LNG is worse for the climate than coal – new study

LNG is worse for the climate than coal. That is the damning conclusion from a new peer-reviewed study published in early October in Energy Science & Engineering.

Much of the global gas industry claims that LNG is displacing coal, particularly in Asia, resulting in a modest climate benefit. That narrative suggests that LNG can act as a “transition fuel,” achieving cuts to emissions while buying time for the expansion of renewable energy.

But the latest study pours cold water on that logic. It estimates that the full life-cycle emissions of LNG are 33 percent higher than coal, severely undercutting the notion that LNG is at all compatible with a climate-secure future.

The study’s author, Robert Howarth of Cornell University, said that much of the research to date has tended to under-appreciate all the pollution that occurred long before gas was delivered to customers.

His study found that burning gas by the end-user overseas only accounts for 35 percent of the full lifecycle of LNG. Meanwhile, nearly half of the total occurred upstream and midstream — the diesel used for running drilling rigs, and the methane leaking from well pads, compressor stations, and pipelines.

“It turns out that not only are methane emissions greater for gas than for coal, but that shale gas is a more energetically intensive form of energy than is coal,” Howarth told Gas Outlook in an email. “I and others have generally not considered these upstream CO2 emissions in earlier work.”

He also looked at a variety of LNG tanker models, some more efficient than others. In addition, when those tankers travel across the ocean, some of the liquefied gas turns back into gaseous form. This “boil off” can be used to fuel the tankers, but it can also escape into the atmosphere as unburned methane, which is 80 times more powerful than CO2 over a 20-year period.

Howarth has been studying the climate impacts of U.S. shale gas for more than a decade, with a particular focus on methane emissions. He was one of the earliest critics of the excessive methane leaks from gas drilling operations, which he found made shale gas no better than coal. That research was first published as early as 2011, but his voice was a lonely one, as the consensus among the industry and lawmakers around the country was that the coal-to-gas transition was resulting in huge climate benefits.

In the ensuing years, studies on methane in the oil and gas industry began to multiply. While the specific estimates on leaks varied from study to study, Howarth’s work has since been largely corroborated by extensive research that finds enormous quantities of methane spewing from American shale fields.

Most recently, Carbon Mapper published its first batch of data from its satellite that was launched two months ago. It found methane plumes at landfills, coal mines, and oil and gas operations around the world. Notably, the satellite detected a large methane plume in the Permian basin in late September.

“Since 2008, methane emissions from shale gas in the United States may have contributed one-third of the total (and large) increase in atmospheric methane globally,” Howarth’s latest paper said.

Methane and LNG

One of the main problems with getting an accurate picture of the methane crisis is that the U.S. Environmental Protection Agency uses data that is sent to the agency by the oil and gas industry. This self-reported data, which relies not on measurements but on assumptions of leak rates from specific pieces of equipment, shows low methane leaks from drilling operations. Many studies find that the EPA’s inventory does not reflect reality and vastly undercounts actual methane emissions.

Howarth’s study assumes that 2.8 percent of total natural gas that is produced is leaked into the atmosphere. For a long time, the general rule of thumb is that if 3 percent or more is leaked, then gas has a worse climate impact than coal. Howarth said his 2.8 percent figure is “the very latest and I think best estimate” for methane, and he pointed to a 2024 study that conducted nearly a million aerial measurements. That study found that methane emissions are three times higher than what the EPA says.

That means that even for gas used domestically in gas-fired power plants, its damage to the climate is roughly equivalent to coal. But exporting it in the form of LNG requires more energy, and more methane leaks all along the supply chain, including at the export terminals themselves and from tankers as they cross the ocean.

Howarth’s research has had a major impact on public policy. An earlier draft version of his study was instrumental in the Biden administration’s “pause” on new LNG permitting.

His influence on that decision raised the ire of the gas industry, which disputes the accuracy of his research.

“The Howarth study is not only flawed and contested, but it is not new – it was published a year ago and has been amended several times since its initial release,” Charlie Riedl, executive director at the Center for LNG, an industry trade association, told Gas Outlook. Reidl added that gas has helped lower power sector emissions and “helped grow renewable energy sources to 24% of total power generation.”

“U.S. LNG is a critical tool for countries looking to do the same and ensure their energy security,” Reidl said.

Opponents of LNG see things differently.

“This report proves that the United States cannot simultaneously be the world’s largest exporter of liquefied natural gas and reduce greenhouse gas emissions,” said Lauren Pagel, policy director at Earthworks, an environmental group that has documented methane leaks at LNG sites. “LNG has no role in the transition to a clean energy future.”

The study “is an important data point suggesting that U.S. LNG exports harm the climate,” and that it will inform the Department of Energy’s ongoing assessment about whether increasing LNG exports is in the U.S. “public interest,” said Tyson Slocum, energy programme director at Public Citizen, a consumer advocacy organisation. 

“DOE appears to be on schedule to release its updated public interest assessment in December, which will also evaluate LNG exports’ impact on American families’ energy burdens, environmental justice and other issues,” Slocum told Gas Outlook.

Howarth has long warned that the expansion of shale gas was exacerbating the methane crisis. Contrary to popular narratives that LNG offers marginal climate benefits over coal, he says the rush to build new LNG export and import terminals around the world poses a dire threat to the climate.

“The oil and gas industry is on a massive building spree, expanding LNG liquefaction and regasification plants, building pipelines to support these, and building a lot of new LNG tankers as well,” Howarth told Gas Outlook. “This requires a very large investment, and makes no sense to anyone unless you assume you will be peddling LNG 30 to 50 years into the future.”

“The world cannot afford to be using much of any fossil fuels of any sort 30 to 50 years from now, and this is particularly true for LNG, which has a larger greenhouse gas footprint than any other fossil fuel, including coal.”