It's hot, but just wait for global warming

London basked in exceptionally warm and sunny conditions today - officially the second hottest of the year so far in the capital after Bank Holiday Monday.

The warmest spot in the country was Charlwood near Gatwick Airport, where temperatures reached 23C before noon.

The Met Office said the pleasant conditions - caused by an area of high pressure over the North Sea - were set to continue through the weekend. But future Londoners may not be so lucky, as the Government warned today that the capital's streets and buildings may become uncomfortably hot with climate change.

Ministers urged town hall chiefs to plan how to cool roads, and also warned of the threat of growing levels of pollution by busy roads, acute water shortages in the South East and of the prospect of more devastating floods.

To cut the risk of flooding, homeowners are to be banned from paving over their front gardens unless they use permeable materials or get planning permission.

"Urban areas will have to plan to avoid water quality problems, and uncomfortably hot streets," the Government said in reply to the Royal Commission on Environmental Pollution's report on urban areas.

"When it is well designed, the urban environment can provide buffers against pollution, noise and the extreme weather events that we are increasingly experiencing." Poor quality air is expected to reduce people's life by on average seven to eight months, and in some urban areas the impact of pollution is growing - reversing steady improvement since the industrial revolution.

The Department for Environment, Food and Rural Affairs added: "Long-term trends are flattening out or even getting worse at a number of locations alongside busy roads and in urban hotspots, despite current measures to reduce them." Ministers also stressed the need for better urban areas, including more cycling and walking routes, to tackle the obesity epidemic in Britain. They added: "Across the UK today we face an epidemic of life-style diseases. "Heart disease, stroke, cancer and diabetes take the place of 19th-century epidemics as the illnesses that curtail life prematurely."

Britain's 16 million hayfever sufferers, particularly those living on the east coast, could suffer this week as extra tree pollen is forecast to be blown in from the Continent.