Why did we decide that having all the roofs in the world be black was a good idea? I mean, I know, tar is black, and that's what most roofs are sealed with, but I really can't imagine a much dumber decision.
Sure, it's great in the winter, when the roof becomes a giant solar heat collector. But there's no way to turn that giant solar heat collector off when the summer rolls around.
Simply painting roofs white in warm climates could decrease air conditioning bills for those buildings by 20%. That's one reason why California has required all new buildings to have white roofs for the past few years.
But now there's even more reason to spend the extra dough. It looks like, if all the roofs in the world were white, enough sunlight would reflect back into the atmosphere to significantly reduce the effects of global warming. WTF?! Such a simple change, such a massive effect!
This new study says that if the 100 biggest cities painted all their roofs white, and switched their road materials to lighter colors (concrete instead of asphalt) it would reflect enough light and heat back into space to entirely offset the warming of the last few decades.
It's not a true fix for the problem, obviously, for that, we need clean, sustainable energy. But it could buy us enough time to make the changes we truly need.
http://www.ecogeek.org/content/view/2125/82/
