Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


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.

Home Arguments Software Resources Comments The Consensus Project Translations About Donate

Twitter Facebook YouTube Pinterest

RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

Keep me logged in
New? Register here
Forgot your password?

Latest Posts


Climate Hustle

John Cook

John is an Research Assistant Professor at the Center for Climate Change Communication at George Mason University. He holds a PhD in cognitive psychology at the University of Western Australia and a Bachelor of Science at the University of Queensland, achieving First Class Honours with a major in physics. He co-hosts the podcast Evidence Squared with Peter Jacobs. He co-authored the 2011 book Climate Change Denial: Heads in the Sand with Haydn Washington, and the 2013 college textbook Climate Change Science: A Modern Synthesis with Tom Farmer. He also lead-authored the paper Quantifying the Consensus on anthropogenic global warming in the scientific literature, which was tweeted by President Obama and was awarded the best paper published in Environmental Research Letters in 2013.


Cook, J., Lewandowsky, S., & Ecker, U. (2017). Neutralizing misinformation through inoculation: Exposing misleading argumentation techniques reduces their influence. PLoS ONE, 12(5): e0175799.

Skuce, A. G., Cook, J., Richardson, M., Winkler, B., Rice, K., Green, S. A., ... & Nuccitelli, D. (2017). Does It Matter if the Consensus on Anthropogenic Global Warming Is 97% or 99.99%? Bulletin of Science, Technology & Society, 0270467617702781.

Cook, J. (2017). How to Effectively Debunk Myths About Aging and Other MisconceptionsPublic Policy and Aging Report. 27(1), 13-17. doi: 10.1093/ppar/prw034

Cook, J. (2016). Closing the “consensus gap” by communicating the scientific consensus on climate change and countering misinformation. (Doctoral dissertation, University of Western Australia).

Bedford, D., & Cook, J. (2016). Climate Change: Examining the Facts. Santa Barbara, CA: ABC-CLIO.

Cook, J. (2016). Countering Climate Science Denial and Communicating Scientific Consensus. Oxford Encyclopedia of Climate Change Communication. London: Oxford University Press.

Lewandowsky, S., Cook, J., & Lloyd, E. (2016). The ‘Alice in Wonderland’mechanics of the rejection of (climate) science: simulating coherence by conspiracismSynthese, 1-22.

Cook, J., Oreskes, N., Doran, P. T., Anderegg, W. R., Verheggen, B., Maibach, E. W., Carlton, J. S., Lewandowsky, S., Skuce, A. G., Green, S. A., & Nuccitelli, D. (2016). Consensus on consensus: a synthesis of consensus estimates on human-caused global warming. Environmental Research Letters, 11(4), 048002.

Cook, J. & Lewandowsky, S. (2016). Rational Irrationality: Modeling Climate Change Belief Polarization Using Bayesian Networks. Topics in Cognitive Science8(1), 160-179.

Cook, J., Schuennemann, K., Nuccitelli, D., Jacobs, P., Cowtan, K., Green, S., Way, R., Richardson, M., Cawley, G., Mandia, S., Skuce, A., & Bedford, D. (April 2015). Denial101x: Making Sense of Climate Science Denial. edX

Benestad, R. E., Nuccitelli, D., Lewandowsky, S., Hayhoe, K., Hygen, H. O., van Dorland, R., & Cook, J. (2015). Learning from mistakes in climate researchTheoretical and Applied Climatology, 1-5.

Lewandowsky, S., Cook, J., Oberauer, K., Brophy, S., Lloyd, E. A., & Marriott, M. (2015). Recurrent Fury: Conspiratorial Discourse in the Blogosphere Triggered by Research on the Role of Conspiracist Ideation in Climate DenialJournal of Social and Political Psychology3(1), 142-178.

Cook, J., & Cowtan, K. (2015). Reply to Comment on ‘Quantifying the consensus on anthropogenic global warming in the scientific literature’Environmental Research Letters10(3), 039002.

Cook, J., Ecker, U. & Lewandowsky, S. (2015). Misinformation and how to correct it, Emerging Trends in the Social and Behavioral Sciences. Robert Scott and Stephen Kosslyn (Eds.), Hoboken, NJ: John Wiley and Sons.

Cook, J., Bedford, D. & Mandia, S. (2014). Raising Climate Literacy Through Addressing Misinformation: Case Studies in Agnotology-Based Learning. Journal of Geoscience Education, 62(3), 296-306.

Cook, J., Jacobs, P. (2014). Scientists are from Mars, Laypeople are from Venus: An Evidence-Based Rationale for Communicating the Consensus on Climate. Reports of the National Center for Science Education. 34, 6, 3.1-3.10.

Cook, J. (2014). Research on Climate Consensus Provokes Strong Reactions. The Winnower. Available at

Verheggen, B., Strengers, B., Cook, J., van Dorland, R., Vringer, K., Peters, J., Visser, H. & Meyer, L. (2014). Scientists’ views about attribution of global warmingEnvironmental science & technology48(16), 8963-8971.

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

Cook, J., Nuccitelli, D., Skuce, A., Way, R., Jacobs, P., Painting, R., Lewandowsky, S. & Coulter, A. (2014). 24 critical errors in Tol (2014): Reaffirming the 97% consensus on anthropogenic global warming.

Cook, J. (2014). How Has the Carbon Tax Affected the Public ‘Debate’ on Climate Change? Quiggin, J., Adamson, D., & Quiggin, D. (Eds.), In Carbon Pricing: Early Experience and Future Prospects (pp. 49-64). Cheltenham Glos: Edward Elgar Publishing.

Abraham, J. P., Cook, J., Fasullo, J. T., Jacobs, P. H., Mandia, S. A. & Nuccitelli, D. A. (2014). Review of the Consensus and Asymmetric Quality of Research on Human-Induced Climate Change, Cosmopolis, 2014-1, 3-18.

Farmer, G. T. & Cook, J. (2013). Climate Change Science: A Modern Synthesis. Dordrecht, Netherlands: Springer Science+Business Media.

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+.

Bedford, D., & Cook, J. (2013). Agnotology, Scientific Consensus, and the Teaching and Learning of Climate Change: A Response to Legates, Soon and Briggs. Science & Education, 22(8), 2019-2030.

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, 376(45), 3466-3468.

Lewandowsky, S., Ecker, U. K., Seifert, C. M., Schwarz, N., & Cook, J. (2012). Misinformation and its correction continued influence and successful debiasing. Psychological Science in the Public Interest, 13(3), 106-131.

Washington, H., & Cook, J. (2012). Climate change denial: Heads in the sand. Routledge.

Cook, J., & Lewandowsky, S. (2011). The Debunking Handbook. St. Lucia, Australia: University of Queensland. ISBN 978-0-646-56812-6. [available at].


Recent blog posts

Inoculation theory: Using misinformation to fight misinformation

Posted on 17 May 2017 by John Cook &

The ConversationJohn Cook, Research Assistant Professor, Center for Climate Change Communication, George Mason University.  This article was originally published on The Conversation. Read the original article.

As a psychologist researching misinformation, I focus on reducing its influence. Essentially, my goal is to put myself out of a job.

Recent developments indicate that I haven’t been doing a very good job of it. Misinformation, fake news and “alternative facts” are more prominent than ever. The Oxford Dictionary named “post-truth” as the 2016 word of the year. Science and scientific evidence have been under assault.

Fortunately, science does have a means to protect itself, and it comes from a branch of psychological research known as inoculation theory. This borrows from the logic of vaccines: A little bit of something bad helps you resist a full-blown case. In my newly published research, I’ve tried exposing people to a weak form of misinformation in order to inoculate them against the real thing – with promising results.

Two ways misinformation damages

Misinformation is being generated and disseminated at prolific rates. A recent study comparing arguments against climate science versus policy arguments against action on climate found that science denial is on the relative increase. And recent research indicates these types of effort have an impact on people’s perceptions and science literacy.

A recent study led by psychology researcher Sander van der Linden found that misinformation about climate change has a significant impact on public perceptions about climate change.

The misinformation they used in their experiment was the most shared climate article in 2016. It’s a petition, known as the Global Warming Petition Project, featuring 31,000 people with a bachelor of science or higher, who signed a statement saying humans aren’t disrupting climate. This single article lowered readers’ perception of scientific consensus. The extent that people accept there’s a scientific consensus about climate change is what researchers refer to as a “gateway belief,” influencing attitudes about climate change such as support for climate action.

At the same time that van der Linden was conducting his experiment in the U.S., I was on the other side of the planet in Australia conducting my own research into the impact of misinformation. By coincidence, I used the same myth, taking verbatim text from the Global Warming Petition Project. After showing the misinformation, I asked people to estimate the scientific consensus on human-caused global warming, in order to measure any effect.

I found similar results, with misinformation reducing people’s perception of the scientific consensus. Moreover, the misinformation affected some more than others. The more politically conservative a person was, the greater the influence of the misinformation.

Response to misinformation about climate change. Cook et al. (2017), CC BY-ND



Podcast on National Review & the science of climate science denial

Posted on 15 May 2017 by John Cook &

National Review recently published an article by Oren Cass that misrepresents a 2016 paper on the scientific consensus on climate change, written by coauthors of 7 leading consensus studies and members of the Skeptical Science team (coauthors include Naomi Oreskes, Peter Doran, William Anderegg, Bart Verheggen & Stuart Carlton). I asked National Review for a right-of-reply and to their credit, they agreed. Here is my reply to Oren Cass: How to Recognize ‘Science Denial’.

National Review also published a reply-to-my-reply from Oren Cass: John Cook’s Leap of Faith. Unfortunately, Cass justifies his use of the fake expert strategy because, well, Bernie Sanders. He also misrepresents Gavin Schmidt and the IPCC, attempting to argue that I am an outlier compared to them

Interestingly, this is the same strategy that Richard Tol once tried in arguing our 97% was an outlier compared to other consensus studies, which led to my co-authoring the 2016 consensus-on-consensus study with other consensus researchers (which was the paper that Cass misrepresents, everything is coming full circle). The position of the IPCC, Gavin Schmidt and myself are in perfect agreement: our best estimate of human contribution to global warming is 100% with the lowest bound being around 50%.

Anyway, I also recorded an Evidence Squared podcast with Peter Jacobs, where we critique the original National Review article. We discuss the techniques of climate science denial, focusing on the technique of fake experts that Cass uses to cast doubt on expert agreement.



Evidence Squared #10: Debunking William Happer's carbon cycle myth

Posted on 2 May 2017 by John Cook & PeterJ

In the first “Breaking Debunking” mini-episode of the Evidence Squared podcast, John Cook and Peter Jacobs explain how the carbon cycle works (the CO2 we breath out originally came from the air) and debunk William Happer’s myth from CNN that breathing adds CO2 to the atmosphere.



Evidence Squared: Episode 9

Posted on 28 April 2017 by John Cook &

In Episode 9 of their podcast, John Cook and Peter Jacobs talk about the March for Science, including interviews with people from the DC march.



Heartland Institute's misinformation campaign into schools

Posted on 21 April 2017 by John Cook &

Last month, the Heartland Institute sent a climate denial booklet to 25,000 teachers around the US. In Episode 8 of the Evidence Squared podcast, we look at the why and how of this book. What is the chief motivation for the book’s misinformation and what are the techniques they employ to cast doubt on climate science?

Follow Evidence Squared on iTunesFacebookTwitterYouTube and Soundcloud.



New podcast Evidence Squared by John Cook & Peter Jacobs

Posted on 29 March 2017 by John Cook &

Since arriving in the US two months ago, I've been developing a podcast with Peter Jacobs, a PhD student studying paleoclimate at George Mason University. While there are a number of podcasts about climate change, there were no podcasts about the science of science communication, how to talk about climate change. Today, we've launched our podcast, Evidence Squared.

You can check us out on iTunes and listen to our first four episodes (more on those in a moment). Be sure to subscribe and rate us



What do gorilla suits and blowfish fallacies have to do with climate change?

Posted on 10 February 2017 by John Cook &

The ConversationThis article was originally published on The Conversation. Read the original article.

A famous psychology experiment instructed participants to watch a short video, counting the number of times players in white shirts passed the ball. If you haven’t seen it before, I encourage you to give the following short video your full attention and follow the instructions:


At the end, participants discovered the point of the video when asked if they had observed the gorilla walking through the players. Half the participants didn’t notice the gorilla at all. The lesson? When we laser-focus on specific details (like players in white shirts), we can miss the gorilla in the room.

What does this have to do with climate change? I’m a cognitive psychologist interested in better understanding and countering the techniques used to distort the science of climate change. I’ve found that understanding why some people reject climate science offers insight into how they deny science. By better understanding the techniques employed, you can counter misinformation more effectively.

Every movement that has rejected a scientific consensus, whether it be on evolution, climate change or the link between smoking and cancer, exhibits the same five characteristics of science denial (concisely summarized by the acronym FLICC). These are fake experts, logical fallacies, impossible expectations, cherry picking and conspiracy theories. When someone wants to cast doubt on a scientific finding, FLICC is an integral part of the misinformation toolbox.

The five characteristics of science denial. Skeptical Science, CC BY-ND



Skeptical Science at AGU 2016 - a recap

Posted on 26 December 2016 by BaerbelW & John Cook

This year's Fall Meeting of the American Geophysical Union (AGU) has come and gone and quite a lot happened during the week from Dec. 12 to 16. As mentioned in our earlier post, several SkS teammembers were actively involved with giving talks and/or presenting posters while others were there to take it all in as was the case for me with attending AGU for the very first time.

This post is a (long) recap divided into the following sections:

SkS presentations

Denial101x featured in a poster session

Rally to stand up for Science

ERL's 10th anniversary reception

NCSE Friend of the Planet awards

Interviewing Stephan Lewandowsky

Further Reading


Some impressions from AGU 2016 (photos: Baerbel Winkler)

SkS presentations

John Cook presented a talk A Brief History of Consensus (PPT 6.8Mb), outlining the misinformation campaign against consensus, the studies quantifying the level of scientific agreement and how to neutralise misinformation.

Dana Nuccitelli presented a talk on climate model accuracy – comparing past global temperature projections to observations, and effectively debunking associated myths.  The model-data comparisons can be seen in the video below.



Skeptical Science at AGU 2016

Posted on 11 December 2016 by John Cook &

Next week is going to be an exciting and busy period for Skeptical Science. Several of us will be presenting talks and posters at this week's AGU 2016 Fall Meeting.


John Cook and Dana Nuccitelli will each be presenting talks in a Monday morning session on climate literacy (session ED12A in Moscone South, room 307). This session will also feature Naomi Oreskes, Richard Alley, Mark Jacobson, Peter Sinclair, Stephan Lewandowsky and Alan Robock - not to be missed!)

John Cook will be presenting a poster about our Denial101x MOOC  in a poster session on science communication through curricula (ED13A-0923) on Monday afternoon. You can check out the poster below (full PDF 28Mb):

Sarah Green (who happens to cameo in John Cook's poster shown above, sporting a very fashionable jacket!) is also presenting a poster Monday afternoon:



Trump or NASA – who's really politicising climate science?

Posted on 25 November 2016 by John Cook &

This article was originally published on The Conversation. Read the original article.The Conversation

Climate research conducted at NASA had been “heavily politicised”, said Robert Walker, a senior adviser to US President-elect Donald Trump.

This has led him to recommend stripping funding for climate research at NASA.

Walker’s claim comes with a great deal of irony. Over the past few decades, climate science has indeed become heavily politicised. But it is ideological partisans cut from the same cloth as Walker who engineered such a polarised situation.

Believe it or not, climate change used to be a bipartisan issue. In 1988, Republican George H.W. Bush pledged to “fight the greenhouse effect with the White House effect”.

Since those idealistic days when conservatives and liberals marched hand-in-hand towards a safer climate future, the level of public discourse has deteriorated.

Surveys of the US public over the past few decades show Democrats and Republicans growing further apart in their attitudes and beliefs about climate change.

For example, when asked whether most scientists agree on global warming, perceived consensus among Democrats has steadily increased over the last two decades. In contrast, perceived consensus among Republicans has been in stasis at around 50%.

Polarisation of perceived consensus among Republicans and Democrats. Dunlap et al. (2016)



Get It Here or via iBooks.

The Consensus Project Website



(free to republish)



The Scientific Guide to
Global Warming Skepticism

Smartphone Apps


© Copyright 2017 John Cook
Home | Links | Translations | About Us | Contact Us