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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

"[...] 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 1955 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 26, 2023: The "At a glance" section was updated to improve readability.

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 archive.org)

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.

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 476 to 500 out of 906:

  1. Jonathon I note that you have not addressed either of my comments. However, the consensus view is not that the plausible range is all positive values, if you want to see what the range of plausible values is then lets discuss it on the thread devoted to that issue i.e. How sensitive is our climate?. There you can find peer-reviewed research on the plausible ranges according to different methods. Your argument is essentially a straw man, I don't particularly see any point in arguing about it either, but if you change your mind, please take it to a more appropriate thread.
  2. 475, Jonathan, Your entire rant is simply muddying the waters of what a definition of consensus might mean. As has already been explained and discussed, science doesn't really ever bother with defining and delineating a consensus. The consensus simply is. It is whatever most people in the field understand and agree with. There are always some who agree with X but disagree with Y, or vice versa. There's always a Z that's so basic and given that everyone but crackpots agree with it, and a W that's so far out of the mainstream that no one takes it seriously. The point is that there is no structure. Scientists don't get together once a year at the annual consensus convention and vote on which parts of science will or will not be considered accepted. Scientists get up in the morning. They go to work. They study, research, think and publish, and read each other's papers. Over time, like a hive mind, a social network of understanding evolves. What you are doing with the range of climate sensitivities is to muddle that, by taking the simple idea that every scientist has what he believes is a likely range of sensitivities, and instead conjuring a world where each scientist picks a specific number, and then claiming that because there are so many different numbers, there cannot be a consensus. This is all typical denier nonsense, intended to confuse people and sew doubt. The bulk of scientists know what the likely range of sensitivities is. A small group of fringe scientists expect sensitivities outside of that range. This does not mean that scientists are at all confused on the issue (which is what you ultimately are trying to imply with your own personal redefinition and portrayal of a consensus).
  3. Sphaerica, You are a little late to the party, so I will bring you up to date. 1. The claim has been made here that since atmospheric CO2 leads to increasing temperature that there is a consensus on climate sensitivity, and it is positive. 2. The claim has also been made that the actual range which makes up the climate sensitivity is irrelevant, as long as we all agree on the endpoints of that range. 3. The final claim is that we all agree on that range. I disagree with all three claims. The first two claims are simply ridiculous, as they have no real meaning. It is not enough to know that X influences Y, but we need to know how much X influence Y, and if the influence of X on Y is unlimited, then do we really know anything about X and Y? The third claim is the only one with any real meaning. It is not sufficient for a small group to agree on a range if others do not, and calling Link, Spencer, Pagani, and Hansen "fringe scientists" does not add to your credibility. If you wish to add anything further, I suggest you tone down your attitude and try to become scientific in this discussion.
    Response:

    [DB] "If you wish to add anything further, I suggest you tone down your attitude and try to become scientific in this discussion."

    Good advice; please embody it yourself so others may emulate your positive example.

  4. Jonathan#478: Once again, this is not the thread for detailed sensitivity discussion. By disagreeing with 'claim number one,' are you suggesting that sensitivity is either 0 or negative? If so, you would do well to refer to a sensitivity thread. But you have created new goalposts in the other two of your three claims: 'we all agree.' There is no such specific language in the definition of consensus as 'general agreement.' This is similar to the artifice used by the petition project, which contrived this language: 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" Such language as 'convincing,' 'forseeable,' and 'catastrophic' are non-scientific. And 'we all agree' is higher than most legal burdens of proof.
  5. Muon, See posts #475, #470, #456, and #454 for your answer. Remember, it was the other posts here at SKS who came up with claims, not myself. You would also be wise to learn that Webster defines consensus as "general agreement." If posters here are defining consensus as something else, then that would be reason for confusion.
  6. Jonathan, 'General agreement' was exactly how I defined consensus. You have added 'we all agree,' which requires unanimous consent - a goalpost shift if ever there was one. I doubt you will ever find that.
  7. 478, Jonathan, No, I'm not late to the party. I've read all of the comments. You missed my point. You are the one who is making propositions which others on this thread then try to recast into reasonable statements. You ignore their input and go on and on with your own peculiar interpretation of events as if you are speaking a different language, or rather speaking and not listening. I will repeat: You are personally redefining "consensus" in a way that lets you claim that there is none. The problem lies in your personal definition of consensus. There is a consensus that climate sensitivity is positive. The only people who try to imply otherwise are Lindzen and Spencer, but I don't think that even they would be caught dead actually coming out and saying such foolishness. There is a vague consensus around the likely range of climate sensitivity, based on the growing number of studies that all seem to fall in the 2˚C-4.5˚C range, centered somewhere around 3˚C. You can use the search button at the top of the page to find, read, and argue about such claims. But the point here is consensus. There is a growing consensus, resulting from a growing body of mutually confirming evidence using multiple sources and observations, which helps to bracket likely climate sensitivity. That you refuse to accept this consensus does not dissipate it one whit. That you choose to try to cast the term "consensus," the actual nature of such a consensus, or the body of knowledge behind said consensus into your own "we don't know, we can't know, we should wait" paradigm again does not dissipate the actual consensus one whit.
  8. Muon, [snip] Is that your only issue here? That I used we all agree instead of general agreement?
    Response: [Dikran Marsupial] Inflamatory deleted. Please can everyon involved in this discussion return to a more neutral tone. As there is "general agreement" amongst the climatolgists, but they dont all agree then the difference between definitions is substantive. Please, no more word games, no more discussion of climate sensitivity on this thread. Please get back on topic.
  9. Jonathon#483: If you want to debate the existence or validity of 'consensus,' then it is critical to set a standard. Do you not see the difference between 'general agreement' and 'we all agree'? For example, there is probably 'general agreement' among regular readers here that the Oregon Petition is a waste of time. However, I would not say 'we all agree' about that.
  10. Muon, Any confusion between 'we all agree', 'general agreement' and 'consensus' was unintentional.
  11. There was a concensus that the earth was flat for centuries. Science is about finding a model which not only fits retrospectively observed data but also accurately predicts the future. There is a concensus that the world is warming and that CO2 acts as a warming agent. That's it, there is no concensus on whether CO2 or another warming agent e.g. Methane is the primary warming agent. Nor does the IPCC have confidence in it's modelling, producing 5 potential scenarios in which the climate hardly warms at all, up to a potentially disastrous 4C increase.
    Response: [Rob P] - Indeed there was a consensus on Earth's flatness, but it wasn't a scientific consensus. The ancients Greeks realized the Earth was round two thousand years before Columbus sailed to the Americas, and Eratosthenes (a Greek mathematician) accurately calculated the circumference of the Earth around 200BC. "Nor does the IPCC have confidence in it's modelling" Citation? This isn't the wild, wild west of the intertubes where any old rubbish claim can be made. We expect you to support assertions with references to the relevant peer-reviewed literature, in other words - facts. Also, don't spam the threads. If you have a point to make, find the most appropriate and relevant thread to comment on by using the search function. Please read the comments policy. Failure to comply may result in your comment being deleted.
  12. I don't see any links in the majority of the posts on here. Are you claiming that there is only 1 model predicting climate change increase and this is agreed by all warmists? The fact is that a real scientist seeks the truth by creating a model that fits observed data and then checks it's accuracy against new data. There is no model that has managed to accurately predict climate change. All we have is a load of excuses that no model is accurate over a time period less than 30+ years. No explanation as to why a model should not be accurate over shorter timescales has been presented to the best of my knowledge.
  13. http://www.ipcc.ch/ipccreports/tar/slides/05.02.htm. The link.shows that the IPCC do not have a concensus on how much the earth will warm in future. The claim by warmists is that they can't be expected to accurately predict temperature change in the short term, but judging from the graph, over the long term their guesses just get wider.
    Response: [muon] You seem to have missed the moderator's response immediately above. There is a thread dedicated to climate modeling; use the Search function or view the 'Most Used Climate Myths' to find it. While you're at it, view the Comments Policy.
    Note, too, that unsubstantiated claims such as yours carry little validity and make you seem as if you are not very well versed in this science. Use of terms such as 'warmist' doesn't help make your case either.
  14. So I post a link which shows there's no concensus even amongst the warmists as to what the climate change model is, and muon claims that this is off topic. No scientist threatens to delete posts which don't fit with their view of the world, they seek to uncover the truth and present evidence that cannot be disputed. I don't know what the purpose of this site is but it certainly isn't interested in climate change science
    Response: [muon] We'll try again.
    Perhaps you could start by reading the original post, which deals with the idea of 'consensus' among scientists, not 'convergence' of climate models. Follow that by a thorough reading of the Comments Policy; if you cannot abide by that policy, your comments should indeed be deleted.
    The thread about modeling, if you care to have a look, is #6 on the 'Most Used Climate Myths.' Read and learn. Then start asking questions; you'll find most here are glad to engage in reasonable debate. However, if you are here to just throw around jargon, make unsupported claims and lecture about your views on 'uncovering the truth,' you're wasting everyone's time.
  15. 489, Jdey123, You posted a link that, combined with your interpretation of it, demonstrates that you don't understand how modeling or science work. Climate science is of course inexact due to the large number of variables and the difficulty in measuring them. As a result, predictions must cover a broad range. This does not devalue the predictions or imply a lack of confidence or understanding. You don't complain when the weatherman tells you it will rain tomorrow, but does not accurately predict that the first raindrop will arrive at exactly 3:37 PM. Your observations and complaints in three posts add no value. They advance nothing. They pretty much make you sound like you're really grouchy, and climate science is telling you something you'd rather not hear. That, in and of itself, is nothing new. Lots of deniers do it day in and day out. Do you have anything substantive and meaningful to post, or to ask?
  16. #489, Jdey123, the scenarios in your link in post 488 represent different emissions scenarios not lack of consensus over the climate change models. If anything, there is too much consensus in climate models IMHO. The guesses get wider over the long term because they properly reflect uncertainty in unpredictable natural variations that increase over time. Here's a good explanation of the additive uncertainty http://www.nature.com/climate/2010/1002/full/climate.2010.06.html introduced by lots of factors that each have their own uncertainty. Having a model that produces a number or a small range in a 100 year climate forecast is impossible.
  17. Jdey123 - I dont know whether your post will remain since you seem to be disregarding the comment policy which will not continue. This site is about providing what the science says in response to skeptical arguments. If you want to learn that then stay around. I'm short of time, but lets sort some basics. What model tells you what climate (30 averages of weather) do, given a particular emission scenario. They obviously cannot predict what humans will do - that is for politicians to decide. Its like firing a cannonball. If you choose this angle, then you get this trajectory. However, the force from the gunpowder is subject to uncertainty so the exact landing spot has uncertainty too. The uncertainty is qualified - and shown on the IPCC predictions. It seems to me that you believe that the modellers make claims that no published science in fact makes. You could learn what the models actually do and what they predict. Then you can discuss sensibly what models can and cannot do. Until you do that, your argement makes no sense. You are attacking a strawman - a common tactic. Please go to the "Models are unreliable" thread, and take from there after you have learnt a bit.
  18. scaddenp. No serious scientist deletes posts that disagree with their viewpoint. This magazine labels these as political or even more ridiculously that they're off topic and removes them. We know how much greenhouse gas has been produced by mankind, so assuming that the growth rate continues on trend, then you should be able to predict with a good degree of confidence what the global mean temperature will be in a relatively short time period, 5 years say. If you can't do this, and say that there are too many factors - mankind and nature - that prevent any level of confidence being attributed to your predictions, then your predictions are practically useless. There is still no concensus amongst warmists as to which greenhouse gas is the main culprit. Is it CO2 or methane? Both of which, of course, have both manmade and natural sources.
    Response:

    [DB] "If you can't do this"

    Straw man argument.  Even removing exogenous factors such as volcanic effects and oceanic cycles, a trend of much more than a decade is typically needed for the underlying warming signal inherent in multiple metrics used to monitor global warming due to the noisy nature of the data.

    "There is still no concensus amongst warmists as to which greenhouse gas is the main culprit."

    100% incorrect.  You will need to actually educate yourself more on this topic to understand just how wrong this statement is.  This is the equivalent of saying that 2+2=a porcupine.

    Trolling comments struck out.  Future comments of this nature will be simply deleted.  FYI.

    [not DB] Use the Search box to look for "methane" without the quote marks. Then search for "Scientists can't even predict weather."

  19. Science is about trying to establish truth by coming up with theories and then demonstrating that new data meets the prediction that the theory made. Creating a site where only warmists are allowed to attack arguments that critics of the science (labelled as denialists) have pointed out is not science. 5 years, ago, warmists had even more alarmist scenarios that they claimed would happen to earth. The more alarmist of these have now been dropped leaving just those scenarios which could be credible left. So far, none of these scenarios have been proved, and if you're a scientist then that's what you should concentrate on rather than spouting propaganda.
    Response:

    [DB] "Science is about trying to establish truth by coming up with theories and then demonstrating that new data meets the prediction that the theory made."

    Imprecise; science is about developing an explanation (a hypothesis) that best explains what we can see and measure.  Tests are then devised to either support or disprove the hypothesis.  Those hypothesis that withstand the test of time and much research are then called "theory".  One such is the theory of gravity.  Another is the theory anthropogenic global warming.  This link may help.

    "Creating a site where only warmists are allowed to attack arguments that critics of the science (labelled as denialists) have pointed out is not science."

    Two misconceptions here.  This site was created to debunk the logical fallacies of those who pretend to try to poke holes in the research by ignoring the evidence which contradicts their position.  The second misconception is that the term denialist refers to those who ignore evidence contrary to their position, no matter how damning.  If you prefer, substitute the term fake-skeptic on those occasions you encounter the term "denialist" on this website.  They are interchangeable.

    The remainder of your comment, unfortunately, devolves into ideology and misunderstandings of what science is, and isn't.  Please read the Comments Policy.

    [not DB] Use the Search box to search for "models are unreliable" without the quote marks.

  20. For the record, I don't have a political agenda. I would agree that it makes sense that mankind reduces pollution, not only just in case it'll lead to climate change but because if you live in a country that produces high levels of pollution, the immediate environment is terrible. I have never encountered such a debate as what we have on climate change that is so emotionally charged, however. This website is setup to try to debunk arguments put forward by all and sundry who've spotted holes in the warmist arguments, and there are lots of them. It will naturally attract people who agree and disagree with you. (-Snip-) I don't believe that warmists are a collective group, they represent a range of views of which the only concensus is that they believe that the earth will get warmer due to mankind. There is no concensus on how much warmer, which manmade pollutants are the primary cause of global warming etc.
    Response:

    [DB] "and there are lots of them."

    Unsupported assertions.  Be specific, put your objections on the appropriate threads (use the Search function; 4,700+ threads exist here).

    Your use of the terms "warmists" betrays ideology. Please study the Comments Policy & constructe future comments for better adherence to it.  Future ideological and/or inflammatory comments will simply be deleted and your posting privileges may be curtailed.

    Your use of the term "concensus" shows a lack of understanding of the scientific use of the term.

    Inflammatory snipped.

  21. #493 (or 492 if 492 gets deleted), Jdey123, keep in mind the lower scenarios in the chart in your link are ones that start with the assumption that CO2 output will be greatly curtailed. The scenario with the lowest projected warming, B1, is labeled "global environmental sustainability" which is not currently happening. For each of those scenarios (A1, A2, B1, B2) there is a low to high range of temperature in the year 2100. My understanding is that the low end of the range represents the warming from CO2 and fast feedback which is basically increased vapor due to the CO2-caused temperature increase, but no other feedbacks. The high end of the range includes some "slow" feedbacks like permafrost melting and releasing CO2 and methane. Since that is already happening those are not necessarily slow anymore but there is considerable uncertainty about the future amounts. The darker line inside that range is the current best estimate. The amounts and types of uncertainty around that best estimate are difficult to depict in such a simple chart, and it is worth reading some of the details in the text. For your comments about this website, there are actually quite a few threads that address some of your bones of contention. For example making predictions for 5 years involves climate but also weather and is addressed here Even the difference between skepticism and denial was discussed here. I suggest you read the comments below the opening piece because you will probably find that all or most of your arguments have been offered and responded to there. If you disagree with the response then maybe you should add to that thread.
  22. Eric, when you produce a model that can predict the future global mean temperature, then it becomes science. In the mean time, it's theory. Weather forecasters are at least correct most of the time for a 1 day forecast. They may not be 100% correct, but they're correct often enough that most people have confidence in 1 day forecasts. Most people also have little confidence in forecasts greater than a few days. At 1 point, forecasters rather ambitiously used to issue seasonal forecasts but were wrong so often, they lost complete credibility. With climate change, we're told that the model can't be accurate either in the short or long term due to too many complicating factors. (-inflammatory snipped-). It will no doubt take a supercomputer bigger than what we have today and years of research, but humanity will eventually be able to crack this. As I've mentioned in my last post, I'm fine with the demand that mankind reducing pollution but I'm not ok with calling a theory, scientific fact. What exactly is my supposed political agenda here?
    Response:

    [DB] Please refrain from introducing politics into the discussion.  This is not a thread devoted to politics & climate science (others do exist that cover that).

    Also, your discussion of models is off-topic on this thread.  Please use the Models are unreliable thread for that.  Thanks!

  23. (-Snip-)
    Response:

    [DB] Moderation complaints 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.

  24. Jdey123 - I think you find that this site is happy to argue about different viewpoints - provided the person does so in the correct place, in keeping with the comment policy. Everyone except John is a guest here. it is far more constructive to arguments about models on a models thread. Also, arguments about science need to proceed from discussion of data and publications, not misinformed opinion. So, in keeping with topic of this thread, perhaps you could tell us on basis you make this statement? "There is still no concensus amongst warmists as to which greenhouse gas is the main culprit.". As far as I know, this is flat out wrong. Show me otherwise.
  25. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC27611/?tool=pmcentrez "A common view is that the current global warming rate will continue or accelerate. But we argue that rapid warming in recent decades has been driven mainly by non-CO2 greenhouse gases (GHGs), such as chlorofluorocarbons, CH4, and N2O, not by the products of fossil fuel burning, CO2 and aerosols, the positive and negative climate forcings of which are partially offsetting. The growth rate of non-CO2 GHGs has declined in the past decade. If sources of CH4 and O3 precursors were reduced in the future, the change in climate forcing by non-CO2 GHGs in the next 50 years could be near zero. Combined with a reduction of black carbon emissions and plausible success in slowing CO2 emissions, this reduction of non-CO2 GHGs could lead to a decline in the rate of global warming, reducing the danger of dramatic climate change. Such a focus on air pollution has practical benefits that unite the interests of developed and developing countries. However, assessment of ongoing and future climate change requires composition-specific long-term global monitoring of aerosol properties." Global warming in the twenty-first century: An alternative scenario James Hansen,*† Makiko Sato,*‡ Reto Ruedy,* Andrew Lacis,* and Valdar Oinas*§ June 16, 2000

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