The Kyoto conference on climate change is in full swing. But after they deal with the tough political question of how much to limit emissions of gases like carbon dioxide and methane, the nations involved will have to develop practical methods for cutting back production of these greenhouse gases. The main greenhouse gas that the delegates are examining is carbon dioxide, which is emitted primarily through combustion of carbon-based fuels. Two hundred times as much carbon dioxide as methane is emitted each year, but molecule for molecule, methane is about fifty times more effective at warming the planet. And while much of the global warming debate has focused on huge projects like developing cleaner methods of electricity generation or stopping deforestation, a big difference could come from relatively small sources of methane - like cows.
Cows can only digest some foods after a fermentation process, called rumination.
During this process, bacteria in the cow's stomach produces methane gas. And while the digestive difficulties of one burping cow may not seem like a big deal, the cumulative effects of 1.3 billion cattle producing over 100 million tons of methane annualy can have a significant effect on the world's balance of greenhouse gases. Programs have been in place for several years to monitor the methane output of cows, and to try to develop ways of reducing methane production. Diet adjustments can also raise productivity, allowing cows to fatten faster - making it possible to achieve the same amount of product with fewer cows. India's National Dairy Development Board has estimated that with better feed, the cattle population in India could be reduced from 300 million to 120 million without affecting production.