"Without a drastic reduction in the UK's energy consumption, emissions of carbon dioxide - one of the leading contributors to climate change - could have disastrous results for the UK," EST chief executive Philip Sellwood said.

"Every time a light is switched on or a video is left on standby, carbon dioxide is emitted from a power station into our atmosphere, causing damage to the environment," he added.

The trust, set up by the government to promote responsible energy usage following the 1992 Earth Summit in Rio de Janeiro, said Britain emitted 536 million tonnes of carbon dioxide (CO2) each year of which one-third was due to energy usage in homes.

It said the average home was responsible for six tonnes of CO2 emissions a year - of which one-third could be saved by a switch to energy efficient lifestyles.

This in turn could carve 10 percent off the national total - equivalent to emissions from 30 coal-fired power stations.

"It is imperative that we become more aware of the energy we use in our homes and reduce our carbon dioxide emissions," Sellwood said.

"This can be as simple as turning thermostats down by one degree, replacing ordinary light bulbs with low energy ones or even walking to the shops instead of taking the car," he added.

KYOTO TREATY

The report said climate change could alter the entire face of Britain, with warmer winters spelling the end of several species of plants and trees which need a winter cold snap, and summer droughts burning green pastures to brown.

It came just days after the Russian parliament finally ratified the Kyoto climate change treaty aimed at cutting CO2 emissions by 5.2 percent below 1990 levels by 2012. The treaty - first agreed in 1997 but held in limbo by the refusal in 2001 of key polluter the United States to sign up - will now come into effect.

Critics say the treaty is too little, too late. But the British government's chief scientist David King said recently that as it was the only game in town it had to be made to work.

Britain leads the way in cutting CO2 emissions and creating energy efficient technology, experts say. But scientists and environmentalists have warned for years that a radical change in lifestyles was also necessary.

The south of England is most at risk from rising water levels as the polar ice caps melt and extreme weather events like storms increase.

An indication of the rising threat is the number of times the Thames Barrier has had to be used to prevent London from flooding in the 20 years since it was built.

Barrier manager Andy Batchelor told Reuters it had been used 88 times since it was commissioned - with more than 60 of those instances in the past decade, and anticipation that it might be needed as much as once a day by 2100.