There can be few issues in the climate debate as controversial as fracking for gas. The release of methane from drilling and during the extraction process, plus the extra carbon dioxide from burning gas, makes climate change more rapid and dangerous. One of the arguments against fracking has also been the probability of triggering earthquakes.
But environmental activists who use the earth tremor argument against fracking should probably be cautious if they are in favour of alternative solutions – gaining geothermal energy and lithium via boreholes from hot rocks beneath our feet.
For geothermal power, these extraction systems work by drilling down two deep boreholes into the rocks and then pumping water round a loop. The hot water from the depths is potentially a large source of carbon-free renewable energy.
Lithium, needed for batteries for electric cars, and in demand globally in ever increasing quantities, is extracted by a somewhat similar method, depending on the local geology. The water pumped round the deep boreholes under the West Country dissolves lithium from the rocks that is extracted when the hot water returns to the surface.
Once operational the heat and lithium extraction schemes in Cornwall should have no detrimental effect on the climate, but unsurprisingly the extraction method, as at the Eden Project in Cornwall, also causes earth tremors.
