Owen Paterson in 'lights out' warning over emissions target
The government's energy policy will "fail to keep the lights on", the former environment secretary has said.
Owen Paterson also said climate change forecasts had been "consistently and wildly exaggerated".
The Conservative MP, replaced in July's ministerial reshuffle, criticised "blind adhesion" to emissions targets.
The 2008 Climate Change Act aims to reduce the UK's greenhouse gas emissions by at least 80% by 2050.
Last month Prime Minister David Cameron said the UK was "on track" to hit the target.
But in a speech to climate-sceptic lobby group the Global Warming Policy Foundation on Wednesday evening, Mr Paterson said the legally-binding target should be suspended and possibly repealed.
"The 2050 target commits us to a huge expansion of electricity generation capacity, requiring vast investment," he said, adding that the "huge" costs would be unaffordable.
"Even if it were forthcoming, the scale of the turbine-building programme required is so great that it could not be achieved."
The North Shropshire MP instead proposed the use of shale gas, combined heat and power plants, and "small modular nuclear reactors".
But Andrew Whalley, chief executive of British renewable energy generator REG and a member of the British Wind partnership, said "onshore wind is one of the most affordable options".
"It is secure, abundant, and supported by 70% of the British public, according to the government's most recent annual survey."
Earlier this year, a UN report said the impacts of global warming were likely to be "severe, pervasive and irreversible".
Mr Paterson said he agreed with "the main points of the greenhouse theory" but added that the atmosphere had warmed "nothing like as fast as forecast".
After his speech, he told the BBC a "complete rethink" of Britain's energy policy was needed, calling for a "common sense approach".
Asked why had not spoken up when in office, he said he had been "a loyal member of the government".
The former minister has had a number of clashes with environmental campaigners during his time in office, criticising what he called "the Green Blob" after his sacking.
When he was replaced by Liz Truss in the reshuffle, Friends of the Earth said Mr Paterson had been "the worst environment secretary the UK has had for decades".
Mr Paterson's remarks echo those made in the past by UKIP leader Nigel Farage, who has also called for the Climate Change Act to be scrapped and for "green taxes" to be repealed.
Energy analyst Richard Black said Mr Paterson's intervention was the "the most radical verbal challenge to the cross-party consensus" on energy policy in recent years.
But Mr Black, director of the Energy and Climate Intelligence Unit, said Mr Paterson was wrong if he was suggesting the Climate Change Act mandated wind farms ahead of other power sources.
"I have been through the Climate Change Act line by line, and can find no mention of renewables - or any other specific technology," he wrote on his blog.
"The Act is, in fact, studiously technology-neutral."
The Energy and Climate Intelligence Unit describes itself as a non-profit organisation that "supports informed debate on energy and climate change issues in the UK".
Its financial backers include the European Climate Foundation, the Grantham Foundation for the Protection of the Environment and the Tellus Mater Foundation.
Lord Turner, former chairman of the Climate Change Committee, told the BBC that "the act has not bound us into any one particular technology".
Addressing the UN Climate Summit last month, Mr Cameron defended the Act, saying renewable energy capacity had doubled since 2010.
But the prime minister said there should not be a "trade-off" between reducing carbon emissions and economic growth and warned against "green tape" stifling the flexibility of businesses to choose which technologies were most appropriate.
Labour said it was proud of Britain's "leadership" on tackling climate change.
"To scrap the Climate Change Act now would damage Britain's influence abroad and put a halt to much-needed investment in clean energy here in Britain," shadow energy secretary Caroline Flint said.