Methane leaks: How much comes from fossil fuels industry?

The fossil fuel industry may be emitting twice as much methane as previously thought, a new study finds.

After carbon dioxide, methane is considered the second biggest source of manmade greenhouse gases. The study’s authors have pulled together the most comprehensive methane emissions database yet, and concluded that emissions from fossil fuels are between 60 and 110 percent greater than current estimates. After accounting for “natural geological methane seepage,” methane emissions from coal, oil, and natural gas production are still between 20 and 60 percent higher than previously thought. 

The study’s findings may have important implications for the effort to meet Paris Agreement goals. It’s also possible that the fossil fuel industry can be part of the solution – though others say what’s needed is a more rapid transition to a clean energy economy.

The Paris Agreement goes into force on November 4, after passing the ratification threshold of 55 percent of countries – representing 55 percent of global emissions – on Wednesday. The UN Framework on Climate Change has said that prompt adoption of the agreement will “have a catalytic effect, spurring strong and decisive action.” What does the new study mean for efforts to meet these goals?

“It definitely makes the US goals a bit harder to meet,” says Jeffery Greenblatt, a staff scientist at Lawrence Berkeley National Laboratory. Methane has a shorter life than carbon dioxide, so “If we are able to understand the sources of methane leakage and address them, then it’s certainly possible that we could make changes quickly,” he tells The Christian Science Monitor in a phone interview.

In another recent study, Dr. Greenblatt and fellow Berkeley Lab scientist Max Wei found that the United States may not hit its emissions targets by 2025. If all goes well, the US may reduce emissions up to 356 million tons more than its Paris commitment, but the authors are concerned by the possibility that the US could miss its goal by up to 924 million tons. They therefore present a range of policy options to help meet these goals, including phasing out fossil fuel production, increasing the number of electric cars on the road, and increasing the use of hydrogen and biofuels.

Meanwhile, the oil and gas industry has undertaken efforts to reduce methane leaks, cutting the leak rate by 75 percent over the past three decades, the study found. Though, lead author Stefan Schwietzke tells the Monitor that those reductions have been offset by emissions released due to increased natural gas production.

Dr. Schwietzke told Time magazine that producers’ efforts to improve practices and limit waste may have been a driving force behind this drop in leaks.

BP joined the Climate and Clean Air Coalition’s Oil and Gas Methane Partnership in 2015. “Companies [in this Partnership] analyse sources of methane to evaluate cost-effective technologies for methane emissions reduction,” according to a 2015 Sustainability Report the company provided to the Monitor.

“From the natural gas production system, there do seem to be leaks coming from … relatively few sources,” meaning emissions could be lowered substantially with each fixed leak, Greenblatt tells the Monitor. His report argued that identifying and addressing these "super-emitters" could reduce methane emissions from fossil fuels up to 87 percent. To make that happen, President Obama’s aspirational goal to reduce methane by 40 to 45 percent “needs to become a policy with teeth,” he concludes.

Joeri Rogelj, a research scholar at the International Institute for Applied Systems Analysis in Austria, tells the Monitor that easy solutions to the additional emissions, such as curbing leakage, may paradoxically “make achieving emissions-reduction harder in the long term, because of the lock-in to emission intensive infrastructure.” If countries are not compelled to make structural changes now, they may struggle to do so down the road. However, if the leaks cannot be managed, “it would further jeopardize the environmental integrity and economic viability of the continued use of fossil fuels,” possibly complicating the transition to alternative fuels.

Robert Howarth, professor of ecology and environmental biology at Cornell University, says oil-and-gas industry methane emissions may have fallen over time – as the study concludes – but that is not necessarily a permanent trend. 

“I suspect a large part of that decrease might be attributable to the collapse of the former Soviet Union and the rebuilding of Siberian gas fields and pipelines to Europe using improved technology and building methods after that,” he tells the Monitor in an email. Methane emissions may have started to rise again around 2011, with the expansion of shale gas extraction. “I firmly believe [it will be difficult to reduce] emissions from shale gas, and so we need to accelerate the move to renewable energy and get rid of all fossil fuels…as quickly as possible,” he concludes.

The latest emissions study is one of a number of recent efforts by scholars to understand the sources and effects of methane. A new study in BioScience finds that reservoirs may account for 1.3 percent of global methane emissions. This has raised concerns about the environmental viability of hydropower, particularly large hydropower projects, which has been the renewable energy source of choice for many developing countries. Researchers say that global assessments need to be adjusted again to account for these findings, which in turn will help produce better policy.

“I would say that emission scenarios may need to be adjusted for multiple methane sources. We found that fossil fuel methane emissions are greater than what we previously thought, but microbial sources (including natural wetlands, ruminants (mostly cows), landfills, and rice agriculture are smaller than what we previously thought,” Schwietzke tells The Christian Science Monitor.

[Editor's note: This report has been updated to clarify that reductions in leak rates have been offset by methane emissions released during increased natural gas production.]