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I'm sceptical about this, for a couple of first-year-physics reasons. 1. Matter is conserved. Before carbon can be farted out of a cow, it has to get in to th
by thisrod 10y ago
I'm sceptical about this, for a couple of first-year-physics reasons.
1. Matter is conserved. Before carbon can be farted out of a cow, it has to get in to the cow from somewhere else. I expect most of it was in the atmosphere a year beforehand, then got absorbed by pasture grass and eaten. So this year's farts will end up in next year's cows, and aren't like fossil fuel emissions.
2. Methane decays to carbon dioxide in a decade or two, so today's methane emissions are not really a worse problem than today's carbon dioxide emissions.
- jlmorton 10y ago1. The CO2 issue is not that the cow eats carbon and its manure turns back into CO2. The issue is the land use changes and fossil fuel-derived energy used in the production and transportation of feed. Because the feed to usable meat ratio of beef is somewhere between 7:1 to 20:1, this is significantly more impactful than other foods. 2. CH4 may not have a long half-life, but it has 29x the warming potential of CO2. Methane is thought to contribute about 20% of the current anthropogenic greenhouse gas forcing. Because of the anticipated positive feedbacks from warming, this is very important indeed.
- zardo 10y ago>CH4 may not have a long half-life, but it has 29x the warming potential of CO2. To be clear, methane has 451x the heat trapping ability, the 29x figure is the 100year impact that takes into account the methane breaking down.
- thisrod 10y agoThanks, that makes a big difference. Apparently you can't trust newspapers even on the orders of magnitude for these things.
- thisrod 10y agoI'm sure that's true, but the article explicitly says that 60% of the emissions it quotes are from digestion. It's hard to tell if there is a real problem hidden under the irrelevant data, or if this is propaganda from the animal welfare or energy industry lobbies. It would be great if we could make a material difference to the greenhouse effect just by eating less meat, but that sounds a bit too good to be true.
- gaur 10y ago> I'm sceptical about this, for a couple of first-year-physics reasons. Hmm... I guess I'll trust the experts quoted in the article rather than some rando's vague impressions of first-year physics.
- kpil 10y agoSure. But It would be nice if they sorted out these obvious first-year-physics questions in the article. Just measuring farts isn't really significant. Are there significantly more grazing animals on earth now than there was ever before, for instance? It could very well be: I found this xkcd strip alarming as I had no idea that most animals where actually either people or their livestock. https://xkcd.com/1338/ https://xkcd.com/1338/ But anyway. It's not the cows that are the problem, it's that the human population is growing. This is probably fixable, unless something like reactionary Islamists sends us back to the stone age. ( Right now that is the only scenario where I could see that the population would explode and then collapse into endless suffering, perhaps in Africa first.) The fix is education, education and education.
- kafkaesq 10y agoBefore carbon can be farted out of a cow, it has to get in to the cow from somewhere else. In particular, it comes from the plant matter they digest. Which would otherwise be holding onto those carbon atoms, by and large. (Or releasing them to other organisms via natural decomposition processes). You know, like trees do. Instead being shot into the atmosphere through the cows' hind quarters.
- maxerickson 10y agoNitrogen fertilizers are made using natural gas. Tractors run on diesel. A lot of fossil carbon goes into feed.