Study Finds Methane Leaks Negate Benefits of Natural Gas as a Fuel for Vehicles
▻http://www.nytimes.com/2014/02/14/us/study-finds-methane-leaks-negate-climate-benefits-of-natural-gas.html?_r=1
Des fuites de #méthane plus importantes que ne le dit l’#EPA.
Although burning natural gas as a transportation fuel produces 30 percent less planet-warming carbon dioxide emissions than burning diesel, the drilling and production of natural gas can lead to leaks of methane, a greenhouse gas 30 times more potent than carbon dioxide.
Those methane leaks negate the climate change benefits of using natural gas as a transportation fuel, according to the study, which was conducted by scientists at Stanford University, the Massachusetts Institute of Technology and the Department of Energy’s National Renewable Energy Laboratory.
The study concludes that there is already about 50 percent more methane in the atmosphere than previously estimated by the Environmental Protection Agency, a signal that more methane is leaking from the natural gas production chain than previously thought.
“Switching from diesel to natural gas, that’s not a good policy from a climate perspective,” said the study’s lead author, Adam R. Brandt, an assistant professor in the department of energy resources at Stanford.
▻https://www.sciencemag.org/content/343/6172/733.summary
New Study Shows Total North American Methane Leaks Far Worse than EPA Estimates
▻http://www.desmogblog.com/2014/02/14/new-study-shows-total-north-american-methane-leaks-far-worse-epa-estimat
The researchers also described the effects of switching from coal to natural gas for electricity — concluding that coal is worse for the climate in some cases. “Even though the gas system is almost certainly leakier than previously thought, generating electricity by burning gas rather than coal still reduces the total greenhouse effect over 100 years, the new analysis shows,” the team wrote in a press release.
But they failed to address the climate impacts of natural gas over a shorter period — the decades when the effects of methane are at their most potent.
“What is strange about this paper is how they interpret methane emissions: they only look at electricity, and they only consider the global warming potential of methane at the 100-year time frame,” said Dr. Howarth. Howarth’s 2011 Cornell study reviewed all uses of gas, noting that electricity is only roughly 30% of use in the US, and describing both a 20- and a 100-year time frame.
