CAMBRIDGE, Massachusetts — IN the northeast Chinese city of Harbin last week, the air pollution was so thick that schools were closed, traffic became gridlocked and flights in and out of the metropolis were canceled. For years, severe air pollution and rising carbon emissions have been downsides to China’s economic growth, even as that growth has lifted more than 600 million people out of poverty.

It may come as a surprise, then, that China has spent enormously to reduce air pollution and to limit carbon dioxide emissions, the main driver of climate change. In fact, its investments to decarbonize its energy system have dwarfed those of any other nation. And its forceful regulation to reduce sulfur dioxide emissions from power plants may be one of the most swiftly effective air pollution policies ever implemented anywhere. Those emissions fell sharply from 2006 to 2010, according to a new study by Chinese and American researchers that we took part in, preventing as many as 74,000 premature deaths from air pollution in 2010.

So why are China’s efforts at emissions control falling short?

There are several reasons. One of them is China’s instinctual response to such challenges: a top-down approach to try to engineer its way through them according to master plans. The result is that China may be winning battles but not the wars on emissions control, because its faith in mandates has met its match: an economy that is growing too fast, and atmospheric challenges that are too multifaceted for even the smartest planners to tame.

Indeed, air quality in many cities has sometimes been terrible this year, especially in the north. Last January, Beijing’s level of fine particles, 2.5 microns in diameter or under and known as PM 2.5, reached at least 20 times the level recommended by the World Health Organization for a 24-hour period. This prompted a scrambling government to ram through new air-quality protections.