Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

European Science Foundation in a 2007 position paper states: There is now convincing evidence that since the industrial revolution, human activities, resulting in increasing concentrations of greenhouse gases have become a major agent of climate change ... On-going and increased efforts to mitigate climate change through reduction in greenhouse gases are therefore crucial.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

7–10 "There is now convincing evidence that since the industrial revolution, human activities, resulting in increasing concentrations of greenhouse gases have become a major agent of climate change.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

While ‘climate change’ can be due to natural forces or human activity, there is now substantial evidence to indicate that human activity – and specifically increased greenhouse gas (GHGs) emissions – is a key factor in the pace and extent of global temperature increases.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Rennie 2009: "Claim 1: Anthropogenic CO2 can't be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

The balance of evidence suggests a discernible human influence on global climate (considerable progress since the 1990 report in distinguishing between natural and anthropogenic influences on climate, because of: including aerosols; coupled models; pattern-based studies) Climate is expected to continue to change in the future (increasing realism of simulations increases confidence; important uncertainties remain but are taken into account in the range of model projections) There are still many uncertainties (estimates of future emissions and biogeochemical cycling; models; instrument data for model testing, assessment of variability, and detection studies) The Third Assessment Report (TAR) was completed in 2001 and consists of four reports, three of them from its Working Groups: Working Group I: The Scientific Basis Working Group II: Impacts, Adaptation and Vulnerability Working Group III: Mitigation Synthesis Report A number of the TAR's conclusions are given quantitative estimates of how probable it is that they are correct, e.g., greater than 66% probability of being correct.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Climate change can have an effect on the [[carbon cycle]] in an interactive "feedback" process .


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Attribution of the temperature change to natural or anthropogenic (i.e., human-induced) factors is an important question: see global warming and attribution of recent climate change.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

There are many facts that point to the existence of climate change.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Anthropogenic climate change is caused by human activity, as opposed to changes in climate that may have resulted as part of Earth's natural processes.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

There is no convincing scientific evidence that human release of carbon dioxide, methane, or other greenhouse gases is causing or will, in the foreseeable future, cause catastrophic heating of the Earth's atmosphere and disruption of the Earth's climate.


Question: Human-produced carbon might be one of the factors of climate change, but there’s simply no evidence that it is a significant one.

Singer argues, contrary to the scientific consensus on climate change, that there is no evidence that global warming is attributable to human-caused increases in atmospheric carbon dioxide, and that humanity would benefit if temperatures do rise.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

This graph extended the similar graph in Figure 3.20 from the IPCC Second Assessment Report of 1995, and differed from a schematic in the first assessment report that lacked temperature units, but appeared to depict larger global temperature variations over the past 1000 years, and higher temperatures during the Medieval Warm Period than the mid 20th century.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

The schematic was not an actual plot of data, and was based on a diagram of temperatures in central England, with temperatures increased on the basis of documentary evidence of Medieval vineyards in England.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

However, that view was questioned by other researchers; the IPCC First Assessment Report of 1990 discussed the "Medieval Warm Period around 1000 AD (which may not have been global) and the Little Ice Age which ended only in the middle to late nineteenth century."


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

The IPCC First Assessment Report included a "schematic diagram" of global temperature variations over the last thousand years which has been traced to a graph based loosely on Hubert Lamb's 1965 paper.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

The Medieval Warm Period (MWP) also known as the Medieval Climate Optimum, or Medieval Climatic Anomaly was a time of warm climate in the North Atlantic region lasting from c. 950 to c. 1250.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

The Medieval Warm Period (MWP) is generally thought to have occurred from c. 950–c.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

The IPCC First Assessment Report in 1990 noted evidence that Holocene climatic optimum around 5,000-6,000 years ago had been warmer than the present (at least in summer) and that in some areas there had been exceptional warmth during "a shorter Medieval Warm Period (which may not have been global)" about AD 950-1250, followed by a cooler period of the Little Ice Age which ended only in the middle to late nineteenth century.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

Thus current evidence does not support globally synchronous periods of anomalous cold or warmth over this interval, and the conventional terms of "Little Ice Age" and "Medieval Warm Period" appear to have limited utility in describing trends in hemispheric or global mean temperature changes in past centuries.... [Viewed] hemispherically, the "Little Ice Age" can only be considered as a modest cooling of the Northern Hemisphere during this period of less than 1°C relative to late twentieth century levels.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

This was the basis of a "schematic diagram" featured in the IPCC First Assessment Report beside cautions that the medieval warming might not have been global.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

This was the basis of a "schematic diagram" featured in the IPCC First Assessment Report of 1990 beside cautions that the medieval warming might not have been global.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

1995 saw the creation of the phrase "preventing dangerous anthropogenic interference with the climate system" (also called "avoiding dangerous climate change") first appeared in a policy document of a governmental organization, the IPCC's Second Assessment Report: Climate Change 1995. and in 1996 the European Union adopt a goal of limiting temperature rises to a maximum 2 °C rise in average global temperature.


Question: The original global temperature schematic which appeared in the IPCC First Assessment Report and seemed to show the Medieval Warm Period (MWP) hotter than Present was based on the central England temperature record, and ended in the 1950s.

"Estimating Changes in Global Temperature since the Preindustrial Period".


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

Human activities have caused CO 2 to increase above levels not seen in hundreds of thousands of years.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

In the scientific literature, there is an overwhelming consensus that global surface temperatures have increased in recent decades and that the trend is caused mainly by human-induced emissions of greenhouse gases.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

The spatial and temporal fingerprint of warming can be traced to increasing greenhouse gas concentrations in the atmosphere, which are a direct result of burning fossil fuels, broad-scale deforestation and other human activity.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

The introduction includes this statement: There is strong evidence that the warming of the Earth over the last half-century has been caused largely by human activity, such as the burning of fossil fuels and changes in land use, including agriculture and deforestation.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming, and give some indication of which countries have contributed most to human-induced climate change.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

While ‘climate change’ can be due to natural forces or human activity, there is now substantial evidence to indicate that human activity – and specifically increased greenhouse gas (GHGs) emissions – is a key factor in the pace and extent of global temperature increases.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

... there is a strong, credible body of evidence, based on multiple lines of research, documenting that climate is changing and that these changes are in large part caused by human activities.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

While CO 2 absorption and release is always happening as a result of natural processes, the recent rise in CO 2 levels in the atmosphere is known to be mainly due to human (anthropogenic) activity.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

US National Academy of Sciences: "In the judgment of most climate scientists, Earth's warming in recent decades has been caused primarily by human activities that have increased the amount of greenhouse gases in the atmosphere.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

Human activities, primarily the burning of fossil fuels (coal, oil, and natural gas), and secondarily the clearing of land, have increased the concentration of carbon dioxide, methane, and other heat-trapping ("greenhouse") gases in the atmosphere...There is international scientific consensus that most of the warming observed over the last 50 years is attributable to human activities.


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

Multiple lines of evidence support attribution of recent climate change to human activities:


Question: There are many lines of evidence which clearly show that the atmospheric CO2 increase is caused by humans.

The reason for this is that human activities are adding CO2 to the atmosphere faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a complete explanation).


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

The sea level rose quickly after that, stabilizing at the current level about 4,000 years ago, leaving the mainland of South Florida just above sea level.


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

Between 1900 and 2016, the sea level rose by 16–21 cm (6.3–8.3 in).


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

Florida is a state located in the Southern United States.


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

"20th century acceleration in global sea-level rise".


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

Since at least the start of the 20th century, the average global sea level has been rising.


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

Sea level rise will continue over many centuries.


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

This is a timeline of the U.S. state of Florida.


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

"Contribution of Antarctica to past and future sea-level rise".


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

"Climate-change–driven accelerated sea-level rise detected in the altimeter era".


Question: In South Florida, "we've had nine inches of sea-level rise since the 1920s."

Episode 2 (11), "Gathering Storm" (November 2, 2016): Jack Black explores how Miami and other low-lying coastal areas can survive rising sea-levels caused by climate change.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

A 2007 study by David Douglass and coworkers, concluded that the 22 most commonly used global climate models used by the IPCC were unable to accurately predict accelerated warming in the troposphere although they did match actual surface warming, concluding "projections of future climate based on these models should be viewed with much caution".


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

Over several decades of development, models have consistently provided a robust and unambiguous picture of significant climate warming in response to increasing greenhouse gases.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

The Intergovernmental Panel on Climate Change, Third Assessment Report, says: "While the radiative forcing due to greenhouse gases may be determined to a reasonably high degree of accuracy... the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time".


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

Climate models include different external forcings for their models.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

Climate research is made difficult by the large scale, long time periods, and complex processes which govern climate.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

The paper was criticized by numerous climate scientists.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

In the context of global warming, different measures of climate sensitivity are used.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

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.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

There are more than two dozen scientific institutions that develop climate models.


Question: But it is part of a long list of studies from independent teams (as this interactive graphic shows), using a variety of methods that take account of critical challenges, all of which conclude that climate models exhibit too much sensitivity to greenhouse gases.

Most climate models include the radiative effects of greenhouse gases such as carbon dioxide.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The Cretaceous–Paleogene (K–Pg) extinction event, also known as the Cretaceous–Tertiary (K–T) extinction, was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The most recent and arguably best-known, the Cretaceous–Paleogene extinction event, which occurred approximately 66 million years ago (Ma), was a large-scale mass extinction of animal and plant species in a geologically short period of time.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

"Fossil record supports evidence of impending mass extinction".


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

For the first time since the demise of the dinosaurs 65 million years ago, we face a global mass extinction of wildlife.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The Quaternary period (from 2.588 ± 0.005 million years ago to the present) saw the extinctions of numerous predominantly megafaunal species, which resulted in a collapse in faunal density and diversity and the extinction of key ecological strata across the globe.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

Steven Amstrup and other U.S. Geological Survey scientists have predicted two-thirds of the world's polar bears may disappear by 2050, based on moderate projections for the shrinking of summer sea ice caused by climate change, though the validity of this study has been debated.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

One of the main theories to the extinction is climate change.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The Agreement on the Conservation of Polar Bears is a multilateral treaty signed in Oslo, November 15, 1973 by the five nations with the largest polar bear populations : Canada, Denmark (Greenland), Norway (Svalbard), the United States, and the Soviet Union.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

While the paper was cited by Sarah Palin to justify opposition to listing polar bears on the endangered-species list, its findings were contradicted by reports from the U.S. Geological Survey and other independent researchers, who concluded that man-made climate change was likely to devastate polar-bear populations by 2050.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

Polar Bears are increasing in number.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

A subsequent in depth international independent study, Re-Assessment of the Baffin Bay and Kane Basin Polar Bear Subpopulations: Final Report to the Canada-Greenland Joint Commission on Polar Bear has determined that polar bear populations are not declining overall and are increasing significantly in some areas.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The extinction risk of global warming is the risk of species becoming extinct due to the effects of global warming.


Question: The failure of the 2007 polar bear survival model is a simple fact that explodes the myth that polar bears are on their way to extinction.

The species is now considered vulnerable to extinction.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

These include carbon dioxide (chemical formula: CO 2), methane (CH 4), nitrous oxide (N 2O), and a group of gases referred to as halocarbons.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

The reason for this is that human activities are adding CO2 to the atmosphere faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a complete explanation).


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs, and nitrous oxide.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

However, this excludes the balancing fluxes of CO 2 into the atmosphere from the geological reservoirs, which have slower characteristic rates.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

As the planet warms, it has been predicted that soils will add carbon dioxide to the atmosphere due to increased biological activity at higher temperatures, a positive feedback (amplification).


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

Unanimous agreement was found among the models that future climate change will reduce the efficiency of the land and ocean carbon cycle to absorb human-induced CO. As a result, a larger fraction of human-induced CO will stay airborne if climate change controls the carbon cycle.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

"How the oceans absorb carbon dioxide is critical for predicting climate change".


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

<poem>Models consistently suggest that SRM would generally reduce climate differences compared to a world with elevated GHG concentrations and no SRM; however, there would also be residual regional differences in climate (e.g., temperature and rainfall) when compared to a climate without elevated GHGs...


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

Some climate change denial groups say that because CO 2 is only a trace gas in the atmosphere (roughly 400ppm, or 0.04%, 4 parts per 10,000) it can only have a minor effect on the climate.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

It should in principle, however the atmosphere is very complicated and one cannot simply argue that just because CO is a greenhouse gas it causes warming.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

Most climate models include the radiative effects of greenhouse gases such as carbon dioxide.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

This article is about climate change scenarios.


Question: In addition, [climate models] ignore the fact that enriching the atmosphere with CO2 is beneficial

The CO2 fertiliser effect has been greatly overestimated during Free-Air Carbon dioxide Enrichment (FACE) experiments where results show increased CO2 levels in the atmosphere enhances photosynthesis, reduce transpiration, and increase water use efficiency (WUE).


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

These early towers were positioned either on the rooftops of buildings or as free-standing structures, supplied with air by fans or relying on natural airflow.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

Although these large towers are very prominent, the vast majority of cooling towers are much smaller, including many units installed on or near buildings to discharge heat from air conditioning.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

All flight operations were controlled from an air conditioned observation room in the control tower of this building, which had windows overlooking the runway and landing mat areas.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

The building contained Bink's Paint Spraying and Air Washing Equipment, including blowers, air washing and purifying devices, and exhaust fans, installed to minimize danger of explosions and inhalation of fumes.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

A third, the Stanford station, located beside Alma Street at Embarcadero Road, is used for occasional sports events (generally football) at Stanford Stadium.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

Buildings are ventilated and their temperature regulated.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

Weather is driven by air pressure, temperature and moisture differences between one place and another.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

It hosts a ground of meteorological observation and recording.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

It traps heat in the atmosphere.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

For example, an air conditioner uses more energy during the afternoon when it is hot.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

: Radar-Derived Statistics and the Behavior of Moist Convection'' examined 28 target cities and random control points in the U.S..


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

The troposphere is heated from below by latent heat, longwave radiation, and sensible heat.


Question: "We found [U.S. weather] stations located next to  the exhaust fans of air conditioning units, surrounded by asphalt  parking lots and roads, on blistering-hot rooftops, and near sidewalks  and buildings that absorb and radiate heat.

Surfaces in the urban areas tend to warm faster than those of the surrounding rural areas.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Since it is absurd to have no logical method for settling on one hypothesis amongst an infinite number of equally data-compliant hypotheses, we should choose the simplest theory: "Either science is irrational [in the way it judges theories and predictions probable] or the principle of simplicity is a fundamental synthetic a priori truth."


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Thus, complex hypotheses must predict data much better than do simple hypotheses before researchers reject the simple hypotheses.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Minimum description length Minimum message length – Formal information theory restatement of Occam's Razor Newton's flaming laser sword Philosophical razor – Principle or rule of thumb that allows one to eliminate unlikely explanations for a phenomenon Philosophy of science – The philosophical study of the assumptions, foundations, and implications of science Simplicity "Ockham's razor does not say that the more simple a hypothesis, the better."


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

In the 25 papers with quantitative comparisons, complexity increased forecast errors by an average of 27 percent.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Population genetics must either model this complexity in detail, or capture it by some simpler average rule.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Climate models forced by natural factors and increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Insertion of bugs into climate models?


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

The Intergovernmental Panel on Climate Change, Third Assessment Report, says: "While the radiative forcing due to greenhouse gases may be determined to a reasonably high degree of accuracy... the uncertainties relating to aerosol radiative forcings remain large, and rely to a large extent on the estimates from global modelling studies that are difficult to verify at the present time".


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Though the model showed no significant changes to the climate in areas other than the Tropics, this may not be the case since the model has possible errors and the results are never absolutely definite.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

It should in principle, however the atmosphere is very complicated and one cannot simply argue that just because CO is a greenhouse gas it causes warming.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Rennie 2009: "Claim 1: Anthropogenic CO2 can't be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

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.


Question: Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect.

Since orbital variations are predictable, any model that relates orbital variations to climate can be run forward to predict future climate, with two caveats: the mechanism by which orbital forcing influences climate is not definitive; and non-orbital effects can be important (for example, Human impact on the environment principally increases in greenhouse gases result in a warmer climate).


Question: “We’ve known about [the greenhouse effect] for more than a century.

Scientists have known for over a century that even this small proportion has a significant warming effect, and doubling the proportion leads to a large temperature increase.


Question: “We’ve known about [the greenhouse effect] for more than a century.

In 1896, he published the first climate model of its kind, showing that halving of CO 2 could have produced the drop in temperature initiating the ice age.


Question: “We’ve known about [the greenhouse effect] for more than a century.

This phrase next appeared in a November 1957 report in The Hammond Times which described Roger Revelle's research into the effects of increasing human-caused CO 2 emissions on the greenhouse effect: "a large scale global warming, with radical climate changes may result".


Question: “We’ve known about [the greenhouse effect] for more than a century.

The effect of combustion-produced carbon dioxide on the global climate, a special case of the greenhouse effect first described in 1896 by Svante Arrhenius, has also been called the Callendar effect.


Question: “We’ve known about [the greenhouse effect] for more than a century.

The "greenhouse effect", substantially responsible for Earth's global warming, was first described in 1824 by the French mathematician Joseph Fourier.


Question: “We’ve known about [the greenhouse effect] for more than a century.

Global warming refers to the warming caused by human technology since the 19th century or earlier.


Question: “We’ve known about [the greenhouse effect] for more than a century.

A runaway greenhouse effect involving carbon dioxide and water vapor has long ago been hypothesized to have occurred on Venus, this idea is still largely accepted[citation needed].


Question: “We’ve known about [the greenhouse effect] for more than a century.

Climate change is a long-term, sustained trend of change in climate.


Question: “We’ve known about [the greenhouse effect] for more than a century.

Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere.


Question: “We’ve known about [the greenhouse effect] for more than a century.

Carbon dioxide is often mentioned in the context of its increased influence as a greenhouse gas since the pre-industrial (1750) era.


Question: “We’ve known about [the greenhouse effect] for more than a century.

The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond the temperature it would have in the absence of its atmosphere.


Question: “We’ve known about [the greenhouse effect] for more than a century.

Increases in atmospheric concentrations of CO 2 and other long-lived greenhouse gases such as methane, nitrous oxide and ozone have correspondingly strengthened their absorption and emission of infrared radiation, causing the rise in average global temperature since the mid-20th century.


Question: “We’ve known about [the greenhouse effect] for more than a century.

There is considerable evidence that over the very recent period of the last 100–1000 years, the sharp increases in human activity, especially the burning of fossil fuels, has caused the parallel sharp and accelerating increase in atmospheric greenhouse gases which trap the sun's heat.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

CO2 emissions are continuing to rise due to the burning of fossil fuels and land-use change.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs, and nitrous oxide.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

The largest human influence has been the emission of greenhouse gases such as carbon dioxide, methane, and nitrous oxide.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming, and give some indication of which countries have contributed most to human-induced climate change.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

GHG emissions due to anthropogenic (human) activity are the dominant cause of observed global warming (climate change) since the mid-20th century.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Modern climate change is driven by the human emissions of greenhouse gas from the burning of fossil fuel driving up global mean surface temperatures.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

International Council of Academies of Engineering and Technological Sciences (CAETS) in 2007, issued a Statement on Environment and Sustainable Growth: As reported by the Intergovernmental Panel on Climate Change (IPCC), most of the observed global warming since the mid-20th century is very likely due to human-produced emission of greenhouse gases and this warming will continue unabated if present anthropogenic emissions continue or, worse, expand without control.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Man-made carbon dioxide according to the IPCC contributes to global warming.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Human activities (primarily greenhouse gas emissions) are the primary cause.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

One argument is that of global warming occurring due to human-caused emission of greenhouse gases, particularly carbon dioxide produced by the burning of fossil fuels.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

There is a scientific consensus linking human activities to global warming due to industrial carbon dioxide emissions.


Question: Humans are small but powerful, and human CO2 emissions are causing global warming.

Pollutants emitted into the atmosphere by human activity include: Carbon dioxide (CO 2) – Because of its role as a greenhouse gas it has been described as "the leading pollutant" and "the worst climate pollutant".


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

The spread of land plants is thought to have reduced CO 2 concentrations during the late Devonian, and plant activities as both sources and sinks of CO 2 have since been important in providing stabilising feedbacks.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

The seven sources of CO 2 from fossil fuel combustion are (with percentage contributions for 2000–2004): Carbon dioxide, methane, nitrous oxide (N 2O) and three groups of fluorinated gases (sulfur hexafluoride (SF 6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs)) are the major anthropogenic greenhouse gases, and are regulated under the Kyoto Protocol international treaty, which came into force in 2005.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Between the period 1970 to 2004, greenhouse gas emissions (measured in CO 2-equivalent) increased at an average rate of 1.6% per year, with CO 2 emissions from the use of fossil fuels growing at a rate of 1.9% per year.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

The sharp acceleration in CO 2 emissions since 2000 to more than a 3% increase per year (more than 2 ppm per year) from 1.1% per year during the 1990s is attributable to the lapse of formerly declining trends in carbon intensity of both developing and developed nations.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Along with the burning of coal, petroleum combustion may be the largest contributor to the increase in atmospheric CO. Atmospheric CO has risen over the last 150 years to current levels of over 390 ppmv, from the 180 – 300 ppmv of the prior 800 thousand years This rise in temperature has reduced the Arctic ice cap to , smaller than ever recorded.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Atmospheric CO2 has risen over the last 150 years to current levels of over 390 ppmv, from the 180 – 300 ppmv of the prior 800 thousand years This rise in temperature has reduced the Arctic ice cap to 1,100,000 sq mi (2,800,000 km2),[citation needed] smaller than ever recorded.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

The Arctic region is one of the many natural sources of the greenhouse gas methane.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Keeling’s Tellus article of 1960 presented the first monthly CO 2 records from Mauna Loa and Antarctica (1957 to 1960), finding a “distinct seasonal cycle…and possibly, a worldwide rise in CO2 from year to year.” By the 1970s, it was well established that the increase of atmospheric carbon dioxide was ongoing and due to anthropogenic emissions.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

Climate change can increase atmospheric methane levels by increasing methane production in natural ecosystems, forming a Climate change feedback.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

High-latitude tundra and boreal forests are particularly at risk of climate change-induced


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

As a result of this feedback process, “BC on snow warms the planet about three times more than an equal forcing of CO.” When black carbon concentrations in the Arctic increase during the winter and spring due to Arctic Haze, surface temperatures increase by 0.5 °C.


Question: Data from NOAA’s Barrow Alaska station ‘indicate that October through December emissions of CO2 from surrounding tundra increased by 73 percent since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO2.’”

The Woods Hole Research Center, citing two 2015 studies on permafrost carbon says there may be a self-reinforcing tipping point where an estimated equivalent of 205 gigatons of carbon dioxide in the form of methane could cause up to 0.5 °C (up to 0.9 °F) warming by the end of the century, which would trigger more warming.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

Animal husbandry is also responsible for greenhouse gas production of CO 2 and a percentage of the world's methane, and future land infertility, and the displacement of wildlife.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

Other anthropogenic GHG emissions associated with livestock production include carbon dioxide from fossil fuel consumption (mostly for production, harvesting and transport of feed), and nitrous oxide emissions associated with use of nitrogenous fertilizers, growing of nitrogen-fixing legume vegetation and manure management.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

The IPCC (Intergovernmental Panel on Climate Change) has estimated that agriculture (including not only livestock, but also food crop, biofuel and other production) accounted for about 10 to 12 percent of global anthropogenic greenhouse gas emissions (expressed as 100-year carbon dioxide equivalents) in 2005 and in 2010.Cows produce some 570 million cubic metres of methane per day, that accounts for from 35 to 40% of the overall methane emissions of the planet.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

The vast majority of anthropogenic carbon dioxide emissions come from combustion of fossil fuels, principally coal, oil, and natural gas, with additional contributions coming from deforestation, changes in land use, soil erosion and agriculture (including livestock).


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

Greenhouse gases (GHGs) can be emitted through land clearance and the production and consumption of food, fuels, manufactured goods, materials, wood, roads, buildings, transportation and other services.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

The chart at right attributes anthropogenic greenhouse gas emissions to eight main economic sectors, of which the largest contributors are power stations (many of which burn coal or other fossil fuels), industrial processes, transportation fuels (generally fossil fuels), and agricultural by-products (mainly methane from enteric fermentation and nitrous oxide from fertilizer use).


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

In the UK, for example, agricultural-related emissions may account for approximately 40% of the overall food chain (including retail, packaging, fertilizer manufacture, and other factors), whereas greenhouse gases emitted in transport account for around 12% of overall food-chain emissions.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

The greenhouse gases carbon dioxide, methane and nitrous oxide are produced during the manufacture of nitrogen fertilizer.


Question: Burning fuel to produce fertiliser to grow feed, to  produce meat and to transport it - and clearing vegetation for grazing -  produces 9 per cent of all emissions of carbon dioxide, the most common  greenhouse gas.

Coal production is a major contributor to global warming: burning coal generates large quantities of carbon dioxide and mining operations can release methane, a known greenhouse gas, into the atmosphere.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

"How do we know more CO2 is causing warming?".


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming, and give some indication of which countries have contributed most to human-induced climate change.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

On March 9, 2017, in an interview on CNBC's Squawk Box, Pruitt stated that he "would not agree that" carbon dioxide is "a primary contributor to the global warming that we see" backing up his claim by stating that "measuring with precision human activity on the climate is something very challenging to do and there's tremendous disagreement about the degree of impact."


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

In March 2017, Pruitt said that he does not believe that human activities, specifically carbon dioxide emissions, are a primary contributor to climate change, a view which is in contradiction with the scientific consensus.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

"EPA chief Scott Pruitt says carbon dioxide is not a primary contributor to global warming".


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

As stated earlier, the US is not part of the Kyoto treaty, and is a major contributor to global annual emissions of carbon dioxide (see also greenhouse gas#Regional and national attribution of emissions).


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

As stated by the Intergovernmental Panel on Climate Change (IPCC), the largest contributor to global warming is the increase in atmospheric carbon dioxide (CO) since 1750, particularly from fossil fuel combustion, cement production, and land use changes such as deforestation.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

Rennie 2009: "Claim 1: Anthropogenic CO2 can't be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming along with ocean acidification.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

United States Secretary of Energy Rick Perry, in a 19 June 2017 interview with CNBC, acknowledged the existence of climate change and impact from humans, but said that he did not agree with the idea that carbon dioxide was the primary driver of global warming pointing instead to "the ocean waters and this environment that we live in".


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

Man-made carbon dioxide according to the IPCC contributes to global warming.


Question: Carbon dioxide is not "a primary contributor to the global warming that we see."

In the 1998 paper, "CO2-induced global warming: a skeptic's view of potential climate change" Idso said: "Several of these cooling forces have individually been estimated to be of equivalent magnitude, but of opposite sign, to the typically predicted greenhouse effect of a doubling of the air’s CO2 content, which suggests to me that little net temperature change will ultimately result from the ongoing buildup of CO2 in Earth's atmosphere.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

If cloud cover increases, more sunlight will be reflected back into space, cooling the planet.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Greenhouse gases trap heat radiating from the Earth to space.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

It traps heat in the atmosphere.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Greenhouse gases trap outgoing radiation warming the atmosphere which in turn warms the land.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

The greenhouse effect is the process by which radiation from a planet's atmosphere warms the planet's surface to a temperature above what it would be without this atmosphere.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Water vapor and CO allow the earth's atmosphere to catch and hold the Sun's energy through a phenomenon called the greenhouse effect.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

The large amount of CO2 in the atmosphere together with water vapour and sulfur dioxide create a strong greenhouse effect, trapping solar energy and raising the surface temperature to around 740 K (467 °C), hotter than any other planet in the Solar System, even that of Mercury despite being located farther out from the Sun and receiving only 25% of the solar energy (per unit area) Mercury does.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Since water vapor is a greenhouse gas, the increase in water vapor content makes the atmosphere warm further; this warming causes the atmosphere to hold still more water vapor (a positive feedback), and so on until other processes stop the feedback loop.


Question: If there is  a cloud cover, the heat is trapped by water vapour as a greenhouse gas  and the temperature stays quite warm.

Greenhouse gases, such as , methane and nitrous oxide, heat the climate system by trapping infrared light.


Question: The atmospheric residency time of carbon dioxide is five years

The atmospheric lifetime of CO 2 is estimated of the order of 30–95 years.


Question: The atmospheric residency time of carbon dioxide is five years

The average residence time of a water molecule in the atmosphere is only about nine days, compared to years or centuries for other greenhouse gases such as CH 4 and CO 2.


Question: The atmospheric residency time of carbon dioxide is five years

Black carbon stays in the atmosphere for only several days to weeks, whereas carbon dioxide () has an atmospheric lifetime of more than 100 years.


Question: The atmospheric residency time of carbon dioxide is five years

Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere.


Question: The atmospheric residency time of carbon dioxide is five years

While the lifetime of atmospheric methane is relatively short when compared to carbon dioxide, with a half-life of about 7 years, it is more efficient at trapping heat in the atmosphere, so that a given quantity of methane has 84 times the global-warming potential of carbon dioxide over a 20-year period and 28 times over a 100-year period.


Question: The atmospheric residency time of carbon dioxide is five years

This is due to carbon dioxide's very long lifetime in the atmosphere.


Question: The atmospheric residency time of carbon dioxide is five years

Carbon dioxide has a variable atmospheric lifetime, and cannot be specified precisely.


Question: The atmospheric residency time of carbon dioxide is five years

Recent warming is followed by carbon dioxide levels with only a 5 months delay.


Question: The atmospheric residency time of carbon dioxide is five years

Carbon dioxide in Earth's atmosphere is a trace gas, currently (mid 2018) having a global average concentration of 409 parts per million by volume (or 622 parts per million by mass).


Question: “Underneath the permafrost there are sediments full of methane hydrates.

(2008) estimate that not less than 1,400 gigatonnes of carbon is presently locked up as methane and methane hydrates under the Arctic submarine permafrost, and 5–10% of that area is subject to puncturing by open taliks.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Significant reservoirs of methane clathrates have been found in arctic permafrost and along continental margins beneath the ocean floor within the gas clathrate stability zone, located at high pressures (1 to 100 MPa; lower end requires lower temperature) and low temperatures (< 15 °C; upper end requires higher pressure).


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Methane clathrate, or hydrates, occur within and below permafrost soils.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

It also contains gas hydrates in places, which are a "potential abundant source of energy" but may also destabilize as subsea permafrost warms and thaws, producing large amounts of methane gas, which is a potent greenhouse gas.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Large quantities of methane are stored in the Arctic in natural gas deposits, permafrost, and as submarine clathrates.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Methane gas has been found under methane hydrate, frozen methane and water, beneath the ocean floor.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Permafrost, permanently frozen ground found in periglacial zones


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Permafrost is soil, rock or sediment that is frozen for more than two consecutive years.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

In 2008, a research expedition for the American Geophysical Union detected levels of methane up to 100 times above normal in the Siberian Arctic, likely being released by methane clathrates being released by holes in a frozen 'lid' of seabed permafrost, around the outfall of the Lena River and the area between the Laptev Sea and East Siberian Sea.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Subsea permafrost occurs beneath the seabed and exists in the continental shelves of the polar regions.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

In geology, permafrost is ground, including rock or (cryotic) soil, with a temperature that remains at or below the freezing point of water for two or more years.


Question: “Underneath the permafrost there are sediments full of methane hydrates.

Methane clathrate, also called methane hydrate, is a form of water ice that contains a large amount of methane within its crystal structure.


Question: Underground temperatures control climate.

Some of the meteorological variables that are commonly measured are temperature, humidity, atmospheric pressure, wind, and precipitation.


Question: Underground temperatures control climate.

Increases in greenhouse gases, such as by volcanic activity, can increase the global temperature and produce an interglacial period.


Question: Underground temperatures control climate.

Any imbalance results in a change in the average temperature of the earth.


Question: Underground temperatures control climate.

Alterations in the quantity of atmospheric greenhouse gases determines the amount of solar energy retained by the planet, leading to global warming or global cooling.


Question: Underground temperatures control climate.

Ice caps form because high-latitude regions receive less energy as solar radiation from the sun than equatorial regions, resulting in lower surface temperatures.


Question: Underground temperatures control climate.

Carbon dioxide may be stored deep underground.


Question: Underground temperatures control climate.

In some places where groundwater temperatures are maintained by this effect at about 10 °C (50 °F), groundwater can be used for controlling the temperature inside structures at the surface.


Question: Underground temperatures control climate.

Greenhouse gases trap heat radiating from the Earth to space.


Question: Underground temperatures control climate.

It traps heat in the atmosphere.


Question: Underground temperatures control climate.

Buildings are ventilated and their temperature regulated.


Question: Underground temperatures control climate.

Temperature increases with increasing depth into the Earth's crust.


Question: Underground temperatures control climate.

The Borehole Thermal Energy System is located underground to store large quantities of heat collected in the summer to be used in the winter.


Question: Underground temperatures control climate.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

At present, the primary source of CO 2 emissions is the burning of coal, natural gas, and petroleum for electricity and heat.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

The vast majority of anthropogenic carbon dioxide emissions come from combustion of fossil fuels, principally coal, oil, and natural gas, with additional contributions coming from deforestation, changes in land use, soil erosion and agriculture (including livestock).


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Burning hydrocarbons as fuel, producing carbon dioxide and water, is a major contributor to anthropogenic global warming.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Global warming is the result of increasing atmospheric carbon dioxide concentrations which is caused primarily by the combustion of fossil energy sources such as petroleum, coal, and natural gas, and to an unknown extent by destruction of forests, increased methane, volcanic activity and cement production.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Human activities, primarily the burning of fossil fuels (coal, oil, and natural gas), and secondarily the clearing of land, have increased the concentration of carbon dioxide, methane, and other heat-trapping ("greenhouse") gases in the atmosphere...There is international scientific consensus that most of the warming observed over the last 50 years is attributable to human activities.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Global warming refers to the warming caused by human technology since the 19th century or earlier.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Many of the actions taken by humans that contribute to a heated environment stem from the burning of fossil fuel from a variety of sources, such as: electricity, cars, planes, space heating, manufacturing, or the destruction of forests.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Coal production is a major contributor to global warming: burning coal generates large quantities of carbon dioxide and mining operations can release methane, a known greenhouse gas, into the atmosphere.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

As stated by the Intergovernmental Panel on Climate Change (IPCC), the largest contributor to global warming is the increase in atmospheric carbon dioxide (CO) since 1750, particularly from fossil fuel combustion, cement production, and land use changes such as deforestation.


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Some of the main human activities that contribute to global warming are:


Question: "Global warming is mostly due to heat production by human industry since the 1800s, from nuclear power and fossil fuels, better termed hydrocarbons, – coal, oil, natural gas.

Cumulative anthropogenic (i.e., human-emitted) emissions of CO 2 from fossil fuel use are a major cause of global warming, and give some indication of which countries have contributed most to human-induced climate change.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Since the Industrial Revolution anthropogenic emissions – primarily from use of fossil fuels and deforestation – have rapidly increased its concentration in the atmosphere, leading to global warming.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Between 1993 and 2017, the global mean sea level rose on average by 3.1 ± 0.3 mm per year, with an acceleration detected as well.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

CO2 emissions are continuing to rise due to the burning of fossil fuels and land-use change.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

To keep warming below 2 °C, more stringent emission reductions in the near-term would allow for less rapid reductions after 2030.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming along with ocean acidification.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

International Council of Academies of Engineering and Technological Sciences (CAETS) in 2007, issued a Statement on Environment and Sustainable Growth: As reported by the Intergovernmental Panel on Climate Change (IPCC), most of the observed global warming since the mid-20th century is very likely due to human-produced emission of greenhouse gases and this warming will continue unabated if present anthropogenic emissions continue or, worse, expand without control.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Carbon dioxide is the most significant long-lived greenhouse gas in Earth's atmosphere.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

The Intergovernmental Panel on Climate Change (IPCC) reports that increased quantities of the greenhouse gas carbon dioxide within the atmosphere will "very likely" lead to higher average temperatures on a global scale (global warming).


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Earth's increasing surface temperature will accelerate the inorganic carbon cycle, reducing CO 2 concentration to levels lethally low for plants (10 ppm for C4 photosynthesis) in approximately 100–900 million years.


Question: CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century.

Global warming is the long-term rise in the average temperature of the Earth's climate system.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

"Big Oil Let Off Hook Days After EU Drops Wall Street Probe".


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Partly based on such litigation experience, Congress enacted the Federal Water Pollution Control Act of 1972, better known as the Clean Water Act.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Maurice Riel, (April 3, 1922 -- July 20, 2007) was a lawyer and Canadian Senator.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Martin Brian Mulroney (born March 20, 1939) is a Canadian politician who served as the 18th Prime Minister of Canada from September 17, 1984, to June 25, 1993.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Marjory LeBreton, PC (born July 4, 1940) is a former Leader of the Government in the Canadian Senate, a cabinet-rank position ; and past national chair of Mothers Against Drunk Driving in Canada.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Raymond Gravel, Canadian political figure


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

George S. Mickelson (1941 -- 1993), American politician


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

The nuclear option is a parliamentary procedure that allows the United States Senate to override a rule or precedent by a simple majority of 51 votes, instead of by a supermajority of 60 votes.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Albert Arnold Gore Jr. (born March 31, 1948) is an American politician and environmentalist who served as the 45th vice president of the United States from 1993 to 2001.


Question: Sen. George LeMieux voted to let oil companies off the hook and overturn pollution rules.

Raymond Lavigne (born November 16, 1945) is a former Canadian senator and businessman, and a former Member of Parliament (MP).


Question: There seems to be evidence for a link between solar activity and water levels.

"High Concentrations of Silica Indicate Considerable Water Activity on Mars – SpaceRef".


Question: There seems to be evidence for a link between solar activity and water levels.

On November 4, 2018, geologists presented evidence, based on studies in Gale by the Curiosity rover, that there was plenty of water on early Mars.


Question: There seems to be evidence for a link between solar activity and water levels.

In 2009, further evidence was provided that changes in solar insolation provide the initial trigger for the earth to warm after an Ice Age, with secondary factors like increases in greenhouse gases accounting for the magnitude of the change.


Question: There seems to be evidence for a link between solar activity and water levels.

There is considerable evidence that over the very recent period of the last 100–1000 years, the sharp increases in human activity, especially the burning of fossil fuels, has caused the parallel sharp and accelerating increase in atmospheric greenhouse gases which trap the sun's heat.


Question: There seems to be evidence for a link between solar activity and water levels.

Eight times as much deuterium was inferred at the polar deposits of Mars than exists on Earth (VSMOW), suggesting that ancient Mars had significantly higher levels of water.


Question: There seems to be evidence for a link between solar activity and water levels.

It has been estimated that there are of water on Earth.


Question: There seems to be evidence for a link between solar activity and water levels.

Three mechanisms are proposed by which solar activity affects climate:


Question: There seems to be evidence for a link between solar activity and water levels.

More broadly, links have been suggested between solar cycles, global climate and regional events such as El Niño.


Question: There seems to be evidence for a link between solar activity and water levels.

"Recent oppositely directed trends in solar climate forcings and the global mean surface air temperature" (PDF).


Question: There seems to be evidence for a link between solar activity and water levels.

"Sun's Shifts May Cause Global Warming".


Question: There seems to be evidence for a link between solar activity and water levels.

The assessment of the solar activity/climate relationship involves multiple, independent lines of evidence.


Question: There seems to be evidence for a link between solar activity and water levels.

stated that while "There is ... growing empirical evidence for the Sun's role in climate change on multiple time scales including the 11-year cycle", "changes in terrestrial proxies of solar activity (such as the 14C and 10Be cosmogenic isotopes and the aa geomagnetic index) can occur in the absence of long-term (i.e., secular) solar irradiance changes ... because the stochastic response increases with the cycle amplitude, not because there is an actual secular irradiance change.


Question: There seems to be evidence for a link between solar activity and water levels.

Long-term secular change in sunspot number is thought, by some scientists, to be correlated with long-term change in solar irradiance, which, in turn, might influence Earth's long-term climate.


Question: Modellers assume carbon dioxide drives climate change

Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change.


Question: Modellers assume carbon dioxide drives climate change

"Massive peat burn is speeding climate change".


Question: Modellers assume carbon dioxide drives climate change

Unanimous agreement was found among the models that future climate change will reduce the efficiency of the land and ocean carbon cycle to absorb human-induced CO. As a result, a larger fraction of human-induced CO will stay airborne if climate change controls the carbon cycle.


Question: Modellers assume carbon dioxide drives climate change

Most climate models include the radiative effects of greenhouse gases such as carbon dioxide.


Question: Modellers assume carbon dioxide drives climate change

"How the oceans absorb carbon dioxide is critical for predicting climate change".


Question: Modellers assume carbon dioxide drives climate change

Rennie 2009: "Claim 1: Anthropogenic CO2 can't be changing climate, because CO2 is only a trace gas in the atmosphere and the amount produced by humans is dwarfed by the amount from volcanoes and other natural sources.


Question: Modellers assume carbon dioxide drives climate change

Carbon dioxide is a greenhouse gas that increases radiative forcing and contributes to global warming along with ocean acidification.


Question: Modellers assume carbon dioxide drives climate change

Network of African Science Academies: "A consensus, based on current evidence, now exists within the global scientific community that human activities are the main source of climate change and that the burning of fossil fuels is largely responsible for driving this change."


Question: Modellers assume carbon dioxide drives climate change

Modern climate change is driven by the human emissions of greenhouse gas from the burning of fossil fuel driving up global mean surface temperatures.


Question: Modellers assume carbon dioxide drives climate change

The two opposing pH levels correspond with climate change models that predict future atmospheric CO2 levels.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

In his first paper on the matter, he estimated that global temperature would rise by around 5 to 6 °C (9.0 to 10.8 °F) if the quantity of CO 2 was doubled.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

The TAR estimate for the climate sensitivity is 1.5 to 4.5 °C; and the average surface temperature is projected to increase by 1.4 to 5.8 Celsius degrees over the period 1990 to 2100, and the sea level is projected to rise by 0.1 to 0.9 metres over the same period.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

In 2018 the IPCC published a Special Report on Global Warming of 1.5 °C which warned that, if the current rate of greenhouse gas emissions is not mitigated, global warming is likely to reach 1.5 °C (2.7 °F) between 2030 and 2052, risking major crises.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

The 1990 IPCC First Assessment Report estimated that equilibrium climate sensitivity to a doubling of CO 2 lay between 1.5 and 4.5 °C (2.7 and 8.1 °F), with a "best guess in the light of current knowledge" of 2.5 °C (4.5 °F).


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

The "likely" range (as assessed to have a greater than 66% probability of being correct, based on the IPCC's expert judgment) is a projected increase in global mean temperature over the 21st century of between 1.1 and 6.4 °C.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

In the 1998 paper, "CO2-induced global warming: a skeptic's view of potential climate change" Idso said: "Several of these cooling forces have individually been estimated to be of equivalent magnitude, but of opposite sign, to the typically predicted greenhouse effect of a doubling of the air’s CO2 content, which suggests to me that little net temperature change will ultimately result from the ongoing buildup of CO2 in Earth's atmosphere.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

IPCC has only one scenario (they call it a "Representative Concentration Pathway" RCP) which limits warming to 3.6 °F: "RCP2.6 is representative of a scenario that aims to keep global warming likely below 2°C above pre-industrial temperatures.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

Models referenced by the Intergovernmental Panel on Climate Change (IPCC) predict that global temperatures are likely to increase by 1.1 to 6.4 °C (2.0 to 11.5 °F) between 1990 and 2100.


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

In preparation for the 2021 6th IPCC report, a new generation of climate models are being developed: some show climate sensitivity around , meaning temperature can rise by 6.5 - 7 degree by 2100 in the worst socio-economic scenario ("SSP5 8.5 – rapid economic growth driven by fossil fuels without mitigation").


Question: His best estimate is that the  warming in response to a doubling of CO2 concentration, which may happen  this century unless the usual suspects get away with shutting down the  economies of the West, will be a harmless 1 Fahrenheit degree, not the 6  F predicted by the IPCC."

The Intergovernmental Panel on Climate Change (IPCC) reports that increased quantities of the greenhouse gas carbon dioxide within the atmosphere will "very likely" lead to higher average temperatures on a global scale (global warming).


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Using the long-term temperature trends for the earth scientists and statisticians conclude that it continues to warm through time.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

This long-term trend is the main cause for the record warmth of 2015 and 2016, surpassing all previous years—even ones with strong El Niño events."


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Between 1850 and 1950 a long-term trend of gradual climate warming is observable, and during this same period the Marsham record of oak-leafing dates tended to become earlier.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Climate change is a long-term, sustained trend of change in climate.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

The warming has not been globally uniform.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Human-induced warming of the climate is expected to continue throughout the 21st century and beyond.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

There are expected to be various long-term effects of global warming.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Global warming is the long-term rise in the average temperature of the Earth's climate system.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

Global warming refers to the long-term rise in the average temperature of the Earth's climate system.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

The current scientific consensus on climate change is that the Earth underwent global warming throughout the 20th century and continues to warm.


Question: ‘We don’t expect record years every year, but the ongoing long-term warming trend is clear.’”

The data show a long-term negative trend in recent years, attributed to global warming, although there is also a considerable amount of variation from year to year.


Question: Arctic sea ice has been retreating over the past 30 years.

Due to the poleward migration of the planet's isotherms (about 56 km (35 mi) per decade during the past 30 years as a consequence of global warming), the Arctic region (as defined by tree line and temperature) is currently shrinking.


Question: Arctic sea ice has been retreating over the past 30 years.

Global warming has led to decades of shrinking and thinning of the Arctic sea ice, making it vulnerable to atmospheric anomalies.


Question: Arctic sea ice has been retreating over the past 30 years.

A composite record of Arctic ice demonstrates that the floes' retreat began around 1900, experiencing more rapid melting beginning within the past 50 years.


Question: Arctic sea ice has been retreating over the past 30 years.

The amount of multi-year sea ice in the Arctic has declined considerably in recent decades.


Question: Arctic sea ice has been retreating over the past 30 years.

"A sea ice free summer Arctic within 30 years?".


Question: Arctic sea ice has been retreating over the past 30 years.

In recent decades, sea ice in the Arctic Ocean has been melting faster than it re-freezes in winter.


Question: Arctic sea ice has been retreating over the past 30 years.

Accelerated decline in the Arctic sea ice.


Question: Arctic sea ice has been retreating over the past 30 years.

Projection models of the evolution of the arctic ice floe are based on the last 30 years.


Question: Arctic sea ice has been retreating over the past 30 years.

The Earth has been in an Ice House Climate for the last 30 million years.


Question: Arctic sea ice has been retreating over the past 30 years.

Large-scale measurements of sea-ice have only been possible since the satellite era, but through looking at a number of different satellite estimates, it has been determined that September Arctic sea ice has decreased between 1973 and 2007 at a rate of about -10% +/- 0.3% per decade.


Question: Arctic sea ice has been retreating over the past 30 years.

Surface temperature increases are greatest in the Arctic, which has contributed to the retreat of glaciers, permafrost, and sea ice.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Ocean acidification is the ongoing decrease in the pH of the Earth's oceans, caused by the uptake of carbon dioxide (CO 2) from the atmosphere.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

With the production of CO2 from the burning of fossil fuels, oceans are becoming more acidic since CO2 dissolves in water and forms the acidic bicarbonate ion.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

The ocean would not become acidic even if it were to absorb the CO2 produced from the combustion of all fossil fuel resources.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

It is expected to drop by a further 0.3 to 0.5 pH units (an additional doubling to tripling of today's post-industrial acid concentrations) by 2100 as the oceans absorb more anthropogenic CO 2, the impacts being most severe for coral reefs and the Southern Ocean.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Although the natural absorption of CO 2 by the world's oceans helps mitigate the climatic effects of anthropogenic emissions of CO 2, it is believed that the resulting decrease in pH will have negative consequences, primarily for oceanic calcifying organisms.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Addition of carbon dioxide to the ocean water makes the oceans more acidic.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Ocean acidification is the increase in the acidity of the Earth's oceans caused by the uptake of carbon dioxide () from the atmosphere.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

As the concentration of carbon dioxide increases in the atmosphere, the increased uptake of carbon dioxide into the oceans is causing a measurable decrease in the pH of the oceans, which is referred to as ocean acidification.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Rising levels of carbon dioxide are resulting in influx of this gas into the ocean, increasing its acidity.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Carbon dioxide emissions cause ocean acidification, the ongoing decrease in the pH of the Earth's oceans as CO 2 becomes dissolved.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

These rising levels of carbon dioxide are acidifying the oceans.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

As more CO and heat are absorbed by the ocean, it is acidifying and ocean circulation can change, changing the rate at which the ocean can absorb atmospheric carbon.


Question: The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.

Ocean acidification is an effect of rising concentrations of [[Carbon dioxide|CO]] in the atmosphere, and is not a direct consequence of global warming.


Question: Geologists say that humans are now pumping the gas into the air much faster than nature has ever done.

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs, and nitrous oxide.


Question: Geologists say that humans are now pumping the gas into the air much faster than nature has ever done.

The reason for this is that human activities are adding CO2 to the atmosphere faster than natural processes can remove it (see carbon dioxide in Earth's atmosphere for a complete explanation).


Question: Geologists say that humans are now pumping the gas into the air much faster than nature has ever done.

Human activities have caused CO 2 to increase above levels not seen in hundreds of thousands of years.


Question: Geologists say that humans are now pumping the gas into the air much faster than nature has ever done.

Gases are more available in terrestrial ecosystems than in aquatic ecosystems.