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100 years of shale gas? Only if you’re not bothered about climate change

  • 13 Feb 2012, 15:00
  • Robin Webster

How can we meet our carbon emissions targets whilst keeping down energy bills? With the development of carbon capture and storage technology still stalled, those who believe in a fossil fuelled future are promoting the use of 'shale gas' - gas extracted from rock by an extraction process known as 'fracking'. It's more expensive than conventional gas, but still relatively cheap.

Sounds good - but there are a couple of important caveats. Although there's lots of shale gas in the US and industry there is booming, it hasn't really got off the ground yet in Europe. And gas of any kind is still a fossil fuel - so it still produces greenhouse gas emissions.

Nevertheless, here is plenty of enthusiasm for shale gas in some sections of the media. The lead article in this week's Spectator argues that shale gas, in contrast to the "expensive and unreliable" renewables, is a "vast and hitherto unexploited resource" which should be embraced here, as it has been in the States:

While Britain and Europe (sic) have been throwing hundreds of billions in subsidies at renewable energy, the US shale gas industry has expanded to account for one quarter of all the country's gas production - all without subsidies. In doing so it has caught many environmentalists completely unawares. The energy-scarce world of their dreams has been put off for a couple of centuries at least; instead we are staring at a future of potential energy abundance....

Concluding:

Britain could be on the cusp of a new era of clean, cheap shale energy - but only if we seize the opportunity, as the Americans have.

The expansion of shale gas in the States has certainly had dramatic impacts on their energy politics. In the US, shale gas has " rocked the world," according to the European Energy Review, But the same piece also notes the things which make it more difficult to develop the fuel in Europe - high population density, higher well costs, and vocal public opposition being the key reasons.

How much gas is there?

So are we on the verge of the 'clean cheap shale energy' era? The Spectator article suggests that Britain's reserves of shale gas are estimated at 20 trillion cubic feet, and this could produce "enough energy for the next 100 years".

It's not too clear where this comes from. The statistics agency of the US Department of Energy estimated in a report published in April 2011 that the UK has 20 trillion cubic feet of "technically recoverable shale gas resources". Using figures from the British Geological Survey, the UK Parliament Energy and Climate Change Committee calculated last year however that this is equivalent to 5.6 years' of the UK's current gas consumption, or 56 years' worth of liquified natural gas imports.

Late last year the company Cuadrilla Resources claimed to have discovered 200 trillion cubic feet of shale gas under Lancashire. They say this is enough to provide "another 65 years worth of natural gas" for British consumers - a statement repeated in yesterday's Sunday Times. But the Economist suggest that only 10-20% of this may prove recoverable, whilst the British Geological Society are described as sceptical about the accuracy of the estimate. The BGS are currently working on a new estimation for the amount of shale gas available in the UK, but it's too soon to suggest that UK shale can provide energy for the next hundred years.

Shale gas and emissions reduction

However much shale gas is discovered in this country, there's another hidden assumption in the Spectator's argument, and it's about greenhouse gas emissions. The Spectator leader argues:

"...exploitation of shale gas is not at odds with carbon reduction policies: kilo­watt for kilowatt, energy generated from shale gas emits only half as much carbon as coal - the energy source which it is already beginning to replace in many American states"

It is true that burning gas emits about half the emissions of coal, but there are complicating factors. In 2008, research from Cornell University suggesting that gas leakage from the extraction process could drive up the emissions footprint of shale so that is almost as high as coal. The Cornell study has been heavily criticised, and several other studies disagree with it - but the early bits of hard data on methane emissions from the process, which appeared in Nature last week, appeared to agree with it. So the jury is still out.

Even assuming that shale gas has the same impact on the climate as 'conventional' gas, it's still a fossil fuel. In a special report published last year, the International Energy Agency modelled the impacts of a 'golden age of gas' scenario where production and consumption of gas is ramped up worldwide. It concluded that the scenario - which was modelled up until 2035 -

"....puts emissions on a long-term trajectory consistent with stabilising the concentration of greenhouse gases in the atmosphere at around 650 ppm, suggesting a long-term temperature rise of over 3.5°C. To limit the increase in global temperature to 2°C requires a greater shift to low carbon energy sources, increased efficiency in energy usage and new technologies, including carbon capture and storage."

The Spectator proposes that shale gas could provide "enough energy for the next 100 years" - with editor Fraser Nelson paraphrasing their argument - that shale gas "could keep Britain in energy for the next 100 years without the need to build another windmill".

In the UK, the Government's Climate Change Committee has advised that, in order to keep to the targets of the climate change act, emissions from the power sector need to be reduced by 90% by 2030. They say that this would require that the carbon-intensity of the electricity we use to fall from around 500 gCO2/kWh today to around 50 gCO2/kWh in 2030. The average carbon intensity of UK gas in 2009 was 405 gCO2/kWh.

The graph below shows how the Climate Change Committee envisages the 'carbon intensity' of the UK power supply developing to 2050, moving towards an 80% reduction in total emissions:

CCC_image

Domestic shale gas probably has a role in the UK, not least in offsetting some of our gas imports. But overall, it's difficult to see how we could fulfill the Spectator's vision of using lots more gas for many decades without either busting our emissions reduction targets, or the (very) large scale deployment of carbon capture and storage - not something we've worked out how to do.

It may well be that the Spectator believes climate change targets don't matter. The magazine often takes a climate skeptic line on climate science, recently for example putting questionable claims about sea level made by climate skeptic Nils Axel-Morner on the front page of the magazine, and last year publishing another front-page story which presented a scientific debate around warming in Anarctica as evidence of more "shaky global warming data". If that is its message however, it should probably just say so.

 

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