The vast network of natural gas wells, pipes and processing facilities across the U.S. and Canada is “leaky” and needs a fix, according to a new study.
Government authorities are underestimating how much methane, a potent greenhouse gas, is escaping into the atmosphere from the natural gas system, says the report, entitled Methane Leaks from North American Natural Gas Systems, that was released Thursday by journal Science.
With the gas being championed in Canada and the U.S. as a “bridge fuel” to a “decarbonized” energy system, the authors say a concerted effort is needed to get a more accurate read on the emissions and plug the leaks.
Natural gas is predominately composed of methane, a molecule that is about 30 times better than carbon dioxide at trapping heat in Earth’s atmosphere.
The team of U.S. and Canadian researchers has found that official inventories “consistently underestimate” actual CH4 (methane) emissions.
“People who go out and actually measure methane pretty consistently find more emissions than we expect,” lead author Adam Brandt, an energy resources engineer at Stanford University said in a statement Thursday.
Atmospheric tests indicate U.S. methane emissions are about 50 per cent more than the estimates made by the U.S. Environment Protection Agency. “And that’s a moderate estimate,” said Brandt.
The study focuses mainly on the United States, but the researchers suggest the story is much the same in Canada.
“The same challenges apply here as well,” co-author Sarah Jordaan, a specialist in energy policy and politics at the University of Calgary, told Postmedia News. She said better monitoring of the natural gas system and other sources of methane in Canada is needed to better understand where the gas in atmosphere is coming from.
“We need to focus on getting the measurements right, and from this we can reduce emissions,” Jordaan said, noting that reducing leakage and “fugitive emissions” can be profitable for industry.
The study, with co-authors from 14 universities and research agencies, reviewed 20 years of data collected in the U.S. and Canada by everything from instruments on aircraft to inspectors on the ground.
It suggests some of the excess methane in the atmosphere could be explained by gas leaking out of abandoned oil and gas wells and wetlands and other natural sources not included in government inventories.
But the researchers also found emissions and leakage from the natural gas system is often underestimated and that opportunities to find and reduce leakage “abound.”
Experiments have indicated that a few leaks – or “superemitters” — in the natural gas system may account for much of the leakage. One assessment of 75,000 components at processing plants found 50 faulty components were causing 60 per cent of the leaks.
The researchers say the natural gas system is “almost certainly leakier than previously thought” and must clean up to deliver on its promise of being a clean fuel. But they conclude the leakage is “unlikely” to be large enough to negate the climate benefits of switching from coal to natural gas as a source of energy. Burning coal generates far more carbon dioxide, and mining it, releases methane.
Environment Canada and Natural Resources Canada had no comment on the report and its call to get a better read on methane.
Environment Canada’s website says “methane releases from oil and natural gas systems represent almost half of Canada’s total methane emissions” and notes there has been a major effort to reduce venting and flaring of gas at energy plants.
“Alberta has achieved over 50 per cent reduction in venting of associated gas at crude oil and crude bitumen facilities between 2000 and 2010, although emissions since 2006 have begun to rise again due to significant increases in production of bitumen,” the website says.
Geoff Morrison, manager of B.C. operations for the Canadian Association of Petroleum Producers, said the industry has “long-known” about its “fugitive” emissions and is working to improve reporting and to reduce emissions where it is financially and environmentally effective.
He noted that methane is “very small” proportion of total greenhouse gases in both Canada and the U.S.
“The positive take away” from the study, said Morrison, is that it found that switching from higher carbon fuels to lower carbon fuels, including natural gas with the fugitives, should be an improvement for total greenhouse gas emissions.
mmunro@postmedia.com
Twitter.com/margaretmunro
