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:
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.