Greater use of fracking is backed by UK's environment watchdog

Fracking, the controversial technique for extracting the new energy source of shale gas, should be allowed to go ahead, Britain's top environmental regulator has said.

The hydraulic fracturing of shale rock, which has been blamed for causing earthquakes and polluting ground water and has generated fierce opposition from environmentalists, should proceed as long as it is monitored carefully and is accompanied by measures to minimise carbon emissions, said the chairman of the Environment Agency, Lord Smith of Finsbury.

In a speech in London, Lord Smith – who as Chris Smith MP was Culture Secretary in Tony Blair's first administration – said that, as an energy source, fracking "potentially ticks the boxes on energy security, on availability and on cost". As to whether the technology was satisfactory in its environmental impact, he said: "The answer is complex, and is something like 'up to a point'.

"But, with careful use of the drilling technology, with rigorous monitoring and inspection, and with the development of a major programme of carbon capture and storage for gas-fired power generation, then shale gas could be a truly useful part of our energy mix."

Lord Smith's qualified endorsement of fracking will further encourage the Government to permit widespread use of the technology, which involves pumping a mixture of water, sand and chemicals under very high pressure into underground shale rock deposits, to blow them apart and release the natural gas they contain.

In the US, shale gas has provided an energy bonanza in recent years, and has caused gas prices to tumble. The downside is that fracking is known to be responsible for causing seismic movements – small earthquakes – and in America there are allegations that the chemicals used, and the shale gas itself, pollute groundwater. In the UK, an energy company, Cuadrilla Resources, has discovered a substantial shale gas field near Blackpool.

But the company has admitted that operations at its Preese Hall well were responsible for two earth tremors, of magnitude 2.3 and 1.5, on 1 April and 27 May last year, which were felt in the area, although no one was injured and no structural damage was caused. While Cuadrilla accepts that 50 seismic movements were caused by its operations, most of them tiny, an independent panel of scientists recommended three weeks ago that this should not prevent fracking going ahead, as long as the drilling operations were monitored very carefully.

Nathan Roberts, from the anti-fracking group Frack Off, criticised Lord Smith's position. "Lord Smith's endorsement of commercial-scale fracking in the UK suggests the Environment Agency is either ignorant of the facts or ignoring them," he said.

Joss Garman, a Greenpeace campaigner, said: "Evidence from America suggests fracking for shale gas could be as damaging to the climate as coal burning."

Lord Smith made his comments on fracking in a wide-ranging speech on the green economy delivered at the Royal Society of Arts, in which he also said that the UK could lead the world on wave and tidal-energy generation, and should fast-track other low carbon or renewable energy sources.

He made clear his support for several controversial technologies to be used in the fight against climate change. On the question of nuclear energy, he said: "If you had asked me 20 years ago about nuclear power, I would have taken the traditional green view and said something like 'Over my dead body'.

"I am happy to admit, however, that I have changed my mind – and it is the prospect of climate change that has changed it for me."