A record was broken in a new poll from Gallup, which found that 65% of Americans believe that increases in the earth's temperature over the last century are due more to "the effects of pollution from human activities" than to "natural causes in the environment that are not due to human activities." According to Gallup, "This represents a striking 10-percentage-point increase in the past year and is four points above the previous high of 61% in 2007."
Speculating on the cause of the increase, Gallup suggested, "Several years of unseasonably warm weather — including the 2011-2012, 2012-2013 and 2015-2016 winters — has potentially contributed to this shift in attitudes. If that's true, continuation of such weather patterns would likely do more than anything politicians and even climate-change scientists can to further raise public concern."
The poll also asked (PDF) respondents whether they believed that most scientists believe that global warming is occurring, most scientists believe that global warming is not occurring, or most scientists are unsure. Sixty-five percent of respondents selected the first option — which is correct — while 7% selected the second option, 25% selected the third option, and 3% expressed no opinion.
The poll was "based on telephone interviews conducted March 2-6, 2016, with a random sample of 1,019 adults, aged 18 and older, living in all 50 U.S. states and the District of Columbia. For results based on the total sample of national adults, the margin of sampling error is +/-4 percentage points at the 95% confidence level." Both cellphone and landlines were used; numbers were selected using random-digit-dial methods.