How Painting Roofs White Can Help ‘Turn Off The World For A Year’


Written by Stephen Lacey

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.

The film below documents what the organization is trying to accomplish. 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 post was originally published by Climate Progress.


Related Stories:

World’s First Vertical Forest

Biophilic Cities: Nature Meets Urban

Climate Change is Frying Our Cities


Photo from Michael R. Allen via flickr

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.11 months ago

Thank you I am glad about the encouragement! I love your site, you post outstanding.

Ashlyine B.
Ashlyine B.2 years ago

The content on your web site never confuses me. Keep it up!!

Fred Hoekstra
Fred Hoekstra2 years ago

Thank you ClimateProgress, for Sharing this!

Kat Head
Katherine H.3 years ago


Susan Cole
Susan C.3 years ago

Obama suggested this when he 1st took office & like most everything he's tried to do, it went by virtually unnoticed...

Tricia T.
Tricia B.3 years ago

Come to Bermuda and see every house, office building with white-painted roofs (rooves?).

Valerie Hammett
Valerie Hammett3 years ago


John S.
Past Member 3 years ago

Thanks for the information, I've found as a consultant that the simple ideas are easy to implement and provide fast ROI for companies. The ideas are not new but effective - but how many people drive white vehicles?

Kelly Rogers3 years ago

Thanx, for the information. I hope businesses and others begin to implement this idea

Miranda Lyon
Miranda Lyon3 years ago

Hi Agnes, good question about how white roofs would effect heating costs in winter. We have had the metal roof on our house "cool-coated white" for over 20 years. Living in a desert environment without AC or an evaporative cooler...and with a metal's been great.

In winter our temperatures drop well below freezing, in the the 20sF regularly and colder during storms. When there's any sun at all, the double glazed French door sized windows on the winter season sunny side of the house do a pretty good job of heating until mid-late afternoons, then the wood stove is lit. We've actually had little change in winter temps in the house since white coating the roof...I think it actually helps keep the metal warmer in winter, especially during snows and icy sleet storms!

The answer to your question about heating costs really is that folks have to find new and better ways to heat their homes, lowering costs and being good for the world at the same time.

As for the glare from white roofs, hey, get some sunglasses if it's really a problem.