The International Monetary Fund announced last year that China has overtaken the United States as the world's largest economy, accounting for 16.5% of the 2014 global gross domestic product in terms of purchasing-power parity. This achievement comes at a huge price for China.

It is well documented that China's industrial boom is causing a dangerous deterioration in air quality, as well as widespread land degradation and water and soil contamination. In 2013, 71 out of 74 Chinese cities failed to meet ambient air-quality standards (see go.nature.com/ndujl3; in Chinese).

Long-term exposure to air pollution has led to an average drop of 5 years in life expectancy for 500 million people in north China (Y. Chen et al. Proc. Natl Acad. Sci. USA 110, 12936–12941; 2013). According to the World Health Organization, respiratory disease could kill more than 3 million Chinese people every year by 2030 (V. Hughes Nature 489, S18–S20; 2012).

China must tackle its air pollution — to mitigate climate and as a priority for human health (see also J. Schmale et al. Nature 515, 335–337; 2014).