evidence: President Trump's head of the Environmental Protection Agency says he does not believe that carbon dioxide is a major cause of global warming. "I would not agree that [CO2] is a primary contributor to the global warming that we see," Scott Pruitt said Thursday in an interview with CNBC's Joe Kernen. [...] Those statements are at odds with an overwhelming body of scientific evidence showing that humans are causing the climate to warm by releasing CO2 into the atmosphere. The view that CO2 is a major heat-trapping gas is supported by reams of data, included data collected by government agencies such as NASA and the National Oceanic and Atmospheric Administration.