US Energy Secretary vows to save the planet one roof at a time
America is just catching on to what people in the Middle East and Mediterranean regions have known for some time: white roofs can save in air conditioning costs and keep buildings cool in the summer. But new research indicates they can do much more. Scientists at California’s Lawrence Berkeley National Laboratory (LBL) say that by simply painting all roofs white we can dramatically impact global warming. This research has won the backing of Steven Chu, a world-renowned scientist who is also the US Energy Secretary.
Chu, who was in London recently pitching the idea of global whitewashing to a crowd of Nobel Laureates, said he would do everything he could to make the switch from black to white in support of green, including changing US building regulations to require white roofs on all buildings.
California was the first state to jump on the cool roof bandwagon. In 2005, it mandated the use of white reflective materials for flat roofs. This coming July, it is extending that legislation to include sloped roofs, where “cool coloured” surfaces will now be required. While California’s efforts are laudable, theirs alone cannot significantly impact global warming. To drum up border support, scientists at Lawrence Berkeley Labs are taking their show on the road, launching an all out international campaign touting the benefits of cool roofs, particularly in urban areas where their use can cool the air temperature by as much as 10 degrees.
To get the attention of world leaders, Lawrence Berkeley’s scientists have put their research in terms that everyone can understand. “If only roofs are changed from the 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 only 20 years to implement just the cool roofs portion, it’s the equivalent of taking half the cars in the world off the road for 20 years.”
For architects, such legislation could have dramatic aesthetic results. It’s hard to think of a region in the US, including California, where white roofs are the norm, especially on sloped surfaces. Such a policy as that being proposed could bring an aesthetic uniformity to a country known for its regional architectural differences. Roofing industry experts indicate there may be more ways to skin the global warming cat, such as opting for dark roofs with high emissivity which don’t radiate as much heat back into the environment as their black roof counterparts. Such roofs may be a reasonable alternative to white roofs, which are not without their drawbacks. While white roofs typically have a longer life span than black roofs, they need to be cleaned and re-coated to maintain optimal performance. This is especially the case in areas where there is smog and heavy particulates in the air.
While the white roof argument is compelling it remains to be seen whether and to what extent it will take the US, if not also the world, by storm.