Hurricane Sandy is likely to have been a heart-stopping event for officials in many coastal cities around the world — particularly in Shanghai, given its low elevation and complementary status to New York as the financial hub of China.

Shanghai's flood barrier was built more than 20 years ago to protect the old city in Puxi along the Huangpu River waterfront. It could be inadequate against a sea-level rise resulting from this century's predicted 2 °C temperature increase due to climate change.

The new financial district across the river in Pudong was constructed at a higher elevation, but its defences could be breached if temperature rises are larger, such as the potential 6 °C increase identified as an upper threshold by the PricewaterhouseCoopers Low Carbon Economy Index (see

Officials in other low-lying coastal cities that are principal economic centres, including Tokyo, Hong Kong, Mumbai and Sydney, need to work out how best to enhance their own protection.