"Bright Roofs, Cool World"

[handmade34]

http://news.sciencemag.org/sciencenow/2012/04/scienceshot-bright-roofs-cool-wo.html

"Making urban roofs and pavements more reflective could cool Earth's climate slightly but measurably at little or no cost, researchers say. Altogether, urban and suburban areas between the latitudes of 45°N and 45°S—a swath that stretches from near Minneapolis, Minnesota, to south-central Chile—cover about 2 million square kilometers, an area slightly larger than Mexico. Because roofs and pavements account for more than 60% of urban surfaces (see image), using lighter-colored roofing materials (concrete versus asphalt, for example) could boost average albedo, or reflectivity,

enough to drop global average temperature by as much as 0.07°C, the researchers report online today in Environmental Research Letters. Achieving the same amount of cooling by slashing carbon dioxide emissions would require taking every automobile on the planet off the road for about 50 years

researchers estimate. Although brightening all of the roofs and pavements in every urban and suburban area worldwide sounds like a Herculean task, it could be done rather easily and relatively quickly with little added expense: Roofs are typically replaced or resurfaced every 20 to 30 years, and streets and roads are repaved every 10 years or so, with brighter alternatives often costing little or no more than the materials now in place, the researchers claim."

[bloomington-lib]

1. I've thought about doing this to my roof with white (or similar) paint

I wonder about a few things though:

Would it make it too slippery to do any future repair or replacement work?
Would it last longer since there is another coating to shield it from the elements?
What kind of paint would work best?

[handmade34]

2. ???

[corkhead]

3. Great tip. I was looking for something exactly like this. Thanks for posting.

[allan01]

4. re:"Bright Roofs, Cool World"

White roofs are manditory in Los Angles county

[harmonicon]

5. For what structures?

I definitely didn't see any white roofs on the housing developments I saw going up when I lived there 6 - 10 years ago. It seemed like most of the newer houses had clay tile roofs, but the old places I lived in definitely had normal old black roofing shingles.

[madokie]

6. I've thought this for a long time

All the heat absorbed and re radiated out into the environment from the dark colors on our asphalt hiways, parking lots and roofs plus the heat we move from the inside to the outside of our dwellings has to have some effect on the warming of our world. Of course when I mentioned this here a few time over the years I was serverly beaten about the head and shoulders for thinking such nonsense. In the end I was right after all.
Thanks for this post and link.
Peace