Livestock Absolved of Causing Global Warming

Livestock could actually be good for the environment according to a new study that found grazing cows or sheep can cut emissions of a powerful greenhouse gas.

In the past, environmentalists have urged people to stop eating meat because the methane produced by cattle causes global warming.

However a new study found that cattle grazed on the grasslands of China actually reduce another greenhouse gas, nitrous oxide.

Authors of the paper, published in Nature, say the research shows that 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 United States can also 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.

Butterbach-Bahl said the study overturned assumptions about grazing goats and cattle.

"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.

Estimated nitrous oxide emissions from temperate grasslands in places like Inner Mongolia as well as vast swatches of the United States, Canada, Russia and China account for up a third of the total amount of the greenhouse gas produced every year. Nitrous oxide is the third most important greenhouse gas after carbon dioxide and methane.

eprinted in part from Telegraph.co.uk