Climate change makes it at least three times more likely that tropical superstorms such as Hurricane Sandy will hit north-eastern cities in the US in coming decades.
In 2012, Sandy flooded parts of New York and New Jersey with three metres of storm surge on top of a high tide and altogether caused $71bn in damage and claimed 157 lives.
Climate change could also mean that the chances of megadroughts – 35 years or more of parched soils – could become much more likely in the US Southwest during this century.
The good news is that both events are naturally rare. And, even better, the future risks in each case could be reduced by sharp cuts in global greenhouse gas emissions.
But the findings, in recent studies led by Princeton and Cornell universities, represent an identifiable future cost of climate change under the business-as-usual scenario, in which fossil fuel combustion continues to increase at present rates.