EcoGeek

White roofs for a green planet

Why did we decide that having roofs be black was a good idea? I know tar is black, and that's what most roofs are sealed with ... but I really can't imagine a much dumber choice.

Sure, black is great in the winter, when the roof becomes a giant solar heat collector. But there's no way to turn that giant solar heat collector off when the summer rolls around. Simply painting roofs white in warm climates decreases air conditioning bills for those buildings by 20 percent. That's one reason why California has required all new buildings to have white roofs for the past few years.

Now there's even more reason to spend the extra dough. If all the roofs in the world were white, enough sunlight would reflect back into the atmosphere to significantly reduce the effects of global warming. Such a simple change, such a massive effect!

This new study says that if the 100 biggest cities painted all their roofs white, and switched their road materials to lighter colors (concrete instead of asphalt) it would reflect enough light and heat back into space to entirely offset the warming of the last few decades.

It's not a true fix for the problem, obviously. For that, we need clean, sustainable energy. But it could buy us enough time to make the changes we truly need.

Via TreeHugger

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comments from our community

Showing 16 - 30 of 125 comments

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  • Posted by bmclay711 Tue May 26, 2009 8:09pm PDT
    What about all the energy required to produce so much white paint? Where does the paint go when it starts to chip away? Into the ground? That doesn't sound very green to me! Ridiculous.
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  • Posted by joshikad Tue May 26, 2009 8:09pm PDT
    Interesting, but flawed theory.
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  • Posted by California Kid Tue May 26, 2009 8:10pm PDT
    True. California spans vast latitudes and altitudes. But majority of the population is concentrated in the Bay Area and so cal area extending from the valley to San Diego. These areas receive plenty of sunshine, save for San Francisco, maybe. It would make a big difference to paint the roofs of the buildings in these areas. The mountain top communities can keep their shingles if they want.
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  • Posted by bec Tue May 26, 2009 8:14pm PDT
    oh yes...lets just have the government mandate more rules for us to follow and hire more bureaucrats to enforce these new laws and then raise your taxes so that you can pay for those rules to be enforced by more government payed employees etc etc...
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  • Posted by redcup7 Tue May 26, 2009 8:14pm PDT
    EVERYONE CALM DOWN. All the data in the original article is nothing new. I don't know if painting every rooftop white is the right thing to do or not. I own the fact that I don't know this. But I'm not enraged about it and I'm spewing out rage, hate and bad information like many people are doing. Most of us need to research the pros and cons of this proposal. Knowledge is power - so educate yourself before getting upset.
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  • Posted by Wayne G Tue May 26, 2009 8:14pm PDT
    It is so funny that you have finally caught up to Bermuda.Our rooves have always been white.they are also stepped to collect rain water that goes into a tank under the house.You newbie green folks have a lot to learn since we have been doing this all our lives.Come on down and get a lesson from people whose Island has white rooves every where accept one or two.Even commercial building have white rooves.Now catching the water is your answer to drought and it is purified by having a stepped roof.I am close to sixty and this was going on before my time.So Cali and the rest of y'all welcome to the real world of green.P.S. we also have a few other things you can learn about green.
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  • Posted by MICHAEL C Tue May 26, 2009 8:15pm PDT
    Sounds like a bunch of white lies to me
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  • Posted by BloggerGallupPoll Tue May 26, 2009 8:19pm PDT
    I have a better idea, why not ban air conditioning? It's not good for humans, causes post nasal drip, etc. and it's not good for the environment. Geez, humans got along for thousands of years without it. My parents and grandparents didn't have it and they lived to be in their 90s. I don't use it. People today are too coddled and buildings are freezing in the name of AC.
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  • Posted by Tim Tue May 26, 2009 8:27pm PDT
    Dude..Lets paint everything rainbow colors..Ohhhh man how narly would that be: )
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  • Posted by distorteddragon Tue May 26, 2009 8:37pm PDT
    Wouldnt the paint fumes from the sudden massive "gone-white" trend defeat the purpose all together?
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  • Posted by Wayne G Tue May 26, 2009 8:53pm PDT
    To 'never again" you are very naive,for even Ross Perot,Prime Minister Berlusconi,Michael Douglas and any person living on thr island of bermuda has a white roof.Also as a builder you can aceppt the fact that ! I live near the ocean(less than fifty feet away) for it is my backyard.In a Hurricane which has the potential to devistate this island as well as your whole state,we do not leave our white roof h and because our drinking water and bathing water come from the tank beneath our homes,the salt spray does not even become a factor even then.As a builder you would get an education on building by learning the Bermuda way of dealing with hurricanes.Sir you build cheap and inadequate housing that cannot withstand a large blow from eveen a Tropical storm.You run of the emouth about being a builder weel come and learn from the real buiders that never leave home in a hurricane.Any detruction is quickly and immmedtiately dealt with and thus we are the only place in the world that can recover immediately within in two weeks.SoNeverAgain you are weeeak as a builder and a mason and a man to even suggest that white rooves are ugly.Before you open you mouth again research the topic before you commment.as it stands right now I wouldn't buy anything from you for you are a Real Idiot not Real Estate builder.
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  • Posted by Mary Lou Tue May 26, 2009 8:53pm PDT
    Like many innovative ideas, the initial concept could use some refining. I have a suggestion for regions where the seasonal temperatures sometimes require air conditioning and sometimes heating -- don't paint the roofs white, just cover them in summer with white plastic sheeting fastened down securely. When fall comes, remove the white sheeting so the sun can help warm the inside of the house. In hot climates, people already select light-colored shingles much of the time. Widespread information campaigns about exactly how much air conditioning could be saved would persuade many more folks to get light-colored roofing. Hey, similar publicity worked for the coiled fluorescent light bulbs!
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  • Posted by Ricardo Tue May 26, 2009 8:54pm PDT
    wouldn't this be a bad idea? what if the U.S. is attacked by terrorist planes during the night? they'll easily spot houses and other buildings.
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  • Posted by Live Music is BEST Tue May 26, 2009 8:55pm PDT
    I guess the ideal would be to have a whole WARDROBE of roofs.... then we could change them as needed. "Cold Climates" can also be hysterically HOT in their summers (I've been in Minnesota and they get streaks of 90's every single summer, it was in the 90's just a week ago there) and "Warm Climates" can get COLD, I've been in the tip of Texas when it got to be freezing and ruined the citrus crop. So, what we really need is Change we can Believe in, IOW, a Remote Controlled Changeable Roof Color!! Who knows maybe it needs to be Paisley, Plaid, or a Fiobinacci series of Rainbow Colors, and that will finally please the gods.....
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  • Posted by jaugar842003 Tue May 26, 2009 9:08pm PDT
    yes,go ahead and make it a requirement to paint roofs white nad while your at it make it a requirement for that state to pay for the roof to be redone.when a roof needs resealed the tar will not stick to the paint nad you will have to remove old tar because of the paint??????????duh
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