At a panel in front of Prince Charles as well as 20 Nobel laureates, Secretary Chu unveiled his new energy-reduction plan:

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.

Great idea. What about in New York City, and other places that have a season called “winter.” Wouldn’t a black roof help reduce energy costs by keeping the buildings warmer when it’s, you know, cold outside?