How painting roofs white can help ‘turn off the world for a year”

I’m drawn to “boring” ways to change energy use: things like daylighting, reducing packaging, and making company supply-chains more efficient. Without these methods to help reduce our energy demand, the “exciting” solutions like renewable energy are less valuable.

And what could be more boring than painting a roof white? Turns out, it’s also an important solution for reducing energy use and lowering carbon dioxide emissions.

A NASA survey of New York City’s rooftops last July showed that dark, heat-absorbing rooftops were up to 42 degrees F hotter than white rooftops. And that difference in heat can make a big difference in on-site energy use; painting a roof white can reduce air conditioning demand as much as 20 percent.

In February, researchers at Concordia University estimated that painting one percent of the world’s urban surfaces white (rooftops and pavement) could reduce CO2 emissions by 130 gigatons over the next 50-100 years. In 2011, global CO2 emissions from fossil fuel combustion reached 31.5 gigatons.

Clearly, white roofs are a major opportunity. But while we’ve seen a proliferation of companies selling on-site solar and efficiency services, there’s been only modest activity in this market. Why aren’t more companies jumping on this around the country?

“I’m not sure why an organization doesn’t exist like this in every city. And it should,” says Juan Carlos, founder of the White Roof Project, a non-profit based in New York City that harnesses volunteers to provide roof painting services.

Having found a good niche with decent demand, the organization is now trying to branch out of New York and take its rooftop painting model nationwide. According to Carlos, painting 5% of the world’s rooftops white per year by 2030 could save enough emissions to equal the world’s carbon output in 2010.

“That would essentially turn off the entire world for an entire year,” he says.

With cities around the world adopting building codes to promote white roofs, the opportunities for this solution are increasing. But we’ve still got a long way to go before we can service so many rooftops per year.

This story first publised in Climate Progress. Reproduced with permission.