Temperatures could soar 4C in Britain putting coast at risk, warn top scientists

The UK and EU are attempting to limit global warming to no more than a 2C temperature rise above pre-industrial times to avoid dangerous climate change.

But Professor Bob Watson, the chief scientific adviser to the Department for the Environment, Food and Rural Affairs, said there was a good chance that Britain will face a 4C rise.

Soaring temperatures could lead to a retreat from the coast, Sir David King has warned

'There is no doubt that we should aim to limit changes in the global mean surface temperature to 2C above pre-industrial, Prof Watson told The Guardian.

'But given this is an ambitious target, and we don't know in detail how to limit greenhouse gas emissions to realise a 2C target, we should be prepared to adapt to 4C.'

His concerns were echoed by the Government's former chief scientific adviser, Sir David King.

He said that a two-and-half-year analysis on the implications for coastal defences had a major impact on government thinking about the effects of climate change, with officials even considering one day having to retreat from parts of Britain that it cannot protect from rising sea levels.

'No other single factor focused the minds of the Cabinet more than the analysis that I produced through that ... We begin to have to talk about ordered retreat from some areas of Britain because it becomes impossible to defend,' he said.

Commuters will suffer as temperatures continue to rise

London at risk

The soaring temperatures would impact on agriculture, coastal erosion and flood protection.

It would also put hundreds of millions of people in small islands and coastal cities such as London and New York at risk of flooding because of rising sea levels.

To emphasise the impact of a 4C rise, the report states that we are now only around 5C warmer than in the last ice age.

Sir David warned that even with a comprehensive global deal to keep carbon dioxide levels in the atmosphere at below 450 parts per million there is a 50 per cent likelihood that temperatures would exceed 2C and a 20 per cent probability they would exceed 3.5C.

'Even if we get the best possible global agreement to reduce greenhouse gasses on any rational basis you should be preparing for a 20 per cent risk so I think Bob Watson is quite right to put up the figure of four degrees,' he said.

A rescue team walks down a flooded road in Tewkesbury, Gloucestershire in July 2007. Flooding will become more frequent, a top scientist has warned