WASHINGTON -- The House passed an amendment to the National Defense Authorization bill on Thursday that would bar the Department of Defense from using funds to assess climate change and its implications for national security.

The amendment, from Rep. David McKinley (R-W.Va.), passed in what was nearly a party-line vote. Four Democrats voted for the amendment, and three Republicans voted against it. The bill aims to block the DOD from taking any significant action related to climate change or its potential consequences. It reads:

None of the funds authorized to be appropriated or otherwise made available by this Act may be used to implement the U.S. Global Change Research Program National Climate Assessment, the Intergovernmental Panel on Climate Change's Fifth Assessment Report, the United Nation's Agenda 21 sustainable development plan, or the May 2013 Technical Update of the Social Cost of Carbon for Regulatory Impact Analysis Under Executive Order 12866.

"This amendment will prohibit the costs of the President's climate change policies being forced on the Department of Defense by the Obama Administration," wrote McKinley in a memo to House colleagues on Thursday that was obtained by The Huffington Post. "The climate is obviously changing; it has always been changing. With all the unrest around the [world], why should Congress divert funds from the mission of our military and national security to support a political ideology?"

Research suggests, however, that the Department of Defense has a number of reasons to be worried about climate change. The department said in its own evaluation last year that climate change presents infrastructure challenges at home and abroad. Meanwhile, a March Pentagon report found that climate change impacts are "threat multipliers," and that the rapid rise of global temperatures and associated extreme weather events could exacerbate issues like "poverty, environmental degradation, political instability and social tensions -- conditions that can enable terrorist activity and other forms of violence."

Nor is climate change a threat that the Obama administration dreamed up to distract the DOD. A National Intelligence Assessment issued during the George W. Bush administration concluded that climate change poses a significant threat to national security. And just this week, Tom Ridge, who served as homeland security secretary under Bush, said that climate change is "a real serious problem," one that "would bring destruction and economic damage" if we ignore it.

Reps. Henry Waxman (D-Calif.) and Bobby Rush (D-Ill.) sent a letter to colleagues on Thursday calling the McKinley measure "irresponsible."