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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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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:

Acknowledgements

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

Update

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

Comments

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Comments 801 to 843 out of 843:

  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.

    Response:

    [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.   

  3. Please forgive me if this sub-issue has been covered already... I read the first few pages where it was being discussed without resolution, and in the last few pages it is not mentioned.

    But what exactly is "the consensus"?  That the AGW hypothesis is true and it will have increasing implications on global weather patterns?  Or that there it is a catastrophic situation and human must immediately and completely restructure our social and economic systems if the species is to survive?

    In some of the arguments I've read so far, the believers seemed to be defending the former, and the skeptics were challenging the latter.

    In the previous post (sorry, I don't know how to do that thing that references it yet) Eclectic seemed to criticize anti-AGW propaganda films masquerading as information, yet the same critiques could be made of the propaganda films from the other side, like Gore and DiCapprio's popular films, full of dramatic music and hyperbole.

    I find it surprising that any intelligent and well meaning people still take the position that AGW is a complete hoax, but there is certainly a huge space for reasonable debate on the costs and risks of various strategies to reduce it or mitigate the damage.

    Furthermore, I suggest it is the fact that so many people are taking a rather extreme alarmist position (if we don't do something radical in the next xyz years, we're doomed!) that make many other people rebel, and say obviously that's ridiculous, I think you're making the whole thing up.

    It really is a thorny problem, considering the vast number of people now coming out of poverty, and having access to electricity and other technologies for the first time.  And I see no recognition of the logarithmic nature of the greenhouse effect, which makes the political problems almost insurmountable.

  4. Cstrouss;

    There are different measures of the consensus but Cook et al used the IPCC reports.  Since these are scientific reports that have been accepted line by line by all nations in the world they are a god pace to start.  Many people feel that they are too conservative but deniers say scientists are all alarmists.

    The most recent IPCC report says that we have only 12 years from January 1, 2018 to reduce emissions to zero if we want to limit waring to 1.5C.  For that we have a 66% chance of keeping warming less than 1.5C.  Already we have severe heat waves: over 75,000 hospitalized in Japan alone.  Half of the Great Barrior reef is dead.  Unprecedented floods in the US this year have seriously lowered food production.  If we succeed, little action has been taken as yet, we still have a 33% chance of greater than 1.5C.  

    10 years ago I wondered if I would see the effects of climate change in my lifetime (I am currently 60).  Now we see terrible floods and heatwaves.  Houses and towns are flooded by record rainfall and affected by sea level rise.  Many migrants coming to the US are fleeing AGW caused drought. Gore underestimated the problems in his movie.  The changes currently at 1C are dramatic.  How bad do they have to get before you become concerned?

    Watch some of Greta Thunbergs talks on line.  She speaks clearly about the science and does not pull punches.  As she says, this is an emergency and shoud be treated as such.

    Your suggestion that there are two sides is inaccurate.  One side is what people who have studied climate for 100 years have learned and the other is what fossil fuel executives tell you.  One side only cares about what will happen to their chilldren and the other only cares about their bonus this quarter.  Who do you trust?

  5. Michael:  Seriously, you're pointing to a 16 year old Swedish actress as a source of information?  Why not that kid from Titanic?  He made a movie about climate, too.

    I've actually answered my own question now, as I'm learning to use this site, and you got the consensus very wrong. The "advanced" tab gives the actual proposition: "Surveys of the peer-reviewed scientific literature and the opinions of experts consistently show a 97–98% consensus that humans are causing global warming." 


    Most of the IPCC signatories don't even agree with the entire report.  So the IPCC report is not the consensus.

    Also, it's wrong to suggest that everyone who isn't a full bore alarmist is an oil industry shill. If it's all about bias, let's not forget that Gore became extremely wealthy with his "post-carbon" portfolio, but his profit motive does not invalidate his arguments. 

    As far as an indisputable expert who I think is reasonably unbiased and presents a non-alarmist position, my first thought would be to point to Cliff Mass at University of Washington.

     So then there are deeper questions... What can realistically be done to slow or mitigate AGW, given the global political implications, the millions of people rising out of poverty, and the logarithmic nature of the greenhouse effect.. but that is not the topic for this thread.

    The consensus being discussed in this thread is clear... AGW exists, which is a rather trivial conclusion... so I will search elsewhere on the site to see if anyone is diving into the more complicated and practical issues.

  6. Cstrouss , you give the strong impression you are not really interested in the climate science or the scientific consensus.

    Are you interested in the consensus of the world's leading economists — which is that the cost of not  taking action against AGW is far, far higher than the cost of phasing-in "renewables" to replace fossil-fuels.

    It is grossly alarmist to represent that "renewables" change-over as the immediate and complete restructure of our social and economic systems . . . don't you think ?

  7. Eclectic, I'm 100% in favor of conservation and a change-over to renewables as they become more economically feasible... more importantly I advocate serious investment in research to hasten that process.  That is not an issue.

    The issue is radical transformations that have been proposed like "the Green New Deal," which would have a devastating effect on low income people like myself, who will not be able to afford used electric vehicles for another decade or two.  And it would have ZERO direct affect on AGW, given the logarithmic nature of the greenhouse affect and the number of people receiving electrification for the first time.

    So I think it is important to view it as a long-term issue, that will necessarily involve innovation and mitigation of climate changes that cannot be avoided.

    But as I said, that is all off-topic for this thread.  This is about the consensus that AGW exists, not about the magnitude or solutions.

  8. Cstrouss , 

    the scientific consensus is about the science, not the political response required.

    The so-called Green New Deal which might "radically transform" the U.S. economy (in less than 12 years?!?! ) . . . is mere fanciful hyperbole.   Nor would it directly involve the other 95% of the world's population.

    Cstrouss, you are using the GND as a strawman (straw-woman??).   Please take a sensible look at the scientific facts — and the facts indicate that it would be foolish to delay the conversion to a renewables-based economy.  Is there any other conclusion to be drawn from the consensus?

    Cstrouss, if you have a point to make then please make it clearly and simply (and on another, more appropriate thread).

    No need for straw.

  9. cstrouss...

    "That the AGW hypothesis is true and it will have increasing implications on global weather patterns? Or that there it is a catastrophic situation and human must immediately and completely restructure our social and economic systems if the species is to survive?

    Why is this an either/or question? Can they not both be true?

    Think of climate change impacts as a sliding scale that vary based on our total emissions. Within a reasonable range of uncertainty, probably the best understood elements of AGW are the basics of radiative forcing and the response in global mean temperature. The concensus is that we'll likely see about 2.8°C of warming for each doubling of CO2 over preindustrial levels. I think almost every scientist working in the field would agree with that statement.

    We also know for certain, the more we push the system, the more damage we're ultimately going to see. Again, that's not a controversial statement for scientists.

    What you're doing, though, is running off into hyperbole. I don't think many scientists would agree that we must "...immediately and completely restructure our social and economic systems if the species is to survive." Our species is likely to survive whatever happens. We're extraordinarily adaptable. But, most of the natural world that we rely on to sustain 7+ billion people on the planet is not nearly as adaptable as we are.

    Therein lay the problem. Yes, if we continue to burn everything we can get dig out of the earth, most scientists will likely agree that would probably mean a total collapse of modern civilization. Lots of death, destruction and suffering.

    Can we avoid that? Yes, of course. We are going to see significant challenges and costs due to our emissions so far. We are already seeing very good signs of progress with the cost of wind and solar continuing to fall. But there are so many more challenges we're going to see.

    Nothing I'm saying here is controversial, and I believe this would all fall within the definition of the "scientific consensus on AGW." 

    Here's what should give you the most concern about all this: thermal inertia.

    I hope you agree that we are now seeing many of the impacts of climate change starting to emerge. Melting ice sheets, extreme weather events, heat waves, etc. Now, consider that there is a 30 year lag in the climate system since most of the heat goes into the world's oceans. That heat takes time to come into equilibrium with the land, ice and atmosphere. Thus the impacts we're seeing today are the result of where CO2 levels were some 30 years ago. 

    If we were to stop all carbon emissions tomorrow the planet would continue to warm through the middle of this century. If we're seeing impacts already you can bet your bottom dollar they're going to start getting a lot worse over the coming three decades. Best case scenario says we'll be able to bring emissions to zero by ~2050. That means continued warming through 2080 at a minimum.

    Also consider that, in the past at 450ppmv CO2 levels, there were no ice sheets on this planet. The planet was too warm to sustain them. It'll take another 1000 years to melt them entirely, but we're talking about sea levels rising to up to 70m over the coming centuries. That's a completely different planet than we currently live on. No Florida at all. It's gone. LA, SF, NYC, Tokyo, and 100's of other cities. All under water. 

    It's not the end of our species but replacing entire cities ain't gonna be cheap. The better investment is to reduce our carbon emissions as quickly as we can and keep CO2 levels as low as we possibly can. That's an enormous task. It's one that needs to happen fast.

    Again, none of this is controversial. Gore, DiCaprio and Thunberg are not scientists but they are doing their level best to help convey to the world what is overwhelmingly agreed in the scientific community.

  10. You know, I bet you might find this short video compelling. 

    Stephen Schneider montage.

  11. Cstrouss,

    It is too bad that you canot afford future electric cars.  According to this white paper put out by BNP Paribas (the eighth largest bank in the world) between 2020 and 2022 electric cars using renewable energy (wind and solar) will be by far the cheapest cars.  You will be spending more to pollute the air for the rest of us.

    You show your true colors when you call Greta Thunberg an actor.

    I can see where you are going.  Unfortunately, I do not have time for you today.  Good luck.

  12. This is a genuinely bizarre statement: "Most of the IPCC signatories don't even agree with the entire report. So the IPCC report is not the consensus."

    I'm very curious where you picked that up. 

  13. Eclectic wrote:

    >>> the scientific consensus is about the science, not the political response required. <<<

    Yes, and I'm trying to keep that distinction clear. The consensus is that there is a problem. And given the inherently geo-political nature of the problem, I have not yet seen a workable solution proposed, let alone any wide consensus on it. In fact I very rarely see mention of the logarithmic nature of the problem, which is what makes it so intractable.

    Is there another forum where those issues are discussed?

    >>> ... the facts indicate that it would be foolish to delay the conversion to a renewables-based economy. Is there any other conclusion to be drawn from the consensus? <<<

    Well again we have to be clear on what the consensus is. This thread is about documenting and quanitfying the consensus that AGW exists, not about its scope or the urgency of solutions. Some have asserted in the last few comments that the consensus is that the latest IPCC report is correct, which is a step in that direction, but there is no evidence presented for that or how wide the consensus may be.

    >>> Cstrouss, if you have a point to make then please make it clearly and simply (and on another, more appropriate thread). <<<

    I agree, my question has been answered... the consensus is that AGW exists, as indicated in the formal proposition in the header, and consistent with my other reading. I'm not the one continuing the discussion into separate issues, like the severity, urgency, and strategies.

    I wrote:

    "...That the AGW hypothesis is true... Or that there it is a catastrophic situation and humans must immediately... <<<

    Rob Honeycutt responded:

    >>> Why is this an either/or question? Can they not both be true? <<<

    They can both be true, but are they both the consensus? If the consensus includes the latter, could you present evidence of that?

    >>> What you're doing, though, is running off into hyperbole... <<<

    Yes, guilty, that one thing was a bit overboard. My point is that what is being proposed are some very radical solutions with no real return, unless you go with the idea that if the USA spends a great deal of money, the rest of the world, including much poorer and rapidly developing regions will follow. (I heard Sanders say something along those lines the other day.)

    But of course that gets far outside the domain of climate science. It is a matter for political science and psychology, and necessarily involves a tremendous amount of speculation.

    >>> Therein lay the problem. Yes, if we continue to burn everything we can get dig out of the earth, most scientists will likely agree that would probably mean a total collapse of modern civilization. Lots of death, destruction and suffering. <<<

    Now who is engaging in hyperbole? Are we digging everything we can out of the earth? And if so, who is proposing that we continue doing that? Is the collapse of civilization with continued CO2 emissions also part of the consensus? Documentation?

    >>> Can we avoid that? Yes, of course. We are going to see significant challenges and costs due to our emissions so far. We are already seeing very good signs of progress with the cost of wind and solar continuing to fall. But there are so many more challenges we're going to see. <<<

    Again, we agree on that. I think it is great for wealthy people in wealthy nations to voluntarily adopt more expensive alternative forms of energy. In fact all of my super affluent friends are already making great strides, except for their regular jet travel.

    And no doubt progress is being made on the technology, and the small-scale interim deployments have been helping to refine the tech.  I have two good friends who have been working as engineers on photovoltaic systems for at least 25 years. They tell me we can expect a lot of changes in the next 20 years.

    The issue is what to do with the less affluent population. Will I be left behind? And even though I'm in the lower end of income in the USA, I'm still in the upper end in the world. I can barely afford one tank of gas per month in my 20 year old compact car now.

    I know that places where large numbers of people are rising out of dire poverty for the first time, like areas in Asia and Africa, are on the ragged edge of affording energy in the first place. Even when alternatives are CLOSE to fossil fuel costs, that is a luxury they will not be able to afford. I'm sure you're aware of studies that show people will only sacrifice to improve their natural environment after a certain level of affluence is attained.

    I'm sure you'll agree that it will not address the problem if the richest 20% reduce their emissions by 50%, when a billion or two people are increasing their consumption a great deal from virtually zero. So any attempts to force those nations and people to reduce (instead of increase) their use of fossil fuels will only happen if those rich nations are willing to foot the bill for alternative electrification. Certainly it is technically feasible, and would make a lot of sense, since distributed solar is a more efficient way of building rural electrical systems than power plants and long wired grids, but I have not heard this level of financial assistance being proposed.

    >>> Nothing I'm saying here is controversial, and I believe this would all fall within the definition of the "scientific consensus on AGW." <<<

    Well now we're getting back on topic. Is that your opinion, or do you have studies to back it? This thread refers to several studies that document a strong consensus that AGW EXISTS. I have not scoured the whole thing, but I have not seen any evidence to quantify the consensus for stronger propositions. Certainly that would have to be considerably less than the approximately 97% which apparently accept the minimalist proposition.

    >>> Here's what should give you the most concern about all this: thermal inertia.... Best case scenario says we'll be able to bring emissions to zero by ~2050. That means continued warming through 2080 at a minimum. <<<

    Yes yes, I understand that. But I have not heard any suggestions on how global emissions could realistically go to zero by 2050.

    michael sweet wrote:

    >> It is too bad that you canot afford future electric cars. According to this white paper put out by BNP Paribas (the eighth largest bank in the world) between 2020 and 2022 electric cars using renewable energy (wind and solar) will be by far the cheapest cars. You will be spending more to pollute the air for the rest of us. <<<

    Wow, I'm really sorry I'm so poor I have to inconvenience rich people who can afford new cars. Thank you for the compassion and understanding for those less fortunate than yourself. And by the way, any solutions that do not address the issues of the less affluent masses will never happen.

    By the time a 2020 electric car is affordable for people like me who need simple, reliable 20 year old cars, I'll be dead. Also, given battery life issues, it isn't clear whether any 2020 models will still be serviceable when they are 20 years old.

    >>>... You show your true colors when you call Greta Thunberg an actor. <<<

    I tried to research her. Certainly her parents and grandfather are in show biz. I couldn't find much else about her, but I'm going to assume she is not a published climate scientist who did original research. She seems to be repeating what others have told her... in other words, a celebrity spokesperson, and not a source.

    Rob Honeycutt wrote:

    >>> This is a genuinely bizarre statement: "Most of the IPCC signatories don't even agree with the entire report. So the IPCC report is not the consensus."... I'm very curious where you picked that up. <<<

    Yeah, me too... I can't find it again now. I have seen interviews with signatories who were critical of how the process was segmented, and who very displeased with how the politicians tacked on a "summary for policymakers" that did not follow from the scientific parts of the report.

    And I've read letters from other sigantories who have clarified that they do not agree with all of the conclusions, which of course is inevitable, as you won't ever get 2500 people to agree with everything in a long document, or even 97% of them.

    But since I can't find my references at the moment, I'll retract it unless and until I can document it. Meanwhile, I think the burden of proof is on those who assert that the IPCC report does represent a community-wide consensus.

  14. Cstrouss ,

    I also have a 20-year-old car.  That's not a rare state of affairs.

    But I do not have the anger issues which you are displaying.   If you wish to go further in discussing the range of topics you are raising, then please [in accordance with SkS site posting rules] take each separate aspect to its own appropriate thread.

    The posting rules exist precisely for this purpose — to prevent every thread becoming a chaos of churning unresolving random shoot-em-ups by those without the mental discipline to clearly think through the individual aspects (which make up the "whole").

    But you may find that the Moderators give short shrift to those whose "shotgun pellets" land in a handful of threads simultaneously.   So please draw up your own mental list of matters which trouble or anger you — and select the most important one, and post that.   Once that one has had a reasonable airing [resolved to general satisfaction; or put aside as "agreeing to differ"] then move on to your "second priority" aspect . . . and so on.

    Clear thinking, without the obfuscations & rhetorical deceits & uninsightful semantic confusions . . . is more likely to bring you the satisfaction you are requiring.   Yes, there is the risk that you might find you have to change your current "beliefs" — but I would like to imagine you have the courage to put your intellect ahead of your ego.

    "Motivated Reasoning" is a danger to all of us . . . don't you think?

  15. cstrouss @813,

    While off-topic, this question to you may prove a route to bringing this on-topic.

    I note you mention repeatedly the "logaricmic nature of the greenhouse effect"  which you see as a factor poorly considered in tackling AGW.  "And I see no recognition of the logarithmic nature of the greenhouse effect, which makes the political problems almost insurmountable."

    The logarithmic relationship between CO2 concentrations and the resulting climate forcing isn't usually seen as causing an "almost insurmountable" problem for AGW mitigation so perhaps you could explain.

  16. cstrouss...

    "Now who is engaging in hyperbole? Are we digging everything we can out of the earth? And if so, who is proposing that we continue doing that? Is the collapse of civilization with continued CO2 emissions also part of the consensus? Documentation?"

    In truth, no, I don't think this is hyperbole since it's firmly based in the realm of possibilities. Human's have an enormous capacity for accomplishments on massive scales. As a species, we have the collective nuclear weapony sufficient to end all life on this planet, possibly permanently (or at least for coming many millions of years). Likewise, oil companies have identified reserves sufficient, were it all burned, to raise the surface temp of this planet to levels that would collapse civilization. And they're continuing to locate more.

    Will we nuke the planet? I hope not but it's not outside the realm of possibilities. In that, it's extremely important that nations of the world work together to manage this possibility.

    Will we burn all those reserves? I also hope we won't do that, but it's even more likely than nuclear armageddon, specifically because there is a massive financial incentive for those oil companies to put their sources of energy on the market.

    I'm a firm believer that the problem we face is a market failure: the failure to price the social costs of carbon emissions. If there were a price on carbon emissions then carbon-free sources of energy would be abundantly cheaper than carbon-based energy. There are a lot of very large companies and very wealthy, powerful people who prefer not to seen their sources of wealth conform to a levelized market. ...because they know they'll lose.

    If you want documentation on the impacts of high CO2 levels, I'll have to do some additional reasearch. It seems pretty clear that nearly all the expected effects of high CO2 will negatively affect agriculture. Increased rain intensity. Increased droughts. Desertification. Increase in pest species. There's a lot of research on this and I've even read a bunch of it. It would just take some time to pull together relevant research. I'm sure there are a number of good articles written here on SkS on the topic.

  17. "Well now we're getting back on topic. Is that your opinion, or do you have studies to back it? This thread refers to several studies that document a strong consensus that AGW EXISTS."

    That's been the subject matter of all the studies listed in the OP here. But perhaps you different expectations of what defines a consensus.

    Here's the way I think of it. Much of the human population doesn't have much of a grasp of what is going on with climate change. In the press this issue gets presented as a 50/50 possibility. Two sides arguing whether this is real or not. The point of all these research papers is merely to say, "Hello! Look here! Nearly all scientists agree this is real and that it presents a significant problem for our planet." I believe all of the 97% of working climate scientists out there would agree with that statement.

    The Cook 2013 paper (noted in the OP) specifically tested the notion that AGW exists but would have minimal effects. That position was very low, inclusive of the 3% of studies.

    If you're looking for something that specifically states how damaging AGW will be, I don't think you're going to find that. This is a question that (as Schneider states in that video) this is a systems problem with a wide range of potential outcomes based on both what we do and how the climate system responds. 

    As Yogi Berra said, "Predictions are hard, especially about the future."

    I don't think there are many scientists who would disagree with the idea that this might not be as bad as we expect. They'd also tell you that a very low probability. There's an equally low probability that this will turn out much, much worse that expected, and that's a very scary possibility on par with nuclear armageddon. The mid-range higher probability outcomes are already very bad if we don't get emissions down quickly. 

    Scientists, as I understand it, are not concerned much about the consensus. They're out there grappling with issues like quantifying the pace of ice sheet melt in Antarctica.

    It's real. It's bad. It's us. These are all accepted. The questions are: how bad? How fast is it happening? How quickly can we get to zero emissions?

  18. Robert S.  "Even in periods of end interglacial times, when temps would be expected to slowly cooling down, as you mentioned?"

    Is it a "period of end interglacial time"? Well it depends on what you think causes the glacial periods--if the mechanism isn't there, then it isn't going to happen. If you believe the Milankovitch cycles are what initiates the glacial/interglacial, then we are still a ways from another glacial period. So it is not inconceivable that the planet would experience a warming at this time.

    Then he wrote:
    "Even on that kind of time scale, a blink of an eye really?

    OK, but can you substantiate with references?"

    If you want to take issue with the idea that the planet has had warming similar to the recent warming on both the time scale and in magnitude, be my guest. It would be a losing battle. As for references, all one has to do is a little searching--this interglacial, the last glacial, the last interglacial, etc. It won't be too hard to find warming of this magnitude in this time scale." 

    Glacial and interglacials are caused by orbital patterns. That has been proven. Interglacials last around 15,000 years give or take some. 

    Response:

    [PS] I should just point out that you are responding to a comment from 2008. There are 17 pages of comments here.

  19. I think the whole problem I have with this alleged "scientific consensus" claim is the symantic gymnastics it is they engage in. To hear them talk, ALL scientists, or even ALL climate scientists, agree that climate change is happening and humans are responsible. However, and we'll use the Doran study in this example, we find out that actually isn't the case. If we analyze the Doran study and break it down, 10,257 earth scientists were asked to participate in an online survey. Of those, only 3,146 of those asked participated in the study. And, of those 3,146 earth scientists, 5% were climate scientists. That means some approximate 158 of them were climate scientists. Now, surely, there are more climate scientists than 158 and, there's certainly more earth scientists than 3,146 of them and, we can feel pretty confident that there's more scientists than the 10,257 that were asked to participate. So, that certainly isn't ALL scientists as we might be led, by illusion, into believing. Worldwide, I'd like somebody to tell me approximately how many scientists there are in total to qualify any claim that ALL scientists reach this consensus. I'm betting there's WAY more than 10,000, or 3,000 or, 158. So, where do they get off trying to present this illusion that ALL scientists have this consensus. Then, another article I read said that all articles where the abstracts endorse AGW. Well, if the abstract endorses AGW, of course the author is going to endorse AGW as AGW means Anthropogenic Global Warming. Why would they write an article about it if they don't endorse it? And, of course, these people have made it their academic career to be indoctrinated into the AGW camp. If anyone is looking for an objective opinion about AGW, they certainly don't go to someone who has been taught throughout their entire academic career that human kind is responsible for climate change.

  20. Rob Honeycutt:


    Unless you stop breathing, we'll never get to "zero emissions". Further, if you're suggesting that we're somehow going to stop the planet itself from producing emissions? That's not gonna happen. There's no such thing as "zero emissions".

  21. I've been lurking here at Skeptical Science and Real Climate since their inception.  One of the first things I learned was about the natural carbon cycle.  Put that part aside.  The emmissions being talked about are the ones created by fossil fuels.  That CO2 has a different signature from the natural CO2.

    https://skepticalscience.com/co2-increase-is-natural-not-human-caused.htm

    There is such a thing as zero emmissions.  You just have to learn what type is being talked about.

  22. CThompson @819 ,

    I'm sure that you would agree that "scientists" exist on a spectrum of climate expertise, ranging from extensive climate expertise (involving much research & publication in respected journals) . . . . across to those with almost zero knowledge of the complexities of climate-related science (e.g. the 19,000 scientists who signed the Oregon Petition two decades ago).

    Unsurprisingly, all surveys examining this point do indicate that the higher the climate expertise the higher the "mainstream" consensus percentage.

    CThompson, since you seem unhappy to countenance that point, then perhaps you should try coming at the consensus percentage, from quite the opposite direction :-   Identify the percentage of climate scientists who are outside the consensus.

    That would be much easier — since they are so few in number.   And there is an important second identification which you must make.   In order to cull out the undeserving (i.e. the crackpots, the nutcases, and the Gone-Emeritus types undeserving of your approbation) -— you must simultaneously identify the valid evidence which supports their "contrarian" views.

    #   Because if they don't have any valid evidence for their opinions, then they are not really countable as scientists.

    Shouldn't take you long at all !

  23. Unfortunately, CO2's effects on weather are overly exacerbated by scientists who haven't taken the time to study the behavior of matter in depth with respect to radiation. Until they stop talking about CO2 being responsible and move the conversation to H20, they're consensus doesn't mean anything. Study the matter before you make assumptions. CO2 is a miniscule GG compared to H20 and there's not enough of it to make a comparison at this point.

  24. *their, since i can't edit

  25. JBeez , please also edit/correct: "exacerbated".  If English is not your first language, then you can make a post in your Mother Tongue — but you may be slow to get replies.  There are a few posters who make their post that way; but they are usually wise enough to make an English subscript, even if it comes across a bit clumsily (still, readers are tolerant enough to make the best of it).

    If you wish to improve your knowledge of the relative efficacies of CO2 and H2O, then please make your post in an appropriate thread [not this thread].

    Look at the upper left corner of this page :- "MOST USED Climate Myths" . . . and (from more than 100 threads) choose the best fit.  You might care to select Myth 30 or Myth 36 , perhaps.  Read the Basic (and more Advanced versions) and also look through the 100's of comments (some trashy, some very informative).

    That will help you in getting up to speed, on the science of Greenhouse.  Starting from your base position, you may well need rather more than that.  But, it will be a good first step in understanding what the scientists are talking about.

  26. Hi all!

    First of all, thanks for this magnificent website, lots of interesting material and comments, but still a lot left to read and learn.

    Please, allow me to quickly introduce myself, I live in a place around 66 degrees north and I'd refer to myself as "sceptic", rather than "denier", although I've been labeled in many different ways just because of a different opinion. I would consider myself as some sort of "environmentalist" since I am aware of the planet I live since my young ages and I took care of my actions to preserve my environment as much as possible. Today, I work for a company closely related to environmentalism and I'm trying to teach my child to be aware of our planet, however, in a very different way than other kids of his age are doing every Friday on the street. I am not a scientist of any sort, but I do consider myself fairly smart, especially because I'm in love with scientific method of "question everything" since the same young age, and this is the reason I consider myself a sceptic nowadays, not only when the issue of climate change is in question.

    The same "question everything" method inspired me to register here and ask few questions. I hope that people here are more reasonable and doesn't look at other people's questions as some kind of trolling tactics, as it is happening more and more often in "social media" places. All my questions will be honest and without no bad intentions. They might be silly and "ignorant", but hey, I joined here to learn something new, so apologies in advance for any stupidity coming from my mouth :) Honestly, I am very confused at this point regarding climate discussion because of constant opposing statements, studies, conclusions, I hope I'll get some clarifications here.

    Now, in past 2-3 days, I'm reading a lot around here, especially "Climate Myths" section and all the comments around. Seems like there's lots of smart people here with lots of knowledge about the topic, but what I didn't see often (actually probably never) is someone who would leave an impression of "questioning everything". Why is that so? Especially if someone presents material from contrarian scientists which is trying to "question" the opposing statements. It looks to me like one side is not quite ready to have a debate, while the other one is desperate for it and to send a message which is constantly being silenced. This kind of behaviour is moving me away more and more from my currently shaky belief in climate change, no matter how crazy that sounds.

    I am very happy that I came across this website because it started to bring back some logical conclusions in my mind, but then, just today, I noticed 2 articles which again started forcing me not to take anything written here for granted.

    To make it more interesting, one of the articles is from Myles Allen himself. It's not that he is denying anything, but he is somewhat confirming that lots of people got some things wrong and jumped to wrong conclusions (https://theconversation.com/why-protesters-should-be-wary-of-12-years-to-climate-breakdown-rhetoric-115489). The other article talks about my other point about the debate, and it really sounds to me like lots of other scientists are silenced and no one cares about their opinion. How in the world is that possible in the "science" in the first place? (https://climatechangedispatch.com/500-scientists-no-climate-emergency/). So, I assume that my other question would be, what are your opinios on those 2 articles?

    Thanks for your time and for all the answers!

  27. Errata @826 [perhaps you will later change name to Corrigenda?  ;-)   ]

    the SkepticalScience website is primarily about the science, not "opinion".

    Science is advanced by research - and is published in reputable peer-reviewed journals.  Not every such scientific article is perfect; but en masse and over time the published science has a very good track record (in the "hard sciences" that is ~ not so much in the "medical" or "psychological sciences".)

    That is why opinion is next to worthless ~ except where it is based on real science.

    And that is why opinion-fests such as the ones you mention ~ '12-years-to-climate breakdown' ; and '500-scientists-no-climate-emergency' ~ have little or no relevance to the important questions regarding the recent rapid warming of the physical world.

    The thread here about consensus is really just an indirect way of examining the mainstream climate science.  As I mentioned in my post #822 [above] . . . there are hardly any "climate-skeptical" scientists remaining.  Forty years ago, there was space for scientists to be skeptical about AGW ~ but the current state of "overwhelming consilient evidence" is so clear-cut that "contrarians" have nothing left apart from empty rhetoric to support their so-called position/positions.

    How and why . . . can you yourself benefit your scientific understanding, by spending time on the two rather political opinion-fests you cited?   This website [ "SkS" ] does have a weekly events section, where opinions can be expressed on more sociological aspects of AGW, if that's what you're wishing.  (But that's not really related to this thread's consensus topic. )

    And you'll find that the "500" scientists are talking a great deal of unscientific nonsense (their Motivated Reasoning comes from extremist political positions and from extremist religious positions . . . and they still  don't have any actual evidence to back themselves up ! ).

  28. ERRATA @826,

    I would disagree with Eclectis @827 in that the Myles Allen OP is correctly explaining why the simplistic message “the Intergovernmental Panel on Climate Change (IPCC) says we have 12 years” is being used unscientifically.

    However I would entirely agree with Eclectic @827 that the letter from  "500 prominent scientists" is entirely non-scientific nonsense.

     

    The message from Myles Allen is that this 12 years concerns the time it takes before potentially we hit the +1.5°C of global warming. The adoption of +1.5°C at the COP21 meeting in Paris in 2018 was a wake-up call to global governments from science and it does show that we were potentially 12 years away from breaching that limit although a more likely timing would have been 22 years. Yet the significance of the SR15 report failed to spur governments globally into appropriate action. The wake-up call was given but the world hit the snooze button, again.

    Mind I was using a 12 year message even before SR15. My own version of a 12 year message would be that, at current levels of emissions, we had 12 years' worth of CO2 emissions to play with. That was emissions limits set out against a +1.5°C limit within  the 2013 IPCC AR5 Synthesis Report. (The limit of 550Gt(CO2) from 2011 is buried away in Table 2.2 which represents 14 years of CO2 emissions from 2011.) And note we are now halfway through that 12 years' worth of emissions.

    The IPCC message has always relied on politicians picking up on the dry scientific message that we are stuffing the planet's climate. Emissions targets are watered down and hidden away in documents because many politicians are unable to cope with that reality. Although the messages of the Climate Emergency movements are often less than scientific, if they convinces the world that we do have an emergency on our hands, I for one am not bothered that there is a scientific problem with the message.

     

    And then there is the letter from the usual set of denialists.

    They misrepresent thmselves. They are not "a global network of more than 500 knowledgeable and experienced scientists and professionals in climate and related fields." (At least, when they were 400  "independent Climate Scientists and Professionals" almost all were not "knowledgeable and experienced scientists and professionals in climate and related fields.") They make six unsupported assertions, none of which stand up to scrutiny. If you feel any of their bold claims deserve more than this summary dismissal, do say.

  29. My apologies to MA Rodger.  I was overly brief in my comment above ~ I meant that the sort of "discussions" usually following on the tail of the "12 years" statement (wherever it gains headlines) . . . are discussions/posts which turn into an opinion-fest.

    The statements by author Myles Allen were very calm and reasonably objective, and illustrate how very little time we have to get things on the right path.  The exact amount of time & tonnage of burnt carbon we can "afford" is, of course, rather fuzzy ~ as is the 1.5C figure itself.  It's a reasonable best estimate . . . and we shouldn't let rhetoric (by denialist propagandists) conceal the unpleasant reality of it all.

    The comments following the Myles Allen OP were fairly civil, but slid off into an opinion-fest.  But it was extraordinary to see that the comments were not bombarded by avalanches of bots & intellectually-insane trolls & rabid political extremists & CO2-physics-denying crackpots.  It's almost as though a sensible moderation policy was in full effect !

    OTOH, there's no getting away from the conclusion that "the 500 scientists" was an example of scientific nonsense & false/misleading propaganda . . . so typical of anything involving the hand of "the error-prone Lord Monckton".  Or anything involving the hand of the Heartand Institute or the GWPF or their ilk.  Nothing new, there.

  30. Hi again and thanks a lot for all the answers and links, I extremely appreciate it!
    Unfortunately, I didn't go through all the links and I didn't read a lot since it's a bit late and I'm dead tired and have to wake up early for work. I definitely will read it as soon as I catch some time, but I'll take some time to at least put my thoughts here, hope that you'll feed me with more material so I won't have a chance to be bored tomorrow :)

    First, about the "500 scientist" paper. To be honest, I didn't recognize a single name from people signed there, I'm still fairly new in this whole topic, and I recognize just some names from IPCC, however, before sharing links with you here, I did a bit of a homework and tried to look up names from "500 scientist" letter and the very first name on the list (Professor Guus Berkhout) already did arise some suspicion ((...) once worked in the oil and gas industry and became a respected professor after that. Berkhout started his career working for Shell. — Wikipedia). But digging deeper and deeper, I came across the thing which I really don't like (from any side) - articles which "prove" that some of the conclusions of non-deniers (how do we call them anyways?) were driven by money, greed, political or personal agenda. I don't have links now, but I'll give my best to share them eventually with you. This I find extremely disturbing, because whenever I come across such article/statement, my personal conclusions just fall apart and divert me from logical thinking (I suppose that's the whole point of those in the end). I simply cannot believe that people who we call "scientist" are able to degrade them to such a low level to try to discredit others by silencing them or by using silly "arguments" like pointing out their work history. Both of you (MA Rodger and Eclectic) concluded your comments by completely discrediting their letter. This is exactly what I tried to point out in my previous comment — there is no "questioning" whatsoever. How so? Are you saying that everything stated there is 100% incorrect (well, some of the statements sounds dumb even to me tbh)?
    I tried to look up a bit about Lord Mockton and GWPF, but I'm really tired now and will try to continue with that tomorrow. What I found interesting in that letter what the sentence in the first paragraph on second page - Climate science should be less political, while climate policies should be more scientific. It really might be just a propaganda trick, but that sounds honest to me in some way, and I don't understand why non-deniers sit with them and give them a chance to talk (or did this happen already in the past)?

    About Myles Allen's message... I didn't even notice the comment section, might go through it tomorrow a bit, although I tend to avoid such things just because of mentioned "opinion-fest". But his article somewhat triggered my skepticism again. The first time, it was this particular article which I still cannot explain to myself whether is it true or not?
    (Just a quick digression, while searching for this one, I came across this link in comments section. Is this really true?)

    Anyways, to cut my story short and get to some direct questions, looking forward for your answers!

    @MA Rodger:
    I might be wrong, but you sound a bit more pessimistic than others? Are you saying that in last couple of years there is almost no progress in cutting down emissions, because I personally believe that western world is really giving its best (well, to some extent) to do so.

    To any of you:
    As I said, you discredited completely the "500 scientists" letter with labelling it "unscientific nonsense", "extremist political/religious positions", stating that "they still don't have any actual evidence", "unsupported assertions, none of which stand up to scrutiny", etc. Now, pardon my ignorance, but I personally didn't get and impression that this is politically/religiously motivated and also that there might be "scrutiny material" there (e.g. "Warming is far slower than predicted" or "Climate policy relies on inadequate models"). On the other hand, current "solutions" to climate change problem (e.g. "Green New Deal" or "Climate Strike") have hidden political agendas all over the place (even SR15 report, which I didn't read yet, has a part "efforts to eradicate poverty" in the title description. I still cannot understand what "getting rid of poverty" or has to do with climate change, this sounds very political to me).

    And finally, maybe a bit off topic here, but the thing which is bothering me for some time now is, how comes that no one in this climate change topic is mentioning SOx or NOx emissions? To my understanding (again, pardon my ignorance), those are directly contributing to GHG chemical reactions and we don't have enough knowledge of direct impact on climate, however, they are massively emitted from cargo ships which still make more than 90% of world's transport.

    Thanks again for your time and effort, apologies for any errors/typos and general stupidity, it's getting pretty late now, I should avoid commenting at this hour :)

  31. Errata @830 ,

    no, those "500 scientists" are not fully 100%  wrong.  But if they were an aeroplane . . . then they'd be so far from flightworthy, that no engineer would let them out of the hangar ~ for fear that they'd crash just moving along the taxiing strip.

    In less humorous terms: the "500" letter is so error riddled, that it would take a large number of paragraphs to detail it all.  Not just errors, but deceptive rhetoric.

    Politics :- as of those extremists who think that all the world's scientists are in a century-long plot/conspiracy to impose a communist world government, and are faking all the data to that end.

    Religion :- as of those extremists who think that the Christian Deity is/will step in to correct any significant global warming.   And Prof Lindzen who takes an [Old Testament] view that Jehovah won't allow more than slight warming (at least, that was his view during a 2006? interview with a sympathetic interviewer ~ and I haven't detected any change since.)

    All these guys are intelligent (though the vast majority do not research or publish in the climate field) and all are so strongly influenced by Motivated Reasoning (political/religious) that they end up producing nonsense.

    Errata, if you are not inclined to some hours of heavy reading at websites like NASA, AAAS, U.K. Royal Society, etc . . . . then you might enjoy some youtube videos by Potholer54 (science journalist) on climate matters.  He debunks a lot of the common myths which have been circulating.

    Potholer54 is polite & amusing [ how refreshing ! ].

    You will be especially amused by his 5 short videos exposing the "Monckton Bunkum" mendacities of Lord Monckton (who is a sort of pop star among denialists . . . denialists who fawn on him, especially at WattsUpWithThat website.)

    The partisan "Green New Deal" is just local American politics, and is not a consequence (or reflection) of genuine climate science.  Best to first understand real climate science: and only then give thought to remediation of the AGW situation.

  32. ERRATA @830,

    A quick response to your specific enquiry regarding our global carbon emissions. You suggest that I talk of "almost no progress in cutting down emissions."

    With or without AGW, the emissions from our use of fossil fuel is ever being lessened by the pursuit of fuel efficiency measures. There is also the drive towards renewable power sources which is obviously driven by a desire to combat AGW. Folk can point to the UK where we have reduced our carbon emissions to well below the 1990 levels (I hear the denialists talk of UK carbon emissions being the lowest since the 1890s.) Yet this was achieved very much by exporting those emissions to China and adopting gas rather than coal with fuel efficiency playing a minor role.

    It is the global emissions that are important. Sadly these continue to grow. In successive 5-year periods since 1985 (with 2015-17 extrapolated to a 5-year period) the global growth in carbon emissions (GCP data) has been 6%, 6%, 10%, 18%, 13%, 6%. Until those figures become negative, there is every reason to, well, to be pessimistic or to take the argument to the public/government or to jump up and down and scream at politicians for being useless or to superglue yourself to an underground train to get your message onto the evening news.

    I have not been apart of the direct-action campaigns but have for a quarter of a century been apart of the other three.

  33. That you guys bring in the Doran study and this 97% BS is just laughable and renders any of your claims irrelevant and not to be taken seriously.

    This Doran study was an online survey in which 10,257 earth scientists were asked to participate. Of those 10,257 asked to participate, 3,146 actually completed the survey. And, out of those 3,146, 79 were climate scientists that had also published more than 50% of their recent peer-reviewed papers on the subject of climate change . And, this is where they get their "97%" from, that 76 of 79 had answered "risen" to question 1, "When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?" and, 75 of 77 answered "yes" to the question 2, "Do you think human activity is a significant contributing factor in changing mean global temperatures?" So, apparently, not even all of the 79 individuals in that category even answered question 2 but, instead, only 77 answered it. Also, surely, since I'm quite positive there are WAY more than a total of 79 climate scientists in this world? What's 76 out of 79 climate scientists saying anything even really mean? That's like taking a town that has 500 people in it and saying the opinions of three people in that town is relevant and of significant importance.

    And, since I'm sure all the other studies cited are essentially the same as the Doran study and consist of, likely, essentially the same scientists that participated in the Doran study? I find the only "myth" here is the 97% claim.

    Response:

    [DB] Inflammatory snipped.

  34. CThompson @833 ,

    Why get yourself angry about the Doran study?

    Any online survey, taken strictly on its own, is not necessarily worth much.  However, the Doran study is not an outlier :- all of the ["non-online"] consensus surveys give pretty much the same result of overwhelming consensus.

    Even a 97% figure is a bit out of date in 2019, and is now actually well over 99%.

    As I mentioned in a couple of posts [above] : the thread here about consensus is really just an indirect way of examining the mainstream climate science.  There are hardly any "climate-skeptical" scientists remaining.

    Forty years ago, there was space for scientists to be skeptical about AGW ~ but the current state of "overwhelming consilient evidence" is so clear-cut that "contrarians" have nothing left apart from empty rhetoric to support their so-called position/positions.

    That is why hardly any "contrarian" scientists remain.

  35. There has long been a consensus among climate scientists, based on multiple types of scientific evidence, that greenhouse gas emissions are altering the Earth’s climate. The strength of the scientific consensus on climate change has been established by numerous research studies employing a variety of methods, including surveys of scientists (Carlton et al., 2015; Doran & Zimmermann, 2009; Rosenberg et al., 2010; Stenhouse et al., 2014; Verheggen et al., 2014), analysis of public statements in scientific assessment reports and multi-signatory statements about climate change (Anderegg et al., 2010), and analysis of peer-reviewed studies about climate change (Cook et al., 2013; Oreskes, 2004). These peer-reviewed studies demonstrate a consensus among climate science experts that humans are causing global warming. Estimates of the extent of the consensus among experts—climate scientists who publish peer-reviewed climate research—vary between 90 to 100%; as of 2016 the best estimate, based on a number of studies, was 97% (Cook et al., 2016).

    NASA’s climate change website presents the state of scientific knowledge about climate change.  This includes a webpage on the scientific consensus about human-caused climate change, which captures the robust nature of the scientific consensus by citing multiple peer-reviewed studies from research groups across the world. This approach for assessing and portraying the veracity and consensus of a research result, in this case the scientific consensus on climate change, is consistent with NASA’s scientific research portfolio – namely the reliance on up to date peer-reviewed scientific literature.

    https://climate.nasa.gov/scientific-consensus/

    Here’s a recap of the published research articles appearing in peer-reviewed refereed journals examining the ever-strengthening, consilient consensus present in the primary literature:

    A. Oreskes et al 2004 - The Scientific Consensus on Climate Change
    Science 03 Dec 2004, Vol. 306, Issue 5702, pp. 1686; DOI: 10.1126/science.1103618
    https://science.sciencemag.org/content/306/5702/1686

    B. Doran and Zimmerman 2009 - Examining the Scientific Consensus on Climate Change
    EOS, Volume 90, Issue 3, Pages 22–23, doi: 10.1029/2009EO030002
    https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2009EO030002

    C. Anderegg et al 2010 - Expert credibility in climate change
    PNAS, vol. 107 no. 27, 12107–12109, doi: 10.1073/pnas.1003187107
    https://www.pnas.org/content/107/27/12107.full

    D. Rosenberg et al 2010 - Climate change: a profile of US climate scientists’ perspectives
    Climatic Change, August 2010, Volume 101, Issue 3–4, pp 311–329; DOI 10.1007/s10584-009-9709-9
    https://link.springer.com/article/10.1007/s10584-009-9709-9

    E. Cook et al 2013 - Quantifying the consensus on anthropogenic global warming in the scientific literature
    Environmental Research Letters, 15 May 2013, Volume 8, Number 2; doi:10.1088/1748-9326/8/2/024024
    https://iopscience.iop.org/article/10.1088/1748-9326/8/2/024024

    F. Verheggen et al 2014 - Scientists’ Views about Attribution of Global Warming
    Environ. Sci. Technol., 2014, 48 (16), pp 8963–8971, doi: 10.1021/es501998e
    https://pubs.acs.org/doi/abs/10.1021/es501998e

    G. Stenhouse et al 2014 - Meteorologists' Views About Global Warming: A Survey of American Meteorological Society Professional Members
    Bulletin of the American Meteorological Society, 2014, Volume 95 No. 7, pp 1029–1040, doi: 10.1175/ BAMS-D-13-00091.1
    https://journals.ametsoc.org/doi/full/10.1175/BAMS-D-13-00091.1

    H. Carlton et al 2015 - The climate change consensus extends beyond climate scientists
    Environ. Res. Lett. 10 (2015) 094025, pp 1–12, doi:10.1088/1748-9326/10/9/094025
    https://iopscience.iop.org/article/10.1088/1748-9326/10/9/094025/meta

    I. Cook et al 2016 - Consensus on consensus: a synthesis of consensus estimates on human-caused global warming
    Environ. Res. Lett. 11 (2016) 048002, pp 1–7, doi:10.1088/1748-9326/11/4/048002
    https://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002/meta

    Also linked from NASA’s Scientific Consensus page, but worthy of repeating, a list of scientific organizations that hold the position that Climate Change has been caused by human activities and actions.

    https://climate.nasa.gov/scientific-consensus/
    http://www.opr.ca.gov/facts/list-of-scientific-organizations.html

    In essence, there aren’t any (as in none, not even one) national or international scientific societies disputing the conclusion that most of the warming since 1950 is very likely to be due to human emissions of greenhouse gases.

    To sum: the science underlying and affirming the human-causation is based on over 170 years of research, research integral to the science forming the structural framework of our modern world today.

    From weather balloons to airplanes, from Pershing-2 to cruise missiles guidance and delivery systems, from CD & DVD players to microwave ovens, and from cellphones, GPS locators, HD TVs and the Internet, the radiative physics of CO2 pervasively form the bedrock underpinning our technology today.

    And the ever-strengthening, consilient consensus present in the primary literature merely acknowledges that.

  36. Eclectic @834

    Why get myself angry about the Doran study?

    First, who says I'm "angry"? Second, if they have to overstate the reality with symmatic gymnastics with respect to the Doran study to try and make it appear more dramatic than what it really is, why should I not believe all the rest of them aren't doing the same? They come off with this "97%" figure, hoping people won't actually look at the study and realize that only 79 climate scientists were actually participating in the study and that is pretty much an infinitesimally small number compared to the total number of climate scientists that are in the world. I call that dishonesty and shady. And then, other people take that 97% and try and make it out as if that 97% is indicative of the opinions of the total number of climate scientists in the world when, in reality, it's only the opinion of 75 out of 77 climate scientists in the world. Third, I'm not buying your claim that it's 99%, that there is overwhelming consilient evidence nor, that there are hardly any "climate-skeptical" scientists remaining. Again, this is all likely derived from the same shenanigans pulled in the Doran study. We know they pulled something similar in going through supposed "peer-reviewed" abstracts in the Oreskes, 2004 study which was criticized for overstating the level of consensus acceptance within the examined abstracts so, this pretty much seems to be a pattern and I just don't find myself taking it seriously. It's all cherry-picking, symmatic gymnastics, inconsistent methodologies and all pretty dishonest.

    Response:

    [DB]  Sloganeering and accusations of impropriety snipped.

    Please note that posting comments here at SkS is a privilege, not a right.  This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
     
    Finally, please understand that moderation policies are not open for discussion.  If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

  37. Estoma at 21:29 PM on 25 August, 2019

    I've been lurking here at Skeptical Science and Real Climate since their inception. One of the first things I learned was about the natural carbon cycle. Put that part aside. The emmissions being talked about are the ones created by fossil fuels. That CO2 has a different signature from the natural CO2.

    Uhmmm...emissions by fossil fuels ARE natural CO2. Emissions from fossil fuels are being released in many different forms. When a field is plowed, emissions (CO2) from fossil fuels are released. When a street is being paved, emissions (CO2) from fossil fuels are released. When tree leaves deccompose, emissions (CO2) from fossil fuels are released. Emissions (CO2) from fossil fuels aren't released exclusively when someone punches the gas pedal on an automobile or runs an engine in an industry. There are likely a limitless number of mechanisms for which emissions (CO2) from fossil fuels are released. All carbon has to do is mix with oxygen and you have CO2. When a dust storm happens, there's like emissions (CO2) from fossil fuels being released. So, I don't know where you're getting this CO2 from fossil fuels as being somehow different than so-called "natural" CO2. And, no, there is no different signature between CO2 from fossil fuels and so-called "natural" CO2. CO2 is CO2, whether it comes from the tailpipe of a 1972 Dodge Dart or out of a volcano or, out of the smokestack of industry or, from a forest fire. It's all carbon and oxygen. CO2...carbon atom, two oxygen atoms. There's no distinctive markers that describe where it comes from.

    Response:

    [DB]  "there is no different signature between CO2 from fossil fuels and so-called "natural" CO2"

    Incorrect.  Scientists know conclusively through its distinctive isotopic signature that all of the postindustrial rise in atmospheric concentration of CO2 is from human activities.

    Per Rubino et al 2013,

    "as atmospheric carbon dioxide concentrations in the ice go up after 1800 AD, the carbon isotopic composition of that same carbon dioxide goes down. The change in the isotopic composition is somewhat startling - the atmosphere is happily chugging along at around -6.5‰ and then nosedives to -8.5‰ by 2012"

    And

    "There is really no way around it. Since the dawn of the industrial age, humans have taken carbon locked in organic material and released it into the atmosphere. That burning added huge volumes of carbon dioxide (in 2014, 44 billion tonnes) that all has highly negative carbon isotopic composition. Carbon dioxide goes up, the carbon isotopic composition goes down, all recorded in the ice at the poles."

    http://www.bom.gov.au/state-of-the-climate/2014/

    https://skepticalscience.com/From-eMail-Bag-Carbon-Isotopes-Part-1.html

    https://www.skepticalscience.com/From-eMail-Bag-Carbon-Isotopes-Part-2.html

    https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgrd.50668

    "These declines in δ13CO2 and Δ14CO2 (called the Suess Effect; Keeling, 1979; Suess, 1955) are linked to the burning of fossil fuels. Fossil fuels, such as the vast coal deposits of the Carboniferous period, are composed of the organic remains of organ-isms (mainly plants) that lived millions of years ago. Plants preferentially take up 12C over 13C so have low δ13C (e.g. Farquhar et al., 1989), with most oil deposits having values of −32‰ to −21‰ and coal deposits −26‰ to −23‰ (Sharp, 2007). Consequently, CO2 from fossil fuels contains on average 2% less 13C per mole than atmospheric CO2 (Keeling, 1979). Extraction and burning of these fossil fuel reserves releases this 12C-enriched carbon back into the atmosphere, leading to a decline in δ13CO2. Old carbon from fossil fuels is also virtually free of 14C (Keeling, 1979), since the time between being deposited in the fossil record and burning is many thousands of half-lives of 14C, so the release of this old carbon will lead to a decline in Δ14CO2 in the atmosphere. δ13C changes in the atmosphere have been vital in allowing the Intergovernmental Panel on Climate Change (IPCC) to conclude there is a ‘very high confidence’ that the dominant cause of the observed increase in CO2 concentrations in the atmosphere since the 19th century has been the human burning of fossil fuels (IPCC, 2013)."

    https://www.researchgate.net/figure/d-13-CO-2-from-Antarctic-ice-core-record-Rubino-et-al-2013-d-13-C-record-from_fig1_274469390

  38. CThompson ,

    Interesting, that you don't recognize your own anger.  Anger is the underlying emotion in almost all "contrarians"  ~ anger that the mainstream science shows that the Earth is Round rather than the politically-correct Flatness which the contrarians desire.

    Anger is an emotion leading to Motivated Reasoning  ~ where even some very intelligent people (such as yourself) manage to bamboozle themselves with rhetoric & false logic & semantic confusion . . . and manage to deny the "bleeding obvious".

    Perhaps the isotopes Carbon-12 and Carbon-13 are not so very obvious to you, CThompson, but that is all the more excuse for you to go inform yourself - educate yourself - about carbon sources, carbon dioxide, the carbon cycles, photosynthesis & enzymatic affinities, etcetera.  Then you will see why you are wrong, and the climate scientists are right.

     

    How many climate scientists are there?  Certainly more than 79.  Depending on definition, there are hundreds . . . thousands . . . tens of thousands . . . even more.  There is no precise cut-off between climate scientists and "non-climate" scientists.  There is a spectrum ranging from the most expert (who do climate research & publish papers in reputable scientific journals) through to scientists whose area of expertise is only distantly related to climate.  And on through to the almost-famous "wood engineer" who, many years ago, signed the laughable Oregon Petition of 19,000+ people possessing a science degree, who denounced AGW.  (Denounced AGW, based on almost zero expertise in the field of climate science.)

    Relevantly, CThompson, the consensus studies show that the more climate science expertise a scientist has, the more likely he is to agree with the consensus.

    That is why, CThompson, you have failed to present an impressive list of names of (sane and credible) climate scientists who are not in the 99% consensus.  Because they are way less than 1%.   And if, from such a potential list, you subtracted :-  the "Emeritus" elderly dodderers, the political extremists, the fundamentalist religious extremists, and the delusional citizen-scientist  crackpots . . . then you would have close to zero real scientists left on your list.   That's why the consensus is more like 99% than 97% .

  39. CThompson: Your six-step definition of science is naively simplistic, narrow, and exclusive. To support it you need to show us photos of astronomers experimentally creating alternate versions of neutron stars. Experimentation is but one useful tool in the toolbox of science. Climatologists have done a huge number of experiments on thousands of aspects of climatology, going all the way back, for example, to Eunice Foote in 1856. 

  40. Even though I know this comment likely won't even see the light of day as it will be construed as "inflammatory", even though yours is likewise and remains, by making assumptions about my education and knowledge, I'll give this a try anyway.

    Eclectic at 12:42 PM on 9 October, 2019

    CThompson ,

    Interesting, that you don't recognize your own anger. Anger is the underlying emotion in almost all "contrarians" ~ anger that the mainstream science shows that the Earth is Round rather than the politically-correct Flatness which the contrarians desire.

    Actually, I believe the "politically-correct" description would apply to the Earth is Round crowd, in your analogy. Further, there was never even such thing as anyone believing the world was flat and, that is a myth, just like the 97% claim.

    Perhaps the isotopes Carbon-12 and Carbon-13 are not so very obvious to you, CThompson, but that is all the more excuse for you to go inform yourself - educate yourself - about carbon sources, carbon dioxide, the carbon cycles, photosynthesis & enzymatic affinities, etcetera. Then you will see why you are wrong, and the climate scientists are right.

    Actually, I'm quite familiar with carbon-12 and carbon-13, as well as carbon sources, carbon dioxide, the carbon cycles, photosynthesis and enzymatic affinities. But, this is exactly why I can never take seriously those who advocate global warming/climate change. Their condescending, smug attitude which makes them believe they're the most brilliant people on the face of the planet and no one should even dare challenge them. I thought this discussion was supposed to be about the so-called "consensus", rather than your assumptions about my level of education or my knowledge. You have no idea what my level of education is or what level of knowledge it is I have. And, while my one comment is snipped and flagged as being "inflammatory", your assumptions concerning my education and my knowledge, which could also be construed as "inflammatory", is allowed to remain. But, what can I expect? If one is all for the global warming/climate change hysteria, one can be as inflammatory as one wants. If one isn't, they're shut down.

    Now, why don't you elaborate a little further on what it is carbon-12 and carbon-13 have to do with anything? If you're suggesting someone can determine what carbon dioxide it is that comes from the tailpipe of a Dodge Dart or that which comes from a decaying tree or that which comes from a forest fire has anything to do with carbon-12 or carbon-13, I believe you are mistaken.

    How many climate scientists are there? Certainly more than 79. Depending on definition, there are hundreds . . . thousands . . . tens of thousands . . . even more. There is no precise cut-off between climate scientists and "non-climate" scientists. There is a spectrum ranging from the most expert (who do climate research & publish papers in reputable scientific journals) through to scientists whose area of expertise is only distantly related to climate. And on through to the almost-famous "wood engineer" who, many years ago, signed the laughable Oregon Petition of 19,000+ people possessing a science degree, who denounced AGW. (Denounced AGW, based on almost zero expertise in the field of climate science.)

    Relevantly, CThompson, the consensus studies show that the more climate science expertise a scientist has, the more likely he is to agree with the consensus.

    That is why, CThompson, you have failed to present an impressive list of names of (sane and credible) climate scientists who are not in the 99% consensus. Because they are way less than 1%. And if, from such a potential list, you subtracted :- the "Emeritus" elderly dodderers, the political extremists, the fundamentalist religious extremists, and the delusional citizen-scientist crackpots . . . then you would have close to zero real scientists left on your list. That's why the consensus is more like 99% than 97% .

    Actually, I find the term "climate science" and "climate scientists" to be a misnomer in the first place as I don't believe for a second they know as much about the climate and those mechanisms which drive it as they THINK they know. I don't think "climate scientist" even fits. I believe, for one to be a "climate scientist", one would have to be proficient in almost all, if not all, principles of science. And, I don't believe there's anyone in the world who's smart enough to be proficient in ALL principles of science. They'd have to know how cosmic forces impact our climate, they'd have to know how plants and animals impact our climate, they'd have to know how the many forces that shape this planet impact our climate and, multitudes of other things. That they simply average out temperatures for a 30 year period or precipitation levels over a 30 year period and call themselves "climate scientists" doesn't seem to shed true light on what is needed to understand the climate and what drives it. Now, lastly, your anger is quite clear. Anger is what compels you to make assumptions about my education and knowledge and anger compels you to make smug and condescending statements and acting like no one should even dare challenge you because you're a brilliant know-it-all and there's absolutely no way you're wrong. You know who else believed they were know-it-alls? People who challenged Erin Brockovich. She had no formal legal training and everyone else thought they were so much smarter than her. But, of course, we all know how that turned out.

    (P.S. Just so you know, I don't have to present to you anything, to believe what I believe. But, you're certainly going to have to do better than presenting symmantic gymnastics, as demonstrated in the Doran study, to convince me. See, things are the way they are and, if you want people to believe you in order to initiate change, it's you that has to convince them, not the other way around. I don't have to present anything to believe what I believe, you've got to present something convincing to me, to make me believe differently. Thanks.)

    Response:

    [DB]  Please note that posting comments here at SkS is a privilege, not a right.  This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
     
    Finally, please understand that moderation policies are not open for discussion.  If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

    Moderation complaints, inflammatory tone and baiting snipped.

  41. CThompson ,

    insight is not your strong suit, apparently.  Your claim of familiarity with carbon isotopes etcetera, is not congruous with your dismissal of mainstream physics & biology.

    Just as (by analogy) someone who claims familiarity with mathematics . . . yet who alleges that 2+2=3 . . . is someone who is a tad less expert than he supposes.

    But perhaps, CThompson, you can achieve some credibility by staying on topic.  [Short musical interlude here, while orchestra plays Pride of Erin B  . . . and readers wait for you to also mention Galileo, as well.]  You have been repeatedly asked to say something substantive about the scientific consensus, to back your "beliefs".  But you have produced nothing, so far.

    A good start would be, if you can name a list of some credible scientists who have produced some evidence that the mainstream science is  seriously incorrect.  (And you must show what that evidence is ~ not just handwave at something unspecified.)  If at all possible, please list a sufficiency of names to demonstrate that these alleged contrarians exist in numbers way beyond 1% of climate scientists.  Would 20% "climate-skeptical" genuine climate scientists be achievable for you?  Otherwise, surely your consensus claim falls flat on its face.

    Hint: don't bother to use the delusional citizen-scientist  crackpots, such as Lord Monckton, Dr Tim Ball, or (the late) John Coleman . . . 'cos they ain't no scientists !

    And bear in mind, that the evidence is even more important than the exact percentage of contrarians.  And that is where the contrarian scientists make a double Fail ~ their numbers are shrinking and their hypotheses [cosmic rays; 100-year oceanic cycles; Lindzen's "Iris" ; etcetera] have failed the reality test.

    CThompson, the consensus exists because the evidence is clear.

     

    I can see that you believe what you want to believe ~ and I was never under the illusion that you would be convinced by anything factual.

     

    BTW, CThompson, you can educate me on one point ~ what is the meaning of the word "symmantic"  which you use so often  e.g. the "symmantic gymnastics" you mention in your last paragraph of #841 .   The OED failed to list the word.  Is it a new term for the latest display trick by that amazing young gymnast Ms Simone Biles ?

  42. Concerning the claims up-thread by CThopmspn of the basis for a 97% consensus being "all cherry-picking, symmatic gymnastics, inconsistent methodologies and all pretty dishonest," I note the main object of his criticism Doran & Zimmerman (2009) is only linked to its 'abstract' (or actually its first paragraph. The full (but brief) paper describing the survey is on-line here.

  43. MA Rodger @842 ,

    thank you for the link to Doran & Zimmerman (2009).  My memory of it had faded ~ so it was good to see it freshly.

    It was an online survey, and managed by a third party, and had a 30% "return rate".   So, a respectably large return for that sort of thing.  Large enough to make it highly unlikely (from what we already know of the minuscule numbers of contrarian scientists, even back in 2009) for the survey to be severely distorted by "random omission" of contrarians.

    Yes, the Doran survey was not as unassailable as the subsequent "gold medal"  two-in-one consensus study carried out by Cook et al., in 2013.   Even so, the Doran study leaves no leg for (upthread) poster CThompson to stand on.    Notably, Doran gives much the same result as Cook ~ indeed, all the consensus studies confirm the very high level of consensus.

    CThompson's claims are clearly out of touch with reality.  And he seems to have abandoned the idea of demonstrating the "large" and consensus-busting number of climate experts who are truly contrarian.

  44. I would like to know how this survey of Climate Scientists in the USA , which says that 52% think that human activity is warming the planet, relates with the 97% study. Surely, this is a big difference.

    https://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-13-00091.1

  45. Klmartinson @844 ,

    Unfortunately the study you mention (of the AMS/ametsoc) is of a much lower quality than other "consensus" studies . . . so it is difficult to draw much of a conclusion from it.

    I am not sure where you got the 52 (versus 97%) figure from.  From the chart of stated results, "52" is simply not an accurate representation of the views of the AMS members who participated in the electronic survey.

    ##   Did you yourself read the report ~ or are you only passing on a hearsay version of the survey?

    The other failings of the survey are many :-

    #1.  Only a voluntary survey, and with only a 30% return (Doran, for example, had only a 30% return . . . but the AMS survey returns contained a considerable number where only part  of the survey was answered).

    #2.  The authors admitted a blunder, in that they had asked about causation of global warming over 150 years . . . and a significant number of respondents later made contact to say they would have upgraded their answer if the question had been for the most recent 50 years.

    #3.  The survey was taken in 2012 . . . and a great amount of change has happened in the 7 years since then e.g. the so-called Pause has disappeared, and record high temperatures have followed.

    #4.  The survey was (per definition) limited largely to Americans ~ a nation where there is strange & bizarre percentage of the population who are so influenced by Motivated Reasoning, that they reject plain evidence about AGW, evolution, age of the Earth, etcetera.  So is rather far from representative of meteorologists or scientists worldwide.  You will also notice that only 89% of respondents acknowledged any global warming at all . . . in other words for 11% their beliefs were at the Flat Earth level of science denial.

    #5.  The authors themselves pondered the observation that controversy (at the political/partisan level) had caused a percentage of AMS members to "disengage" with the AGW issue during the (then) recent years, and to express themselves less definitely about the scientific facts.  Sad to see such a defense mechanism!! ~ but it did seem to "tone down" the definitiveness of answers given to the survey.  One would like to think that the meteorologists of the AMS are more courageous in 2019 ~ and I have heard hints that is so . . . but of course that won't show up in the 2012 survey !

    In all, it was an overly-simple survey of 4 main points.  Even so, it was like the other "consensus" surveys, in that it showed that the greater the climate scientific expertise (of the meteorologists) the greater the agreement with the scientific mainstream.

    Klmartinson, you will find much more reliability from consensus surveys such as the contemporaneous Cook et al. 2013 survey, where the "return rate" was in effect about 100% ~ and the clever design of Cook eliminated the influence of bias (bias from personal and social factors) . . . and giving a robust 97%.  (Actually more than 99% consensus, based on recent years' evidence).

  46. Eclectic,  Well, thanks for your wordy reply.

    0. re: "low quality". At 30% reply rate, I don't think that it is valid to just dismiss it as "low quality". Read the paper and you will know where I get the 52% from. I did read it.

    1. Is there such a thing as a mandatory survey?

    2. 50 years vs 150 years. A fair point. The questions could have been better.

    3. I'm sure there have been some record high temperatures in the last few years. And last winter in continental USA was the coldest in 110 years. I don't understand how we can have "record heat" and yet have "record cold seasons".

    4. Yes, limited to Americans. You seem to show your bias here. Yes, it seems a shock to some that 11% of climate scientists (=200 people) in the USA do not accept or don't know that there is any warming at all. Maybe they should explain those opinions in detail, and inform us better. Maybe it has to do with the global cooling period from 1940s to 1979, or something else. I would call it anti-science to call these Science professionals Flat Earthers.

    5. I don't think it is fair to equally compare a direct survey of scientists and a survey of published articles that seem to indicate an opinion.  A comparison of the surveys seems to indicate that there is a correlation between a scientist's opinion and their ability to publish.

    Response:

    [DB]  "And last winter in continental USA was the coldest in 110 years"

    Making things up is unhelpful.  Temperatures last winter in the continental US were well-above the long-term average for winters in the continental US.  These things are easily looked up.

    US Winters - Graph

    US Winters - Map

    Please comport future response to more fully comply with this site's Comments Policy (making things up falls under the category of sloganeering).

  47. Klmartinson @846 , 

    thank you for your "less wordy" reply  ;-)

    Brevity is truly the soul of wit ~ but not always the soul of precision !

    #0.  My comment of "low quality" applies to the AMS survey as a whole, not just to the 30% reply rate.   Indeed, 30% is poor in itself, because of the dangers of self-selection and unrepresentativeness [oh, what a wordy word! ] . . . as I am sure you are very well aware yourself.   As you have scrutinised the report, you will have noticed that the authors were slightly uncomfortable with the over-representation of student members and elderly/retired members (among other selection criticisms).

    Best if the survey were repeated nowadays, and done more carefully, so that the survey could be of high enough quality to achieve a worthy comparison to other surveys of Consensus.

    I agree the 30% is still rather poor, for the widely cited Doran survey ~ but Doran gains in strength because it closely fits with other surveys.   And "your" AMS survey also loses points, because of the lamentable extent of incompletion of those forms actually returned.

    And the fact that your quoted  52% was such an outlier , should have raised your suspicion that you had misinterpreted the figure or its context (or that the survey itself was faulty).

    #1.  Yes, there is such a thing as a "mandatory" survey.

        They are far and away the best sort of survey, in assessing the Consensus accurately.   [see part A of the Cook et al., 2013 survey]

    #2.  50 years vs 150 years in the questions, should have produced the same answers.   That it didn't do so, reflects rather poorly on the AMS members themselves (rather than on the survey itself!)

    #3.  Now you are adducing one winter in CONUS ?!   And you "don't understand how we can have record heat and yet have record cold seasons" ?!

    Hmmm ~ move another tenth of an inch in that direction . . . and some of the readers here will begin  to feel you are being a tad disingenuous   ;-)

    #4.  As I pointed out above, the survey was by definition limited to Americans.   Is that a bias?   It is only a bias, if the survey is falsely represented as worldwide (misrepresenting through omission).

    Though I hear that a percentage of AMS members are "furriners" . . . but only a small percentage.

    No, I am not shocked  at such (11%) a proportion of "Flat-Earther-type" opinions in some alleged scientists.   I myself know a PhD (in biological sciences) who is a proud member of his local Flat Earth Society . . . indeed, it's even worse , because he was born outside the USA !

    Klmartinson, the historic record is so clear on the fact  of modern global warming ~ that it takes an absolute willful blindness for any meteorologist to deny it, even back in 2012 or 2002.

    #5.  (which really deserves to be #6.)   Klmartinson, if you read a dozen or two of the upthread comments, and if you truly think it through, then you will come to see that a survey of published scientific articles is the far superior method of determining the real consensus.

    The analogy might be political surveys (examples: the Dewey/Truman 1948 election and the Clinton/Trump 2016 election) ~ inadequate survey size plus the tendency for "coyness" of replies to the vox-pop microphone or other polling method . . . results in an invalid "figure".   In reality, the accurate figure is the totality of the "on-paper" survey.  ;-)

  48. klmartinson @ 846: "...seems to indicate that there is a correlation between a scientist's opinion and their ability to publish."

    And a strong correlation it is.

    The opinions that are little more than an opinion, use faulty methodology, are internally self-inconsistent, rely on cherry picking, ignore vast swaths of well-established physics, and are largely unsupported by evidence usually find it difficult to make their way into the published literature.

    On the other hand, good science usually manages to overcome the hurdles involved in the publishing process. Not easily though - the review process can be pretty tough, and I"ve seen reviews that can get to be pretty nasty. The papers end up being better as a result.

  49. Also klmartinson @ 846:  I don't understand how we can have "record heat" and yet have "record cold seasons".

    An argument from incredulity is a pretty weak argument. But to take a bite of the apple...

    • The first year measurements are taken will set both a new high and a new low record.
    • The second year will set either a record high, or a record low - except in the rare case of a tie.
    • In subsequent years,the probabilty of setting a new record high or low decreases.
    • In a non-warming world, the probability of seeing a high record set will be the same as the probability of seeing a low record set.
    • What we see is far more high records being set than low records.
    • We still see the occasional low record, and this is not evidence against against the conclusion that things are warming overall.
  50. “Abstract
    The consensus among research scientists on anthropogenic global warming has grown to 100%, based on a review of 11,602 peer-reviewed articles on “climate change” and “global warming” published in the first 7 months of 2019.”

    journals.sagepub.com/doi/abs/10.1177/0270467619886266?journalCode=bsta#articleShareContainer

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