LONDON — The U.K. government lifted its ban on fracking Thursday, citing the need to increase domestic energy supply following the Russian invasion of Ukraine.

In her first major address on Sept. 8, new Prime Minister Liz Truss said ending the ban on extracting the U.K.’s “huge reserves of shale … could get gas flowing in as soon as six months, where there is local support.”

The ban was introduced in November 2019 after several tremors, and finally a magnitude 2.9 earthquake, were recorded near the U.K.’s only active fracking site, in the English county of Lancashire. Fracking, or hydraulic fracturing, involves injecting water, chemicals and sand into cracks in the earth at high pressure, widening them to allow the extraction of oil, or in the U.K.’s case, gas from shale formations. Locals worried about the link — nearly 200 reported damaged to their homes from the earthquake — and made their objections loudly known.

While anything below magnitude 3 is considered a small earthquake and is relatively common, a government report in 2019 concluded a ban on the practice was necessary since it was “not currently possible to accurately predict the probability or magnitude of earthquakes linked to fracking operations.” 

But Truss, and her new business and energy chief Jacob Rees-Mogg, insist fracking will play a key role in making Britain a net energy exporter by 2040. They also want to increase North Sea oil and gas production, announcing a new oil and gas exploration licensing round Thursday, as well as deployment of hydrogen, solar and offshore wind.

Truss’s promise that fracked gas could be powering homes and businesses within six months comes from an estimate by Cuadrilla, operator of the Lancashire site, on how long it would take to restart operations.

However, the requirement for “local support” could push that back a lot further, or even indefinitely.

Support for fracking among the general population has risen amid the energy crisis, according to polling firm YouGov, but remained at only 27% in May; while there are organized campaign groups opposing fracking around the U.K. who say they are ready to spring into action.

The devolved Scottish and Welsh governments and the opposition Labour party are also officially opposed to fracking. So are several politicians from the ruling Conservative Party, including Mark Menzies, member of parliament for the area of Lancashire where the Cuadrilla site is located. On news of the ban lifting, he said it had been “demonstrated without doubt the geology here is not suitable.”

Even the person now holding the reigns of the U.K. economy, Finance Minister Kwasi Kwarteng, publicly claimed as recently as February that fracking would do nothing to cushion people from rising gas and electricity prices, and that it would “take a decade to extract sufficient volumes” while coming “at a high cost for communities and our precious countryside.”

A 2020 review by Warwick Business School estimated fracked gas could account for between 17% and 22% of U.K. energy consumption between 2020 and 2050.

However, according to the London School of Economics, it is unclear how much shale gas (gas extracted from shale formations, the clay-rich areas marked for potential fracking) there is in the U.K. that is technically and economically viable to extract.

A past study found that shale gas operations themselves would contribute relatively little to greenhouse gas emissions. Critics argue the issue is instead around the need to reduce the U.K.’s reliance on natural gas more broadly, which currently accounts for around 40% U.K. energy consumption, and that there should be a focus on keeping polluting fossil fuels in the ground.

Environmental groups such as Friends of the Earth also cite reports warning that fracking could “potentially contaminate” groundwater due to the chemicals used in the process; will increase noise and industrialization in quiet rural areas; uses large amounts of water; and risks further earthquakes of unpredictable frequency and strength.

Cuadrilla says the clay on its site is “very well suited” to fracking and that it would conduct daily seismicity monitoring if operations restart. It also says that polyacrylamide — the chemical it uses — has been assessed by the Environment Agency as non-hazardous to groundwater and forms 0.05% of frack fluid.

A report commissioned by the government in April and published Thursday found it was still not possible to accurately predict geological activity as a result of U.K. fracking operations. But in a reversal of its 2019 position, the government now says more sites will need to be drilled to investigate further, while Rees-Mogg told the BBC this week the government will look to raise the level of seismic activity allowed at fracking sites going forward.

Investors certainly see potential for a restart in operations, with shares of onshore oil and gas company Egdon Resources — listed on the U.K.’s Alternative Investment Market — up 6.3% Thursday and up 365% this year.

However, analysts say many hurdles remain, not least regulation, environmental concerns and the operational complexities. The are four main areas identified as potentially viable for shale gas extraction and more than 100 sites have been granted exploration licenses for fracking, but these still need permits from various regulatory bodies to progress further, along with political backing.

“While currently high energy prices may improve the potential economic viability of fracking in the UK, it may be less certain over the longer term,” Tobias Wagner, senior credit officer at Moody’s, told CNBC.

“It remains to be seen to what degree companies are willing to invest at scale given the uncertainties and concerns,” he said.

This combination of environmental concerns and logistical difficulties mean fracking has never taken off in Europe, and fracking bans remain in many countries, including Germany — though this too is now under debate — France, the Netherlands, Denmark, Bulgaria and the Republic of Ireland.

John Underhill, professor at Aberdeen University and its director for energy transition, told CNBC that beyond the difficulties of winning over public opinion, the U.K.’s geology was another obstacle to fracking.

He published research in 2020 on Cuadrilla’s Bowland Shale which found shale gas exploitation was “technically very challenging” and that its drilling targets had faults in the subsurface that would lead to a tendency for seismic activity.

He added that the geology of the U.K. is very different to the U.S., where energy independence has been achieved largely through ramping up oil and gas fracking, and where shale horizons are unbroken by faulting and run for tens of miles in unpopulated open spaces.

“Whilst large resource estimates are often quoted, the shale gas reserves will only be a fraction of these figures because of the poor quality of the shale, lack of overpressure and discontinuous nature of the shale horizons themselves,” Underhill said.

And in a surprise blow to the pro-fracking movement, Chris Cornelius — the geologist who founded Cuadrilla who has since left the company — shared a similar view in the Guardian newspaper Wednesday, arguing that obstacles of “technical and economic feasibility” and “sociopolitical alignment around scale” make him skeptical there will ever be significant levels of shale gas extraction in the U.K.