It's amazing how little changes to one's home can make a big difference in the pocketbook.

Take for instance the color of your roof. For most Americans, it's a dark hue -- something that's perfect for absorbing the sun's rays and increasing your home's retention of heat. If you live in the Northeast, that may or may not mess with your comfort level indoors; however, head out West -- where air-conditioning is a necessity at all times during the summer -- and you've got a big heat sink over your living space.

The New York Times recently ran an article on the rising popularity of white roofs as a way to combat cooling costs in warm climates. "Studies show that white roofs reduce air-conditioning costs by 20 percent or more in hot, sunny weather," the article states. "Lower energy consumption also means fewer of the carbon dioxide emissions that contribute to global warming. What is more, a white roof can cost as little as 15 percent more than its dark counterpart, depending on the materials used, while slashing electricity bills."

Art Rosenfeld, a member of the California Energy Commission, recently dropped the stat that if all the world's roofs went white over the next 20 years, it would save the equivalent of 24 billion metric tons in carbon dioxide emissions. “That is what the whole world emitted last year,” Rosenfeld told the NY Times. “So, in a sense, it’s like turning off the world for a year.”

Of course, this idea isn't something new. Just like other green building principles, the idea of a lighter roof is something that hot climate inhabitants have been employing for centuries. It just makes sense to reflect as much heat as possible to help stay cool.

But how long would a white roof revolution take to transform America? According to a researcher at Lawrence Berkeley laboratory -- with the average roof lasting 20-25 years, if roughly 5 percent of all roofs that are replaced each year were given cool colors, the country’s transformation would be complete in two decades.

Not a bad timeline for something so simple and incredibly cost-saving for America's energy future. So, when it comes to going green at home, make sure you also go white.

Related on MNN: Toronto's new green roof law a first for North America.

Source: NY Times