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

The 97% consensus on global warming

What the science says...

Select a level... Basic Intermediate Advanced

97% of climate experts agree humans are causing global warming.

Climate Myth...

There is no consensus
The Petition Project features over 31,000 scientists signing the petition stating "There is no convincing scientific evidence that human release of carbon dioxide will, in the forseeable future, cause catastrophic heating of the Earth's atmosphere ...". (Petition Project)

Science achieves a consensus when scientists stop arguing.  When a question is first asked – like ‘what would happen if we put a load more CO2 in the atmosphere?’ – there may be many hypotheses about cause and effect. Over a period of time, each idea is tested and retested – the processes of the scientific method – because all scientists know that reputation and kudos go to those who find the right answer (and everyone else becomes an irrelevant footnote in the history of science).  Nearly all hypotheses will fall by the wayside during this testing period, because only one is going to answer the question properly, without leaving all kinds of odd dangling bits that don’t quite add up. Bad theories are usually rather untidy.

But the testing period must come to an end. Gradually, the focus of investigation narrows down to those avenues that continue to make sense, that still add up, and quite often a good theory will reveal additional answers, or make powerful predictions, that add substance to the theory.

So a consensus in science is different from a political one. There is no vote. Scientists just give up arguing because the sheer weight of consistent evidence is too compelling, the tide too strong to swim against any longer. Scientists change their minds on the basis of the evidence, and a consensus emerges over time. Not only do scientists stop arguing, they also start relying on each other's work. All science depends on that which precedes it, and when one scientist builds on the work of another, he acknowledges the work of others through citations. The work that forms the foundation of climate change science is cited with great frequency by many other scientists, demonstrating that the theory is widely accepted - and relied upon.

In the scientific field of climate studies – which is informed by many different disciplines – the consensus is demonstrated by the number of scientists who have stopped arguing about what is causing climate change – and that’s nearly all of them.

Authors of seven climate consensus studies — including Naomi OreskesPeter DoranWilliam AndereggBart VerheggenEd MaibachJ. Stuart Carlton, and John Cook — co-authored a paper that should settle this question once and for all. The two key conclusions from the paper are:

1) Depending on exactly how you measure the expert consensus, it’s somewhere between 90% and 100% that agree humans are responsible for climate change, with most of our studies finding 97% consensus among publishing climate scientists.

2) The greater the climate expertise among those surveyed, the higher the consensus on human-caused global warming.

consensus studies

Expert consensus results on the question of human-caused global warming among the previous studies published by the co-authors of Cook et al. (2016). Illustration: John Cook.  Available on the SkS Graphics page

consensus vs expertise

Scientific consensus on human-caused global warming as compared to the expertise of the surveyed sample. There’s a strong correlation between consensus and climate science expertise. Illustration: John Cook. Available on the SkS Graphics page

Expert consensus is a powerful thing. People know we don’t have the time or capacity to learn about everything, and so we frequently defer to the conclusions of experts. It’s why we visit doctors when we’re ill. The same is true of climate change: most people defer to the expert consensus of climate scientists. Crucially, as we note in our paper:

Public perception of the scientific consensus has been found to be a gateway belief, affecting other climate beliefs and attitudes including policy support.

That’s why those who oppose taking action to curb climate change have engaged in a misinformation campaign to deny the existence of the expert consensus. They’ve been largely successful, as the public badly underestimate the expert consensus, in what we call the “consensus gap.” Only 16% of Americans realize that the consensus is above 90%.

Lead author John Cook explaining the team’s 2016 consensus paper.

Update July 2015:

Here is the relevant lecture-video from Denial101x - Making Sense of Climate Science Denial


Last updated on 8 May 2016 by BaerbelW . View Archives

Printable Version  |  Offline PDF Version  |  Link to this page

Related Arguments

Further reading

Further viewing

The "Climate Denial Crock of the Week" video series examines the list of "32,000 leading skeptical scientists."

Naomi Oreskes gives a thorough presentation of the development of our scientific understanding of anthropogenic global warming:


Many thanks to Joe Crouch for his efforts in tracking down scientific organizations endorsing the consensus as well as links to their public statements.


On 21 Jan 2012, we revised 'the skeptic argument' with a minor quote formatting correction.


Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  

Comments 801 to 802 out of 802:

  1. I have a few quotes from the article to comment on.

    "Science achieves a consensus when scientists stop arguing." But the arguing continues. When it stops you have orthodoxy and heretics.

    "But the testing period must come to an end." I suspect a lot of testing and improved model building is needed which should keep the testing going.

    "That’s why those who oppose taking action to curb climate change have engaged in a misinformation campaign to deny the existence of the expert consensus." Hey, that's quite a claim. Maybe they believe what they say?

    I don't have a fixed position yet on global warming. I have been looking at some of the scientists who aren't part of the consensus. I hope it's not considered dangerous to look at their views- do we get excommunicated for doing so? Whenever I mention any of the non conforming in other forums- the biggest comeback is that they're all on the take from the fossil fuel industries or they're just stupid. I don't really care who pays them and I'd hardly consider anyone with a Phd as stupid.

    Aside from the many non conforming scientists- I've found one interesting guy, Alex Epstein, a philospher by training who has published his book on the subject, "The Moral Case for Fossil Fuels". I watched him debate Bill McKibben back in 2014. It's on YouTube. I think he held his own in that debate. I don't think it's fair to instantly dismiss such thinkers. He admits upfront that he's had connections with that industry- so no need to point that out. He has a very interesting perspective- worth looking at, even by those convinced of the existential threat of climate change. It doesn't hurt to see what the opposition is up to. I found his book so interesting I'd like to get a discussion going on this forum, if that's possible- but it probably isn't.


    [PS] This thread is for discussion of consensus studies. Please take any discussion of a moral case for fossil fuels to the weekly roundup thread.

  2. JoeZ @801 ,

    Yes, there are "scientists who aren't part of the consensus" ~ but there are hardly any climate scientists who would fit in that category.   That is why the Consensus is only 99+% , not absolutely 100%  .   Far worse for your unstated position, JoeZ, those very few scientists had all produced hypotheses which have been thoroughly disproven (see Svensmark, Lindzen) . . . and worse again, they contain a high percentage of religious crackpots who are not strictly scientific in their mode of thinking.

    Are they "stupid"?   Well, stupid is a rather elastic term.   I myself know a fellow who has a PhD and spent decades in scientific research [but not in climate-related matters] and yet he is a member of the local Flat Earth Society.  Unsurprisingly, he is also in denial about global warming.

    Is he stupid?  He is pleasant, sociable, and intelligent ~ but that doesn't stop him from being quite wrong about important issues.   Just like Lindzen & his comrades who are over-influenced by irrational religious beliefs or extremist political beliefs.   They put their ego ahead of scientific thinking.

    Also rather like your Mr Alex Epstein (who is an author, not a philosopher) who chooses to write a book, not submitting his ideas to the point-by-point criticism which would occur in the process of peer-review in a scientific paper.   JoeZ, it is easy to write a book and have your unbalanced rhetoric sweep your ill-informed readers into a state of intellectual submission & adulation . . . just as it is easy to make a "documentary" film about a subject [ here, "The Great Global Warming Swindle" comes to mind ] where severely-doctored graphs and fallacious logic are employed.  The general reading/viewing public are not to know how fake it all is, unless they take the trouble to apply critical thinking and to educate themselves on the basics of the issue.

    In the end, JoeZ , it all comes down to evidence.   And evidence is the thing lacking in the positions taken by those "non-consensus" scientists.  The climate consensus exists because of the climate evidence.   

Prev  1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  

Post a Comment

Political, off-topic or ad hominem comments will be deleted. Comments Policy...

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

Link to this page

The Consensus Project Website


(free to republish)

© Copyright 2019 John Cook
Home | Links | Translations | About Us | Privacy | Contact Us