Human activity is "beyond any reasonable doubt" the primary cause of warming temperatures, Mr. Holdren said. (snip) "However this controversy comes out, the result will not call into question the bulk of our understanding of how the climate works or how humans affect it," said Mr. Holdren, director of the Office of Science and Technology Policy. He agreed it is important to "get to the bottom of" the emails' meaning, but emphasized that the vast majority of scientists who have studied climate change agree that failure to act promptly to curb emissions of heat-trapping gases is "overwhelmingly likely" to lead...