There has been a sharp decline over the past year in the percentage of Americans who say there is solid evidence that global temperatures are rising.
I tend to think this poll is more a snapshot in time. We're still in a major economic downturn, as Pew research director Andrew Kohut alluded to in this AP story:
The priority that people give to pollution and environmental concerns and a whole host of other issues is down because of the economy and because of the focus on other things. When the focus is on other things, people forget and see these issues as less grave.
Then again, this is a fascinating picture from a war zone. It suggests that some people who have good reason to be distracted from enviromental issues are still focusing on global warming as a major concern.