Want a simple, effective way to make the world green? Turn your roof white.

White roofs reflect sunlight. Traditional dark roofing absorbs it, creating seething, inhumanly hot surface conditions. This wastes phenomenal amounts of energy, as most office building air conditioners are cooling taken from directly above the roof.

“If you have a white roof on your building, that reduces your air-conditioning use, increases comfort and improves the ambient air quality within the city,” says Dr. Hashem Akbari, professor of environmental engineering at Concordia University in Montreal.

Every roof eventually needs to be serviced, or replaced. Doing the job with light-coloured materials is simple — and doesn’t cost a penny extra.


“If you’re building a new office tower, there’s no difference in price between a white roof and a black roof,” notes Jim Harris, management consultant and bestselling author of Blindsided.

“Same thing with shingles on a house. Pick a light colour, like a light gray, as close to white as you can get. There are really simple things that you can do that will make an incredible difference.”

Yes, white roofs get dirty. But even so, they remain vastly more reflective than dark ones. Akbari notes that a typical Canadian house can offset 10 to 20 tons of CO2 emissions just by lightening the colour of its roof.

This simple idea has environmental implications that are — huge.

“If every roof in the world that is a dark colour were white, it would be equivalent to taking 600 million cars off the road for 22 years,” Harris says. “That’s the equivalent saving in carbon emissions that this would reduce. Those emissions come from burning electricity to air-condition air heated by dark roofs.”

“This does not solve the problem of global warming,” Akbari stresses, “but it is a measure that it is effective. It doesn’t cost us anything. It doesn’t have any negative effect. It saves us money, and we can afford to do it right now, while we are getting our act together to do something more serious.”

And in a time when environmental issues get darker every day, it’s a way we can all “lighten up.”

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