DOD must purchase alternative fuels with baseline lifecycle greenhouse gas emissions that are lower than or equal to conventional ones. That’s according to a controversial law entitled the Energy and Security Act of 2007 (EISA 2007). But the devil is in the details, and in 2008, the DOD’s Legal Office expressed concern over the law’s vagaries:
"Section 526 [of the 2007 law] applies to “an alternative or synthetic fuel, including a fuel produced from nonconventional petroleum sources.”…The law’s terms are not defined and some may argue that it covers a very broad range of fuels commonly purchased by DOD…The provision opens the Department up to court or administrative challenges to every fuel purchase it makes, with the inherent potential for an adverse decision that would cover fuels the military already relies on as well as potential reliable sources of fuel that would be developed in the future."
It turns out their fears were justified: in 2010, the Sierra Club took the Defense Logistics Agency to court, arguing purchases of fuel derived from Canadian Tar Sands broke the law. The court ultimately disagreed, finding that tar sands qualified as conventional fuels, and thus not in violation of EISA 2007.
Do other lawsuits lurk? Potentially. EISA 2007 is open to broad interpretation, with environmental groups tending to take a more expansive view of the law’s intent. Like the Sierra Club, environmental groups may seek to challenge other ‘alternative or synthetic’ fuels purchased by DOD that are perceived to have a higher Greenhouse Gas content than conventional sources, like those produced with coal, natural gas, or other fossil fuel sources.
Letter from the General Counsel of the Department of Defense to the Ranking Member of the Senate Committee on Environment & Public Works: http://solveclimatenews.com/sites/default/files/assets/2011-07/DOD%20Response%20re%20526.pdf