Beijing has a new plan to tackle its air pollution: require fewer conventional cars and more hybrid and electric vehicles. The effort is an admirable attempt to deal with a major problem in the Chinese capital, but it will not make a big difference without other, more significant interventions.

The local government says it will reduce the number of license plates it issues over the next four years by 40 percent, to 150,000 a year by 2017. At the same time, it says it will slowly increase the share of plates that are reserved for electric cars and other hybrid vehicles to 40 percent of the total by the end of four years, according to Reuters.

Beijing’s air has been bad for years. The city is surrounded by smoke-belching factories, its streets are choked by a growing number of cars and it sits on a plain that is surrounded by hills that trap pollution. Early this year, the United States Embassy reported that Beijing’s air had hit a record bad reading on an Air Quality Index developed by the American Environmental Protection Agency.

Chinese officials have used various tactics to improve the air in Beijing. During the 2008 Olympics, they shut down factories around the city. In October, local authorities announced that they would ban half the city’s cars from the roads whenever they expected serious pollution.