Scientists and advocates have called for reductions in greenhouse gas emissions for years. But now the White House national security advisor is joining in the chorus. Tom Donilon, the national security advisor to President Barack Obama, gave a lengthy speech in New York City today, to mark the launch of a new energy policy center at Columbia University. During his speech, Donilon said that "the fact that the environmental impacts of climate change present a national security challenge has been clear to this administration from the outset." Donilon went on to cite several recent threat assessment reports from the intelligence and defense departments, saying "this underscores the need — for the sake of our national security — to reduce the greenhouse gas emissions that drive climate change."

Donilon's remarks about the security threats posed by climate change are just the latest in a series by other high-ranking intelligence and defense officials. Last month, the commander of the US Navy's Pacific operations voiced similar concerns. Both the Navy and Army have also been increasing their use of renewable fuels as part of a way to address what they see as a rapidly changing energy market. But Donilon's speech may be the most vocal call yet to address climate change from a security perspective and to slash emissions accordingly.

That's not to say Donilon and the White House don't support the fossil fuel industries: the national security advisor also praised the increased production of natural gas, saying "America’s natural gas boom is helping to spark a domestic manufacturing revival," adding that "domestic economic developments like these improve US standing and send a powerful message that the United States has the resources, as well as the resolve, to remain the world’s preeminent power for years to come."