The draft study, while packed with uncertainties and caveats, showed that these "lifecycle" emissions were generally a good deal lower than using coal mined in those regions, and better than or at least on par with Russian gas sent via pipeline.
But although the report contained good news for export advocates, industry officials are nonetheless pressing the department not to factor the review of these emissions into its decisions on gas-export applications that are piled up before regulators.
An industry group called the Center for Liquefied Natural Gas, in recent comments on the report, argues that weighing the study would run afoul of regulations that govern the National Environmental Policy Act review process.
The industry group also argues that the lifecycle emissions review has no place in DOE decisions about whether applications are in the "public interest" and therefore should be approved.
If the analysis is weighed in those reviews, "DOE could accomplish environmental goals through its own analysis what it cannot do through the NEPA process," such as consider environmental conditions in other nations, the center says in comments submitted last week.
"[S]uch a use outside the NEPA process could lead to inconsistent conclusions on the environmental review ... and subject the public interest determination by DOE to unnecessary legal challenges by those opposing the applications for any perceived deficiencies in DOE's consideration of environmental factors," the group said.
Similarly, the big energy company Dominion doesn't want lifecycle emissions to pay a big role in DOE reviews. The company, which is seeking final clearances to move ahead with a multibillion-dollar liquefied natural-gas project in Maryland, applauded the study as "favorable" to exports, but also notes: "This type of life cycle GHG analysis is in no way required as part of the environmental review of LNG exports."
The company said DOE's approval of export applications doesn't have a clear link to the sum of greenhouse-gas emissions from natural-gas development and use.
"In no sense can DOE's authorization of LNG exports be considered the cause of [greenhouse-gas] emissions ranging all the way from the well-head (wherever that may be for particular feed gas) to the burner-tip (wherever the exported LNG may be burned after regasification under whatever regulatory rules may apply in that country)," the company said.
The draft Energy Department study looks at the so-called global-warming potential of using exported U.S. gas in Asia and Europe over 20-year and 100-year horizons. The latter timeframe is friendlier to gas, because while methane emissions pack a wallop, they are relatively short-lived in the atmosphere.
The study showed that using a 100-year horizon, exported gas is easily more friendly to the climate than using regionally sourced coal in China and Europe. But the advantage shrinks somewhat using the 20-year horizon. And the high end of the estimated climate damage from using imported U.S. gas in China is even slightly worse than the low end of the range of estimates from using coal there.