Arguments
The 97% consensus on global warming
What the science says...
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97% of climate experts agree humans are causing global warming. |
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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 Oreskes, Peter Doran, William Anderegg, Bart Verheggen, Ed Maibach, J. 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.
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
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%.
Last updated on 8 May 2016 by BaerbelW. View Archives
Is there a consensus forming over the behaviour of Arctic sea in 2015?
If there is, what is it?
Bozzza,
Arctic sea ice is hard to predict. Current sea ice area is near record low. Most observers feel that April sea ice area is not predictive of September sea ice area. Last year there was one group that seemed to have a good model that predicted September sea ice area at the end of May, based on the number of melt ponds. Check back at the start of June and there might be better information. You should look at Neven's Arctic Sea Ice Blog for updates and discussion
Does anyone know why Cryosphere Today stopped updating April 12?
Michael,
It seems the CT hiatus is "caused by computer problems, and they hope to have them resolved this week." For alternative sea ice area data until the CT computers are fixed see:
http://forum.arctic-sea-ice.net/index.php/topic,1112.msg50809.html#msg50809
I was looking here for arctic sea ice data...
But that Neven site said some new near-real-time ice thickness maps had just recently been made available from here.
So I guess we'll be talking about 3 metre ice thickness a fair bit from now on... I mean, the trajectory of the 2015 Arctic sea ice as of April 27 looks somewhat interesting. [/understatement mode]
Multi-year ice: I saw something today somewhere on multiyear-ice from 2000- 2009 that looked frightening but is there information on multi-year ice after this? (In the Arctic that is of course!!)
What happened circa 2007- 2008 I wonder?
We seem to wandering rapidly off topic? Perhaps this is a more appropriate location to continue this conversation?
http://www.skepticalscience.com/Has-Arctic-sea-ice-recovered.htm
I think your graphic and other references to the “97%” needs to be changed to emphasize that that figure represents climate scientists who opined on human warming in papers that were included in the study. Otherwise it incorrectly implies that 97% of ALL scientists are included. (Your graphic states this but not prominently.)
Wakeup - The 97% is the percentage of published peer reviewed papers. The actual number of climate scientists supporting the consensus is around 80%.
I should add that the 20% that do not admit to supporting the consensus are not automatically in opposition to it. Some have reservations about some issues and are by no means on the science deniers’ side.
Bozzza
The consensus vis-à-vis the Arctic is that the trend still shows that the ice pack will continue to disappear over time.
2007 was (and still is for those who do not realize that 2012 smoked 2007’s ass and they should now be using 2012 instead of 2007 to con the gullible) the year that some tried to use to peddle the BS that the Arctic ice pack had, or was, recovered.
The consensus that was never there
http://www.mysanantonio.com/opinion/commentary/article/Consensus-on-climate-change-causes-a-myth-6295631.php
97% never did agree, just a myth, http://wattsupwiththat.com/2013/11/20/the-97-consensus-myth-busted-by-a-real-survey/
http://patriotpost.us/articles/28035
http://hockeyschtick.blogspot.com/2010/08/97-consensus-is-only-76-self-selected.html
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Truthdetector, the quality of your sources is duly noted, as is that of your argument. Of course, what little substantive content is in these links has long been addressed, in this thread and others. Readers interested in reality will do their own digging and find out the truthiness of it all.
TD - Repeating foolishness over and over does not improve its quality.
Quite frankly, I find repetetive attacks on consensus, not to mention specific papers or scientists, to be indicators of their quality and veracity - the number of complaints in the denier blogosphere appear to be directly related to how clearly and effectively they demonstrate the actual science that debunks climate denial.
Which 'TruthDetector' has just demonstrated once again.
TruthDetector: For detailed, factual rebuttals to all your linked complaints about the consensus, you should actually read the original post at the top of this thread, including all three tabbed panes--Basic, Intermediate, and Advanced. Then enter the word consensus in the Search field at the top left of the page to find other even more detailed posts that are relevant.
TruthDetector... If there genuinely is no concensus on AGW then it should be quite easy for someone to read a sampling of research and show that there is a high degree of disagreement in the research.
Why has no one produced such a piece of research yet?
Truthdetector,
I notice that the American Academy of Science and the Royal Society (and other national academies) refer to the 97% consensus. Why would these prestigious organizations of scientists refer to the consensus if it did not exist? By refering to the consensus, they validate it.
There is a popular survey being shown around saying that only 52% of meteorologists accept man-made gobal warming (a simple internet search will bring you there). I was talking to a "skeptic" and he pointed to this survey in response to my facts supporting the 97% consensus. He said that meteorologists are relevant to global warming and are a subset of climatologists.
So are they in fact relevant? And is the survey reliable?
anticorcob6... If I'm not mistaken, climatology would be a subclass of meteorology. Meteorology is the study of weather and the atmosphere, where climatology is a specific area of this related to weather over long periods of time. Thus, climate is an area of specialization within meteorology. A climatologist is also a meteorologist, but a meteorologist is not necessarily a climatologist.
I've seen the study that your "skeptic" is talking about and, if I remember correctly, the point of the study is regarding how to raise the level of understanding about climate change within the full ranks of meteorologists.
anticornco6-
"only 52% of meteorologists accept man-made gobal warming"
As worded, that is not a true statement from the survey. It was a very detailed survey with several categories and many possible responses.
Actually, for all respondents to the survey (meteorologists of all disciplines), 73% said humans were "at least partially responsible for global warming." For publishing climate scientists, the survey showed 93% agreed with that statement.
Even more telling, only 5% of all respondents to the survey said global warming was mostly natural.
The authors also acknowledged that because they framed the question with regard to human influence on climate change over the last 150 years, instead of the IPCC mid 20th century time frame, it may have biased their results, stating:
"Six respondents sent e-mails to notify us that their answers would have been different if we had asked about the most recent 50-yr time frame rather than the 150-yr time frame; the time frame used in the question may have also influenced other respondents. Our results therefore may represent a more conservative estimate of the consensus on global warming than would have been obtained had we asked about a 50-yr time frame."
Based on this, I think it's fair to say that "skeptic" you refer to was not at all accurate.
http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-13-00091.1
rkrolph @394.
The URL you provide to the pdf of Stenhouse et al. (2014) 'Meteorologists views about global warming: a survey of American Meteorological Society Professional Members' lacks the papers abstract (& a clickable link to the supplimnatary material for those interested in the detail fo their regression analysis). Abstract (& clickable link) is available with the full article here.
Rob @ 693:
I would tend to call meteorology and climatology as two overlapping subsets of atmospheric science. Climatology places a lot of emphasis on certain prtions of physics that are less important for meteorology - radiation being an example. Some factors do not have a great effect on day-to-day changes (meteorology), but can have significant effect on long-term variation.
Many meteorologists seem to think that climatology is a subset of meteorology, but then they also tend to think of climatology as "statistics applied to meteorology" (which it isn't).
An interesting historical outlook (historical now, not so historical when I first read it in 1985) is:
The abstract says:
Skeptical Science:
Thank you for this. I would also count myself among those who agree that climate change is impacted by human activities. But can you please consider changing your summary of it to more accurately reflect what the study's abstract says? Firstly, this is not a poll of scientists, but a poll of published scientific papers (so there is probably a lot of representation from a handful of prolific scientists). Also, it says that "66.4% of abstracts expressed no position", and 97% of the abstracts that expressed a position endorsed AGW. In total, only 33% of all abstracts (not scientists) explicitly endorsed AGW. Furthermore, there is often a bias against null findings in any field, which encourages "exciting" results to be published while null findings (especially unpopular opinions) may be suppressed by peer reviewers, journal editors, or lack of funding. So really, if you want to rephrase it, it should say "97% of published abstracts that stated a position on AGW agreed with it".
britty5096 - Keep in mind that "unpopular opinions" are absolutely not "null results", but rather the very points that will be noted, especially if they are supported by the evidence.
And the survey (not poll) of abstracts shows very very few items expressing the 'skeptical' "unpopular opinions", and almost none (personally, I can't think of any) that have held up to scrutiny against the evidence.
britty5096... Are you looking at the correct tab? The advanced tab specifically states that it's a survey of research papers.
Interesting that you emphasise the 97% agreement of those expressing a clear view. On the surface this sounds convincing, however when questioned 37% of authors in the sample either did not present a view/ were undecided or rejected the idea of human produced climate change. Even in this, a paper that claims to show consensus, there is a large proportion of climate scientists who are not actively supporting the hypothesis.
[JH] Please document the source of your assertions. Thank you.