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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

"[...] And I'll mention that the stat on the 97% of - of scientists is based on one discredited study." (Ted Cruz)

At a glance

What is consensus? In science, it's when the vast majority of specialists agree about a basic principle. Thus, astronomers agree that the Earth orbits around the Sun. Biologists accept that tadpoles hatch out from frog-spawn and grow into adult frogs. Almost all geologists agree that plate tectonics is real and you'd be hard-placed to find a doctor who thinks smoking is harmless.

In each above case, something has been so thoroughly looked into that those who specialise in its study have stopped arguing about its basic explanation. Nevertheless, the above examples were all once argued about, often passionately. That's how progress works.

The reaching of scientific consensus is the product of an often lengthy time-line. It starts with something being observed and ends with it being fully explained. Let's look at a classic and highly relevant example.

In the late 1700s, the Earth-Sun distance was calculated. The value obtained was 149 million kilometres. That's incredibly close to modern measurements. It got French physicist Joseph Fourier thinking. He innocently asked, in the 1820s, something along these lines:

"Why is Planet Earth such a warm place? It should be an ice-ball at this distance from the Sun."

Such fundamental questions about our home planet are as attractive to inquisitive scientists as ripened fruit is to wasps. Fourier's initial query set in motion a process of research. Within a few decades, that research had experimentally shown that carbon dioxide has heat-trapping properties.

Through the twentieth century the effort intensified, particularly during the Cold War. At that time there was great interest in the behaviour of infra-red (IR) radiation in the atmosphere. Why? Because heat-seeking missiles home in on jet exhausts which are IR hotspots. Their invention involved understanding what makes IR tick.

That research led to the publication of a landmark 1956 paper by Gilbert Plass. The paper's title was, “The Carbon Dioxide Theory of Climatic Change”. It explained in detail how CO2 traps heat in our atmosphere. Note in passing that Plass used the term "Climatic Change" all the way back then. That's contrary to the deniers' frequent claim that it is used nowadays because of a recent and motivated change in terminology.

From observation to explanation, this is a classic illustration of the scientific method at work. Fourier gets people thinking, experiments are designed and performed. In time, a hypothesis emerges. That is a proposed explanation. It is made on the basis of limited evidence as a starting point for further investigation.

Once a hypothesis is proposed, it becomes subject to rigorous testing within the relevant specialist science groups. Testing ensures that incorrect hypotheses fall by the wayside, because they don't stand up to scrutiny. But some survive such interrogation. As their supporting evidence mounts up over time, they eventually graduate to become theories.

Theories are valid explanations for things that are supported by an expert consensus of specialists. Gravity, jet aviation, electronics, you name it, all are based on solid theories. They are known to work because they have stood the test of time and prolonged scientific inquiry.

In climate science today, there is overwhelming (greater than 97%) expert consensus that CO2 traps heat and adding it to the atmosphere warms the planet. Whatever claims are made to the contrary, that principle has been established for almost seventy years, since the publication of that 1956 landmark paper.

Expert consensus is a powerful thing. None of us have the time or ability to learn about everything/ That's why we frequently defer to experts, such as consulting doctors when we’re ill.

The public often underestimate the degree of expert consensus that our vast greenhouse gas emissions trap heat and warm the planet. That is because alongside information, we have misinformation. Certain sections of the mass-media are as happy to trot out the latter as the former. We saw a very similar problem during the COVID-19 pandemic and it cost many lives.

For those who want to learn more, a much longer detailed account of the history of climate science is available on this website.

Please use this form to provide feedback about this new "At a glance" section. Read a more technical version below or dig deeper via the tabs above!

Further details

We know full well that we don’t have the time or capacity to learn about everything, so we frequently defer to the conclusions of experts. Without experienced people using their expertise to perform many vital tasks – and without new people constantly entering such occupations – society would quickly disintegrate.

The same is true of climate change: we defer to the expert consensus of climate scientists. Indeed, public perception of the scientific consensus with regard to global warming has been found to be an important gateway into other enlightened climate-related attitudes - including policy support. 

Nine consensus studies

Let's take a look at summaries of the key studies, featured in the graphic above, into the degree of consensus. These have been based on analyses of large samples of peer-reviewed climate science literature or surveys of climate and Earth scientists. These studies are available online through e.g. Google Scholar. That slightly different methodologies reached very similar conclusions is a strong indicator that those conclusions are robust.

Oreskes 2004

In this pioneering paper, a survey was conducted into all peer-reviewed abstracts on the subject 'global climate change', published between 1993 and 2003. The work showed that not a single paper, out of the 928 examined, rejected the consensus position that global warming is man-made. 75% of the papers agreed with the consensus position while 25% made no comment either way.

Doran & Zimmerman 2009

A survey of 3,146 Earth scientists asked the question, "Do you think human activity is a significant contributing factor in changing mean global temperatures?" Overall, 82% of the scientists answered yes. However, what was most interesting was the type of response compared to the level of expertise in climate science. Of scientists who were non-climatologists and didn't publish research, 77% answered yes. In contrast, 97.5% of actively-publishing climatologists responded yes. As the level of active research and specialization in climate science increases, so does agreement that humans are significantly changing global temperatures. The paper concludes:

"It seems that the debate on the authenticity of global warming and the role played by human activity is largely non-existent among those who understand the nuances and scientific basis of long-term climate processes. The challenge, rather, appears to be how to effectively communicate this fact to policy makers and to a public that continues to mistakenly perceive debate among scientists."

Anderegg et al. 2010

This study of 1,372 climate science researchers found that (i) 97–98% of the researchers most actively publishing in the field support the tenets of anthropogenic climate change (ACC) as outlined by the IPCC and (ii) the relative climate expertise and scientific prominence of the researchers unconvinced of ACC are substantially below that of the convinced researchers. 

Cook et al. 2013

A Skeptical Science-based analysis of over 12,000 peer-reviewed abstracts on the subject 'global climate change' and 'global warming', published between 1991 and 2011, found that over 97% of the papers taking a position on the subject agreed with the consensus position that humans are causing global warming. In a second phase of the project, the scientist authors were emailed and rated over 2,000 of their own papers. Once again, over 97% of the papers taking a position on the cause of global warming agreed that humans are causing it.

Verheggen et al. 2014

Results were presented from a survey held among 1868 scientists studying various aspects of climate change, including physical climate, climate impacts, and mitigation. The survey was at the time unique in its size, broadness and level of detail. Consistent with other research, it was found that as the level of expertise in climate science grew, so too did the level of agreement on anthropogenic causation. 90% of respondents with more than 10 climate-related peer-reviewed publications (about half of all respondents), explicitly agreed with anthropogenic greenhouse gases (GHGs) being the dominant driver of recent global warming. The respondents’ quantitative estimate of the GHG contribution appeared to strongly depend on their judgement or knowledge of the cooling effect of aerosols.

Stenhouse et al. 2014

In a survey of all 1,854 American Meteorological Society members with known e-mail addresses, achieving a 26.3% response rate, perceived scientific consensus was the strongest predictor of views on global warming, followed by political ideology, climate science expertise, and perceived organisational conflict.

Carlton et al 2015

Commenting that the extent to which non-climate scientists are skeptical of climate science had not so far been studied via direct survey, the authors did just that. They undertook a survey of biophysical scientists across disciplines at universities in the Big 10 Conference. Most respondents (93.6%) stated that mean temperatures have risen. Of the subset that agreed temperatures had risen, the following question was then asked of them: "do you think human activity is a significant contributing factor in changing mean global temperatures?" The affirmative response to that query was 96.66%.

Cook et al. 2016

In 2015, authors of the above studies joined forces to co-author a paper, “Consensus on consensus: a synthesis of consensus estimates on human-caused global warming”. Two key conclusions from the paper are as follows:

(i) Depending on exactly how you measure the expert consensus, somewhere between 90% and 100% of climate scientists agree humans are responsible for climate change, with most of our studies finding 97% consensus among publishing climate scientists. (ii) The greater the climate expertise among those surveyed, the higher the consensus on human-caused global warming.

Lynas et al. 2021

In this paper, from a dataset of 88,125 climate-related peer-reviewed papers published since 2012, these authors examined a randomly-selected subset of 3000 such publications. They also used a second sample-weighted approach that was specifically biased with keywords to help identify any sceptical papers in the whole dataset. Twenty-eight sceptical papers were identified within the original dataset using that approach, as evidenced by abstracts that were rated as implicitly or explicitly sceptical of human-caused global warming. It was concluded that the scientific consensus on human-caused climate change, expressed as a proportion of the total publications, exceeds 99% in the peer reviewed scientific literature.

Myers et al. 2021

This study revisited the 2009 consensus among geoscientists, while exploring different ways to define expertise and the level of agreement among them. The authors sent 10,929 invitations to participate in the survey, receiving 2,780 responses. In addition, the number of scientific publications by these self-identified experts in the field of climate change research was quantified and compared to their survey response on questions about climate change. Perhaps not surprisingly, the study found that agreement on anthropogenic global warming was high at 91% to 100% and generally increases with expertise. Out of a group of 153 independently confirmed climate experts, 98.7% of those scientists agreed that the Earth is warming mostly because of human activities such as burning fossil fuels. Among the subset with the highest level of expertise, these being independently-confirmed climate experts who each published 20+ peer-reviewed papers on climate change between 2015 and 2019, there was 100% agreement.

Public Polls and Consensus

Opinion polls are not absolute in the same way as uncontestable scientific evidence but they nevertheless usefully indicate in which way public thinking is heading. So let's look at a couple taken 13 years apart. A 15-nation World Public Opinion Poll in 2009 PDF), with 13,518 respondents, asked, among other questions, “Is it your impression that among scientists, most think the problem is urgent and enough is known to take action?” Out of all responses, just 51% agreed with that. Worse, in six countries only a minority agreed: United States (38%), Russia (23%), Indonesia (33%), Japan (43%), India (48%), and Mexico (48%). Conversely, the two highest “agree” scores were among Vietnamese (69%) and Bangladeshis (70%) - perhaps unsurprisingly.

The two other options people had to choose from were that “views are pretty evenly divided” (24% of total respondents), or “most think the problem is not urgent, and not enough is known to take action“ (15%). American and Japanese respondents scored most highly on “views are pretty evenly divided” (43 and 44% respectively).

How such a pervasive misperception arose, regarding the expert consensus on climate change, is no accident. Regular readers of this website's resources will know that instead, it was another product of deliberate misinformation campaigning by individuals and organizations in the United States and other nations around the world. These are people who campaign against action to reduce carbon emissions because it suits their paymasters if we continue to burn as much as possible. 

Step forward to 2022 and the situation has perhaps improved, but there's still some way to go. A recent poll, Public Perceptions on Climate change (PDF), was conducted by the Policy Institute, based at King's College London, UK. It quizzed samples of just over 2,000 people from each of six countries (UK, Ireland, Norway, Poland, Italy and Germany). The survey asked the question: “To the best of your knowledge, what percentage of climate scientists have concluded that human-caused climate change is happening?” The following averages were returned: the UK sample thought 65%, the average of the whole survey was 68% and the highest was Ireland at 71%. Clearly, although public perception of expert consensus is growing, there's still plenty of room for strategies to communicate the reality and to shield people from the constant drip-feed of misinformation.

Expert and Public Consensus

Finally, let's consider the differences between expert and public consensus. Expert consensus is reached among those who have studied complex problems and know how to collect and work with data, to identify what constitutes evidence and evaluate it. This is demanding work requiring specific skill-sets and areas of expertise, preparation for which requires years of study and training. 

Public consensus, in contrast, tends to occur only when something is blindingly obvious. For example, a serial misinformer would struggle if they tried running a campaign denying the existence of owls. Everyone already knows that of course there are owls. There is public consensus because we see and hear owls, for real or on the TV or radio. But complex issues are more prone to the antics of misinformers. We saw examples of misinformation during the COVID pandemic, in some cases with lethal outcomes when misinformed people failed to take the risks seriously. There's a strong parallel with climate change: it is imperative we accept the expert consensus and not kick the can down the road until the realisation it is real becomes universal – but utterly inescapable.

Update May 1, 2024: Corrected a typo in the publication year for Plass (1956) in the at-a-glance section.

Last updated on 26 May 2023 by John Mason. View Archives

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Further reading

Richard Black at the BBC investigates whether there is a bias against skepticism in the scientific community.

More on what we're talking about when we say "scientific consensus,"  in an essay founded on Denial101x and scientific literature: Scientific Consensus isn’t a “Part” of the Scientific Method: it’s a Consequence of it. (or via

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:

Lead author John Cook explains the 2016 "Consensus on consensus" paper.

Here is a video summary of the various studies quantifying the scientific consensus on human-caused global warming, as well as the misinformation campaigns casting doubt on the consensus.


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


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


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Comments 826 to 850 out of 908:

  1. 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 ( 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? ( 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!

  2. 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 ! ).

  3. 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.

  4. 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.

  5. 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 :)

  6. 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.

  7. 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.

  8. 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.


    [DB] Inflammatory snipped.

  9. 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.

  10. 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.

    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

    B. Doran and Zimmerman 2009 - Examining the Scientific Consensus on Climate Change
    EOS, Volume 90, Issue 3, Pages 22–23, doi: 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

    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

    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

    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

    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

    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

    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

    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.

    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.

  11. 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.


    [DB]  Sloganeering and accusations of impropriety snipped.

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  12. 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.


    [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"


    "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."

    "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)."

  13. 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% .

  14. 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. 

  15. 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.)


    [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.

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    Moderation complaints, inflammatory tone and baiting snipped.

  16. 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 ?

  17. 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.

  18. 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.

  19. 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.

  20. 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).

  21. 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.


    [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).

  22. 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.  ;-)

  23. 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.

  24. 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.
  25. “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.”

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