just as the speed and scale of China’s rise as an economic power have no clear parallel in history, so its pollution problem has shattered all precedents. Environmental degradation is now so severe, with such stark domestic and international repercussions, that pollution poses not only a major long-term burden on the Chinese public but also an acute political challenge to the ruling Communist Party. And it is not clear that China can rein in its own economic juggernaut.

Public health is reeling. Pollution has made cancer China’s leading cause of death,

Nearly 500 million people lack access to safe drinking water.

Chinese cities often seem wrapped in a toxic gray shroud. Only 1 percent of the country’s 560 million city dwellers breathe air considered safe by the European Union.

growth derives, now more than at any time in the recent past, from a staggering expansion of heavy industry and urbanization that requires colossal inputs of energy, almost all from coal,