FREE CHEAP LUNCH….I always thought that methane in the atmosphere was mostly a result of cow farts, but apparently that’s just an old wive’s tale:

About 70 percent comes from human activities ? with most from fossil-fuel extraction. But methane also comes from sources as varied as the digestive tract of cattle and termites, wetlands, rice paddies and garbage dumps.

Why do we care? Because methane is a pretty serious greenhouse gas, and apparently some recent experience indicates that it could be substantially cut back at fairly low cost ? and with no harm to economic growth.

All of this needs to be taken with a grain of salt until it’s confirmed by further studies, but it’s encouraging news anyway.

So will anyone do anything about it? I don’t know. It reminds me of my other current favorite “cheap lunch” story: lead abatement, which would cost around $30 billion or so and could produce IQ gains of about 7 points in 6 million children. (Note: all numbers extremely approximate.) This is something where you could double the cost and halve the gain and it would still be one of the most stupendous social investments you could make. It’s a real no-brainer, and it would probably raise student test scores ? raise them for real ? more than every educational initiative of the last decade put together.

But there doesn’t seem to be any constituency for it, so nobody cares. Will methane reduction be the same?

POSTSCRIPT: Both of these things are still speculative, of course, since I’m not sure the science is firm on either one. Still, I wonder: is there a top ten list somewhere of programs that could benefit society the most at the smallest cost ? with some serious data to back up the claims? I’ll put methane reduction and lead abatement on the tentative list, but what else should go on it?