Prof Mike Stephenson is the Executive Chief Scientist for Decarbonisation and Resource Management at BGS. Here, he tells how geoscience can help play a role in managing and reducing climate change...
A paper out today in the journal Petroleum Geoscience identifies the vital role that geoscience will
play in averting climate change. The paper summarises the views of a hundred of
the world’s top energy geologists who gathered for this year’s Geological
Society Bryan Lovell meeting, and encourages the wider geological community to get
together to develop the tools to decarbonise the energy system.
Geology has always had a lot to do with energy. During the
19th Century - the carbonisation
period we now know as the Industrial Revolution - geology was pivotal. The UK carbonised using its high calorific
value; easily accessible coal, iron ore and limestone, thereby moving away from
the constraints of biosphere carbon to geosphere carbon.
Transitioning from the current ‘oil economy’ to a renewables
economy - decarbonisation - is one of the biggest challenges for the modern
world, alongside communicable diseases and urbanisation. Geology will be just
as important for decarbonisation as it was for carbonisation – a whole range of
options can contribute directly including geothermal, carbon capture and
storage (CCS) and biofuels with CCS (BECCS), and indirectly by contributing to
better energy storage (compressed air energy storage and hydrogen storage).
One clear option for
geological decarbonisation that emerged at the meeting was geothermal. About
20% of the UK’s emissions come from natural gas-fired heating of buildings,
mainly homes. Decarbonising these heating systems is a challenge. You could
perhaps convert to electricity but this would hugely increase demand; you could
convert natural gas heating to hydrogen, which would be expensive; or you could
use geothermal heat. The available heat
in the UK (including deeper hot dry rock and shallow geothermal), is around 200 exajolues (1 EJ is 1018) joules). This is enough for about 100 years of
heat supply at present consumption rates. Perhaps the most suitable for UK
housing would be low-enthalpy (shallow) heat. BGS’s UK Geoenergy Observatory (UKGEOS) Glasgow project is looking right now at the possibilities for shallow heat to be extracted from old coalmines.
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| Borehole at the Glasgow UK Geoenergy Observatory site |
Other ways that
geoscience can contribute to decarbonisation relate to the earth as an energy
store or as a store for CO2. In compressed air energy storage
(CAES), caverns can help to provide grid-scale energy storage to even out the
intermittence of renewables. Caverns can also be used to store hydrogen to cope
with interseasonal variation of hydrogen use on an industrial scale. Perhaps
best known for its direct way of dealing with emissions reduction is carbon
capture and storage (and its relative carbon capture storage and utilisation,
CCUS). The Lovell meeting restated the importance of CCS in its ability to achieve very high emissions reductions from power and
energy-intensive industry, and that it can be scaled up for negative emissions
in the event of emissions reductions not falling within the envelope of the
Paris agreement.
The meeting also
touched on some very innovative ideas for energy storage, for example turning
rocks directly into batteries. Can the distribution of ‘trace’ metals in
mudstones, for example, be used to imitate redox flow batteries? Can we use
salt caverns as reservoirs for battery electrolytes?
The authors of the
paper think that geoscience has an enormous amount to contribute to
decarbonisation. Indeed it may be true that decarbonisation, and ambitious aims
such as the UK’s zero-carbon commitment by 2050, can’t be achieved without
geoscience and the subsurface. Decarbonisation may also be a way to revitalise
the science of applied geology as the oil and gas industry – a long time
sponsor of geoscience and employer of geologists – begins to change its
business model and adapt to a new low-carbon world.
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| Pulling samples at the Glasgow UK Geoenergy Observatory site |
What to do next?
The geoscience decarbonisation
community need to get together more, realise our common challenges and
learn to speak with a common voice so that we get noticed by the legislators
and policy makers. We have a really inspiring and practical message. Let the
geologists get on with helping to decarbonise!
For more information, please visit: https://www.bgs.ac.uk/research/energy/home.html or email enquiries@bgs.ac.uk.
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