Opponents of onshore shale gas in the UK have said new research on global methane emissions supports their call for a ban on fracking on climate change grounds.
But the onshore industry has dismissed the findings as “erroneous”, based on “unrepresentative small datasets”.
The study from Cornell University, published today, concluded that increased levels of climate-altering methane in the atmosphere may be from North American shale gas and oil developments.
Author Robert Howarth, professor of ecology and evolutionary biology, based his theory on the changing chemical composition of methane.
There has been a relative fall in the form of methane typically associated with conventional oil and gas developments, which is high in carbon-13.
Other researchers had ascribed the relative rise of methane low in carbon-13 to livestock farming and wetlands. But Professor Howarth said that the increased emissions were far more likely to be from unconventional gas and oil developments which, he said, was also low in carbon-13.
While acknowledging that his study was based on a small data set, he said:
“Correcting for this difference, we conclude that emissions from shale gas production in North America over the past decade may well be the leading cause of the increased flux of methane to the atmosphere.”
Increased methane from animal and wetland sources were “far less important than indicated by some other recent papers”, he said.
“This recent increase in methane is massive.
“It’s globally significant. It’s contributed to some of the increase in global warming we’ve seen and shale gas is a major player.
“If we can stop pouring methane into the atmosphere, it will dissipate. It goes away pretty quickly, compared to carbon dioxide. It’s the low-hanging fruit to slow global warming.”
The paper notes that the source of methane emissions from unconventional gas and oil could be from deliberate venting, emergency blowdowns and routine maintenance of pipelines and compressor stations.
“Fracking has forced methane emissions to unprecedented levels”
Opponents of UK fracking said the Cornell research supported previous studies, including the Mobbs Report. This challenged government conclusions that fracked gas had a lower carbon footprint than imported liquefied natural gas (LNG).
The Mobbs Report was at the centre of a recent case at the High Court won by the campaign group, Talk Fracking. The judge ruled that in not considering the Mobbs Report a government consultation was so flawed as to be unlawful. The case led to the removal from national planning policy of a requirement to support onshore oil and gas on climate grounds.
Today, Nick Cowern, emeritus professor at Newcastle University, who has given evidence to MPs on the climate impact of fracking, said:
“This work partly explains why the global climate has warmed so strongly in the last few years, affecting summer temperatures, melting sea ice and accelerating sea-level rise.
“Instead of cutting the atmospheric concentrations of powerful greenhouse gases like methane, fossil industry emissions – dominated by emissions from fracking – have forced up methane concentrations to unprecedented levels.”
“Time to ban fracking”
A spokesperson for the campaign network, Frack Free United, said:
“The results in this report confirm the suspicions of climate campaigners everywhere, and shows that fracking is driving climate change: one third of the total increase in global methane emissions since 2008 has come from shale gas, and that shale gas makes up more than half of the global increase in emissions due to fossil fuels.
“Methane is driving climate change faster than ever, and it’s not just that. Methane emissions have done signiﬁcant damage to public health and agriculture and the cost implications alone are huge. Time to act. Time to ban fracking.”
“UK onshore shale must be priority to reduce energy emissions”
The Cornell study was rejected this evening by the UK onshore industry body, UKOOG.
Its chief executive, Ken Cronin, said:
“Unfortunately, this paper amounts to erroneous conclusions drawn from unrepresentative small datasets and just 10% of the publicly available literature on the topic.
“The core tenet of the paper is that increases in global methane abundance have primarily been driven by shale gas production, based on the assumption that shale gas is ‘biogenic’ in nature. Regrettably for its author, academics from Royal Holloway, Cambridge, Bristol and other leading universities recently came to the conclusion that the evidence does not support this theory. Specifically in the case of the UK, they have stated that isotopic analysis of the core samples and gas flow data have confirmed that the resource has a distinct ‘thermogenic’ character.
“In reality, this failure to accept their conclusions, and recent literature which has shown that increases in atmospheric methane concentration have been primarily driven by biogenic sources, means that the study has disregarded 90% of publicly available literature to come to its conclusion. Had the author concluded that coal methane emissions – which do identify as biogenic in many cases – had driven the increase in global methane abundance, there would have been a better case.
“Ultimately, UK shale has been forecast to have a lifecycle methane emission rate of 0.5%, and a pre-combustion footprint half that of the liquefied natural gas (LNG) from Qatar, Russia and the US that we are becoming ever more reliant on. If we do nothing, this trend to import will continue, and by 2035 we’ll be procuring nearly 75% of our gas from these higher emission sources. The evidence is clear: if we want to reduce our energy emissions, developing UK onshore shale must be a priority.”
Ideas and perspectives: is shale gas a major driver of recent increase in global atmospheric methane? is published in the peer-reviewed journal, Biogeosciences