Nearly two in three Americans (63%) believe global warming is happening. Relatively few – only 16 percent – believe it is not. However, since Fall 2012, the percentage of Americans who believe global warming is happening has dropped 7 points to 63%, likely influenced by the relatively cold winter of 2012-13 in the United States and an unusually cold March just before the survey was conducted.
Those who believe global warming is happening are more certain of their convictions than those who do not. Of the 63% of Americans who believe global warming is happening, most say they are “very” (33%) or “extremely sure” (27%). By contrast, of the unconvinced, fewer are very (28%) or extremely sure of their view (18%).
About half of Americans (49%) believe global warming – if it is happening – is caused mostly by human activities, a decrease of 5 points since Fall 2012, but similar to levels stretching back several years.
More Americans believe that “most scientists think global warming is happening than believe there is widespread disagreement among scientists (42% versus 33%, respectively).
About half of Americans (51%) say they are “somewhat” or “very worried” about global warming, a 7 percentage-point decline in worry since Fall 2012.
At least four out of ten Americans say global warming will harm people in their community (45%), their family (44%), or themselves (42%).
Global warming is also perceived as a threat to people in developing countries (55%, down 9 points since September 2012, but similar to March 2012), in other modern industrialized countries (53%, down 4 points since September, but up 4 points since March 2012), and in the United States (52%, down 5 points since September, but up 6 points since March 2012).