"[M]ost Americans are increasingly clear in expressing their views [on climate change], based on the Spring 2017 fielding of the National Surveys on Energy and the Environment (NSEE) from the University of Michigan and Muhlenberg College," reports the Brookings Institute (June 12, 2017).
Asked "From what you've read and heard. Is there solid evidence that the average temperature on earth has been getting warmer over the past four decades?" 70% of respondents said yes, 19% said no, and 11% volunteered that they were unsure.
Those who said yes were asked "How confident are you that the average temperature on earth is increasing?": 68% of respondents were very confident, 26% were fairly confident, 3% were not too confident, 1% were not confident at all, and 1% volunteered that they were unsure.
Those who said yes were also asked "Is the earth getting warmer because of human activity such as burning fossil fuels, or mostly because of natural patterns in the earth's environment?": 44% chose human activity, 17% chose natural patterns, 34% volunteered that it was a combination, and 4% volunteered that they were unsure.
Those who said no were asked "How confident are you that the average temperatures on earth are not increasing?": 50% of respondents were very confident, 36% were fairly confident, 9% were not too confident, 3% were not confident at all, and 2% volunteered that they were unsure.
According to the NSEE data, there were 841 adult respondents for the survey, contacted via land line and cell phones between April 17 and May 16, 2017; the margin of error was +/- 3.5%. The data were weighted by gender, age, race, income, and education.