COWS ABSOLVED OF CAUSING GLOBAL WARMING WITH NITROUS OXIDE
April 12, 2010
In the past, environmentalists from Lord Stern to Sir Paul McCartney have urged people to stop eating meat because the methane produced by cattle causes global warming. However, a new study found that cattle which grazed on the grasslands of China actually reduced another greenhouse gas, nitrous oxide.
Authors of the study, published in Nature, say the research does not mean that producing livestock to eat is good for the environment in all countries. However, in certain circumstances, it can be better for global warming to let animals graze on grassland. The research will reignite the argument over whether to eat red meat after other studies suggested that grass fed cattle in the United Kingdom and the United States can be good for the environment as long as the animals are free range.
Klaus Butterbach-Bahl, of the Karlsruhe Institute of Technology in Germany, carried out the study in Inner Mongolia in China:
- He found that grassland produced more nitrous oxide during the spring thaw when sheep or cattle have not been grazing.
- This is because the greenhouse gas, also known as laughing gas, is released by microbes in the soil.
- When the grass is long snow settles keeping the microbes warm and providing water, however when the grass is cut short by animals the ground freezes and the microbes die.
According to Butterbach-Bahl, the study did not take into account the methane produced by the livestock or the carbon dioxide produced if soil erodes. He also pointed out that much of the red meat eaten in the western world is from intensively farmed animals in southern countries.
Lastly, he said the study does not overturn the case for cutting down on red meat but shows grazing livestock is not always bad for global warming.
Source: Louise Gray, "Cows absolved of causing global warming with nitrous oxide," The Telegraph, April 8, 2010.
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