Study Reveals Exported Gas Has Worse Emissions Than Coal

A new comprehensive study has found that exported liquefied natural gas (LNG) emits significantly more greenhouse gases than coal, contradicting claims by the fossil fuel industry that LNG is a cleaner alternative. This research challenges the rapidly growing LNG export market, particularly the expansion of U.S. gas exports to Europe and Asia.

While coal has long been known as the most polluting fossil fuel, oil and gas companies have promoted LNG as a "bridge" energy source that burns cleaner than coal. This belief has led to the construction of numerous LNG terminals, especially in the United States. However, the study found that over a 20-year period, LNG is responsible for 33% more planet-warming emissions than coal.

"The perception that coal is worse for the environment is incorrect. LNG actually has a bigger carbon footprint than any other energy source," explained Robert Howarth, an environmental scientist at Cornell University and the lead author of the study. "The idea that shipping LNG worldwide as a climate solution is simply wrong. It's greenwashing by the oil and gas industry, underestimating the true emissions from this energy source."

The research highlights that a large portion of the emissions come from the extraction, transportation, cooling, and shipping of gas, with the burning of gas by end-users accounting for only about a third of the total emissions. The study suggests that the LNG process is so energy-intensive that it surpasses coal's environmental impact, leading to the conclusion that "there is no justification for using LNG as a temporary energy source" and that "phasing out LNG should be a global priority."

Published in the Energy Science & Engineering journal, the peer-reviewed research disputes the rationale for the surge in LNG infrastructure along the U.S. Gulf Coast, built to export gas overseas. The United States is now the world's leading LNG exporter, followed by Australia and Qatar.

In previous assessments, government and industry sources claimed LNG emitted significantly less than coal, touting it as a cleaner option for energy-hungry nations such as China, while also helping Europe reduce its reliance on Russian gas due to the war in Ukraine.

Dustin Meyer, the American Petroleum Institute's director of market development, has argued that "U.S. LNG exports can facilitate environmental progress globally by allowing countries to transition to cleaner natural gas and reduce emissions."

However, recent research has shown that the rapid expansion of LNG is incompatible with efforts to avoid dangerous levels of global warming. Studies have also revealed that methane leaks from gas drilling operations—methane being the primary component of natural gas and an especially potent greenhouse gas—are far higher than previously reported.

Howarth's study found that as much as 3.5% of the gas extracted for LNG leaks into the atmosphere before it is even used, a figure much higher than earlier estimates. Methane, which is about 80 times more effective at trapping heat than carbon dioxide over short periods, poses a serious risk to meeting international climate goals as its emissions continue to rise globally.

The study also pointed out that around half of the emissions occur during the transportation of the gas, which is extracted primarily through hydraulic fracturing (fracking) from the U.S.'s vast shale gas fields. Gas is moved through pipelines to coastal export terminals, where it is cooled to -162°C (-260°F) and converted into liquid form for shipping. Once delivered to client countries, the LNG is reheated into gas and burned.

"This entire process is more energy-intensive than coal," said Howarth. "The idea that the gas can be transported across the globe without significant emissions is pure fantasy."

Before its official publication, the paper sparked significant controversy. Climate advocates like Bill McKibben circulated a draft of the study, which reportedly contributed to the Biden administration's decision to pause new permits for LNG exports earlier this year. The move has triggered a legal battle with the oil and gas industry, which has filed lawsuits, and has angered political allies who support LNG development. Four Republican lawmakers even wrote to the U.S. Department of Energy, criticizing Howarth's study as "flawed" and "inaccurate."

Critics of the study, including some energy experts, claim the research overstates the environmental impact of LNG. David Dismukes, an energy consultant from Louisiana, said, "Gas certainly has a climate impact, but to say it's worse than coal? That's hard to believe."

Howarth, who underwent five rounds of peer review for the study, dismissed the criticism as politically motivated. "This is the most scrutiny I've ever experienced for a paper," he said. "I stand by the findings."

As the U.S. faces crucial choices in the next presidential election, the future of LNG expansion is at stake. Donald Trump has pledged to overturn Biden's pause on LNG projects if he returns to the White House, while Vice President Kamala Harris has shifted away from her previous stance on banning fracking but remains committed to climate action.

Last month, over 125 climate, environmental, and health scientists sent a letter to the Biden administration defending Howarth's research and urging the government to maintain the halt on LNG export approvals.

Drew Shindell, a climate scientist at Duke University not involved in the study, said Howarth's findings are "credible." He added, "This research contributes to the growing body of evidence showing that gas is not the cleaner alternative the industry claims. But the real debate should be about how both gas and coal are harmful and must be phased out."