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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 101 to 125 out of 208:

  1. Quietman, "1. Hypothetical, based on poorly written fortran code." I certainly hope this isn't the extent of your understanding of climate science. "2. Historically false, If the CO2 was the powerful GHG it is claimed to be there would be no life on this planet." Non-sequitur. "The alarmists base their science on the concept of equilibrium and deny that the earth goes through cycles" Basic Strawman. No one denies that there is cyclical climate change. American Meteorlogical Society: "Human activities have become a major source of environmental change. Of great urgency are the climate consequences of the increasing atmospheric abundance of greenhouse gases... Because greenhouse gases continue to increase, we are, in effect, conducting a global climate experiment, neither planned nor controlled, the results of which may present unprecedented challenges to our wisdom and foresight as well as have significant impacts on our natural and societal systems.[22] " "prophesized by algore and his followers." Yeah, all those scientists follow Al Gore. How silly. American Physical Society: "The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now." World Meterological Organization: In its Statement at the Twelfth Session of the Conference of the Parties to the U.N. Framework Convention on Climate Change, the World Meteorological Organization (WMO) confirms the need to “prevent dangerous anthropogenic interference with the climate system.” The WMO concurs that “scientific assessments have increasingly reaffirmed that human activities are indeed changing the composition of the atmosphere, in particular through the burning of fossil fuels for energy production and transportation.” The WMO concurs that “the present atmospheric concentration of CO2 was never exceeded over the past 420,000 years;” and that the IPCC “assessments provide the most authoritative, up-to-date scientific advice". American Geophysical Union: "The Earth's climate is now clearly out of balance and is warming. Many components of the climate system—including the temperatures of the atmosphere, land and ocean, the extent of sea ice and mountain glaciers, the sea level, the distribution of precipitation, and the length of seasons—are now changing at rates and in patterns that are not natural and are best explained by the increased atmospheric abundances of greenhouse gases and aerosols generated by human activity during the 20th century. Global average surface temperatures increased on average by about 0.6°C over the period 1956–2006. As of 2006, eleven of the previous twelve years were warmer than any others since 1850. The observed rapid retreat of Arctic sea ice is expected to continue and lead to the disappearance of summertime ice within this century. Evidence from most oceans and all continents except Antarctica shows warming attributable to human activities. Recent changes in many physical and biological systems are linked with this regional climate change. A sustained research effort, involving many AGU members and summarized in the 2007 assessments of the Intergovernmental Panel on Climate Change, continues to improve our scientific understanding of the climate. " "This describes the AGW alarmist to a T." The above comments make the following comment: "in this case by infantile name calling." quite ironic.
  2. Re: "Basic Strawman. No one denies that there is cyclical climate change." You obviously have not been reading the comments at this website. This has come up several times, so I am glad you consider it a strawman. I suggest that you read chris' comments.
  3. Re: "American Physical Society: "The evidence is incontrovertible: Global warming is occurring. If no mitigating actions are taken, significant disruptions in the Earth’s physical and ecological systems, social systems, security and human health are likely to occur. We must reduce emissions of greenhouse gases beginning now." I await proof. I wan't to see at least one prediction that is correct. The only accurate predictions have come from the skeptical scientists (deniers) like the late Rhodes Fairbridge. Sorry, but my view of anyone who has not left the IPCC by this point is someone that can not think for themselves. Sheep going along for the ride with what they view as "the winning team". Lots of BS and outright lies fudging numbers and skewing results to get funding.
  4. You don't seem to see what is actually happening. If you take the time to study what is going on inside the earth you would also understand why the IPCC depictions are false. The hotspots relate directly to the earths tectonics. CO2 is not warming the oceans, thats why the results don't match the predictions. Parts of the ocean are warming while others are cooling. The warming parts correspond to undersea vulcanism or what the kids call plate tectonics. That's the driver behind the PDO, AMO, etc. It's the ocean that drives climate, not the other way around. It's the Earth that drives the oceans and it's the sun that drives the earth and the planets, in particular Jupiter that drives the barycenter and alters the way the sun reacts with the Earth. Do the research. Skeptics do!
  5. Re: "American Geophysical Union: "The Earth's climate is now clearly out of balance and is warming." THERE IS NO BALANCE, THAT IS EQUILIBRIUM AND TOTAL BS!
  6. Re: "Yeah, all those scientists follow Al Gore. How silly." You are crediting the IPCC with something it does not have (scientists). It in fact edits and limits the subjects of any and all papers submitted by scientists and is the reason they are leaving the IPCC.
  7. I strongly suggest that you actually read the skeptical papers that are being derided by Hansen and his cronies.
  8. Re #97 from Quietman. Thanks for expanding on your answer. I'll let NewYorkJ's response at #101 stand as a response. You haven't stated what you believe to be an acceptable level of risk - since you seem to believe there is definitely, absolutely, no possibility of AGW via carbon emissions or any other means. This strikes me as sounding more like an assumption than a considered opinion based on known facts. Odd, given the views expressed ('Or you can just assume the alarmist position ... and ignore the arguments entirely. To deny the facts is to show ignorance, that is not what science is about, that attitude belongs firmly in religion and politics'). Or possibly, you consider (like many other 'skeptics') AGW to be a possibility, but not as likely as the IPCC consensus. That would beg the questions, how likely do you consider dangerous AGW to be, and what maximum level of likelihood would warrant a 'business as usual' response? Since you raise the issue of facts, I wonder if there is a consensus between 'skeptics' and the rest of us as to what the facts are. 1. CO2 is a greenhouse gas (leaving aside positive and negative feedback effects). 2. Both positive and negative feedbacks exist in the climate, and are not fully (or even mostly) understood, leading to the possibility of suprises (pleasant or otherwise). 3. CO2 is released by the burning of fossil fuels. 4. Measured atmospheric levels of CO2 are increasing, and are expected to continue to do so under BAU. 5. Fossil fuel use (and thus, CO2 emissions) has increased exponentially since industrialisation. It may take 50 or 100 years to run out of oil, and sufficient coal is left in the ground for a much longer period. If we continue with BAU, atmospheric CO2 levels will get much, much higher. This will occur in a period of decades - an unprecedented rate of change. The climate system as a whole is poorly understood - we are only beginning to build understanding. It is possible the IPCC and the various meteorological and other scientific organisations from around the world that contributed to the consensus view have got it so horribly (wonderfully?) wrong that we all have absolutely nothing to worry about - but how likely is that? So what do you reckon - how likely is AGW, and how much risk is too much?
  9. You misunderstand my position (and most skeptics) entirely. AGW is real. It has a small impact on the planet but not enough to prevent the next glacation. As far as risk goes, you should know better. If you have a choice of a risk of basement floodiing from a broken sprinkler system or your house burning down, which risk do you choose? We have a choice with AGW as well. We can thank AGW for what little extra warmth we have on this planet. Yes, maybe you are uncomfortable in the heat but I can tell you from experience at -60F to +140F that humans can take the heat but we die with the cold. Lets take a look at paleohistory. We evolve from prosimians into true primates in the Eocene and Oligocene. Conditions of the Eocene were high levels of CO2 and high temps all over the planet. And, we evolved in southern Asia, Jungles, Hot, Humid, and spread from there into Africa where there were less predator species (Beard, "Hunt for the Dawn Monkey). The Ice age (No.4) hits us in the Neogene, we continue to evolve along the equator in northern Africa into homonids. By the the the glacial maximum hits we have split from H. erectus into H. sapiens and H. neandertalensis and we are both in deep shit. We both get close to population levels that will quickly end in extinction but things warm back up. We were lucky, our cousins did not fare as well and their population continued to decline while ours recovered. This is history. What do you think would happen if we had a glacial maximum now? Extinction is near certain. So why would we want to actually stop the only thing that could actually reduce the impact of another glacation? Are you crazy or just have a racial death wish?
  10. Neandertal References: ScienceDaily (Sep. 13, 2007) New Evidence On The Role Of Climate In Neanderthal Extinction Adapted from materials provided by University of Leeds ScienceDaily (Dec. 30, 2008) Competition, Not Climate Change, Led To Neanderthal Extinction, Study Shows Journal reference: Banks WE, d'Errico F, Peterson AT, Kageyama M, Sima A, et al. Neanderthal Extinction by Competitive Exclusion PLoS ONE, 2008; 3(12): e3972 DOI: 10.1371/journal.pone.0003972 AGW References: ScienceDaily (Dec. 19, 2008) New World Post-pandemic Reforestation Helped Start Little Ice Age, Say Scientists Adapted from materials provided by Stanford University ScienceDaily (Dec. 18, 2008) Did Early Global Warming Divert A New Glacial Age? Adapted from materials provided by University of Wisconsin-Madison
  11. Re; #110 - thanks for the links. Re: #109 I think I already mentioned that I consider many ACC 'skeptics' to be believers in at least the possibility of ACC, if not the fact. As for the choice you offer - letting the house burn down OR letting the basement flood from a broken sprinkler - this implies we only have an 'either/or' choice. If it were that simple, couldn't we buy insurance AND fix the sprinkler (and you thought my analogy was asinine)? The problem I have with your suggestion is this - you are saying that we can somehow use artifiacial means (of which we understand little) to 'fix' a natural cycle (which we understand even less). It sounds like randomly twiddling the dials on the nuclear reactor (another asinine comparison) because last time we did this, it didn't go into meltdown. Playing with the dials must be preventing a meltdown, so we must do more of it. Continuing with BAU because AGW/ACC might not/probably won't happen is risky. Accepting that this approach is risky, then doing it anyway to try to forestall a natural cycle has to be the definition of insanity. A warmer world is not cost free (droughts, floods, storms, famine kill too). Extinction of the species from either warming or ice age, I would have to imagine, is unlikely, but many things can happen short of extinction. Humans are supremely adaptable (perhaps only outranked in that regard by rats), so my guess is that we would survive either scenario. Civilisation is another matter. In a major tick upwards or downwards in global temperatures, at the very least, we could expect a major loss of material culture - something like slipping from the Roman Empire into the Dark Ages. Worse than this is also possible. Given that atmospheric carbon levels are a major cause of the problem, and given that we are currently accelerating growth in atmospheric CO2 levels, it would be a prudent time to step on the brakes while research into the climate continues. Who knows, you may be right. We may have dodged catastrophe by dumb luck. Touching the brakes now (to slow and maybe pause the warming effect) gives us a bit more time to work out how lucky we are and how lucky we can continue to count on being. Has anyone seen any reliable arithmetic on what deep but realistic cuts in emissions now would do for atmospheric carbon levels (and warming) over the next 100 years or more? Any idea of the kind of timeframe we would need to go into reverse and see a cooling trend (as opposed to cooling cycle)? I am guessing (once again) that the natural carbon sequestration processes are far slower than anthropogenic GHG emissions. Quietman - I will read your links, but I don't doubt your potted paleohistory above. I just doubt it's relevance given historic and projected GHG emissions growth. Deep cuts in emissions now will not cut atmospheric CO2 levels in the near term, only stabilise them. If the warming effect has helped us, it will still be there for a good while.
  12. Risky Re: "A warmer world is not cost free (droughts, floods, storms, famine kill too). Extinction of the species from either warming or ice age, I would have to imagine, is unlikely, but many things can happen short of extinction. Humans are supremely adaptable (perhaps only outranked in that regard by rats), so my guess is that we would survive either scenario." I agree that a few survivors might make it through another glacial maximum if they live close to the equator but without any semblence of civilization remaining. On the other hand we can easily adapt to warming - no problem. Relocation will be much easier than you think because wide tracts of fertile land currently incapable of supporting us will be available. I and most of the other skeptics agree that cleaner environment is essential to our future, it's only CO2 that is the sticking point. We all feel that CO2 is not a problem but essential and increased CO2 will not be catastrophic. Some of the computer sims are hopelessly bad because they lack important factors. One major error is desertification. All the signs point to a warmer, WETTER, world, not drier. If you read those links I posted you will see that the answer lies in growing trees and stopping the massive cutting and burning of our forrests.
  13. ps If you have a good head for math read Patricks comments. He does explain how climate functions and although he doesn't realize it, actually agrees with me.
  14. Quiteman, NewYorkJ: "No one denies that there is cyclical climate change" "You obviously have not been reading the comments at this website. This has come up several times, so I am glad you consider it a strawman. I suggest that you read chris' comments." Which scientist thinks there aren't ice ages, ENSO, etc.? If you're referring to the Chris in the following post, your assertion is demonstrably false. http://www.skepticalscience.com/climate-models.htm "I await proof. I wan't to see at least one prediction that is correct. The only accurate predictions have come from the skeptical scientists (deniers) like the late Rhodes Fairbridge. " Obviously you haven't been paying attention. http://www.skepticalscience.com/climate-models.htm Most contrarians have been so utterly wrong for the past 20 years one has to wonder why anyone would seriously continue to entertain their rantings if one is seeking credible sources in good faith. "THERE IS NO BALANCE, THAT IS EQUILIBRIUM AND TOTAL BS! " Because you say? The CAPS add a nice effect. "CO2 is not warming the oceans, thats why the results don't match the predictions. Parts of the ocean are warming while others are cooling." http://data.giss.nasa.gov/gistemp/graphs/Fig.A4.lrg.gif Globally, the oceans are warming. You also don't understand what the models say. The slower rate vs land is predicted by the models. http://www.agu.org/pubs/crossref/2005/2004GL021592.shtml ENSO creates much of the regional and annual variability. "The warming parts correspond to undersea vulcanism or what the kids call plate tectonics." It's what adults would call a very silly and unsupported assertion. It even made the RC "Most bizarre new contrarian claim" of 2008. "Do the research. Skeptics do! " Climate contrarians aren't big on honest research. They tend to look for very selective data to support their assertions while ignoring the big picture and completely disregarding the wide body of evidence that opposes their pre-determined conclusions. NewYorkJ: "Re: "Yeah, all those scientists follow Al Gore. How silly." "You are crediting the IPCC with something it does not have (scientists). It in fact edits and limits the subjects of any and all papers submitted by scientists and is the reason they are leaving the IPCC." They don't have scientists? Or is it just scientists you don't agree with (which would be the vast majority of them)? http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-annexes.pdf The IPCC, however, tends to be conservative with its predictions - resulting in the conservative common ground that most of its participants can agree upon. It tends to be conservative on sea level rise, for instance, even though real-world observations are showing more rapid melting in the Arctic than they project. "Sorry, but my view of anyone who has not left the IPCC by this point is someone that can not think for themselves. Sheep going along for the ride with what they view as "the winning team". Lots of BS and outright lies fudging numbers and skewing results to get funding. " If you don't like the Nobel Prize-winning IPCC, take your pick. http://en.wikipedia.org/wiki/Scientific_opinion_on_climate_change It's all a vast leftwing conspiracy. Convincing conspiracy theorists is a futile effort. "I strongly suggest that you actually read the skeptical papers that are being derided by Hansen and his cronies. " Hansen must have a lot of "cronies". I've read skeptical studies. There are only a small handful of them that have passed an independent peer review in a reasonably reputable journal, and results have been highly questionable and often later refuted outright. As an example, there are a few studies that made assertions about a potential significant Urban Heat Island Effect. It relied largely on UHA satellite data (managed by 2 "skeptics") that showed little to no warming. The data saw a series of signficant upward corrections which made the studies effectively obsolete. Example: http://www.ssmi.com/papers/mears_science_2005.pdf A discussion: http://www.realclimate.org/index.php/archives/2007/12/tropical-troposphere-trends/ Instead of bothering to scrutinize the satellite record, they just speculated that the surface data was all wrong. As it turned out, the climate contrarians managing the data were all wrong, as usual.
  15. An argument being made here is that human-induced warming could help prevent the next ice age. That argument might make sense if an ice age was known to be imminent (say, 100 years). Most indications are that it's tens of thousands of years away. http://www.sciencemag.org/cgi/content/summary/297/5585/1287 In contrast, human-induced warming is effecting us now and over the next few hundred years, the strongest effects of which will hit us long before the next glaciation. This site has a good list of costs/benefits. http://www.skepticalscience.com/global-warming-positives-negatives.htm A good book on this topic: http://www.amazon.com/Six-Degrees-Future-Hotter-Planet/dp/142620213X This book has hundreds of references to objective peer-reviewed studies on the effects of global warming, at each degree C in global temperature rise. This is better than any indirect speculation. Essentially, costs immediately exceed benefits. With each degree of warming, the cost-benefit gap expands greatly. It may be comforting to hope that a warmer world will be a tropical paradise for Earth's billions of human inhabitants, but that's not the reality.
  16. NewYorkJ Re: "An argument being made here is that human-induced warming could help prevent the next ice age. That argument might make sense if an ice age was known to be imminent (say, 100 years). Most indications are that it's tens of thousands of years away." The problem with your statement is that it does not recognize the fact that we are already in an ice age, the 4th or Neogene-Holocene ice age. If you read those links you will see that we are slowing down the onset of a glacation.
  17. ps Denial of facts will not change them.
  18. Re: "Climate contrarians aren't big on honest research. They tend to look for very selective data to support their assertions while ignoring the big picture and completely disregarding the wide body of evidence that opposes their pre-determined conclusions." Read the links posted in the volcano thread. The data is not selective, it is the facts about how the earth is currently changing and has always done in the past.
  19. Re: "If you don't like the Nobel Prize-winning IPCC, take your pick." Ignorance is bliss.
  20. ps educate yourself http://carbon-sense.com/wp-content/uploads/2009/01/climate-change-perspective.pdf
  21. Scientists abandon global warming 'lie' 650 to dissent at U.N. climate change conference WASHINGTON – A United Nations climate change conference in Poland is about to get a surprise from 650 leading scientists who scoff at doomsday reports of man-made global warming – labeling them variously a lie, a hoax and part of a new religion. Later today, their voices will be heard in a U.S. Senate minority report quoting the scientists, many of whom are current and former members of the U.N.'s own Intergovernmental Panel on Climate Change. About 250 of the scientists quoted in the report have joined the dissenting scientists in the last year alone. In fact, the total number of scientists represented in the report is 12 times the number of U.N. scientists who authored the official IPCC 2007 report. more. As this topic is consensus, I feel that this is somewhat relavent.
  22. Re: #121 Quietman, where is that well-honed skepticism you keep telling us about? You can be quite dismissive of the IPCC ("Sorry, but my view of anyone who has not left the IPCC by this point is someone that can not think for themselves. Sheep going along for the ride with what they view as "the winning team". Lots of BS and outright lies fudging numbers and skewing results to get funding. "). Yet you uncritically post a link to a story that is no more than the annual reheating of that old chestnut, the Leipzig Declaration. I am sure there are some genuine scientists in climate-related fields are among the additional 250. Some of them might even be climate scientists, with published, peer reviewed science to back their skepticism, but the liberal padding of the numbers with T.V. weather reporters and other interlopers does not inspire confidence. If the skeptics genuinely feel they have a good basis for refuting scientific consensus here, why would they need to pad out the list? Obviously they don't feel their scientists are reputable enough, or the science is strong enough. Your basis for skepticism seems to change depending on the discussion - one minute, a believer in CO2 emissions as the only way to forestall a catastrophic ice age, the next minute dismissive of the very idea of ACC (see above 'BS and outright lies fudging of numbers blah blah blah...'). This is not skepticism, it's advocacy. Any argument to avoid deep cuts to emissions will do - even contradictory ones. Any skeptical scientist will do, even the ones who are not scientists, or not even skeptics. As for the story itself: "In fact, the total number of scientists represented in the report is 12 times the number of U.N. scientists who authored the official IPCC 2007 report." A bit of a nothing statement. Kind of like saying that all of our scientists outnumber some of theirs. The site posted does not list an author, but if you are interested, look up Marc Morano. Quietman, as a genuine skeptic, surely you have something better than that?
  23. Yes I do have something better. Tree farming. CO2 is doing as much as a GHG it can right now. But it can do more if we let it. Better management of our forrests will help make the planet more productive. Unfortuantely most states have no green acreas laws. If you wan't to help the environment get your state to pass one. Those states with green acres laws make it a minimum of 2 acres of property per house. Even if they only grow grass it's better than asphalt. This produces O2 and frees up nitrates which combined with CO2 aids in plant growth. One visable truism about past periods of high CO2 concentrations is giganticism. Plants and animals grew much larger than today and covered the entire earth. We don't have much chance of achieving this kind of growth but we could at least increase food production and free up land that is currently incapable of supporting life.
  24. ps I'm not a believer in consensus. The greatest minds in history all went against consensus. It just happens to be the topic of this thread and John wants us to try and stay on topic, hence most of my arguments and links are in the appropriate threads. Just click on "arguments" for the full list.
  25. Re: 116 Actually, if you read the link: http://www.sciencemag.org/cgi/content/summary/297/5585/1287 You'd note the conclusion: "Today's comparatively warm climate has been the exception more than the rule during the last 500,000 years or more. If recent warm periods (or interglacials) are a guide, then we may soon slip into another glacial period. But Berger and Loutre argue in their Perspective that with or without human perturbations, the current warm climate may last another 50,000 years. The reason is a minimum in the eccentricity of Earth's orbit around the Sun. " Ice age cooling, according to this study, won't even begin for tens of thousands of years. But lets say major cooling has already begun. Note how long it takes to reach glaciation. Let's assume it will happen more quickly than recent studies suggest - say 10,000 years. We can expected roughly 6 degrees C of cooling or approximately 0.06 per century. Since global warming is expected to very conservatively warm the Earth about 3 degrees this century on a business-as-usual path (some estimates are much higher), we could count on 2.97 degrees of net warming. Re: 124 Some great minds went against the mainstream many decades ago to propose the hypothesis that human activities would warm the Earth. They were right. Of course, if you examine the quality of minds (measured by the quality of their arguments), that are currently opposing the consensus, you might note that for every theory successfully challenged, there are hundreds that have failed. Failed challenges are often the result of unobjective agendas.

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