Researchers with the National Oceanic and Atmospheric Administration (NOAA) have reconfirmed earlier findings of high rates of methane leakage from natural gas fields. If these findings are replicated elsewhere, they would utterly vitiate the climate benefit of natural gas, even when used to switch off coal.
Indeed, if the previous findings — of 4% methane leakage over a Colorado gas field — were a bombshell, then the new measurements reported by the journal Nature are thermonuclear:
… the research team reported new Colorado data that support the earlier work, as well as preliminary results from a field study in the Uinta Basin of Utah suggesting even higher rates of methane leakage — an eye-popping 9% of the total production. That figure is nearly double the cumulative loss rates estimated from industry data — which are already higher in Utah than in Colorado.
The Uinta Basin is of particular interest because fracking has increased there over the past decade.
How much methane leaks during the entire lifecycle of unconventional gas has emerged as a key question in the fracking debate. Natural gas is mostly methane (CH4). And methane is a far more potent greenhouse gas than (CO2), which is released when any hydrocarbon, like natural gas, is burned — 25 times more potent over a century and 72 to 100 times more potent over a 20-year period.
Even without a high-leakage rate for shale gas, we know that “Absent a Serious Price for Global Warming Pollution, Natural Gas Is A Bridge To Nowhere.” That was first demonstrated by the International Energy Agency in its big June 2011 report on gas — see IEA’s “Golden Age of Gas Scenario” Leads to More Than 6°F Warming and Out-of-Control Climate Change. That study — which had both coal and oil consumption peaking in 2020 — made abundantly clear that if we want to avoid catastrophic warming, we need to start getting off of all fossil fuels.
A March 2012 study by climatologist Ken Caldeira and tech guru Nathan Myhrvold came to a similar conclusion using different methodology (see “You Can’t Slow Projected Warming With Gas, You Need ‘Rapid and Massive Deployment’ of Zero-Carbon Power”). They found that even if you could switch entirely over to natural gas in four decades, you “won’t see any substantial decrease in global temperatures for up to 250 years. There’s almost no climate value in doing it.” And that was using conventional (i.e. low) leakage rates.
But the leakage rate does matter. A major 2011 study by Tom Wigley of the Center for Atmospheric Research (NCAR) concluded:
The most important result, however, in accord with the above authors, is that, unless leakage rates for new methane can be kept below 2%, substituting gas for coal is not an effective means for reducing the magnitude of future climate change.
Wigley, it should be noted, was looking at the combined warming impact from three factors — from the methane leakage, from the gas plant CO2 emissions, and from the drop in sulfate aerosols caused by switching out coal for gas. In a country like the United States, which strongly regulates sulfate aerosols, that third factor is probably much smaller. Of course, in countries like China and India, it would be a big deal.
An April 2012 study found that a big switch from coal to gas would only reduce “technology warming potentials” by about 25% over the first three decades — far different than the typical statement that you get a 50% drop in CO2 emissions from the switch. And that assumed a total methane leakage of 2.4% (using EPA’s latest estimate). The study found that if the total leakage exceeds 3.2% “gas becomes worse for the climate than coal for at least some period of time.”
Leakage of 4%, let alone 9%, would call into question the value of unconventional gas as any sort of bridge fuel. Colm Sweeney, the head of the aircraft program at NOAA’s Earth System Research Laboratory, who led the study’s aerial component, told Nature:
“We were expecting to see high methane levels, but I don’t think anybody really comprehended the true magnitude of what we would see.”
The industry has tended kept most of the data secret while downplaying the leakage issue. The Environmental Defense Fund (EDF) is working with the industry to develop credible leakage numbers in a variety of locations.
The earlier NOAA findings were called into question by Michael Levi of the Council on Foreign Relations. The NOAA researchers “have a defence of the Colorado study in press,” Nature notes.
Right now, fracking would seem to be a bridge to nowhere.