It is common knowledge that wearing a white shirt keeps you cooler than a black shirt on hot summer days. Most people could tell you that this is because black absorbs light and white reflects it, but can this concept be applied to one of the biggest environmental challenges facing the world today? Scientist Hashem Akbari believes so. In his work at the Lawrence Berkley National Laboratory, Akbari has come up with a plan to reduce global warming, using this simple idea.
Akbari is proposing that major urban areas across the globe unite in an effort to paint their rooftops and streets white in order to take advantage of the color's cooling effects. He stated that every 10 square meters of surface converted from dark to light colors equates to preventing the release of a ton of carbon dioxide. Black roofs absorb a great deal of sunlight, heating up buildings, as well as trapping heat in the Earth's atmosphere in the form of infrared light. Making the switch to white roofs and pavements would reflect more heat back into outer space, as well as keeping buildings and urban areas cooler, helping to counter global warming. Cooler buildings also mean less air conditioner use in hot areas, reducing energy use. Numerous scientists are claiming that implementing changes from dark to light roofs and roadways would greatly help reduce global warming for the time being, while better long-term solutions are explored.
Dr. Steven Chu, President Obama's Secretary of Energy is another advocate of the plan. He claims that painting urban surfaces white on a large scale "would be as effective at reducing global warming as taking all the world's cars off the road for 11 years". Large scale projects would be needed in order to carry out this suggestion. Chu and Akbari are both advocating for white roofs to be required on all commercial and governmental buildings, and that incentives should be created for homeowners to switch to white, or just lighter colored roofs. The simplicity of the proposal has given rise to a great deal of support. One scientist in Peru, named Eduardo Gold, is even suggesting that non-toxic white paint be used to counter the loss of snow on glaciers in Peru. The idea is that without the snow covering the area, the dark ground absorbs more heat, which in turn causes more and more snow to melt. Gold has applied the simple science of using white to reflect light to preserving the glaciers of his homeland.
Although there would be major challenges to actually achieving the goals of painting urban areas white, it is an insightful and thought-provoking remedy to the effects of global warming. While white-washing surfaces should not be viewed as a permanent solution, it could be a useful tool in helping buy time and reduce climate change now. It is such a simple concept, yet why more buildings have not already been painted with light colors is a mystery.
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I've thought about this before.. it seems like such a simple solution, so why not mandate it? Will the rays be reflected back as short wave and be able to escape the atmosphere? Could the reflected light have any negative effects? If only all roofs could just be green roofs...
ReplyDeleteI feel like this would work for areas that remain hot year-round but not for colder regions. Residential areas and businesses that are in cold regions year round would ultimately lose energy from white roofs. Therefore, they would have to spend more money and energy to keep the temperature regulated in their homes and buildings.
ReplyDeleteI agree with Erika that heavy-duty white paint is not the most environmentally friendly product in the first place. There is no such thing as a free lunch, so we have to decide if all the thousands of tons more of white paint that will have to be produced and ultimately, will end up either in toxic waste management facilities with other old paints, or in the water system. Is this a worth-while trade off for abaiting global warming? If it really does all those things Lexie said it does, then I think it is.
ReplyDeleteI must point out though that this seems like a scape goat for the fact that we dont want to have to make sacrifices in our personal vehicle lifestyle.
Very interesting blog! I do however agree with Emma as before, while this seems to be an easy and simple solution, it's important to think about the larger picture, including the "cradle to grave" cycle of white paint. Producing and transporting mass amounts of white paint could do more harm than help. However, if this idea were to be implemented on future housing developments, as opposed to attempting to mend previous buildings etc, I think it could come of some use.
ReplyDeleteI thought Erika made a great point above however, concerning the chipping paint getting into our water supplies. This could especially be a concern for painted rooftops that are more likely to deteriorate during rain storms and winters, and would easily flow into our water system.
Another thought, if we are going through the trouble to paint our roofs white, why not look into changing the shingling on our homes to increase insulation, or perhaps installing a green roof.
-- Kirsten Dobson
I agree with Emma that this does seem like a measure to become more environmentally friendly without actually changing our habits or lifestyles--a sentiment that will only delay effective change until it is too late. I wonder if instead of painting existing roofs, there could be some mandate put in place saying that all new buildings must use white shingles/concrete/panels or whatever the material on roofs is. Also, although I am all for green roofs, they are very very expensive and this white roof idea seems much more likely to happen on a large scale because of its simplicity and therefore low cost.
ReplyDeleteThis is an extremely unique idea and solution to counter global warming. Truly an insightful post! However, whitewashing buildings and even mimicking the snows of glaciers in Peru frustrates me. It is a temporary solution to alleviate the problems of global warming rather than an immediate way to counter the continuing climate change that we add to with our power plants, car emissions, etc. I also see this “solution” as a venue for people to do good feel good and think they are solving global warming. Haha I don’t mean to be such a Debbie downer, but I believe enacting these sort of large scale whitewashing projects would divert people from solving the root causes of global warming. I would hope that rather than architects and building construction company focusing on how white their buildings will be, they will focus more on LEED design and smart growth for energy efficiency and conservation. Whitewashing is merely adaptation and should not receive national priority or focus.
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ReplyDeleteIts really amazing that something as simple as changing color can help offset a global crisis of this magnitude. I really hope this method works and support its implementation, but I can see some negative aspects of this. Using this method, it allows us to continue polluting CO2 and other greenhouse gases, and may even allow pollution to get worse. It seems that this would only really slow the problem. I think the priority here in tackling global warming is getting rid of greenhouse gas pollution altogether. I think using the color white to help this process along as well as help cool areas that have gotten hot from the damage already dealt can be effective, but it should not be seen as THE solution to the problem.
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