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. And fewer also see global warming as a very serious problem – 35% say that today, down from 44% in April 2008. The latest national survey by the Pew Research Center for the People & the Press, conducted Sept. 30-Oct. 4 among 1,500 adults reached on cell phones and landlines, finds that 57% think there is solid evidence that the average temperature on earth has been getting warmer over the past few decades. In April 2008, 71% said there was solid evidence of rising global temperatures. Over the same period, there has been a comparable decline in the proportion of Americans who say global temperatures are rising as a result of human activity, such as burning fossil fuels. Just 36% say that currently, down from 47% last year. The decline in the belief in solid evidence of global warming has come across the political spectrum, but has been particularly pronounced among independents. Just 53% of independents now see solid evidence of global warming, compared with 75% who did so in April […]