White roofs and surfaces could be worth a staggering $1,100 billion according to recent research.Nobel prize winner Steven Chu, Obama's Energy Secretary, is promoting this change. Chu says just changing the colour of roofs and blacktopped freeways and streets is equivalent to taking all of the automobiles in the world of the road for eleven years.
White reflects heat and a worldwide change would help cool the world. As a bonus, light surfaces can help reduce the cost of cooling buildings which reduces emissions. However, Hashem Akbari, the lead scientist behind some of this research is careful to point out that converting to cool urban surfaces does not address the underlying problem of global warming.
These impressive numbers from white roads and roofs are not the only option. Living green roofs and walls can drop temperatures (and associated air conditioning costs) by as much as eleven degrees.
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Climate Progress quantifies the greenhouse gas reduction. The calculation is 100 m2 of white roof, instead of a dark roof, offsets the emission of 10 tonnes of CO2.
ReplyDeleteAnd the price - the single cheapest of the 12 to 14 wedges needed to stabilize near 2°C total warming.
Chu's quote, from the video on Times webpage:
ReplyDelete'If you replace all the building roofs today with white roofs and, you go to cement style pavements instead of black top style pavement, it would be a reflection of the sunlight back in to space that would be the equivalent as if you took all of the automobiles in the world of the road for 11 years. And guess what? It’s about the same cost - white versus black - and so I would like to appeal to all people we should covert to white limousines'