A recent PBS Climate Change Special called "Climate of Doubt." (Link)
Here Tom addresses one of the special's points.
PBS Frontline climate change special cites bogus ‘consensus’
by Tom Harris
Besides the obvious bias we have come to expect from most main stream media coverage of climate change, “Climate of Doubt“, aired Tuesday night on PBS’s Frontline, committed one serious mistake that can not be left unaddressed.
Frontline repeatedly implied that there is an overwhelming consensus among climate scientists that our CO2 emissions are driving us to a global climate catastrophe. They cited 97% as the fraction of the climate science community who agreed with climate alarmism.
That number is easily dismissed. It comes from a 2009 online survey of 10,257 earth scientists, conducted by two researchers at the University of Illinois. Strangely, the researchers chose to eliminate almost all the scientists from the survey and so ended up with only 77 people, 75 of whom, or 97%, thought humans contributed to climate change.
Besides the fact that, with tens of thousands of climate scientists in the world, 77 is a trivial sample size, the survey coordinators did not ask respondents how much humans had contributed to climate change. The poll is therefore meaningless.
In reality, no one knows, or even currently can know, what the “consensus” is in the world climate science community. This is because there has never been a meaningful, comprehensive worldwide poll about the topic among the thousands of scientists who specialize in the many relevant disciplines.
Scientific theories are never proven by a show of hands, of course. Otherwise, the Earth would still be considered flat and space travel impossible. It is indeed those who go against the flow—independent, original thinkers –who are usually responsible for our most meaningful advances in science.
But, most reporters, politicians and the public understand little of the scientific method and even less about the exceptionally complex field of climate change science. Consequently, they often look for an indication of ‘consensus’ when trying to decide which science should form the basis of important public policies decisions. Distasteful though this is to pure scientists, it is a reality we need to recognize and it is therefore important to try to decide whether a reliable determination of ‘consensus’ has been made about the causes of climate change.
First, it is important to realize that, of the prominent national and international science bodies that have issued official statements that are in support of the CO2/climate crisis hypothesis, none released results that show a majority of their members agreeing with the assertion.
For example, Fellow of the Royal Society of Canada (RSC) and a leading Canadian energy expert, “Archie” Robinson of Deep River, Ontario, explains what happened with a Royal Society (the world’s oldest scientific organisation) climate initiative supporting the United Nations Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report:
“the president of the Royal Society of London … drafted a resolution in favour and circulated it to other academies of science inviting co-signing. … The president of the RSC, not a member of the [RSC’s] Academy of Science, received the invitation. He considered it consistent with the position of the great majority of scientists, as repeatedly but erroneously claimed by Kyoto proponents, and so signed it. The resolution was not referred to the Academy of Science for comment, not even to its council or president.”
A similar episode happened in the United States and Russia concerning the Royal Society effort and a survey of pronouncements from other science bodies reveals that they are usually just the opinions of the groups’ executives or committees specifically appointed by the executive. The rank and file scientist members are rarely consulted at all.
But what about the supposedly authoritarian United Nations IPCC report that constitutes the foundation of most official climate concerns today? Media and politicians tell us that 2,500 official “expert reviewers” who worked with the UN body on its most recent (2007, the fourth) “Assessment Report” (called “AR4”) agreed with its conclusions. Perhaps most importantly, in Chapter 9 of the IPCC Working Group I report (“The Physical Science Basis”, reporting on the extent and possible causes of past climate change as well as future ‘projections’) appears the following assertion: “Greenhouse gas forcing has very likely caused most of the observed global warming over the last 50 years.”
Determining how many of the “2500 scientists” are known to actually agree with this statement is difficult, but we do know how many commented on anything in Chapter 9. Sixty-two is the number (see this analysis). The vast majority of the expert reviewers are not known to have examined this or related statements. Instead they would have focused on a page or two in the AR4 report that most related to their specialties, usually having little or nothing to do with greenhouse gases (CO2 or otherwise). And, of those sixty-two experts who did comment this chapter, the vast majority were not independent or impartial since most were employees of governments that had already decided before the report was written (indeed, as MIT Professor Richard Lindzen, a past IPCC lead author, explains, before much of the research had even begun) that human CO2 emissions are driving us to climate catastrophe.
When one eliminates reviewers with clear vested interest, we end up with a grand total of “just seven who may have been independent and impartial”, according to Australian climate data analyst, John McLean (see his report). And, two of those are known to vehemently disagree with the statement. Prominent climate scientist and IPCC insider Dr. Mike Hulme even admits that “only a few dozen experts in the specific field of detection and attribution studies”, not thousands as is commonly asserted by the IPCC and others, “reached a consensus that human activities are having a significant influence on the climate” (p. 10, 11 of Hulme’s April 12, 2010 paper in “Progress in Physical Geography” at http://tinyurl.com/2b3cq3r). It is travesty that the UN permits this misunderstanding to continue uncorrected.
To meaningfully assert that there is a consensus in any field, we need to actually have convincing evidence. And the best way to gather this evidence is to conduct unbiased, comprehensive worldwide polls. Since this has never been done in the vast community of scientists who research the causes of global climate change, we simply do not know what, if any, consensus exists among these experts. Lindzen concludes: “there is no [known] consensus, unanimous or otherwise, about long-term climate trends and what causes them.” Frontline did a disservice to the public telling them otherwise.
Astrophysicist Dr Gordon Fulks (see also) response to Tom's piece :
You are correct that the PBS journalists were working from a steadfast belief that a scientific consensus exists on Global Warming and that proves climate alarmists are correct. But that reasoning betrays a great ignorance of how science really works and how it has historically worked. While you may want to argue that their claims of consensus are incorrect, I prefer to take on the notion that consensus has any meaning at all. When I was asked about consensus at a local university where I taught a class recently, I asked the young man how we would argue that the earth is round. Would we say that it has to be round because 97% of scientists say so or because the US National Academy of Sciences has a policy to that effect? NO, we would present logic and evidence. For instance, we might show a photo of the earth taken from the moon. He gave me a big smile, indicating that my logic made sense to him. I had earlier mentioned the controversy surrounding the cause of peptic ulcers, where virtually every physician thought they were stress related. But thanks to two skeptics from Australia (link) who fought against "prevailing dogmas," we now know that a bacterium is involved. The term "prevailing dogmas" comes from the citation read when the two were awarded the Nobel Prize in Medicine in 2005.
See also: The Consensus Myth; 97% of Nothing.