This ought to be one of the easier fixes to slow global warming.  Data released at California's recent annual Climate Change Research Conference indicates that 'if the 100 biggest cities in the world installed white roofs and changed their pavement to more reflective materials -- say, concrete instead of asphalt-based material -- the global cooling effect would be massive".

The LA Times reports that Hashem Akbari, a physicist at the Lawrence Berkeley National Laboratory, along with Surabi Menon, also with the Lawrence Lab, and Arthur Rosenfeld, a physicist at UC Berkeley and a member of the California Energy Commission, have written a paper publishing their research on how roofs and pavement raise urban temperatures.  They say,

"Globally, roofs account for 25% of the surface of most cities, and pavement accounts for about 35%. If all were switched to reflective material in 100 major urban areas, it would offset 44 metric gigatons of greenhouse gases, which have been trapping heat in the atmosphere and altering the climate on a potentially dangerous scale.

That is more than all the countries on Earth emit in a single year. And, with global climate negotiators focused on limiting a rapid increase in emissions, installing cool roofs and pavements would offset more than 10 years of emissions growth, even without slashing industrial pollution."

Akbari added, "First, a cooler environment not only saves energy but improves comfort. Second, cooling a city by a few degrees dramatically reduces smog. And the third win is offsetting global warming."

So, what are we waiting for?  Let's get started.