Wednesday, July 27, 2016

What about methane?

Robert Goodland, the longtime senior environmental advisor to the president of the World Bank, and Jeff Anhang, his colleague at the World Bank Group, have determined that livestock rearing contributes at least 51 percent of total global warming.

The most famous greenhouse gas, the one that gets most of the attention from the media, activists, and policy makers, is CO2. But CO2 is not the only greenhouse gas, and is not in fact the one most sensitive to reduction efforts. Methane (CH4) offers a more promising lever with which to push back global warming. Molecule for molecule, methane is about twenty-five times more potent in trapping heat than carbon dioxide. But more important, methane, with an atmospheric half-life of seven years, disappears from the atmosphere far faster than carbon dioxide, which has a half-life of more than a century. So almost as soon as we eliminate sources of methane, its contribution to the greenhouse effect begins to wane significantly. By contrast, even after we stop releasing CO2, the gas that has already been released will contribute to global warming for decades.

When the amount of methane in the atmosphere is considered over ta twenty-year period, its global warming potential is said to be seventy-two times that of CO2. And methane is largely associated with industrial livestock production. This means that reducing meat consumption, the main driver of the livestock industry, may be the most rapid way to affect global warming. It turns out that our present programs, focused on carbon dioxide reduction, are mostly a lot of hot air—in more ways than one.

If this new assessment of the methane contribution is correct, the implications are momentous. I am puzzled as to why more people in the environmental community aren’t paying attention to this. Do they not want to challenge the livestock industry? Maybe we need bioengineers to figure out how to entrap and safely process cow farts. Failing this, maybe we should stop producing and eating the machines that do the farting.— Whole: Rethinking the Science of Nutrition, pages 168–69 (emphasis original)

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