Opinion polls of climate change
According to a 2007 Newsweek poll, 42% of Americans believe that "there is a lot of disagreement among climate scientists about whether human activities are a major cause" of global warming". I posed the same question to members of the wunderground community on Monday, and even higher 56% of them thought so. However, the results of a poll that appears in this week's edition of the journal EOS, Transactions, American Geophysical Union, reveals that the public is misinformed on this issue. Fully 97% of the climate scientists who regularly publish on climate change agreed with the statement, "human activity is a significant contributing factor in changing mean global temperatures".
Figure 1. Response to the question, "Do you think human activity is a significant contributing factor in changing mean global temperatures?" The general public data come from a 2008 Gallup poll (see http://www.gallup.com/poll/1615/Environment.aspx). Image credit: EOS, Transactions, American Geophysical Union.
The anonymous poll was performed in late 2008 by Peter Doran, University of Illinois at Chicago associate professor of earth and environmental sciences, along with former graduate student Maggie Kendall Zimmerman. Doran and Kendall Zimmerman sought the opinion of the most complete list of earth scientists they could find, contacting more than 10,200 experts at universities and government labs around the world listed in the 2007 edition of the American Geological Institute's Directory of Geoscience Departments. The 2-minute, two-question poll had 3146 responses (30.7% of those polled). Approximately 90% of the scientists who responded were from the U.S., and about 90% held a Ph.D. degree. Of these scientists, 5% were climate scientists who published more than 50% of all their peer-reviewed publications in the past five years on the subject of climate change. The authors noted that the survey included participants with well-documented dissenting opinions on global warming theory. Question #1 was, When compared with pre-1800s levels, do you think that mean global temperatures have generally risen, fallen, or remained relatively constant?" About 90% of all the scientists and 97% of the climate scientists said temperatures had risen. Question #2 was, "Do you think human activity is a significant contributing factor in changing mean global temperatures?" About 82% of all the scientists agreed, and 97% (75 of 77) climate scientists agreed. This contrasts with the results of a recent Gallup poll that suggests only 58% of the general public would answer yes. Interestingly, petroleum geologists and meteorologists were among the biggest doubters in the new EOS poll, with only 47 and 64 percent, respectively, believing in human involvement.
In a press release on the study, author Peter Doran commented, "The petroleum geologist response is not too surprising, but the meteorologists' is very interesting," he said. "Most members of the public think meteorologists know climate, but most of them actually study very short-term phenomenon." He was not surprised, however, by the near-unanimous agreement by climate scientists. "They're the ones who study and publish on climate science. So I guess the take-home message is, the more you know about the field of climate science, the more you're likely to believe in global warming and humankind's contribution to it." Doran and Kendall Zimmerman conclude that "the debate on the authenticity of global warming and the role played by human activity is largely nonexistent 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."
The scientists most involved in assessing the current state of the climate are the most likely to have the "pulse of the planet"--a deep understanding of how the climate works and where we are headed. If 97% of these scientists believe in significant human impact on the climate, then it is probably so. Why is there such a disparity, then, between what they believe, and what the public and other scientists, such as petroleum geologists, believe? Dr. Ricky Rood has some excellent commentary on this issue in his latest wunderground Climate Change blog, and I offer these three reasons:
1) There are a few good climate scientists (3%) that believe humans are not significantly impacting the climate. One tends to hear the beliefs of this tiny minority a disproportionate amount. This is primarily because the fossil fuel industry pumps millions of dollars into PR campaigns to make sure you hear these dissenting views. That's not to say that these scientists are paid lackeys of the fossil fuel industry--that is not the case. These scientists' point of view happens to coincide with arguments that would protect the profits of the fossil fuel industry, so naturally the industry spends a lot of money making sure you hear these points of view. The fossil fuel industry PR campaigns also emphasize the contrarian views of a handful of non-publishing scientists working for private think tanks, who provide a distorted, non-objective view of climate change science (e.g., the attempt to hide summertime Arctic sea ice loss by quoting irrelevant statistics about wintertime global sea ice). These efforts have been highly successful in casting doubt on what is an overwhelming (though not unanimous) consensus among climate scientists. The fossil fuel industry PR campaigns are similar to the ones run by the cigarette industry to cast doubt on the harmfulness of smoking. "Doubt is our product," a cigarette executive once observed, "since it is the best means of competing with the 'body of fact' that exists in the minds of the general public. It is also the means of establishing a controversy." I recommend a reading of the 2008 book, "Doubt is Their Product", which discusses the many efforts by industry over the years to cast doubt on established scientific facts in order to protect industry profits.
2) The media contributes to the disproportionate coverage of the dissenting views, since one can make a news story more compelling by dramatizing conflict and giving equal weight to both sides.
3) Many people have a deep-seated belief in the relative insignificance of humans on a planetary scale. Geologists, who take the long view of time over geologic history, are particularly prone to this. Indeed, the planet is vast, and we are but tiny ants crawling upon its surface during a brief moment in geologic time. However, when one works regularly with the data, it becomes apparent that human activities are beginning to substantially impact weather and climate. When presented with facts contrary to ones beliefs, a good scientist will check the facts extra thoroughly to verify their validity, but then abandon those beliefs that don't fit the facts. The facts as accepted by 97% of our top climate scientists are that atmosphere is but a relatively thin, fragile layer of volatile gases beginning to show unmistakable changes due to the geometric explosion in human population over recent centuries. Those effects are only now beginning to be detectable, which is why human-caused global warming is so controversial in the public's eye. I predict that twenty years from now, climate change will be so obvious that the controversy regarding human responsibility will be gone.
Figure 2. The atmosphere viewed edge on from space. Tall thunderstorm clouds can be seen on the right side of the image, silhouetted against an orange layer of lower atmospheric gases (the troposphere) back-lit by the sun, just below the horizon. Above this layer is the clear blue of the stratosphere and the blackness of space. Seen from space, one can appreciate the thinness and potential vulnerability of the layer of gases that make up our atmosphere. Image credit: NASA Space Shuttle Flight 6 on 4 April 1983.
How representative is this poll?
The findings of another, more in-depth poll of scientists done in 2007 pretty much agreed with this week's Doran/Zimmerman poll, but were much more interesting. The 2007 poll, conducted by Fergus Brown, Roger Pielke, Sr., and James Annan, attempted to assess whether "a significant set of climate scientists agree or disagree with the perspective of the role of humans within the climate system as reported by the 2007 Intergovernmental Panel on Climate Change's (IPCC) Fourth Assessment Report". Out of the 1807 scientists in 53 countries who were contacted, 140 responded. Almost all respondents (at least 97%) concluded that the "human addition of CO2 into the atmosphere is an important component of the climate system and has contributed to some extent in recent observed global average warming". Among the other findings:
1) No scientists were willing to admit to the statement that global warming is a fabrication and that human activity is not having any significant effect on climate [0%].
2) The largest group of respondents (45-50%) agreed with the 2007 IPCC report.
3) A significant minority (15-20%) concluded that the IPCC overstated the role of the human role in affecting the climate.
4) A significant minority (15-20%) concluded that the IPCC understated the seriousness of the threat from human additions of CO2. Ten of the 140 respondents (7%) took the most pessimistic view that we are "seriously damaging the climate" and face "devastating consequences".
Here's the full text of the poll, which I've also put up on my latest wunderpoll to vote on, if you're a Weather Underground member:
Which one statement most nearly matches your personal opinion about the physical science basis of global warming, as exemplified by the 2007 Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report, Working Group 1 (WG1)? [If your personal opinion falls between two adjacent statements, please mark both]
1. There is no warming; it is a fabrication based on inaccurate/inappropriate measurement. Human activity is not having any significant effect on Climate. The data on which such assumptions are made is so compromised as to be worthless. The physical science basis of Anthropogenic Global Warming theory is founded on a false hypothesis.
2. Any recent warming is most likely natural. Human input of CO2 has very little to do with it. Solar, naturally varying water vapor, and similar variables can explain most or all of the climate changes. Projections based on Global Climate Models are unreliable because these are based on too many assumptions and unreliable data sets.
3. There are changes in the atmosphere, including added CO2 from human activities, but significant climate effects are likely to be all within natural limits. The 'scares' are exaggerations with a political motive. The undue emphasis on CO2 diverts attention away from other, important research on climate variability and change.
4. There is warming and the human addition of CO2 causes some of it, but the science is too uncertain to be confident about current attributions of the precise role of CO2 with respect to other climate forcings. The IPCC WG1 overestimates the role of CO2 relative to other forcings, including a diverse variety of human climate forcings.
5. The scientific basis for human impacts on climate is well represented by the IPCC WG1 report. The lead scientists know what they are doing. We are warming the planet, with CO2 as the main culprit. At least some of the forecast consequences of this change are based on robust evidence.
6. The IPCC WG1 is compromised by political intervention; I agree with those scientists who say that the IPCC WG1 is underestimating the problem. Action to reduce human emissions of CO2 in order to mitigate against serious consequences is more urgent than the report suggests. This should be done irrespective of other climate and environmental considerations.
7. The IPCC WG1 seriously understates the human influence on climate. I agree with those scientists who say that major mitigation responses are needed immediately to prevent catastrophic serious warming and other impacts projected to result from human emissions of CO2. We are seriously damaging the Earth's climate, and will continue to face devastating consequences for many years.
Figure 3. Results of the 2007 opinion poll by Fergus Brown, Roger Pielke, Sr., and James Annan of climate scientists, organized by question number (one to seven). In the USA, the mean response was 4.8, compared to 5.2 in all other countries, and 5.6 in EU countries.
The majority of climate scientists polled believe the 2007 IPCC reports essentially "gets it right", which is in part why I like to refer to the IPCC report as representing "the official word" on climate. This report concluded that there was a greater than 90% chance that most of the observed global warming in the past 50 years was due to emission of greenhouse gases by human activity. However, there are substantial minorities that believe the IPCC underestimates or overestimates the potential impacts, and these voices need to be respected, as well.
Dr. Ricky Rood talks in greater depth on this issue in his latest wunderground Climate Change blog: "There are many thousands of scientists, and while large groups of individuals often share many like-minded values and beliefs, they are never in lockstep on the details of all aspects of their beliefs. It is not expected that in a community of thousands of scientists that there is a uniform chant of doctrine. This is especially true given the very nature of scientific investigation of an enormously complex system."
Other voices on climate scientist polls
Dr. James Annan's blog