PULL YOUR WHAT?

Argentinian agricultural scientists in 2008 created a “methane backpack” to collect grazing cows’ emissions (with a tube from the cow’s rumen to the inflatable bag) to see how much of the world’s greenhouse-gas problem was from livestock. Having learned that figure (it’s 25-30 percent), the country’s National Institute of Agricultural Technology announced recently it will start storing the collected methane to convert it to energy. In a “proof of concept” hypothesis, it estimates that about 300 liters of methane could power a refrigerator for 24 hours.