Methane, the main component of natural gas, is about 25 times more powerful as a heat-trapping gas than carbon dioxide, the largest human contributor to climate change; the atmospheric concentration of methane has doubled since the start of the Industrial Revolution. While it largely dissipates in a few decades and there is far less of it in the atmosphere than CO2, it continues to drive global warming. Depending on how much leaks out in the journey from wellhead to homes and factories, some experts say, it could be enough to offset the advantages natural gas has over coal.
“We don’t have enough data to develop sound policy going forward,” said Steven Hamburg, chief scientist of the advocacy group Environmental Defense Fund. He noted that natural gas has a complex supply chain with “different geographies and geologies” along the way.
Hamburg is spearheading a $10 million, two-year effort to measure methane emissions along the nation’s supply chain. As activists and energy executives debate the natural gas industry’s impact and the Environmental Protection Agency weighs whether to impose new regulations, Hamburg said, “it’s critically important” the country develops a better data set on methane leaks.
The group has brought together academics, environmentalists and industry representatives to track different stages of natural gas extraction, production and transmission and will issue its initial report in May.
Other teams also are working to unlock the puzzle.
Bob Ackley spent January driving the city for 10 to 12 hours a day, usually with a researcher riding alongside. Ackley, who runs a methane-detection company, is part of a six-person group financed by Duke University’s Nicholas School of the Environment that has collected data on thousands of methane leaks under Washington’s roads.
On a recent trip through the city, Ackley took the wheel while Duke professor Robert Jackson tracked real-time methane concentrations that an instrument stashed in the car’s trunk fed into a computer. Periodically the readings would spike to unsafe levels, with as much as 32 percent methane escaping from a single manhole.
Last fall, the team published the results of a similar survey of Boston, which showed the city’s aging infrastructure had 3,356 leaks. “Washington is at least as leaky as Boston, if not more,” Jackson said. “It looks like it has both more leaks and bigger leaks than Boston.”
Researchers disagree about how much methane is leaking into the atmosphere.