Britain will shut polluting coal-fired power plants by 2025, its government said Wednesday ahead of key UN climate change talks in Paris.

All coal power stations that do not have the technology to capture carbon emissions will be closed within ten years, the government said in a statement, in line with its pledge to phase out coal.

Environmentalists gave the announcement a cautious welcome, but warned that the government planned to switch to gas, rather than cleaner technology like wind or solar power.

The pledge comes before the UN Conference of Parties (COP21) summit, due in Paris from November 30 to December 11, where world leaders aim to forge an international deal to curb carbon emissions and stave off the worst effects of global warming.

Coal is widely regarded as the power source responsible for most carbon emissions.

"We are tackling a legacy of underinvestment and ageing power stations which we need to replace with alternatives that are reliable, good value for money, and help to reduce our emissions," said British Energy and Climate Change Secretary Amber Rudd.

"It cannot be satisfactory for an advanced economy like the UK to be relying on polluting, carbon intensive 50-year-old coal-fired power stations.

"Let me be clear: this is not the future."

Britain already plans to close three of its 12 coal power stations by 2016, so Wednesday's announcement relates to the nine other facilities.

But coal plants equipped with carbon capture systems will however continue to operate.

Britain is struggling to meet its energy needs as its power capacity has dwindled due to plant closures, while it is under pressure to adopt cleaner energy sources to curb climate change.

The country has placed nuclear at the core of its low-carbon energy policy, in contrast to eurozone powerhouse Germany which seeks phase out nuclear power after Japan's 2011 Fukushima disaster.

- 'From whiskey to port' -

Rudd added Wednesday that more British investment will be ploughed into nuclear energy, while shuttered coal plants could be replaced with new gas-burning power stations.

Former US vice president Al Gore, who won the 2007 Nobel Peace Prize for his work on climate change, described Wednesday's news as "an excellent and inspiring precedent as we head into COP21".

"The UK has become the first major economy to set a clear date to phase out coal, and I am hopeful that others will follow suit as we repower the global economy with the clean energy we need for a sustainable future."

Former New York mayor Michael Bloomberg, who advocates cities tackling climate change, also welcomed the move.

"Coming just weeks before international climate talks are set to begin in Paris, this bold step in the birthplace of the coal-powered industrial revolution sends a clear and unmistakable message to other government leaders," Bloomberg said in a statement.

While gas is less polluting than coal, environmentalists warn that burning gas still releases significant amounts of carbon dioxide and recommend investment in renewable energy sources such as wind or solar power.

"Phasing out coal -- if that's what's being suggested -- is essential for the climate," said Simon Bullock, senior energy campaigner for environmental group Friends of the Earth.

"But switching from coal to gas is like an alcoholic switching from two bottles of whiskey a day to two bottles of port."

Scientists warn that unless global warming is tackled, the world will have to deal with submerged cities, heatwaves, droughts, and huge refugee crises due to rising seas and the effects of extreme weather on harvests.