April 8, 2010

Cows Found To Actually Reduce Nitrous Oxide

A new study found that cattle grazed on the grasslands of China actually helps reduce the greenhouse gas nitrous oxide.

Environmentalists have been urging people for years to stop eating meat because the of methane produced by cattle.

According to the Telegrpah, the researchers said this does not mean that producing livestock to eat is good for the environment in all countries.  However, it can be better for global warming to let animals graze on grassland in certain circumstances.

The research, which was published in Nature, reignites the argument over whether to eat red meat after other studies say that grass fed cows in the U.K. and U.S. 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.

Butterbach-Bahl discovered that grassland produced more nitrous oxide during the spring when sheep or cattle have not been grazing.  This is because microbes in the soil release nitrous oxide, also known as laughing gas.  Once 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.

He said the study turns assumptions about grazing goats and cattle around.

"It's been generally assumed that if you increase livestock numbers you get a rise in emissions of nitrous oxide. This is not the case," he said.

According to estimates, nitrous oxide emissions account for a third of the total amount of the gas produced every year in places like the U.S., Canada, Russia and China.  The greenhouse gas is the third most important greenhouse gas after carbon dioxide and methane.

Butterbach-Bahl said, however, that the study did not take into account the methane produced by the livestock or the carbon dioxide produced if soil erodes. 

He said that much of the red meat eaten in the western world is from intensively farmed animals in southern countries.

According to Butterbach-Bahl, the study does not overturn the case for cutting down on red meat, but it does show grazing livestock is not always bad for the environment.


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