Catastrophic Chinese floods triggered by air pollution

The worst flooding to hit China in 50 years was happening in Sichuan province, in the same place that had been devastated by a massive earthquake just 5 years earlier. Over the course of 5 days, 73 centimeters of rain pounded the mountains, peaking at 29 centimeters in a single day.

Geography and pollution combined to make the floods intensely severe, Fan says. And she suspects the combination is not unique. Catastrophic floods in Pakistan only a month later, she says, may have involved the same factors: heavy industry plus a mountain backdrop.