London will feel the heat as climate changes

Underground trains hot beyond bearing, working conditions constantly uncomfortable, air pollution in the streets steadily worsening and flooding that devastates housing and transport – such may be life in London during the coming century, a conference on climate change and the capital was told yesterday.

All of the possible consequences of global warming may affect London in a more severe way, speakers told the conference, because of the "urban heat island" effect – the rise in temperature caused by thousands of homes and businesses in close proximity.

Furthermore, its position on the edge of the Thames estuary makes the capital vulnerable to sea-level rises, with £80bn worth of land and property at risk – nearly a 10th of the national assets.

A study on the likely impact of climate change on London was launched at the conference, which was held at City Hall, the Greater London Assembly building, and addressed by the Mayor, Ken Livingstone, and the Environment Minister, Michael Meacher.

Mr Meacher painted a stark picture. "Climate change could be a particular problem for London because of urban heat island effect," he said. "London is five to six degrees warmer than its rural surroundings on summer nights, and climate change will certainly intensify this effect.

"By the end of the century, summers could be as hot as those of present-day New York, and buildings could become uncomfortable to live and work in. We could experience some very, very high temperatures in the London underground, where it has already reached 40C on one occasion."

Extreme weather events, such as heatwaves, storm surges and heavy spells of rain would become more frequent, Mr Meacher said. "During a rainstorm in August this year over an inch of rain fell on London in a half-hour period, leading to closure of five of the capital's mainline railway stations. That's just one example and, I repeat, we are at the beginning of a rising curve."

Climate change was also increasing the flood risk to London from storm surges and sea-level rise, Mr Meacher said. "The city has a far greater potential for damage from flooding than any other urban area in the UK."

Last year, the Thames barrier was closed 13 times, the greatest number of closures in its 18-year record. The Environment Agency had estimated that an additional £4bn will need to be invested over the next 40 years to protect London from rising sea levels.

The urban heat island effect might mean poorer health and comfort in the capital, a greater demand for cooling, and poorer air quality, Dr Rob Wilby of King's College London said. It might also affect wildlife, and some species – such as the rosy-ringed parakeet breeding in some London parks – might do well.

The weather patterns to be expected in summer, with high pressure systems giving more sunshine and lower wind speed, would exacerbate the poor air quality problems, Dr Wilby said.

Jim Kersey of the environmental consultancy Entec said the rise in temperatures could mean workplaces will be uncomfortable for a quarter of the capital's population by 2050. There could be some benefits for tourism and leisure, with a growth in pavement café culture. "But, in general, the effect on society will be more negative than positive," Mr Kersey said.