Stretches of Sussex coastline could end up under water unless the Government acts quickly to tackle climate change.

The Environment Agency has warned that plans to build 800,000 new homes in the South East in the next 20 years could set off an environmental timebomb, with an expanding population burning more fossil fuels, leading to warmer temperatures and rising sea levels.

Coastlines and low-lying areas are particularly vulnerable and the agency painted a nightmare vision of Sussex residents fleeing their flooded homes.

Lewes, Shoreham and Lancing were identified as high-risk areas.

The agency said planned flood defences were designed to withstand one serious flood every 200 years and might not prove so effective against repeated battering.

Meanwhile, the longer, drier summers that climate change is expected to trigger will place more pressure on water supplies than ever before, the agency predicted.

A spokeswoman said: "A growing population means more demand for water, which stretches resources, and more demand for energy, which will add to the greenhouse gases that cause climate change.

"Stormier weather and rising sea levels are also putting increased stress on existing flood defences.

"The development of housing will exacerbate all these threats to the environment and the effects of climate change are set to become more severe unless the environment is made a higher priority.

"Low-level properties on the coast are likely to be submerged, while residents face stormy winters, long dry summers, hosepipe bans and standpipes in the streets.

"Sussex is very dry and doesn't have much water to share around, particularly in the north."

Regional planning guidance provides for more than 5,000 homes to be built in Sussex every year.

Over 20 years, this would add up to more than 100,000 homes.

The agency called for the new homes to be built sustainably and to strict environmental guidelines, avoiding flood plains, building additional waste and sewage treatment facilities, ensuring sufficient green spaces to absorb excess carbon dioxide and provide drainage for rainfall, and increasing the use of renewable energy.

The agency's bleak warning followed Prime Minister Tony Blair's comments earlier this week that global warming "has become alarming and is simply unsustainable in the long term".

The government said it was already taking on board environmental considerations in the early stages of its housing plans.

But Councillor Bill Randall, of the Brighton and Hove Green Party, said proposals to build in the South East should be sent back to the drawing board.

Pointing out that thousands of homes in the North stood empty, he said: "The south of England is already desperately overcrowded and the city of Brighton and Hove is at bursting point.

"We need robust regional policies that create jobs in the North rather than these short-sighted proposals that will turn the South East into a concrete desert."

Thursday September 16, 2004