An update to a U.S. Department of Energy study of greenhouse gas emissions associated with U.S. LNG exports still supports shipping natural gas to world markets.
The update to the DOE study did not change any of the top-line conclusions that support LNG exports. The DOE found that the update is "fundamentally sound and supports the proposition that exports of LNG from the Lower 48 states will not be inconsistent with the public interest," according to a formal response published Jan. 2 in the Federal Register that addressed public comments.
The DOE has used the study, originally developed in 2014 by the department's National Energy Technology Laboratory, to help determine whether granting licenses for LNG export activity is in the public interest. The DOE approved a series of such applications in 2019 under an administration that has promoted LNG exports as beneficial to the environment and to the U.S. economy. But the question of how regulators should evaluate the climate impacts of gas infrastructure is the subject of ongoing public debate, including at the Federal Energy Regulatory Commission, which grants certificates that are required before developers build LNG export infrastructure.
The update, released in September 2019 for public review, maintained that gas-fired power generation in Europe and Asia has lower life-cycle greenhouse gas emissions than power generated by regional coal. It also found that using U.S. LNG over alternative supplies of natural gas would have no significant climate impact.
In its Jan. 2 comments, the DOE pushed back on feedback from groups opposed to LNG exports that argued the update did not go far enough.
"Based on the evidence, we see no reason to conclude that U.S. LNG exports will increase global [greenhouse gas] emissions in a material or predictable way," the DOE said in the formal response, signed by Steven Winberg, the assistant secretary for fossil energy.
The update resulted in three principal changes to the original study. It incorporated more recent information from the National Energy Technology Laboratory about upstream gas production. The study updated information about processes for gas liquefaction, ocean transport and regasification. Finally, the study updated the 100-year global warming potential for methane to reflect the current assessment of the Intergovernmental Panel on Climate Change, which the DOE said led to a slightly higher value.
The Sierra Club had said "the updated study repeats, rather than corrects, the flaws of its predecessor," in comments at the close of the public comment period Oct. 21, 2019. The Sierra Club said the study should be broadened to include considerations such as the potential for LNG exports to displace renewable energy sources abroad or to increase overall energy consumption in other countries. The Sierra Club also argued that increased LNG exports will spur domestic gas-to-coal switching by increasing gas prices.
The DOE responded that expanding the study's scope to include modeling of complex market dynamics in other countries would make the analysis "too speculative to inform the public interest determination." The DOE also pointed to 2017 decisions by the U.S. Court of Appeals for the District of Columbia Circuit that rejected the Sierra Club's claims that the department had failed to adequately evaluate the environmental effects of LNG exports.
The Sierra Club had also said the updated study underestimated emissions, as did the Industrial Energy Consumers of America, which has also opposed the buildout of LNG export infrastructure.
Gas industry groups that supported the study's main conclusions also suggested deficiencies in its modeling of emissions. The American Petroleum Institute and the Center for Liquefied Natural Gas said the update likely overestimated emissions. But the DOE defended the technical merits of the study.