Britain faces drought and floods by the 22nd century

Britain's climate will heat faster in the next 100 years than at any time since the end of the Ice Age, with droughts in summer and floods in winter becoming more common in the south and east, the Government warned yesterday.

The changes are inevitable, said the Department for Environment, Food and Rural Affairs, using data from the Hadley Centre, Britain's premier climate-study facility.

The Environment Agency, responsible for monitoring recent river flooding and protecting the British environment, said tackling the effects of climate change was already proving costly, and added: "Our emergency workforce is the 'thin green frontline' when it comes to flood events."

The gloomy picture of a climate out of control, and of defences being overwhelmed, brought renewed calls for faster and more radical government action, especially by the United States, the largest generator of the carbon dioxide that is a key greenhouse gas leading to warming.

The analysis found that on average Britain would warm by between two and five degrees centigrade in the coming century, though the rise would be greater over land, reaching up to eight degrees centigrade in the south and east. To stabilise the levels of carbon dioxide would become harder, the Defra report said.

"We're already seeing the some change created by the greenhouse emissions of the Seventies," said Geoff Jenkins, head of the climate prediction group at the Hadley Centre. "We expect the trend to continue."

In the south and east, which are most affected by the continental land mass, summer sunshine will increase by 20 per cent, but winter rainfall will increase by 25 per cent, and summer rainfall could halve.

"The United Kingdom is facing a future of unprecedented change," Defra said. "Cutting emissions now and in the future will go some way to prevent the worst effects, but our past emissions mean some degree of change is inevitable."

A spokesman for the environment group Greenpeace said: "Things need to be done now. Global warming is happening and it will affect people in the developing world more than anywhere else. Many lives are going to be lost to global warming unless action is taken now. One would hope that this report is a spur for White House action."

America has been reluctant to make firm commitments to reducing carbon dioxide emissions, having snubbed the Kyoto Treaty, which was intended to reduce emissions from industrialised countries below their 1990 levels by 2010. Britain has committed itself to meeting those targets.

But measurements taken by the Hadley Centre show "carbon feedback" from forests and natural vegetation – as rain forests are cut down and burnt – is rising and could accelerate global warming even further.

The atmospheric concentration of many greenhouse gases reached their highest levels in 2001; global temperatures continued to rise with 2002, 2001 and 1998 being the hottest years on record.

Defra said it had strategies in place to cope with flooding.