Cows And Warming

By M H Ahssan

Bovine diets being redesigned to curb methane emissions

Now cows are being fed a diet that will help them belch less methane, one of the more potent heat-trapping gases linked with climate change. Several farms in Vermont, USA, participated in an experiment that altered traditional diets of cows to include more alfalfa and flaxseed that will produce far less methane than a diet of corn and other current feedstock would. In fact, researchers say the new diet in a way mimics the cows’ traditional grass diet. Since the experiment began in January, the cows reportedly emit 18 per cent less methane than they did before.

This problem might not have arisen nor corrective action required if cows were left to eat grass at their pace. It is the compulsions of large-scale industrialised farming and ambitious production targets that have led to altering bovine diets in the first place, leading to the huge increase in livestock populations as well as methane-packed belches.

As a greenhouse gas, methane is 20 times more potent than carbon dioxide. It is reported that methane emissions generated on account of human activity far exceed those from natural sources. Total methane emissions amount to 320 million tonnes annually. Since the pre-industrial period, methane concentrations in the atmosphere have more than doubled from approximately 750 parts per billion (ppb) in 1,800 to approximately 1,750 ppb now. The main source of human activity induced methane gas emissions are mining – extraction of coal, oil and gas – waste treatment and landfills, rice cultivation, biomass burning and ruminant livestock. Permafrost exposure due to ice sheets melting in the Polar region is releasing huge amounts of methane that lay trapped beneath for thousands of years. Another big natural source is wetlands.

While concern about greenhouse gases centres on carbon dioxide emissions from automobiles or industrial activity, a good deal of warming may be due to methane emissions as well, with dairy farming and livestock breeding playing an important role. That means attention needs to be paid not only to cars, factories and power plants, but also to dairy farming practices and livestock rearing for meat and wool, to improve the quality and safety of landfills, and to trapping and diverting coal methane in mines to supplement our energy requirements to reduce human impact on climate change.