The Controversy Over Methane Releases from Fracking

30 Jul

There are many controversial aspects about fracking for natural gas, such as depleting and polluting water supplies, disposal of drilling wastes, noise pollution, and so on, however, not to be overlooked is the controversy over whether fracking releases unacceptable amounts of methane into the atmosphere, thus worsening global warming.  Methane, remember, is a potent greenhouse gas and the second most prevalent emitted linked to human activities. Although its atmospheric lifetime is much shorter than CO2, it’s still a major player in the global warming picture because over a 100 year period methane is 20-25 times more potent than carbon dioxide as a heat-trapping agent.FrackingDiagram

Given methane’s potency as a greenhouse gas, the controversy is whether or not fracking releases so much methane that it negates the advantages of natural gas, which is considered to be cleaner fuel than either oil or coal. Put differently, in our rush to increase production of natural gas through fracking might we be actually aggravating the global warming problem?

Opinions differ on this matter, thus the controversy. Essentially two issues underlie the controversy: how much methane is released during fracking and, second, whether the methane can be effectively captured before in the drilling process before it is emitted into the atmosphere.

Below are some choice paragraphs from two recent news articles and one Op-Ed piece on the topic. The hot links take you to the full articles.

Christian Science Monitor, June 23,  2013, “Methane leaks of shale gas may undermine its climate benefits” (here)

“Debate about the environmental impact of hydraulic fracturing or fracking usually centers around the potential risks to our water supply from contamination by toxic fracking fluids, which are pumped at high pressure over a mile under the ground to break up gas-bearing shale formations. In recent months, however, there has been renewed controversy over the effect that gas drilling has had on greenhouse gases in the atmosphere.

Proponents of fracking assert that the boom in natural gas has helped to cut America’s emissions of carbon dioxide, by encouraging coal-burning power plants to switch over to the cheaper and cleaner burning natural gas. CO2 output is now at its lowest level since the early 1990s, due in part to the increasing use of natural gas, and also to greater fuel efficiencies and the slow but steady growth in renewables.

But critics counter that the climate advantage of less CO2 may be canceled out by higher emissions of methane. Natural gas is primarily methane, the most powerful of the greenhouse gases, and the next most abundant in the atmosphere after CO2. The critical question is how much methane leaks during the drilling process, and also subsequently during processing and transport of the gas. The Environmental Defense Fund (EDF) says that if leak rates are greater than 3 percent of the total output, then fracking may actually be increasing America’s greenhouse gas load rather than diminishing it, as the industry claims.”

Wall Street Journal, April 28, 2013, “EPA methane report further divides fracking camps” (here)

“The Environmental Protection Agency has dramatically lowered its estimate of how much of a potent heat-trapping gas leaks during natural gas production, in a shift with major implications for a debate that has divided environmentalists: Does the recent boom in fracking help or hurt the fight against climate change?

Oil and gas drilling companies had pushed for the change, but there have been differing scientific estimates of the amount of methane that leaks from wells, pipelines and other facilities during production and delivery. Methane is the main component of natural gas.

The new EPA data is “kind of an earthquake” in the debate over drilling, said Michael Shellenberger, the president of the Breakthrough Institute, an environmental group based in Oakland, Calif. “This is great news for anybody concerned about the climate and strong proof that existing technologies can be deployed to reduce methane leaks.”

The scope of the EPA’s revision was vast. In a mid-April report on greenhouse emissions, the agency now says that tighter pollution controls instituted by the industry resulted in an average annual decrease of 41.6 million metric tons of methane emissions from 1990 through 2010, or more than 850 million metric tons overall. That’s about a 20 percent reduction from previous estimates. The agency converts the methane emissions into their equivalent in carbon dioxide, following standard scientific practice.”

“Gangway to a Warm Future” (an Op-Ed piece by Anthony Ingraffea in the NY Times, July 29, 2012) (here)

“Many concerned about climate change, including President Obama, have embraced hydraulic fracturing for natural gas. In his recent climate speech, the president went so far as to lump gas with renewables as “clean energy.”

As a longtime oil and gas engineer who helped develop shale fracking techniques for the Energy Department, I can assure you that this gas is not “clean.” Because of leaks of methane, the main component of natural gas, the gas extracted from shale deposits is not a “bridge” to a renewable energy future — it’s a gangplank to more warming and away from clean energy investments.

Methane is a far more powerful greenhouse gas than carbon dioxide, though it doesn’t last nearly as long in the atmosphere. Still, over a 20-year period, one pound of it traps as much heat as at least 72 pounds of carbon dioxide. Its potency declines, but even after a century, it is at least 25 times as powerful as carbon dioxide. When burned, natural gas emits half the carbon dioxide of coal, but methane leakage eviscerates this advantage because of its heat-trapping power.

And methane is leaking, though there is significant uncertainty over the rate. But recent measurements by the National Oceanic and Atmospheric Administration at gas and oil fields in California, Colorado and Utah found leakage rates of 2.3 percent to 17 percent of annual production, in the range my colleagues at Cornell and I predicted some years ago. This is the gas that is released into the atmosphere unburned as part of the hydraulic fracturing process, and also from pipelines, compressors and processing units. Those findings raise questions about what is happening elsewhere. The Environmental Protection Agency has issued new rules to reduce these emissions, but the rules don’t take effect until 2015, and apply only to new wells.”Natural gas as a bridge to nowhere?

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Posted by on July 30, 2013 in Global Environment


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