Gas flares aren’t as efficient at burning off methane as assumed

In many oil and gas producing regions, flames light the sky. The flares burn off 98 percent of the escaping natural gas, oil and gas companies claim. But observations of three U.S. oil and gas fields show efficiency is only around 91 percent, scientists report in the Sept. 30 Science. Making up the difference would be the equivalent of taking nearly 3 million cars off the road. 

The natural gas escaping is primarily methane. This greenhouse gas lingers for only nine to 10 years in the atmosphere, but its warming potential is 80 times that of carbon dioxide. So oil and gas…