Air pollution in China on some days is at dangerous levels. Grey smog covers Beijing and it is difficult to breathe. This pollution threatens to block new president, Xi Jinping’s, vision; he has popularised the idea of a "Chinese dream", which involves increasing wealth at home and increasing power abroad.

However, the choking smog suggests that the leadership needs to rethink its national goals. After all, what is the point of rapid economic growth if it creates cities in which it is dangerous to breathe?

One study, published in The Lancet medical journal last year, suggested that air pollution might have caused about 1.2 million premature deaths in China in 2010 alone. Beijing has registered a 60% rise in lung cancer cases in the past decade.

The pollution in Beijing is also an international embarrassment; the first thing any foreign visitor wants to talk about is the pollution, and many expats talk about leaving.

China’s leaders have to breathe the same air as their citizens. Therefore, one might expect them to make pollution their top priority. But the signs are that rapid growth remains goal number one.