Yes, there is a strong consensus on climate change

I have been corresponding about these matters with one of the authors (Dana Nuccitelli) of the lead paper on the subject ( Cook et al. 2013 “Quantifying the consensus on anthropogenic global warming in the scientific literature“) for some years.

Arctic Sea Ice Volume, from Polar Science Center (http://psc.apl.uw.edu/)

Climate change denial shares many interesting features of evolution denial. Misrepresentation of data, accusations of fraud (remember Climategate?), allegations of non-existent scientific disagreement, reporting on genuine scientific debates about rates and mechanisms as if they were fundamental disagreements of principle, and repeated attempts (especially in the US, at state level) to pass laws requiring schools to “teach the controversy”. In the US, although not as far as I know in the UK, there is strong overlap between evolution denial and climate change denial, both being linked to the Evangelical Right that has more or less captured the Republican Party. In both cases, there are Orwellian mislabellings. Thus the Cornwall Alliance for the Stewardship of Creation is dedicated to the unrestricted exploitation of the planet’s resources, while Evolution News and Views consists of nothing but attacks on the science that supports evolution. We also have the endless and shameless repetition of blatant falsehoods. Creationists keep on telling us that evolution has never been observed, that the fossil record is too sparse to be interpreted, and that there is a “missing link” between humans and their common ancestors with other apes. Climate change deniers seem oblivious to the massive loss of Arctic ice, while trumpeting every intermittent uptick as a major recovery, and use the then unique 1998 spike (exceeded several times since) as if it were an appropriate baseline. Other climate denial falsehoods that refuse to go away include the allegations (repeated on UK TV Channel 4 and elsewhere) that volcanoes emit more carbon dioxide than humans (the reverse is true, by a factor of over 100), and that present warming is due to Milankovich cycles (no; it is much too fast for that). Both have their own glossy websites, and setting up counters to these (such as talkorigins and pandasthumb for evolution, and Skeptical Science for climatology) is a major cottage industry.

Climate change denialists, however, take quote mining and misattribution to a whole new level. Thus denialists regularly accuse climate scientists of having switched from talking about global warming to talking about climate change or vice versa because the case for warming was so weak or because global warming sounds more frightening (versions vary). In reality, it was the denialist Frank Luntz who proposed the change in vocabulary, in an internal thinktank memo leaked to Mother Jones:

It’s time for us to start talking about “climate change” instead of global warming and “conservation ” instead of preservation. “Climate change’’ is less frightening than “global warming”

(In this memo, Luntz shows mastery of how to use words for effect; we would do well to study his methods closely.) And while both kinds of denialists accuse the scientists they are attacking of wholesale fraud, at least the evolution denialists do have one real case they can cite (Piltdown Man), while despite half a dozen investigations in two continents into alleged misconduct, the climate denialists have none.

There are two other important differences. One is scale of funding. The funding available to promote climate change denial is major, large enough to finance attempts to set up an entire bogus curriculum. The other is potential impact. If large numbers of people persist in a creationist view of reality, remaining obstinately misinformed about what kind of universe we inhabit and what kind of creatures we are, that is an enormous pity but has no obvious further implications. But if large numbers of voters, especially in the US, persist in denying our influence on climate, the implications for policy making are very serious indeed.

The Logic of Science

Even if you have never paid any real attention to the climate change “debate,” you have probably seen someone say that, “97% of climatologists agree that we are causing climate change.” This is a number that I have personally cited on numerous occasions, and it is a number that is highly contested by the climate change deniers. Indeed, I rarely mention the consensus without people responding by adamantly proclaiming that the 97% number is a myth, and the study that produced it (Cook et al. 2013) has been debunked. Therefore, in this post, I want to deal with the consensus on climate change from several angles. First, I want to focus on the prominent Cook et al. study and explain what the authors actually did, what they found, and why their study was robust. I also want to deal with some of the common criticisms of their study. Finally, I…

View original post 3,907 more words