Paint cities white to tackle global warming, scientist says

Roads and buildings should be painted white in order to tackle global warming, according to a scientist.

Jon Swaine, The Telegraph 16 Jan 09;

Hashem Akbari believes that whitening 100 of the world's largest cities could wipe out the effect of the expected increase in emissions over the next decade.

White buildings and surfaces reflect far more sunlight than dark ones. Reflected sunlight does not contribute to the greenhouse effect, unlike the heat energy emitted by dark surfaces heated by the sun.

Dr Akbari, of the Lawrence Berkeley National Laboratory, California, also argues that if built-up areas were made white, less heat would accumulate within them, allowing residents and workers to reduce their use of air-conditioning units, which use a large amount of power.

Dr Akbari has calculated that making 100 of the largest cities white would increase the amount of sunlight reflected by Earth by 0.03 per cent. He believes it would cancel out the warming caused by 44billion tonnes of carbon emissions.

He told The Guardian: "Roofs are going to have to be changed one by one and to make that effort at a very local level, we need to have an organisation in place to make it happen."

He argued that while the move would not address the cause of climate change - rising carbon emissions - it would delay its effects.

"We can give the atmosphere time to breathe," he said. "I just don't see a downside to this idea. It benefits everybody and you don't have to have hard negotiations to make it happen."