US Energy Secretary and Nobel Prize winning scientist Steven Chu came up with a new plan to paint roofs and pavements white or light colored in the US to cut greenhouse gas emissions. With this change to roofs and roads, it can have the equivalent effect of taking every car in the world off the road for 11 years. By reflecting sunlight back into space, it can increase the reflectivity of the Earth. It can also reduce the amount of electricity used for air conditioning if houses are cooler. Painting cars a lighter color can also save your energy bill for air conditioning with a similar effect.

This is an interesting idea that sounds logical but why hasnt it been implemented for all this time? Actually, there are white roofs in different parts of the world and even in Southern Florida and the Caribbeans. Black roofs can trap in the heat in the winter but it actually takes more energy to cool a house as opposed to warming a house. In cold places, the roof is often covered in snow in the winter so it is technically white anyways. The issue with white roofs, however, is that they can get dirty easily and after a while, they wouldnt really be white anymore. A dirty roof is also not very attractive as opposed to a black roof, which would look a lot better regardless of whether it was clean or dirty. I assume this is probably the reason why roofs are black.

via Yahoo Green and The Independent and RTN Roofing Systems