Here’s what we already knew about methane: It’s the primary component of natural gas. It’s much more potent as a greenhouse gas than carbon dioxide. And a non-zero amount of it is escaping into the atmosphere as a result of natural gas extraction and delivery.
Until recently, exactly how much methane the industry emits has been uncertain. State and federal regulators maintain official inventories based on limited and largely self-reported data, but academic research increasingly suggests government estimates have been far too conservative.
Here in Pennsylvania, the nation’s second-largest producer of natural gas, a recent analysis by the Environmental Defense Fund (EDF) found that actual methane emissions were likely as much as five times the amount recorded in the state Department of Environmental Protection’s inventory.
Scientist David Lyon talks about EDF’s Pennsylvania methane report on the PEC podcast
The Pennsylvania study was one in a series produced by EDF over the last few years, focusing on various locales and points along the natural gas supply chain. But there hasn’t been much in the way of a comprehensive, national-level assessment of discrepancies between government and scientific emissions estimates — until now.
When scaled up nationally, our facility-based estimate of 2015 supply chain emissions is 13 ± 2 Tg/y, equivalent to 2.3% of gross U.S. gas production. This value is ~60% higher than the U.S. EPA inventory estimate…
– Science 21 Jun 2018
According to a new report appearing this week in the journal Science, actual methane emissions nationwide are upwards of 13 million metric tons, “equivalent to 2.3% of gross U.S. gas production.” That figure is 60% higher than the Environmental Protection Agency’s official estimate.
Carnegie Mellon University Professor Allen Robinson on the knowns and unknowns of natural gas methane emissions in Pennsylvania. Learn more at ch4nge.com.
The news dramatically undercuts arguments for the viability of natural gas as a more climate-friendly alternative to other fossil fuels. While it remains true that natural gas combustion emits far less carbon than oil and coal, those benefits are largely offset by emissions in the supply chain.
Basically, you’re doubling the climate impact of using natural gas over a 20-year time frame because of these methane emissions.
– Steve Hamburg, EDF Chief Scientist
StateImpact Pennsylvania, June 21, 2018
And methane emissions aren’t just exacerbating climate change on a larger scale than we knew — they’re also creating unnecessary economic costs. “The wasted gas is enough to fuel 10 million homes for a year,” says EDF, “lost gas that’s worth an estimated $2 billion.”
But it doesn’t have to be this way.
The analysis, based on research by more than 140 experts in academia and industry, shows the largest source of emissions by far is during the extraction phase of natural gas production, where the gap between official and scientific estimates is widest.
The evidence bolsters an increasingly widely-held view among researchers that abnormal operating conditions — leaks and equipment malfunctions — are the most likely culprit, particularly so-called “super-emitters” like the 2015 Aliso Canyon leak in California.
The good news is that ‘a lot of the leaks, these abnormal ones, are not that hard to fix,’ said Allen Robinson, one of the study’s co-authors and a professor of engineering and public policy at Carnegie Mellon University. ‘The challenge is identifying them efficiently.’
– Pittsburgh Post Gazette, June 21 2018
That, in turn, suggests the solution may be relatively simple: “Significant emission reductions,” the authors note, “are feasible through rapid detection of the root causes of high emissions and deployment of less failure-prone systems.”
Fortunately, leak detection technology is advancing rapidly, creating jobs in the nascent methane mitigation industry in Pennsylvania and beyond. With the recent finalization of new state requirements for monitoring and emission reduction, that market is poised for further growth.
With more effective permitting rules now in place for new and modified natural gas operations in Pennsylvania, PEC is focused on pushing for comparable controls on existing sources. If equipment malfunctions and undetected leaks indeed account for the bulk of non-inventoried emissions, further reductions will hinge upon greater scrutiny and closer attention to established and often aging facilities.
As the study series shows, there’s little time to waste if we want to avoid the worst impacts of climate change.
For its part, EDF plans to continue expanding its research base to provide both meaningful data and effective tools to drive policy change at the state, federal, and even global levels. “We’ve uncovered practical, cost-effective solutions that are possible now, and we’re driving innovation to develop new ones,” the group says in a blog post announcing the new report. “Armed with evidence of methane’s true threat, we’re doing more than ever to attack it.”
To learn more about the movement for reasonable controls on natural gas methane emissions in Pennsylvania, visit ch4nge.com.