Over to the Dark Side
Curry’s saga began with a Science paper she co-authored in 2005, which linked an increase in powerful tropical cyclones to global warming. It earned her scathing attacks on skeptical climate blogs. They claimed there were serious problems with the hurricane statistics the paper relied on, particularly from before the 1970s, and that she and her co-authors had failed to take natural variability sufficiently into account. “We were generally aware of these problems when we wrote the paper,” Curry says, “but the critics argued that these issues were much more significant than we had acknowledged.”
She did not necessarily agree with the criticisms, but rather than dismissing them, as many scientists might have done, she began to engage with the critics. “The lead author on the paper, Peter J. Webster, supports me in speaking with skeptics,” Curry says, “and we now have very cordial interactions with Chris Landsea (whom we were at loggerheads with in 2005/2006), and we have had discussions with Pat Michaels on this subject.” In the course of engaging with the skeptics, Curry ventured onto a blog run by Roger Pielke, Jr., a professor of environmental studies at the University of Colorado who is often critical of the climate science establishment, and onto Climate Audit, run by statistician Steve McIntyre. The latter, Curry adds, “became my blog of choice, because I found the discussions very interesting and I thought, ‘Well, these are the people I want to reach rather than preaching to the converted over at [the mainstream climate science blog] RealClimate.’”
It was here that Curry began to develop respect for climate outsiders—or at least, some of them. And it made her reconsider her uncritical defense of the IPCC over the years. Curry says, “I realize I engaged in groupthink myself”—not on the hurricane paper per se but more broadly in her unquestioning acceptance of the idea that IPCC reports represent the best available thinking about climate change.
She says she always trusted the IPCC to gather and synthesize all the disparate threads in this complex and multifaceted area of science. “I had 90 to 95 percent confidence in the IPCC Working Group 1 report,” she states, referring to the basic-science section of the three-part report. But even then, she harbored some doubts. In areas where she had some expertise—clouds and sea ice, for example—she felt that the report’s authors were not appropriately careful. “I was actually a reviewer for the IPCC Third Assessment Report,” Curry says, “on the subject of atmospheric aerosols [that is, particles such as dust and soot that affect cloud formation]. I told them that their perspective was far too simplistic and that they didn’t even mention the issue of aerosol impacts on the nucleation of ice clouds. So it’s not so much as finding things that were wrong, but rather ignorance that was unrecognized and confidence that was overstated.” In retrospect, she laughs, “if people expert in other areas were in the same boat, then that makes me wonder.”
Apparently few others felt the same way; of the many hundreds of scientists involved in that report, which came out in 2001, only a handful have claimed their views were ignored—although the Third Assessment Report could not possibly reflect any one scientist’s perspective perfectly.
Still, once Curry ventured out onto the skeptic blogs, the questions she saw coming from the most technically savvy of the outsiders—including statisticians, mechanical engineers and computer modelers from industry—helped to solidify her own uneasiness. “Not to say that the IPCC science was wrong, but I no longer felt obligated in substituting the IPCC for my own personal judgment,” she said in a recent interview posted on the Collide-a-Scape climate blog.