How we know the Earth is warming and humans are responsible

This is the authors' abstract. We don't add key points for this paper.

Only two-thirds of Americans are confident in the knowledge that global warming is happening, and a bare majority understand that it’s mostly caused by human activities. One-third of Americans continue to believe that global warming is mostly natural. In reality, the scientific evidence demonstrating that global warming is happening and human-caused is overwhelming, which is why there is a 90 to 100 percent expert consensus on human-caused global warming.