on July 1 , 2012 . He is known for his research into Arctic sea ice and the glaciers of Greenland , and how they are affected by global warming . He has often traveled to Greenland to study these glaciers firsthand ; for example , when studying Petermann Glacier for three weeks in 2004 , Steffen did so from a camp set up 4,000 feet up the flanks of the glacier 's ice cap . He also operates a network of 20 weather stations on the Greenland ice sheet , the first of which , Swiss Camp , he established in 1990 . He has argued that due to this ice sheet melting faster than anticipated , sea levels could rise by about 3 feet by 2100 , considerably higher than the IPCC 's upper limit of 59 cm , and that Greenland might lose all its ice in 10,000 years , but Antarctica would take considerably longer , since it is so much bigger .

negative: Meltwater pulse 1B Meltwater pulse 1B ( MWP1b ) is the name used by Quaternary geologists , paleoclimatologists , and oceanographers for a period of either rapid or just accelerated post-glacial sea level rise that occurred at the beginning of the Holocene and after the end of the Younger Dryas . Meltwater pulse 1B is also known as catastrophic rise event 2 ( CRE2 ) in the Caribbean Sea . Other named , postglacial meltwater pulses are known most commonly as meltwater pulse 1A0 ( meltwaterpulse19ka ) , meltwater pulse 1A , meltwater pulse 1C , meltwater pulse 1D , and meltwater pulse 2 . It and these other periods of proposed rapid sea level rise are known as meltwater pulses because the inferred cause of them was the rapid release of meltwater into the oceans from the collapse of continental ice sheets .

negative: Ice-sheet dynamics Ice sheet dynamics describe the motion within large bodies of ice , such those currently on Greenland and Antarctica . Ice motion is dominated by the movement of glaciers , whose gravity-driven activity is controlled by two main variable factors : the temperature and strength of their bases . A number of processes alter these two factors , resulting in cyclic surges of activity interspersed with longer periods of inactivity , on both hourly and centennial time scales . Ice-sheet dynamics are of interest in modelling future sea level rise .   __ TOC __

negative: Extreme points of Antarctica The tallest mountain in Antarctica is Mount Vinson rising 4,892 metres ( 16,050 feet ) above sea level .  The lowest point in Antarctica is within the Bentley Subglacial Trench , which reaches 2,555 metres below sea level . This is also the lowest place on Earth not covered by ocean ( although it is covered by ice ) .  The lowest accessible point in Antarctica is the shore of Deep Lake , Vestfold Hills , which is 50 m beneath sea level .  The point on land farthest from any coastline on the Antarctic Continent is located at . This is also known as the South Pole of inaccessibility .  Antarctica is the southernmost land mass on Earth . The Geographical South Pole lies on the Polar Plateau at . It is here that the southernmost human habitation on Earth is located : Amundsen -- Scott South Pole Station ( U.S. Administered Base ) .  Vostok Station is the most isolated research base on the continent ( located at ) , and it is situated over the southernmost lake in the world , Lake Vostok , a subglacial lake 4,000 metres ( 13,000 feet ) under the surface of the ice where the station sits . Formerly administrated by the Soviets , it is now operated by Russia .  The southernmost volcano on the planet -- Mount Erebus -- is in Antarctica on the world 's southernmost island reachable from the sea : Ross Island .  The southernmost island is Berkner Island . It is embedded in the ice shelf , fully covered by ice and fully below sea level .  The Ross Sea is the southernmost sea in the world , with its southernmost extremity ( Gould Coast ) at the foot of the Horlick Mountains approximately 200 miles ( 320 km ) from the Geographic South Pole . However , this area is covered by the Ross Ice Shelf . The southernmost open sea is also part of Ross Sea , namely Bay of Whales at 78 ° 30 'S , at the edge of Ross Ice Shelf .  The northernmost extremity of the Antarctic mainland ( without nearshore islands ) is Prime Head , at the northern tip of the Trinity Peninsula at . The Antarctic Peninsula is the largest contiguous part of the continent projecting north of the Antarctic Circle and thus has many of the continent 's research bases . Prime Head is 609 mi ( 980 km ) from Cape Horn . The northernmost research base on the mainland is Esperanza Base .

negative: Metres above sea level Redirected here : feet above sea level ; AMSL means `` above mean sea level '' , and may be used for heights specified in any units .  Metres above mean sea level ( MAMSL ) or simply metres above sea level ( MASL or m a.s.l. ) is a standard metric measurement in metres of the elevation or altitude of a location in reference to a historic mean sea level . Mean sea levels are affected by climate change and other factors and change over time . For this and other reasons , recorded measurements of elevation above sea level might differ from the actual elevation of a given location over sea level at a given moment .

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: Jones Ice Shelf Jones Ice Shelf was the ice shelf occupying the Jones Channel , between the Arrowsmith Peninsula and Blaiklock Island , on the west coast of Graham Land , Antarctica . It was named by the UK Antarctic Place-Names Committee in 1981 in association with the channel .   The shelf was stable between 1947 and 1969 , rising from 3 to above sea level as it blocked the channel . It started to retreat in the 1970s and by 2003 had completely disappeared .

negative: Greenland Sea The Greenland Sea is a body of water that borders Greenland to the west , the Svalbard archipelago to the east , Fram Strait and the Arctic Ocean to the north , and the Norwegian Sea and Iceland to the south . The Greenland Sea is often defined as part of the Arctic Ocean , sometimes as part of the Atlantic Ocean . However , definitions of the Arctic Ocean and its seas tend to be imprecise or arbitrary . In general usage the term `` Arctic Ocean '' would exclude the Greenland Sea . In oceanographic studies the Greenland Sea is considered part of the Nordic Seas , along with the Norwegian Sea . The Nordic Seas are the main connection between the Arctic and Atlantic oceans and , as such , could be of great significance in a possible shutdown of thermohaline circulation . In oceanography the Arctic Ocean and Nordic Seas are often referred to collectively as the `` Arctic Mediterranean Sea '' , a marginal sea of the Atlantic .   The sea has Arctic climate with regular northern winds and temperatures rarely rising above 0 ° C . It previously contained the Odden ice tongue ( or Odden ) area , which extended eastward from the main East Greenland ice edge in the vicinity of 72 -- 74 ° N during the winter and acted as a key winter ice formation area in the Arctic . The West Ice forms in winter in the Greenland Sea , north of Iceland , between Greenland and Jan Mayen island . It is a major breeding ground of harp seal and hooded seal that has been used for seal hunting for more than 200 years .

negative: Besh Barmag Mountain Besh Barmag ( Beş Barmaq ) literally translated as Five Finger Mountain , is in Siazan District of Azerbaijan , not far from the Caspian Sea .   It rises to 382 m above the sea level overlooking the Baku-Quba Highway . The mountain is a solid rock and is one of the most famous mountains in the Caucasus , known for its mythical stories . It is a sacred place for regular visitation by pilgrims .   Tide marks on the mount attest to meltwater inundation from the northern glacial ice caps and date back to the end of the last ice age . The tidelines confirm the theory of a Holocene outflow of meltwater from the Black Sea to the Mediterranean Sea , rather than a direct incursion of sea water into the Black Sea as a result of global sea level rise . Estimates of the increase in Caspian Sea level height are between + 20 and 30 meters .

negative: James O'Brien (oceanographer) James O'Brien ( born August 10 , 1935 , died September 20 , 2016 ) is the emeritus Robert O. Lawton Professor of Meteorology and Oceanography at Florida State University . He believes sea levels are rising but predicts a more modest 18 in rise instead of 6 ft by 2100 targeted by some other scientists . He stated that `` sea level in Florida is going to continue to rise period . Unless we go back into an Ice age , we will continue to rise at over 8 in in 10 year . That 's without any global warming . ''

negative: North Ice North Ice was a research station of the British North Greenland Expedition ( 1952 to 1954 ) on the inland ice of Greenland . The coordinates of the station were , at an altitude of 2341 m above sea level . The British North Greenland Expedition was led by Commander James Simpson RN . The station recorded the lowest temperature ever in North America with -66.1 C on 9 January 1954 . The name of the station contrasts to the former British South Ice station in Antarctica .

negative: 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 .

negative: Effects of global warming The effects of global warming are the environmental and social changes caused ( directly or indirectly ) by human emissions of greenhouse gases . There is a scientific consensus that climate change is occurring , and that human activities are the primary driver . Many impacts of climate change have already been observed , including glacier retreat , changes in the timing of seasonal events ( e.g. , earlier flowering of plants ) , and changes in agricultural productivity .   Future effects of climate change will vary depending on climate change policies and social development . The two main policies to address climate change are reducing human greenhouse gas emissions ( climate change mitigation ) and adapting to the impacts of climate change . Geoengineering is another policy option .   Near-term climate change policies could significantly affect long-term climate change impacts . Stringent mitigation policies might be able to limit global warming ( in 2100 ) to around 2 ° C or below , relative to pre-industrial levels . Without mitigation , increased energy demand and extensive use of fossil fuels might lead to global warming of around 4 ° C. Higher magnitudes of global warming would be more difficult to adapt to , and would increase the risk of negative impacts .

negative: Antarctic Plate The Antarctic Plate is a tectonic plate containing the continent of Antarctica and extending outward under the surrounding oceans . After breakup from Gondwana ( the southern part of the supercontinent Pangea ) , the Antarctic plate began moving the continent of Antarctica south to its present isolated location causing the continent to develop a much colder climate . The Antarctic Plate is bounded almost entirely by extensional mid-ocean ridge systems . The adjoining plates are the Nazca Plate , the South American Plate , the African Plate , the Indo-Australian Plate , the Pacific Plate , and , across a transform boundary , the Scotia Plate .   The Antarctic plate has an area of about 60,900,000 km2 . It is the Earth 's fifth largest plate .   The Antarctic plate 's movement is estimated to be at least 1 cm per year towards the Atlantic Ocean .

negative: Canadian Arctic Archipelago The Canadian Arctic Archipelago , also known as the Arctic Archipelago , is a group of islands north of the Canadian mainland .   Situated in the northern extremity of North America and covering about 1424500 km2 , this group of 36,563 islands in the Arctic Sea comprises much of the territory of Northern Canada -- most of Nunavut and part of the Northwest Territories . The Canadian Arctic Archipelago is showing some effects of global warming , with some computer estimates determining that melting there will contribute 3.5 cm to the rise in sea levels by 2100 .

negative: Mediterranean–Dead Sea Canal The Mediterranean -- Dead Sea canal ( MDSC ) is a proposed project to dig a canal from the Mediterranean Sea to the Dead Sea , taking advantage of the 400-metre difference in water level between the seas . It is not to be confused with the Red Sea -- Dead Sea Water Conveyance . The project could correct the drop in the level of the Dead Sea observed in recent years . The canal could also be used to generate hydroelectric power because of surface difference and maybe by salinity gradient power , and desalinate water by reverse osmosis .

negative: Arctic geoengineering Temperatures in the Arctic region have tended to increase more rapidly than the global average . Projections of sea ice loss that are adjusted to take account of recent rapid Arctic shrinkage suggest that the Arctic will likely be free of summer sea ice sometime between 2059 and 2078 . Various climate engineering schemes have been suggested to reduce the chance of significant and irreversible effects such as Arctic methane release .   Several climate engineering proposals have been made which are specific to the Arctic . They are usually hydrological in nature , and principally centre upon measures to prevent Arctic ice loss .   In addition , other solar radiation management climate engineering techniques , such as stratospheric sulfate aerosols have been proposed . These would cool the Arctic by adjusting the albedo of the atmosphere .

negative: 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 .

negative: Undulation of the geoid Undulation of the geoid is the mathematical process of determining the height in metres above the geoid ( relative to the mean sea level ) from the height provided by the GPS system which uses the ( WGS84 ) ellipsoid as reference . In maps and common use the height over the mean sea level is used to indicate the height of elevations while the ellipsoidal height results from the restrictions that apply for the GPS system .   The process of the undulation is not standardised , as different countries use different mean sea levels as reference but mostly refers to the EGM96 geoid . Calculating the undulation factor is mathematically challenging . This is why many handheld GPS receivers have built-in undulation lookup tables to determine the height above sea level .   The deviation between the ellipsoidal height and the orthometric height can be calculated by   Likewise , the deviation between the ellipsoidal height and the normal height can be calculated by

negative: 75th meridian west The meridian 75 ° west of Greenwich is a line of longitude that extends from the North Pole across the Arctic Ocean , North America , the Atlantic Ocean , the Caribbean Sea , South America , the Pacific Ocean , the Southern Ocean , and Antarctica to the South Pole .   The mean solar time of this meridian is the base for the Eastern Time Zone ( UTC-5 during standard time ) .   Stations belonging to the American Weather Service begin submitting weather reports when the mean solar time of this meridian is 8:00 am . Report collection ends 30 -- 40 minutes later and the data is used to create the day 's weather forecast .   The 75th meridian west forms a great circle with the 105th meridian east .