The challenge of climate-change neoskepticism

Opponents of policies to limit anthropogenic climate change (ACC) have offered a changing set of arguments-denying or questioning ACC's existence, magnitude, and rate of progress, the risks it presents, the integrity of climate scientists, and the value of mitigation efforts (1). Similar arguments have characterized environmental risk debates concerning arsenical insecticides in the late 1800s (2), phosphates in detergents in the 1960s (3), and the pesticide DDT in the 1960s and '70s (4). Typically, defenders of business as usual first question the scientific evidence that risks exist; then, they question the magnitude of the risks and assert that reducing them has more costs than benefits. A parallel rhetorical shift away from outright skepticism (5-7) led us to identify "neoskepticism" as a new incarnation of opposition to major efforts to limit ACC (8). This shift heightens the need for science to inform decision making under uncertainty and to improve communication and education.