The dangers of fracking for shale gas have been “greatly overestimated” because of incorrect estimates about the damaging effect of methane leaking into the atmosphere, according to a study published today by a leading think-tank.
The report The Facts About Fugitive Methane, published by the Centre for Policy Studies, says previous estimates of methane leakage in the extraction of shale gas by hydraulic fracturing have been over-estimated.
According to the study, opponents of shale gas have argued that the high global warming potential of methane, the main component of natural gas, means just one or two per cent leaking into the atmosphere would wipe out its advantage over coal.
But authors Elizabeth and Richard Muller say this estimate is incorrect, adding: “Over a 100 year time span, an implausible 12 per cent of the produced natural gas used today would have to leak in order to negate an advantage over coal.”
It comes as environmental campaigners nationwide gear up to oppose possible shale gas extraction at dozens of sites across the country, including a number in Yorkshire.
In August, the Oil and Gas Authority announced 27 locations in northern England and the Midlands where licences to frack for shale oil and gas will be offered.
The licences covering land south of Wetwang and north of Mexborough awarded to Cuadrilla are among seven set to be issued in West and South Yorkshire.
The Government will also consult over plans to issue further licences covering areas of land on the Yorkshire coast, parts of the North York Moors National Park and around York, Doncaster, Sheffield and Chesterfield.
Licences give each company the sole right to explore for shale gas in the area covered, but planning permission still needs to be granted by local councils for each well site.
The report by the Centre for Policy Studies, a right-of-centre think-tank, says objections have been raised to natural gas extraction “although, in principle, natural gas offers a very large greenhouse benefit compared to coal”.
These are said to include the worry that natural gas is not a zero-carbon source of energy, the fact that it could delay the development of zero-carbon alternatives, and that fracking leads to “local problems”.
It said: “But there is a fourth concern which has not yet been properly addressed: the threat from leaked ‘fugitive’ methane.
“For there is a concern, held by many thoughtful people and others, that the danger of fugitive methane is a compelling reason to stop all development of shale gas.
“For example, a simple number published by Alvarez et al has been widely used by policy makers: they say that for equivalent greenhouse emissions compared to a coal plant, the maximum leakage is 3.2 per cent.
“They do accept that that value is for immediate effect only, and does not take into account the short lifetime of methane in the atmosphere. It is on this question that the dangers of shale gas is greatly overestimated.”
The authors say that the best current estimates for the average leakage across the whole natural gas supply chain are below three per cent, even at three per cent leakage natural gas would produce less than half the warming of coal averaged over the 100 years following emission.
Elizabeth Muller is co-founder of research group Berkeley Earth, while Richard A Muller is Professor of Physics at the University of California, Berkeley.
Friends of the Earth energy campaigner Tony Bosworth said: “The academic jury is still out about how much methane escapes during shale gas production. But the bottom line is, if we want to avoid the worst impacts of climate change then we have to leave 80 per cent of known fossil fuel reserves underground.
“Drilling more fossil fuels, such as shale gas, is the wrong direction for energy policy. Instead we should be pushing the boat out on the real solutions - energy efficiency and renewable power.”