We're not making great progress cutting carbon dioxide emissions on a global scale, so the U.S. has been working with other nations on the less controversial strategy of reducing methane and soot. These pollutants have more severe immediate impacts on the climate than does CO2, and they break down much more quickly in the atmosphere.
But research published this week in Proceedings of the National Academy of Sciences suggests that this strategy would be less effective than previously believed.
Scientists modeled the climatic effects of a dreamy scenario: Methane emissions are reduced to the greatest extent thought possible; the use of wood- and coal-burning stoves and heating systems is phased out worldwide by 2035; and strict controls are placed on vehicle exhaust. They found that this would reduce global average temperature just 0.04 to 0.35 degrees Celsius by the year 2050, much less than the 0.5-degree reduction suggested in previous research.