What is fracking and why is it controversial?
The government has ordered a new review into the controversial process of fracking, as the debate over UK energy supplies intensifies.
There has been a UK moratorium on fracking since November 2019, on the basis of evidence that it was not possible to accurately predict tremors associated with shale gas extraction.
On Tuesday, business secretary Kwasi Kwarteng wrote to the British Geological Survey asking for a report on the latest science around fracking including new techniques, improvements in geological modelling or areas outside of Lancashire – where fracking has taken place – less at risk of tremors.
Boris Johnson is due to reveal his government's new energy strategy amid a global supply crisis.
What is fracking?
Fracking is a form of gas extraction that involves liquid being pumped deep underground at high pressure to fracture shale rock and release gas or oil trapped within it.
Gas is found in shale deep in the earth made up of loose deposits of silt, clay and rocks.
Sometimes controlled explosions are carried out after the miners have drilled into the deposit to loosen the shale.
Then water mixed with sand and a series of chemicals is pumped at high pressure into the deposit cracking the shale and forcing the gas out.
Why is it controversial?
Fracking requires huge amounts of freshwater (which has to be transported to the site) to extract the gas, and once this water is mixed with the sand and chemicals it becomes extremely toxic.
This risks polluting nearby water supplies by mixing with underground water.
The release of the gas from the earth can also cause methane to leak into the atmosphere, harming the environment.
Fracking is often unpopular with local communities due to the risk of tremors in the earth, which can cause minor earthquakes.
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This is considered to be acceptable in places like the US where there is vast amounts of space with no one living nearby, but in the UK most of the countryside is either protected or near a village.
The process has been mired in controversy in the UK since it hit the headlines in 2011 for causing two minor earthquakes in Lancashire, prompting a temporary ban.
That was later lifted, with controls put in place to prevent tremors, but fracking continued to draw opponents who fear it can also cause water contamination, noise and traffic pollution.
Fracking at the site was suspended indefinitely after a record-breaking tremor measuring 2.9 on the Richter scale in August 2019, with the moratorium or “pause” coming in a few months later.
Earlier this year, Cuadrilla, who operated the site was ordered to permanently cap and abandon the only two horizontal shale wells that have been drilled in the UK.
Which countries use fracking?
The most notable country that widely uses fracking is the USA, with almost all of all global fracking taking place there.
Fracking was successful in the US in the early 2000s and 2010s, making the country almost entirely energy independent.
This energy revolution sparked a flurry of interest in fracking across the world, with many keen to replicate the USA's success.
Energy independence has been thrown into the spotlight by Russia's invasion of Ukraine.
Russia, one of the world's biggest suppliers of energy, has become an international pariah, forcing countries to re-examine their energy strategies.
Many European nations have attempted to frack in the past, but it has been met with fierce opposition from local populations and has struggled to be commercially successful.
Outside of the US, the only other countries that have successful commercially viable fracking operations are Canada, China and Argentina.