So if they paint the Hummer white

Does this mean we have to stop pointing and laughing?

LONDON(AFP) (AFP) - US Energy Secretary Steven Chu said Tuesday the Obama administration wanted to paint roofs an energy-reflecting white, as he took part in a climate change symposium in London.

The Nobel laureate in physics called for a "new revolution" in energy generation to cut greenhouse gas emissions.

But he warned there was no silver bullet for tackling climate change, and said a range of measures should be introduced, including painting flat roofs white.

Making roads and roofs a paler colour could have the equivalent effect of taking every car in the world off the road for 11 years, Chu said.

It was a geo-engineering scheme that was "completely benign" and would keep buildings cooler and reduce energy use from air conditioning, as well as reflecting sunlight back away from the Earth.

For people who found white hard on the eye, scientists had also developed "cool colours" which looked to the human eye like normal ones, but reflect heat like pale colours even if they are darker shades.

And painting cars in cool or light colours could deliver considerable savings on energy use for air conditioning units, he said.