Climate change could seriously threaten quality of life in London and the capital's position as a leading world city, Mayor Boris Johnson has warned today.
Mr Johnson issued the warning as he launched a strategy detailing the action that needs to be taken in London to cope with global warming.
It outlines measures such as "greening" the city and cutting water use which will be needed to help London adapt to the higher risk of floods, droughts and heatwaves expected in the future.
The strategy said London is not currently prepared to cope with the more frequent extreme weather events or the changes in the seasons - including warmer, wetter winters and hotter drier summers - that climate change will bring.
But London is well-placed to lead the world on adapting to climate change, with clear economic opportunities such as developing "green" jobs in the city, it said.
Mr Johnson said: "We need to concentrate efforts to slash carbon emissions and become more energy efficient in order to prevent dangerous climate change. But we also need to prepare for how our climate is expected to change in the future.
"The strategy I am launching today outlines in detail the range of weather conditions facing London, which could both seriously threaten our quality of life - particularly that of the most vulnerable people - and endanger our pre-eminence as one of the world's leading cities."
He said all major cities were at risk from climate change, and by producing the strategy - which is a legal requirement under the Greater London Authority Act - London was being put in a strong position.
The strategy said the main dangers climate change poses the capital are flooding, drought and heatwaves.
Some 1.25 million people are at risk of flooding, along with almost half a million properties, 441 schools, 75 Underground and DLR stations and 10 hospitals.
The Thames region has lower water availability per person than Morocco, but Londoners consume on average 18 litres per day more than the national average while some 600 million litres a day are lost through leaks.
Summer temperatures in the capital have been rising in recent decades and the August 2003 heatwave killed at least 600 people in the city.
The strategy outlines a series of measures to help the capital cope with the problems climate change is set to bring.
- "Urban greening", with the use and design of green spaces, green roofs and tree planting to absorb and retain rainwater and help cool the city;
- Raising the public awareness of flood risk, and improve flood risk management on the Thames tributaries where properties are at significant risk of flooding;
- Promoting less water loss by reducing leakage from water mains;
- Encouraging people to use less water by promoting and aiding compulsory water metering in developments where feasible and retrofitting of existing homes to help them become more water efficient;
- Designing new buildings and adapting old ones to minimise the need for cooling facilities.
Speaking today at the Thames Barrier in east London, Mr Johnson said he wanted "many more" roof gardens across the city and wanted to protect existing back gardens.
Mr Johnson also said work was continuing to cool down the tube system and that 40% of the underground trains would be air-conditioned by 2010.
He said: "If you look at the Stern Report and you look at the risks that are involved in catastrophic climate change, we have got to guard against it."
Referring to the Thames Barrier, he added: "This is a structure that's built to guard against a catastrophic event that has not yet happened. But we've got to be ready to cope with it.
"We have to be realistic about the risks posed by climate change and make sure the city is in a position to cope."