New research reinforces human-caused global warming and a climate that’s highly sensitive to an increased greenhouse effectNew research suggests that clouds amplify global warming, and the sun plays a minor role. Photograph: Frank RumpenhorstOver the past few weeks, several important new papers related to human vs. natural climate change have been published. These papers add clarity to the causes of climate change, and how much global warming we can expect in the future.First, a paper published in the Journal of Climate by Jara Imbers, Ana Lopez, Chris Huntingford, and Myles Allen examines the recent IPCC statement that expressed with 95 percent