Wednesday, 27 May 2009

Huge paint job 'could avert global warming'

Whitewashing roofs, roads and pavements to reflect sunlight and heat could play a big part in containing climate change, the US Energy Secretary and Nobel prize-winning physicist Steven Chu told the Nobel Laureate Symposium in London yesterday. Pale surfaces refect up to 80% of the sunlight that falls on them, compared with about 20% for dark ones.

At the same symposium Prof. Jack Steinberger, director of CERN, said that all of the world's known reserves of fossil fuels, including oil, gas and coal, would be depleted within 60 years, and that the energy of the future would be thermal solar.

The full story can be found in The Times (May 27th, pages 16-17).


  1. For those of you who don't live in the UK, and so have no access to a copy of The Times, here is the link to the online version:

  2. Thanks Amanda. I forgot it was also online. There are around 50 comments on this article already, including my thoughts:

    Is this something that Prof. Chu dreamed up on April 1st? According to the UN Population Division 0.2% of the Earth’s surface is occupied by urban regions. Multiply this by several factors (all much lower than 1), such as the fraction of an urban area occupied by roads and roofs, the average amount of daily sunshine being available, the efficiency of the white roofs and roads over existing colours etc etc, and it is apparent to anyone that the effect would be miniscule. And how long would a white road remain a white road?

  3. Surely every little counts?

    Prof Chu said: By lightening paved surfaces and roofs to the colour of cement, it would be possible to cut carbon emissions by as much as taking all the world’s cars off the roads for 11 years.

    Obviously it would be good to see how he or his colleague arrived at this figure, but if we accept that it's correct then it seems like a simple way of contributing to the fight against global warming.


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