Urban Heat Island Mitigation

Here's a proposal for a low-cost, easy-to-implement way of slowing global warming, reducing carbon emissions, and conserving energy: Make roofs and pavements more reflective and plant large numbers of trees.

According to Lawrence Berkeley National Laboratory’s Hashem Akbari and California Energy Commissioner Arthur Rosenfeld:

If only roofs are changed from their current dark colors to white for flat roofs and cool colors for sloped roofs, we can offset 24 billion tonnes of CO2. If we take 20 years to implement just the cool roofs portion, it’s the equivalent of taking half of the cars in the world off the road for every year of the 20 year program.

If this is true, then it looks like we've found a good place for some of the economic stimulus.