The past couple of years have been a trying time for those who believe humans are primarily responsible for global warming.
The "Climategate" scandal in 2009 shook the foundations of the academic community by showing scientists aren't above suppressing research that contradicts their global warming claims. The "hockey stick" graph that supposedly demonstrates rapid and unprecedented warming linked to greenhouse gas emissions has received sharp criticism.
And, the western world's economy has hit the skids, which means people are more worried about their immediate economic future than their distant meteorological one.
As a result, the American public's inclination to accept the scientific claims that the world's in for a heap of trouble if humanity doesn't stop burning carbon-dioxide-producing fossil fuels has dropped substantially, from more than 70 percent four years ago to well under 50 percent today.