Natural gas has been touted as the ‘clean’ fossil fuel in large part because it emits less carbon dioxide than oil or coal when burned. A new study out of Cornell suggests precisely the opposite – natural gas could actually contribute more to climate change than oil or coal through the emissions of methane during the extraction process. The researchers estimate that up to 8% of the gas extracted escapes into the atmosphere during the production process. This is big – natural gas is 90% methane, a far more potent greenhouse gas than carbon dioxide.
This ProPublica article helpfully (and less technically) delves into research conducted by the EPA that buttresses the conclusions of the Cornell research team:
Advocates for natural gas routinely assert that it produces 50 percent less greenhouse gases than coal and is a significant step toward a greener energy future. But those assumptions are based on emissions from the tailpipe or smokestack and don’t account for the methane and other pollution emitted when gas is extracted and piped to power plants and other customers.
The EPA’s new analysis doubles its previous estimates for the amount of methane gas that leaks from loose pipe fittings and is vented from gas wells, drastically changing the picture of the nation’s emissions that the agency painted as recently as April. Calculations for some gas-field emissions jumped by several hundred percent. Methane levels from the hydraulic fracturing of shale gas were 9,000 times higher than previously reported.