How Bad Is LNG for the Climate, Really?

President Biden’s decision to pause approving liquified natural gas export terminals until it can better study their climate effects — functionally delaying or even outright preventing their construction — got real political, real fast. Almost immediately, West Virginia Senator Joe Manchin called for a hearing on the president’s decision-making.

“If the Administration has the facts to prove that additional LNG export capacity would hurt Americans, they must make that information public and clear,” he said in a statement last week. “But if this pause is just another political ploy to pander to keep-it-in-the-ground climate activists at the expense of American workers, businesses and our allies in need, I will do everything in my power to end this pause immediately.”

While Senator Manchin is not exactly the administration’s biggest fan lately, he’s also asking some pretty interesting questions. One of the animating ideas of the past few months in climate politics has been the argument that LNG (and maybe even pipeline gas) are in fact far worse for the global climate even than coal, which has long been assumed to be the dirtiest, most carbon-intensive fossil fuel around. That view is based on research by Cornell University scientist Robert Howarth and has been expounded by climate advocates and elected officials alike.

But that research has not yet passed through peer review. Even if it had, Howarth’s past research has gotten criticism from other climate scientists for using some idiosyncratic assumptions that yield more dramatic results.

Make no mistake, meeting the goals of the Paris Agreement and holding global warming to 1.5 degrees Celsius over pre-industrial levels requires winding down our use of fossil fuels as quickly as possible. If we meet those goals, the natural gas export terminals delayed by the Biden administration’s decision will likely go dormant well before the end of their expected lifespans. But it’s not the case that in all possible worlds, continuing or even expanding natural gas production and exports would actually be worse for the climate.

The basic physics of coal emissions versus LNG emissions are just part of the equation. When it’s burned, natural gas releases carbon dioxide, the primary source of human-caused climate change, albeit less carbon dioxide than coal. But natural gas is itself mostly methane, CH4, which traps far more heat than CO2 when it leaks from wells, pipelines, and production facilities. (LNG is also much more energy-intensive to extract, produce, and store than regular natural gas, since it has to be cooled to -260 degrees Fahrenheit, sailed across the ocean and then “regasified” and shipped via pipeline on the other side.) While CH4 is more potent than CO2 from a warming perspective, it also breaks down much more quickly in the atmosphere, which means the warming effect doesn’t last as long.