A new poll on public attitudes toward Pope Francis's encyclical on climate change included questions on the occurrence of climate change itself. Asked "Do you think that global warming is happening, or do you think global warming is not happening?" 69% of respondents said yes, 16% said no, 15% said that they were not sure, and 1% skipped or refused to answer the question.
Those who answered yes were asked about the cause of global warming: 11% said it is caused entirely by human activities, 41% said that it is caused mostly by human activities, 38% said that it is caused about equally by human activities and natural changes in the environment, 6% said that it is caused mostly by natural changes in the environment, 2% said that it is caused entirely by natural changes in the environment, and 2% said that they were not sure.
The survey was conducted by the Associated Press-NORC Center for Public Affairs Research; 1030 people completed the survey. According to the report (PDF), "Interviews for this survey were conducted between July 17 and July 19, 2015, with adults age 18 and over from the 50 states and the District of Columbia. ... The overall margin of sampling is +/- 4.4 percentage points at the 95 percentage confidence level."