Saturday, June 09, 2007

Another weapon against warming?

Paint?
The Earth has an albedo of 0.29, meaning that it reflects 29 per cent of the sunlight that falls upon it. With an albedo of 0.1, towns absorb more sunlight than the global average. Painting all roofs white could nudge the Earth's albedo from 0.29 towards 0.30. According to a very simple "zero-dimensional" model of the Earth, this would lead to a drop in global temperature of up to 1 °C, almost exactly cancelling out the global warming that has taken place since the start of the industrial revolution. A zero-dimensional model, however, excludes the atmosphere and, crucially, the role of clouds. [But!] It would be interesting to see if more sophisticated models predict a similar magnitude of cooling.
My father in law has helped with a green roof project in the past. I wonder if we'll start seeing more and more of these micro efforts to halt warming.

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