evidence: Thirty prominent climate scientists sent a letter to Environmental Protection Agency Administrator Scott Pruitt on Monday, refuting his recent false statement that carbon dioxide is not a primary driver of climate change. [...] It joined the avalanche of response to Pruitt’s statement last week in an interview on CNBC that he did not agree carbon dioxide was the primary contributor to global warming, a statement contrary to the overwhelming scientific consensus. [...] "I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact," Pruitt said. The doubts he expressed went further than in his testimony before Congress, however, as he said of carbon dioxide, "No, I would not agree that it’s a primary contributor to the global warming that we see."