Here's a stat that might blow your mind: "Painting 100 square feet of roof space white offsets the effect of one ton of CO2 emissions." So say a team of scientists from the Lawrence Berkeley National Lab, who contend that the simple act of painting roof tops, parking lots, and other dark surfaces a lighter shade could have a dramatic impact on emissions and, by extension, climate change. How much of an impact? Enough to delay the effects of global warming for 11 years. There's an economic incentive too: the scientist argue that the emissions savings are equivalent to $1 trillion.Read some thoughtful commentary on the idea over at Infrastructurist, who are championing its shovel-readiness, and wondering where the money for this in the stimulus bill is. And read more about how it works here. (And see our previous coverage here.)Photo (cc) by Flickr user Racineur.