If every roof on every building in the world was painted white would tht b enough to reverse the effects of GW

Question

by GW i mean global warming

Answer 1

No.

Studies have shown that urban heat island effects don't have an impact on global warming. Cities just cover too tiny of a portion of the Earth's surface to make a difference.

Painting every roof white will help make a city cooler on the local level, but it won't have any measureable impact on global warming.

Answer 2

Probably not. We would need to reflect about 1% more light back to space than we do now and I don't think there are enough roofs on all the buildings in the world to do that. Partly because those roofs are not totally black now and white still does not reflect 100% of the energy that hits it. So you would need to paint more than 1% of the Earth's surface white, and that could include the oceans too. If you limit the painting to land, it would have to be more like 4%. If you assume that each roof reflects 50% now and could reflect 75% if it was white, then you would need 16% of the land area of the world. That is far more than the area occupied by roofs I think.

Answer 3

Painting all roof surfaces white could be compared to lighting one little candle rather than curse the darkness. Yes, if all buildings, vehicles, parking lots, driveways, and roadways were white we might increase global reflectivity by 2%. But the heat gain in cities, in particular could make life a bit more livable during periods of extreme heat. Go a bit further, and make all the walls of buildings white too. When we have dark red bricks on a building it does take in a lot of heat. Paint on a blacktop surface may require some materials evaluation.

Answer 4

Of course not. Even theoretically it would not happen because what a white roof does is reflect the heat so the inside of the building doesn't get as hot. It's not doing anything to reduce heat in the atmosphere. Besides that, it's not a source of the chemicals responsible for warming. (Except maybe in it's production.)

Answer 5

What Global Warming?

The earth's Mean Surface Temperature hasn't climbed in 10 years - as a matter of fact, during ongoing buildup of "Greenhouse Gasses" the temperature of the earth has dropped trivially. (1998 through 2006 and most of 2007).

The computer models that track best with the current temperature trend project continuation at this temperature for the "foreseeable" (HA, as if these models could foresee anything) future.

It seems that the Earth is regulating it's own temperature right now, despite our minor adjustments to these trace gasses.

Answer 6

It would help reverse the usual result of urban development which is to absorbe heat.

Can't say whether it would reverse global warming completely because future global warming is an unknown quantity.

Answer 7

It might make it worse.

The best way is to make "green roofs" by planting on them. Its becoming a growing industry.

Placing plants on roofs keeps the building cooler and warmer, and provides biological gas exchange as with any garden.

Answer 8

I don't know about reversing, but it could help slow down the effects. White reflects most sunlight that hits it. Plus White-colored things don't radiate heat as quickly. (I often wondered why darker colored people lived in warmer climates; the darker skin radiates heat better.) This could reduce heating bills and the amount of fossil fuels we burn. Though its likely we'd be compensating by running our AC units longer at night during the summer.

Answer 9

It probily make it worst white objects will bounce UVs 2× the normal level it came. but it will make the air around it slightly cooler. try a checkered paint aproch. the black to reduce and absorb UVs,and heat,the white to bounce back the heat,and UV etx.depends on the paint contents or material your painting on.

Answer 10

No, but if every roof was covered with vegetation it would help.