Mudslinging about climate change science, of course, is nothing new. What struck me about this dispute is the form of the mudslinging. The Royal Society took particular issue with the following passage from Exxon's 2005 "Corporate Citizenship Report": "While assessments such as those of the IPCC have expressed growing confidence that recent warming can be attributed to increases in greenhouse gases, these conclusions rely on expert judgment rather than objective, reproducible statistical methods" (emphasis supplied).
The quoted passage is a prime example of the use of the rhetoric of science to "play defense" (as I described it in Science Plays Defense: Natural Resource Management in the Bush Administration, 32 Ecology L Q 249 (2005)) not only against regulation but against public understanding of the extent and significance of existing evidence. In this case, the Royal Society points out that the expert judgment Exxon views as unscientific was the product of (among other things) quantitative analyses. But even putting that to one side, expert judgment has always been an inevitable and healthy aspect of the scientific process. Exxon, and others who adopt the same rhetorical tactic, are quietly working to persuade the public that there is no middle ground in science. They would have the public believe that in the absence of "objective, reproducible statistical methods," at a 95% or higher level of certainty, there can be no evidence worth taking into account in public or private decisionmaking. That's not how science works, nor is it how ordinary people make decisions. The Royal Society is right to criticize Exxon for this misdirection. But if it wants to raise the level of public debate, the Royal Society and other scientific organizations should also spend some time talking directly to the public about what uncertainty in science does and does not mean.