Capturing Methane Emissions from Cows
Cows may look pretty benign as they languidly chew on grass in farm fields, but some environmentalists warn that the animals' farting, belching and pooping is a major contributor to climate change. A 2006 United Nations report estimated that cows, along with other livestock like sheep and goats, contribute about 18 percent of the greenhouse gases that are warming the planet -- more than cars, planes and all other forms of transportation put together [source: Lean]. That's largely true because bovine emissions are rich in methane, a gas that's 21 times more efficient than carbon dioxide at trapping heat in the atmosphere [source: Los Angeles Times].
But cow fanciers should fear not, because scientists are busy finding ways to turn this smelly problem into a solution. They've already developed a method for extracting methane from cow excrement and converting it to a biogas fuel that's of sufficient quality to be fed into a standard natural gas pipeline. In Kern County, Calif., a company called BioEnergy Solutions uses that method to produce 650,000 cubic feet (18,406 cubic meters) of biogas from manure, enough to power 200,000 households [source: Levinson].
Harnessing cow farts as a fuel source might be tricky, but it isn't inconceivable, either. In Argentina -- a major beef producing nation where the collective herd of 55 million cattle outnumbers the human population -- researchers have developed a special bovine backpack that captures a cow's emissions via a tube attached to the cow's stomach, and discovered that the animals produce between 800 and 1,000 liters of gas each day [source: Zyga].