The announcement this morning by President Obama of a revised target for US methane emissions is not just another gimmick to shackle the American oil and gas industry. Nor is it new.
Back in 1971, the world’s scientists thought that methane directly affected neither the climate nor the biosphere and was relatively unimportant. However, in the 2001 climate report from the UN, the experts were whistling a different tune–based on multiple lines of evidence discovered during the intervening 30 years.
NASA’s Gavin Schmidt, a research scientist at the NASA Goddard Institute for Space Studies and Center for Climate Systems Research, provided an excellent summary of the science 10 years ago. Subsequent studies have clearly validated the newer conclusions. In fact, methane estimates have gone up and up.
The government’s detailed Strategy to Cut Methane Emissions, which was leaked to the press on Tuesday, has announced a goal of cutting methane emissions by 40-45% from 2012 levels by 2025. The methane plans do not not cover pipeline transmission and gas distribution losses, which can be considerable. The administration will also continue its policy of suggesting and supporting voluntary oil and gas industry efforts to harness methane from drilling.
The Bureau of Land Management will propose guidelines for well emissions on public lands; the Department of Transportation will consider methane leaks when issuing new pipeline safety standards; and the Energy Department will research ways to reduce the cost of detecting leaks and issue energy efficiency standards for natural gas air compressors.
Today’s methane plans follow on from the US Climate Action Plan announced last March, which the President later elaborated at Georgetown University. He directed his 2014 administration to put together a comprehensive interagency strategy for reducing emissions of this harmful gas, the sneakiest of atmospheric pollutants.
Here’s how scientists describe methane :
Methane (CH4) is the second most prevalent greenhouse gas emitted in the United States from human activities. In 2012 CH4 accounted for about 9% of all U.S. greenhouse gas emissions from human activities. Here are some global numbers.
Methane is emitted by natural sources such as wetlands, as well as human activities such as leakage from natural gas systems and the raising of livestock. Natural processes in soil and chemical reactions in the atmosphere help remove CH4. [Note: The 17% cited above for fossil fuels and biomass is low: fossil fuel emissions are also implicated in the waste and hydrate/permafrost release totals, as well as by exacerbating wildfire severity.]
Methane’s lifetime in the atmosphere is much shorter than carbon dioxide (CO2), but CH4 is more efficient at trapping radiation than CO2. Pound for pound, the comparative impact of CH4 on climate change is over 20 times greater than CO2 over a 100-year period…. Natural gas and petroleum systems are the largest source of CH4 emissions from industry in the United States. Methane is the primary component of natural gas.
In 2012, NOAA and University of Colorado, Boulder, researchers found that drillers in the Denver-Julesburg Basin were losing about 4% of their raw gas to the atmosphere—more than double the official EPA inventory. Estimates in one area were over twice as high as that. This amount does not include additional losses in pipeline transit and distribution. The oil and gas industry actively denied this research.
Last year, in the American Chemical Society publication Environmental Science and Technology (followed up in Scientific American), Carnegie-Mellon and NOAA scientists Stefan Schwietzke, W. Michael Griffin, H. Scott Matthews, and Lori M. P. Bruhwiler elaborated: “Methane emissions released by the natural gas industry [are] a critical and uncertain value for various industry and policy decisions, such as for determining the climate implications of using NG over coal. Previous studies have estimated fugitive emissions rates… on few and outdated measurements, and some may represent only temporal/regional NG industry snapshots.”
The table below expresses EPA’s strategy on methane emissions until today.
“One of the biggest [climate] fights involves how much effort to put into stopping leaks of methane gas into the atmosphere,” said Justin Gillis of The New York Times last July. “It may sound like an obscure topic, but the leaks could have a great effect on the climate that people living today experience.”
As noted in my own article after the ACS publication,
“The President has started backpedaling on the greenhouse gas issue a bit since the National Climate Assessment and other studies earlier this year began clarifying the emissions scenarios. Now that he appears to know the real score on fracking and fugitive emissions, however, perhaps we can expect further efforts on renewables. After all, they’re cheaper and farther along in development than carbon capture and storage.”
Environmental activists now say that we need even deeper cuts than those noted in the methane plan to reach or exceed the climate change pledges we made with China last fall and formalized at the international COP20 meeting in Lima.
New methane plan rules are expected to be finalized in 2016. By that deadline, the administration will be able to examine further findings on methane and have a better idea whether additional cuts will be needed.