英语作文：Pollution Awry in the sky

China has won battles against its choking air, but not the war

AT NANYAWO elementary school in Hebei province, near Beijing, the temperature in early December fell below freezing, both outside and in. The teachers took to instructing the six-year-old children in the playground. At least outside it was sunny. The classrooms were unusable because the locAl government had dismantled the coal-fired boilers for environmental reasons, but not yet installed a replacement heating system. There have been several such incidents this winter in northern China. In Linfen, in neighbouring Shanxi province, villagers say their coal-fired heaters have been taken away but the pipes linking them to the gas system have not arrived. A new slogan recently appeared on walls in the town: “If you burn coal, we’ll see you in the detention centre.”

The authorities in northern China have imposed emergency restrictions until mid-March to control air pollution, which spikes during the winter. Twenty-six cities plus Beijing and Tianjin (which count as provinces) had promised to replace heating systems that run on coal with ones using electricity or gas for 3m households this year. But they failed to complete the work on time, forcing a rare U-turn: they have allowed a certain amount of coal to be burned in places without any alternative. The government has also limited the output of iron, steel and aluminium smelters, mothballed many big construction projects—leaving cranes atop unfinished skyscrapers motionless against cornflower skies—and, in Beijing and its surroundings, created a new Environmental Protection Agency, with tough enforcement powers.

All countries use a mixture of carrots and sticks in their environmental policies. China does, too (next year it is planning to open the world’s biggest carbon market, for instance). But its sticks—that is, outright bans on polluting activities—are unusually stout. That makes it a good place to judge the impact of command-and-control measures to rein in pollution, as opposed to subsidies or taxes. So far the lesson seems to be that bans work, but only when conditions are right.