Simon--

I don't believe in anthropogenic global warming -- looks to me like the world is cooling even as CO2 levels keep rising -- but if the moonbats insist on Doing! Something! Now! to combat it, painting roofs white is probably the cheapest and least destructive thing they could do.

It's also the most easily reversible. If it works too well -- that is, if afterward it snows in LA in July -- we just paint the roofs black.

No muss, no fuss. And in the process we create a few million minimum-wage temp jobs.

Simon--

This idea is absurd. The math:
earth surface = 197,000,000 sq miles

Area covered by human buildings, etc.
Estimate 1,000 sq feet for every one of 7,000,000,000 estimated population gives
1K x 7B / (5280 x 5280) = 250,000 sq miles or .1275 % of the earth's surface. Assume total reflectivity into space so none of that area adds to the earth's temperature, i.e that area goes to 0 degrees Kelvin while the average earth temperature is 50 degrees C or about 330 Kelvin we get an average reduction of .4 degrees K or C. If we get a 30 degree reduction in the effected area, your average decrease is .04 degrees, 10 degree in the effected area means the decrease is .012 degrees.

rick,

Then the Alice in Wonderland music is appropriate along with the reference to painting the roses red.

Rick--

Average earth temperature is closer to 10C (50F) than 50C (122F).

For Dr. Roy Spencer's take on this, see: http://www.drroyspencer.com/2009/05/white-roofs-and-global-warming-a-more-realistic-perspective/

There can be little argument that the most ecologically correct roofing material is thatch. The Owens-Corning Corporation is capable of producing weather-resistant and fireproof thatching material. It will look funny on top of Gore House and the Capitol, but hey. We all need to make sacrifices.