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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Dana Nuccitelli is an environmental scientist at a private environmental consulting firm in the Sacramento, California area. He has a Bachelor's Degree in astrophysics from the University of California at Berkeley, and a Master's Degree in physics from the University of California at Davis.

Dana has been researching climate science, economics, and solutions since 2006, and has contributed to Skeptical Science since September, 2010.  He also blogs at The Guardian, and is the author of Climatology versus Pseudoscience.  He has published climate-related papers on various subjects, from the build-up of heat in the Earth's climate system to the expert consensus on human-caused global warming.

Follow him on Twitter.


Nuccitelli, D., Way, R., Painting, R., Church, J., & Cook, J. (2012). Comment on ocean heat content and Earth's radiation imbalance. II. Relation to climate shifts. Physics Letters A.

Cook, J., Nuccitelli, D., Green, S.A., Richardson, M., Winkler, B., Painting, R., Way, R., Jacobs, P., & Skuce, A. (2013). Quantifying the consensus on anthropogenic global warming in the scientific literature. Environmental Research Letters, 8(2), 024024+. 

Cook, J., Nuccitelli, D., Skuce, A., Way, R., Jacobs, P., Painting, R., Honeycutt, R., Green, S.A. (2014). Reply to Comment on ‘Quantifying the consensus on anthropogenic global warming in the scientific literature: a Reanalysis’. Energy Policy. DOI: 10.1016/j.enpol.2014.06.002

Nuccitelli, D. A., Abraham, J. P., Benestad, R. E., & Mandia, S. A. (2013). Comment on: Akasofu, S.-I. On the Present Halting of Global Warming. Climate 2013, 1, 4–11. Climate, 1(2), 76-83.
Abraham, J., Cook, J., Fasullo, J., Jacobs, P., Mandia, S., & Nuccitelli, D. (2014). Review of the consensus and asymmetric quality of research on human-induced climate changeCosmopolis2014(1), 3-18.

Benestad, R. E., Hygen, H. O., Dorland, R. V., Cook, J., & Nuccitelli, D. (2013). Agnotology: learning from mistakes. Earth System Dynamics Discussions, 4(1), 451-505.

Nuccitelli, D., Richter, M. J., & McCall, B. J. (2005). A search for interstellar carbon-60. In IAU Symposium (Vol. 235, p. 236P).

Encrenaz, T., Bézard, B., Greathouse, T., Holmes, S., Richter, M., Nuccitelli, D., & Forget, F. et al. (2006, February). Ground-based high-resolution IR spectroscopy of Mars: H2O and H2O2 mapping, search for CH4, and determination of CO2 isotopic ratios. In Second Workshop on Mars Atmosphere Modelling and Observations, held February.


Recent blog posts

The Republican Party stands alone in climate denial

Posted on 5 October 2015 by dana1981 &

A paper published in the journal Politics and Policy by Sondre Båtstrand at the University of Bergen in Norway compared the climate positions of conservative political parties around the world. Båtstrand examined the platforms or manifestos of the conservative parties from the USA, UK, Norway, Sweden, Spain, Canada, New Zealand, Australia, and Germany. He found that the US Republican Party stands alone in its rejection of the need to tackle climate change and efforts to become the party of climate supervillains.

Republicans would be fringe in any other country

As Jonathan Chait wrote of Republican presidential candidate Jeb Bush’s proposals to eliminate all significant American national climate policies,

In any other democracy in the world, a Jeb Bush would be an isolated loon, operating outside the major parties, perhaps carrying on at conferences with fellow cranks, but having no prospects of seeing his vision carried out in government. But the United States is different. Here in America, ideas like Bush’s fit comfortably within one of the two major political parties. Indeed, the greatest barrier to Bush claiming his party’s nomination is the quite possibly justified sense that he is too sober and moderate to suit the GOP.

So, what’s different about the United States? One factor is the immensely profitable and politically influential fossil fuel industry. However, Canada and Australia serve as useful analogues. With Australian coal reserves and Canadian tar sands, fossil fuels account for a larger share of both countries’ economies. Nevertheless, Båtstrand noted,

The [Republican] party seems to treat climate change as a non-issue ... this appears to be consistent with the U.S. national context as a country with large reserves of coal.



Is the fossil fuel industry, like the tobacco industry, guilty of racketeering?

Posted on 29 September 2015 by dana1981 &

ExxonMobil has become infamous for its secretive anti-climate science campaign, having spent $30 million funding groups denying the scientific evidence and consensus on human-caused global warming.

Last week, after an eight-month investigation, InsideClimate News revealed that from the late-1970s to the mid-1980s, scientists at Exxon were in fact at the cutting edge of climate science research.

Exxon documents show that top corporate managers were aware of their scientists’ early conclusions about carbon dioxide’s impact on the climate. They reveal that scientists warned management that policy changes to address climate change might affect profitability. After a decade of frank internal discussions on global warming and conducting unbiased studies on it, Exxon changed direction in 1989 and spent more than 20 years discrediting the research its own scientists had once confirmed.

In an internal September 1982 document, Exxon scientists summarized the expert consensus on human-caused global warming, and the consistency of their own research with that expert consensus.

The consensus is that a doubling of atmospheric CO2 from its pre-industrial revolution value would result in an average global temperature rise of (3.0 ± 1.5)°C … There is unanimous agreement in the scientific community that a temperature increase of this magnitude would bring about significant changes in the earth’s climate, including rainfall distribution and alterations in the biosphere … the results of our research are in accord with the scientific consensus on the effect of increased atmospheric CO2 on climate.

It’s ironic that 33 years ago, the world’s largest oil company accepted and concurred with the scientific consensus on human-caused global warming thatmany people continue to deny to this day.

In another internal company document in November 1982, Exxon scientists illustrated the rapid global warming they expected to occur over the following century due to rising carbon pollution from burning fossil fuels. A year earlier, Exxon scientists were discussing the distinct possibility that the consequences of climate change could become catastrophic in the near future.

exxon temp projections

Exxon’s 1982 projections of how human carbon pollution would cause global temperatures to rise.



Celebrated NASA planet hunter shifts his sights back to climate change on Earth

Posted on 24 September 2015 by dana1981 &

William Borucki has had an amazing scientific career. One of his first jobs was at NASA Ames Research Center, where he worked on the Apollo moon missions, including helping to develop the heat shield for the space shuttle. After the successful moon landings, Borucki shifted to NASA’s Theoretical Studies Branch in the 1970s, where he developed models of the Earth’s atmosphere to predict the effects of nitric oxides and chlorofluoromethanes on the ozone layer. Both were determined to contribute to the problem of ozone depletion and the hole in the ozone layer.

In the 1980s, Borucki began advocating the development of a space mission that could detect Earth-size planets. He published a paper in 1984 showing that a photometer 1,000 times more precise than any in existence could detect Earth-size planets. Undeterred by rejections of four proposals in the 1990s for a planet-finding mission, Borucki was ultimately appointed Principle Investigator in 2001 for NASA’s new Keppler Mission to discover these planets. During its four years of its operation, the Kepler Mission discovered over 4,600 planetary candidates, confirmed more than 1,000 as planets, and made numerous contributions to stellar astrophysics.

For his work in conceiving and leading the Kepler Mission, Borucki was awarded the Shaw Prize in astronomy. He decided to donate a portion of the award to the Union of Concerned Scientists (UCS) to support the organization’s work in addressing climate change, explaining,



Republicans are becoming the party of climate supervillains

Posted on 14 September 2015 by dana1981 &

As Politico recently reported in a news story that seems better suited for bad a Hollywood movie script, Republican Party leaders are actively trying to sabotage the critical international climate negotiations that will happen in Paris at the end of this year.

Top Republican lawmakers are planning a wide-ranging offensive — including outreach to foreign officials by Senate Majority Leader Mitch McConnell’s office — to undermine President Barack Obama’s hopes of reaching an international climate change agreement that would cement his environmental legacy.

Republican Party leaders have often argued that the United States shouldn’t take action to curb its carbon pollution unless China and other countries do as well.

Climate Desk mash-up of Republican leaders calling for China and other countries to cut their carbon pollution.

Now these countries are working to reach an international agreement in which all cut their carbon pollution, and Republican leaders are trying to undermine it. It’s as though they’re just looking for excuses to prevent the United States from reducing its fossil fuel consumption. As Jonathan Chait wrote,

In any case, the old conservative line, with its explicit or implicit promise that international agreement to reduce emissions might justify domestic emissions cuts, has suddenly become inoperative. The speed at which Republicans have changed from insisting other countries would never reduce their greenhouse-gas emissions to warning other countries not to do so — without a peep of protest from within the party or the conservative movement — says everything you need to know about the party’s stance on climate change.



Republican leaders should take their own advice and listen to climate scientists

Posted on 11 September 2015 by dana1981 &

Republican presidential candidate Rick Santorum recently said we should “leave science to the scientists.” That’s good advice; especially since Republican Party leaders’ response when asked about climate change is inevitably “I’m not a scientist.” When it comes to questions of science, listening to scientific experts is always a good idea.

 John Cook’s Denial101x consensus lecture.

The problem is that in this case, Republican leaders are failing to follow their own advice.

Rick Santorum denies the 97% climate consensus

Santorum was a guest on the August 28th episode of the HBO show Real Time with Bill Maher, in which climate change was the primary topic of discussion. During the interview, Santorum made several false statements denying the 97% expert consensus on human-caused global warming.



What Emma Thompson got right and wrong on climate change

Posted on 7 September 2015 by dana1981 &

Actress and Greenpeace activist Emma Thompson was interviewed on BBC Newsnight about Shell’s drilling in the Arctic and associated climate change threats. In the interview, Thompson made some inaccurate statements about the timescales associated with those climate threats. However, her concerns are generally justified.

 Emma Thompson on BBC Newsnight.

Many critics have latched onto the following inaccurate statement,

if they take out of the earth all the oil they want to take out, you look at the science – our temperature will rise 4 degrees Celsius by 2030, and that’s not sustainable.

This is incorrect. According to the latest IPCC report, by 2030, global surface temperatures probably won’t be more than 2°C hotter than pre-industrial levels. A 2010 study led by Met Office climate scientist Richard Betts called “When could global warming reach 4°C?” answered the titular question as follows,

…our best estimate is that the [fossil fuel intensive] emissions scenario would lead to a warming of 4°C relative to pre-industrial during the 2070s. If carbon-cycle feedbacks are stronger, which appears less likely but still credible, then 4°C warming could be reached by the early 2060s

So, Thompson was off by three to four decades. However, because of the lag between the time when we emit greenhouse gases and when their full warming influence in realized, the highest emissions scenario considered in the latest IPCC report suggests we would commit ourselves to 4°C warming by 2050. 

That day could arrive even earlier because as the Betts study noted, carbon-cycle feedbacks may be stronger than currently simulated in climate models. Moreover, it takes time to transition our infrastructure away from fossil fuels. If we haven’t taken major steps in that direction in the coming years, we’ll commit ourselves to a very hot planet.



Global warming intensified the record floods in Texas and Oklahoma

Posted on 2 September 2015 by dana1981 &

We know that as humans emit greenhouse gases into the atmosphere, it causes the Earth to warm. But it also causes other climate changes that are less obvious. In some instances, it makes areas wetter (because there is more moisture in the air as temperature increases). This can lead to increased flooding. In other instances, it speeds evaporation so that droughts can set in more quickly and deeply. While it would appear these affects would offset each other, in reality more droughts or floods occur depending on where you are located. 

In some instances, areas are experiencing more severe droughts and more flooding as the weather systems swing from dry to wet quickly. Added to this is the fact that ocean temperatures have an enormous influence on weather. 

As an example, an El Niño, which is the appearance of a warm water pool in the Pacific Ocean, can influence weather across the globe. Human-caused warming of the oceans adds to the El Niño cycles, which in turn affect the atmosphere. The real scientific question is, do human greenhouse gases influence a specific flood or drought event? A growing body of science is finding that the answer to this question is yes.

A paper just published in Geophysical Research Letters looked at the May 2015 floods in Texas and Oklahoma in the USA, which resulted from the wettest single month on record in both states. The lead author, Dr. Wang from Utah State and his colleagues examined the role of strengthened El Niño teleconnections on the flood event. Before getting into their conclusions, a little background is important. 

In the Pacific Ocean, there is a water temperature oscillation that occurs every few years. This oscillation happens near the equator and stretches from South America almost all the way to Australia. During one part of the oscillation, there is colder than normal waters (called the La Niña phase) while in the other part of the oscillation, the waters are warm (called El Niño). Many times, the water temperatures are near normal, and we call that a neutral phase.

This process has large global consequences. First, when the ocean is in the warm El Niño phase, global surface temperatures rise temporarily. When in the La Niña phase, the temperatures temporarily drop. These short-term rises and falls last just a year or so and are superimposed on a long-term temperature increase from greenhouse gases. The cycle also has big implications for rainfall patterns around the globe.



Citi report: slowing global warming would save tens of trillions of dollars

Posted on 31 August 2015 by dana1981 &

Citi Global Perspectives & Solutions (GPS), a division within Citibank (America’s third-largest bank), recently published a report looking at the economic costs and benefits of a low-carbon future. The report considered two scenarios: “Inaction,” which involves continuing on a business-as-usual path, and Action scenario which involves transitioning to a low-carbon energy mix.

One of the most interesting findings in the report is that the investment costs for the two scenarios are almost identical. In fact, because of savings due to reduced fuel costs and increased energy efficiency, the Action scenario is actually a bit cheaper than the Inaction scenario.

What is perhaps most surprising is that looking at the potential total spend on energy over the next quarter century, on an undiscounted basis the cost of following a low carbon route at $190.2 trillion is actually cheaper than our ‘Inaction’ scenario at $192 trillion. This, as we examine in this chapter, is due to the rapidly falling costs of renewables, which combined with lower fuel usage from energy efficiency investments actually result in significantly lower long term fuel bill. Yes, we have to invest more in the early years, but we potentially save later, not to mention the liabilities of climate change that we potentially avoid.

The following figure from the Citi report breaks down the investment costs in the Action ($190.2 trillion) and Inaction ($192 trillion) scenarios.

action vs inaction

Investment costs of climate Action and Inaction scenarios. Source: Citi GPS.



Here’s what happens when you try to replicate climate contrarian papers

Posted on 25 August 2015 by dana1981 &

Those who reject the 97% expert consensus on human-caused global warming often invoke Galileo as an example of when the scientific minority overturned the majority view. In reality, climate contrarians have almost nothing in common with Galileo, whose conclusions were based on empirical scientific evidence, supported by many scientific contemporaries, and persecuted by the religious-political establishment. Nevertheless, there’s a slim chance that the 2–3% minority is correct and the 97% climate consensus is wrong.

To evaluate that possibility, a new paper published in the journal of Theoretical and Applied Climatology examines a selection of contrarian climate science research and attempts to replicate their results. The idea is that accurate scientific research should be replicable, and through replication we can also identify any methodological flaws in that research. The study also seeks to answer the question, why do these contrarian papers come to a different conclusion than 97% of the climate science literature?

This new study was authored by Rasmus Benestad, myself (Dana Nuccitelli), Stephan Lewandowsky, Katharine Hayhoe, Hans Olav Hygen, Rob van Dorland, and John Cook. Benestad (who did the lion’s share of the work for this paper) created a tool using the R programming language to replicate the results and methods used in a number of frequently-referenced research papers that reject the expert consensus on human-caused global warming. In using this tool, we discovered some common themes among the contrarian research papers.



Fox News' inner struggle with climate misinformation

Posted on 17 August 2015 by dana1981 &

Research has shown that Fox News is a major driving force behind climate denial, decreasing viewer trust in scientists and the existence of global warming. In 2013, only 28% of Fox News’ climate science segments were accurate, although that was an improvement over its 7% accuracy in 2012.

Fox News anchor Shepard Smith has been one of the few voices on the network willing to accept the scientific reality of human-caused climate change. On the August 10 edition of Fox News’ Shepard Smith Reporting, Smith reported on biased industry-funded science by Coca Cola, and made the connection to fossil fuel-funded climate denial studies.

Lisa Kennedy Montgomery: It’s actually very brilliant marketing on the part of Coca Cola, because they realize that if someone hears that there’s a scientific study behind a reported fact, then they take that, they internalize it and take it to be true … So, what Coca Cola has decided to do is use that “science” in their favor. And if only they could find a few scientists willing to report that it’s not the calories but the lack of exercise that’s making people obese, then they can use this as a sort of an underground marketing strategy.

Shepard Smith: Well this reminds me of two things. The article in the New York Times this weekend pointed out, it reminds you of exactly what the tobacco industry did back in the day, and more recently it also reminds you of what the climate deniers, the climate change deniers are doing as well.

 August 10, 2015 segment on Shepard Smith Reporting.

In fact, just 2 days later, the Fox Business News show Varney & Co. used that strategy in an interview with Roy Spencer. Spencer is one of the fewer than 3% of climate scientists whose research rejects or minimizes the human contribution to global warming, and who infamously made comments about “global warming Nazis.”



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