If Kerry becomes the next secretary of State, he will likely raise climate change to a top-tier priority.

“No senator since Al Gore knows as much about the science and diplomacy of climate change as Kerry,” said David Goldwyn, an international energy consultant who served as Clinton’s special envoy and coordinator for international energy affairs. “He would not only put climate change in the top five issues he raises with every country, but he would probably rethink our entire diplomatic approach to the issue.”

Kerry has been engaged with climate policy since he attended the first major U.N. climate summit in Rio de Janeiro in 1992. He was coauthor, along with Sens. Lindsey Graham, R-S.C., and Joe Lieberman, ID-Conn., of sweeping legislation that would have capped U.S. emissions of greenhouse gases, although the bill fell apart before making it to the Senate floor. In 2007 he and his wife, Teresa Heinz Kerry, coauthored a book, This Moment on Earth: Today’s New Environmentalists and Their Vision for the Future…

“Kerry’s been one of the most active champions on the Arctic. He’s out there saying, ‘The Arctic ice is melting, we’ve got to do something,’ ” said Charles Ebinger, director of the Foreign Policy and Energy Security Initiative at the Brookings Institution.