Decades of land development in the eastern United States and the Caribbean have increased the impact of the 2017 hurricanes Harvey, Irma and Maria. Because such events are likely to intensify as a result of climate change, societies must bolster natural defences and cease contributing to their own vulnerability.

We know from many examples worldwide that dense urbanization of low-lying coastal areas makes them more prone to the impacts of flooding, especially where buffering ecosystems have been squeezed. Take Saint Martin, the Caribbean island that was one of the most severely hit by Hurricane Irma in September. Since 1986, it has been subject to uncontrolled urbanization of its barrier beaches. A category-4 tropical cyclone known as Luis wiped out settlements there in 1995, but the public authorities did not prevent developers and residents from rebuilding them. This explains the extent of the damage by Irma.

We urgently need to reverse and stop large-scale developments that prevent buffering by natural ecosystems. Only then can we counter the threat of natural hazards and stimulate adaptation pathways to climate change.