Saturday, September 03, 2016

An Update on Methane Emissions from Fracking (in the US)

A large increase in U.S. methane emissions (Credit:
A relatively large number of research publications has appeared in the peer-reviewed literature since we last updated our readers on fracking and methane (CH4) emissions.  We cannot discuss them all here.  However, in summary, it can be concluded from these papers that EPA is very likely underestimating fossil fuel related methane emissions in its greenhouse gas inventory, anywhere between 30% and 100%, possibly even more.  Meaning, in order for the US to effectively lower its greenhouse gas emissions, it also needs to get fugitive methane emissions under control.
What does it all mean?
Keeping global warming below 2 degrees Celsius relative to pre-industrial average surface air temperatures requires keeping most of the known fossil fuel reserves in the ground. The term unburnable carbon has become widely used to describe how much fossil fuel assets could become stranded assets in the coming years, were we to follow the goals as laid out by the Paris agreement.  While industry is heavily promoting the replacement of coal with natural gas to lower CO2 emissions from electricity production, now, an additional caveat has been proposed, namely that the amount of unburnable carbon is in fact even larger considering the amount of methane that may be leaked while exploring the fossil carbon already on the books (aka “burnable carbon”).  The authors call it “unleakable carbon”, stating that

We demonstrate that unless unleakable carbon is curtailed, up to 80–100% of our global natural gas reserves must remain underground if we hope to limit warming to 2°C from 2010 to 2050.
Their best case scenario assumes that relative leak rates, globally, are about 50% higher than what EPA currently estimates (based on Brandt et al., 2014).  Since we know by now that even that could be too optimistic, it becomes more and more obvious that a switch from coal to natural gas for electricity production is not likely to curb global warming effectively, but rather delay effective measures further.

Read more at An Update on Methane Emissions from Fracking (in the US)

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