ABSTRACT
Let me begin with a pregnant fact about US voters. In 1997 there was virtually no difference between Democratic and Republican voters in their views on global warming, with around half saying warming had begun. In 2008, reflecting the accumulation and dissemination of scientific evidence, the proportion of Democratic voters taking this view had risen from 52% to 76% (Maibach, Roser-Renouf and Leiserowitz 2009). But the proportion of Republican voters fell from 48% to 42% – a 4% gap had become a 34% gap. What had happened?
