Paint your way to a cooler planet

White Is the New Green - Science - RedOrbit

I think I may have seen this mentioned somewhere else; I am not sure. In any event, this article claims that, due to the cost of solar panels, you can do substantially more for global warming in the short term by painting your roof white. Here's the key paragraphs:

If, instead of a black solar panel absorbing light and producing electricity, you simply painted that square meter white, it would reflect back into outer space perhaps 50 of the 300 watts incident from the sun. So it would take about 25 days for the solar panel to catch up with the more efficient reflection of sunlight that the white-painted panel would provide in a single day.

This seems counterintuitive, of course, as solar panels are net-positive in reducing global warming. And, in many cases, you could install the black solar panel on an existing black building roof, so you wouldn't be "adding" yet another black, heat-absorbing surface [another "albedo-decreaser"] to the earth.

Except for the small issue of money. A 20%-efficient, 1-square-meter solar panel costs about $1,000. For $1,000, you can buy 40 cans of good quality white paint. Each can covers 2,000 square meters with a nice bright reflecting film. So for the same $1,000 investment you could buy one square meter of photovoltaic cells, or cover 2,000 square meters with white paint. It would take more than 2,000 times 25 days, or about a century, for the CO mitigation from $1,000 of solar panels to catch up with the albedo increase of a large painted roof!

So what's a conscientious environmentalist to do? Unquestionably, we need solar panels for electricity. You can't run a washing machine on white paint. But, for every dollar spent on solar panels, we should spend at least a dime on white paint for every roof, parking lot, and road in the country.

There is a mistake in the sentence between the highlighted ones. (The total area that can be covered with $1000 worth of paint is surely 2,000 m2, not 2,000 m2 per can.)

However, it is an interesting argument, to say the least.