News today that a committee of experts has recommend a resumption of ‘fracking’ in the UK. At first I was surprised that this earthquake-inducing technology had been approved. But on reflection I see that the approval is really a measure of just how addicted we are to hydrocarbon consumption.
I expect the media will shortly have stories about the prospect of a financial bonanza, lower gas prices and independence from ‘foreign’ influence. These are all excellent economic reasons to invest in fracking. There will also be stories about the environmental risks, which are real and significant. And the balance between environmental risk and economic benefit will be the conflict at the heart of the media ‘stories’. But the stories will probably miss the one real reason why fracking may just possibly be justified: it could reduce carbon emissions
As I write this, the UK is using 31.87 GW of electricity of which 45% is being generated by coal – the most carbon intensive fuel we have. Only 19% is being generated by gas. Because each unit of electricity generated by coal emits twice as much carbon dioxide as a unit of electricity generated by gas, this means that right now, 83% of electricity-associated carbon dioxide emissions are coming from coal-fired power stations. If we replaced them with gas we would make a big contribution to reducing our carbon dioxide emissions. This is the real argument for increasing the supply of gas: switching off our coal-fired stations and building new gas stations could be achieved in a decade or so and would be less controversial and have a lower capital cost than switching to nuclear.
Could fracking really be a sensible option? The answer is ‘possibly’ but there is considerable reason to be skeptical. The problem arises because (evaluated over a century), methane is roughly 20 times more effective than carbon dioxide as a greenhouse warming gas. Switching from burning coal to burning methane, we can reduce carbon dioxide emissions by 50%. However, if in mining and delivering methane to the power stations we leak just 1 part in 20 (about 5%) then we save nothing in carbon emissions. And unless we had measured the loss, we might not even know about it. And if we leaked more than 1 part in 20 of the methane, we have actually made things worse.
Can you tell what comes next? Yes, recent measurements of the amount of methane which leaks from US fracking fields reveal that the losses almost completely cancel the benefit of burning gas.
If I was in charge, I would skip the fracking adventure and I would try to drag the UK kicking and screaming into a genuinely sustainable way of living. I think we need an economic and social response to the hazard from carbon emissions on the scale of a war. But I am not in charge. So if we do embark on this fracking adventure then it is essential that we:
- do not leak methane hither and thither, and
- that we use the gas to eliminate coal-fired electricity generation.
Otherwise fracking will become the UK’s tar sands disaster.