Posted on behalf of Amber Dance
Want to save the planet? Grab a can of white paint — and a ladder. At the Global Climate Change Conference this week in Sacramento, California, scientists from the Lawrence Berkeley National Laboratory presented a plan to offset 44 gigatonnes of atmospheric carbon dioxide with a hefty dose of whitewash.
The study is the first to put numbers on what people have known for years — whiter roofs reflect more solar radiation, thus reducing global warming while saving money on air conditioning bills (Los Angeles Times). The research paper is in press at Climate Change.
White-topping the roof of an average family home is like sucking 10 tonnes of carbon dioxide out of the air, says study author Hashem Akbari. It also cuts energy costs by 20 percent, says co-author Art Rosenfeld of the California Energy Commission (East Bay Business Times). If major cities in tropical and temperate zones adopted paler roofs and pavements, the authors estimate, it could offset 44 gigatonnes’ worth of atmospheric carbon dioxide. That’s more than the world emits in a year.
California has required flat-topped, commercial buildings to go white since 2005, and will require new and retrofitted buildings to use cool-color roofing starting in 2009. These shingles and coatings look like their high-absorbing counterparts, but reflect more of the sun’s rays.
However, those white shingles have to be clean to work their magic, and the chore of regular roof-washing could eliminate the appeal of less power use. Akbari’s group reports on its web site that manufacturers have come up with self-washing white shingles.
“I call it win-win-win,” Akbari says. Cities are cooler and more comfortable, home- and business owners save on their summer electricity bills, and everyone feels good about slowing the process of climate change. The scientists hope to persuade the United Nations to help get cities to go white.
Image: Briny Breezes, Boynton Beach by Christopher Dick, via Flickr