Opinion

The Great Debate

Painting Bill Clinton’s “white roofs” into reality

By Juan Carlos Pineiro Escoriaza
July 21, 2011

By Juan Carlos Pineiro Escoriaza
The opnions expressed are his own.

White Roofs Project volunteers paint the roof of the Bowery Mission in New York City. Photo courtesy of David Epstein.

If you’ve been outside recently, you probably realize that this summer is hot. With the latest heat wave now spreading across the country, it’s worth pointing out that many Americans are unknowingly contributing to the soaring temperatures. How? Millions of rooftops in America are made of black tar; and they absorb and trap an enormous amount of heat during the summer months. It’s also worth pointing out that there’s an easy fix to the black roofs problem that people of all political stripes can get behind: paint the black roofs white.

Painting black tar roofs with a white, solar-reflective coating is a low cost, quick and tangible way to reduce the risk of power grid ‘brown-outs’, save millions of dollars in energy costs, and curb climate change. The statistics are as simple as they are staggering: A roof covered with solar-reflective white paint reflects up to 90% of sunlight as opposed to the 20% reflected by a traditional black roof. On a 90°F day, a black roof can be up to 180°F. That heat has a major impact on interior building temperature, potentially heating your room to between 115 – 125°F. A white roof stays a cool 100°F. Plus the inside of the building stays cooler than the air outdoors, around 80°F in this example, reducing cooling costs.

White roofs also reduce the “urban heat island” effect in which temperatures rise in dense urban areas because of the proliferation of heat-radiating, black tar surfaces. For example, the Urban Heat Island effect causes New York City to be about 5 degrees warmer than surrounding suburbs and accounts for 5 to 10 percent of summer electricity use.

In New York City alone, 12% of all surfaces are rooftops. It’s estimated that implementing a white roof program in 11 metropolitan cities could save the United States 7 gigawatts in energy usage. That’s the equivalent of turning off 14 power plants, and a cost savings of $750 million per year.

Recently, former President Bill Clinton wrote in Newsweek, “Every black roof in New York should be white; every roof in Chicago should be white; every roof in Little Rock should be white. Every flat tar-surface roof anywhere! In most of these places you could recover the cost of the paint and the labor in a week.” The former president regularly touts the white roofs as one of those win-win scenarios that could also help create jobs and stimulate the economy.

The folks at White Roof Project agree. Last year, a progressive group of young people got together to found the project and get it going at the grassroots level. When 150 volunteers showed up to coat the historic Bowery Mission in New York City (our first project) it was a watershed moment. Volunteers saw that all it takes is a paint roller, some solar-reflective white coating and a little hard work to start curbing climate change. Since then we’ve been educating and activating our neighbors around the white roof movement that Bill Clinton has called on someone to build.

This year, White Roof Project will triple the amount of roofing it coated last year and is also launching a campaign to educate more homeowners and organizations about the benefits of white rooftops.

If we were to coat 5 percent of rooftops per year worldwide, we would be finished by 2030. This would save the U.S. 24 billion metric tons in CO2. That happens to be exactly how the world as a whole emitted in 2010. So, in essence, this would be like turning the world off for an entire year — while also saving some money on the energy bills while doing it.

A White Roof Project is a common sense concept that’s easy to implement and creates tangible change for individuals, our communities, and even globally. As we head towards the dog days of August, there’s no better time to grab a brush — except it’s probably a good idea to wait for a cooler day.

Photo: White Roofs Project volunteers paint the roof of the Bowery Mission in New York City in 2010. Courtesy of David Epstein.

Comments
17 comments so far | RSS Comments RSS

and letting MTA keep train doors open while trains are waiting at their terminal stations–ac going full blat–complained about it for years–has no effect on local temperatures?–what about massive amounts of cement being created to be used for cosmetic effects on sidewalks–Mayor Bloomberg is in no position to make any suggestions about energy and CO2 issues

Posted by ilaboo | Report as abusive
 

Does the reduced temperature of the roof extend it’s life? You would think it couldn’t hurt

Posted by auger | Report as abusive
 

Sounds like a good idea.. but what happens in winter? Will it increase the heating bill in the same way?

Posted by lganggang | Report as abusive
 

I agree. It would be good to put some tax incentives to encourage this. Currently in our mostly mid-rise area outside New York city there are builder incentives for LEED certified buildings – which is the European green standard. As a result, our building and two other new ones have lawns and wildflowers covering the roof – which also helps filter water and create pollination zones for insects. However its fairly expensive so many builders opt out. Painting white seems a lot, lot cheaper – even though its not as nice for kids.

Posted by John2244 | Report as abusive
 

Sounds great. What happens in the winter, though?

Posted by CorwinofAmber | Report as abusive
 

Good idea but wouldn’t it be easier to just stop cutting down all the trees, plowing over the forests and stop urban sprawl..??

Posted by 123jack | Report as abusive
 

Well before you start doing this and trying to make some federal law mandating that I paint my roof white… consider this.

1) Energy that was making that black roof hot isn’t just vanishing into thin air… it is being reflected back into the atmosphere where greenhouse gases help turn it into heat elsewhere in the atmosphere. So is it better to heat up the entire planet vs the top of buildings? It is a bit like toxic waste… is it better to keep it all in select pools or should we just dump it all in the worlds oceans? Frankly I don’t know, but I do know that this question hasn’t been given any consideration.

2) What about the winter time… yes you might lower the cost of cooling a building in the summer but you also increase the cost of heating it in the winter.

3) Does it really matter? With proper insulation it doesn’t matter whether the roof is black or white. Go into a new home that uses foam insulation and you can walk in the attic whether the roof is white or black and the attic is comfortable… and guess what that insulation will help in the winter too not just the summer as painting a roof white will.

Posted by Yirmin | Report as abusive
 

Can you change it to black for the winter?

Posted by Bob9999 | Report as abusive
 

@ilaboo, unless by “local temperatures” you mean in the areas directly next to the trains then no, that has no effect on local temperatures.

Posted by iflydaplanes | Report as abusive
 

@Bob9999

Sure, but that would require more paint.

@Yirmin

I believe the reflected energy is mostly sent back into space and not trapped on earth. Water vapor can trap reflected energy to some degree, but if you are eliminating ground level causes of evaporation (i.e. reducing abient heat), you are reducing water vapor…and allowing more energy to reflect back into space.

I think the salient argument is with older, poorly insulated structures in an urban setting and how to cool them at the lowest price. A white roof has been a long time reliable (and cheap) solution, and if it saves 5%-15% of the normal energy use, the savings are considerable.

Posted by NobleKin | Report as abusive
 

can you really just paint over tar paper with no adverse effect? that does not seem like its something anyone can just do. what happens when in a couple years you roof starts leaking as it will naturaly do after a while? can they just tar right over the paint or do they need to rip all the old stuff up and put down new paper? making this a very costly idea in the long run. i do love the ideas of roof gardens and all this “green” thinking but sometimes things are a certain way because they need to be.

Posted by bahbow1000 | Report as abusive
 

also it is nothing like toxic waste in any way. a black roof absorbs light and radiates heat. a white roof reflects the LIGHT that WOULD create heat IF absorbed. this whole idea has less to do with cooling your home as it does cooling the neighborhood. if all the buildings inside the downtown area of any major city had white roofs the temperature in the surrounding area would go down dramaticaly. also how does it even matter in the winter what color your roof is if there is any snow fall? and snow is a wonderful insulation in itself.

Posted by bahbow1000 | Report as abusive
 

I’m so glad that I already did this last month on my mobile home. It made the house 15 degrees cooler inside as a result, now it’s normally whatever the outside air temperature is which is still hot but a lot less than it was.

I will also recommend window awnings, just built and installed two. It helps create an air gap between your window and the sun as well as cuts down on direct light.

Posted by brianbigel | Report as abusive
 

it is a great idea and was around for a long time, I ma glad finally is getting the attention it deserves.

BTW black or white the color does not matter in winter where the solar radiation is much less.

Have municipalities include a mandatory white roof in their building code!

Posted by robb1 | Report as abusive
 

@Yirmin

Before you start trying to direct federal law based on a poor understanding of thermodynamics, consider this:

1) This question hasn’t been given any consideration because it doesn’t make any sense. It has nothing to do with solar energy ‘heating up your home vs. the Earth somewhere else.’ Hell, the heat rejected by your AC still goes ‘somewhere else’, it just is a less efficient heat rejection method than painting your roof white, i.e. you have to put more energy into rejecting heat via AC than you would painting your roof.

2) It takes much more energy goes to cool a hot building than it does to heat a cold one. That’s why brownouts happen in the SUMMER.

3) It’s much easier to paint a roof white than to add insulation. See point 2 about why summer/winter trade-offs are nonsensicle. Finally, while in-wall insulation cuts down on heat transfer via convection, it does nothing for radiative and conductive heat exchanges.

Posted by RexMax46 | Report as abusive
 

While this is a very good idea to reduce summer electric usage, one still must take in to consideration the growing demand for food because of an ever growing world population. Agriculture disrupts natural buffering by vegetation of atmospheric CO2. Modern industrial agriculture is growing and a major contributor of hot house gases. The increased demand for meat further exacerbates the matter as fifteen pounds of vegetation is required for every pound on the hoof. We are turning forests into farms which will eventually turn to desert. One only needs to look at Brazil or the American Midwest through Google Earth Satellite photos to see for one’s self.

We are charting a dangerous path that challenges the Malthusian Principal. It is unfortunate that we must measure everything by economic benefit. If we do not control our numbers and our consumption, Mother Nature will do it for us.

Posted by coyotle | Report as abusive
 

Well, there are some intelligent responses and some not so intelligent responses. But the most important thing to remember is that these hypotheses can all be very easily tested. (except for this malthusian stuff and the climate control on the trains. stay on topic. we’re talking about whether or not to paint a roof white to save on energy costs.) I am going to have mine painted white next week, so I’ll let you know if it helps.

Posted by nadadisponible | Report as abusive
 

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