US coastal areas are set to be deluged by far more frequent and severe flooding events if greenhouse gas emissions aren’t slashed, with rare floods becoming the norm for places such as New York City, Seattle and San Diego, new research has found.

The study, undertaken by researchers from Princeton and Rutgers universities, found that along all of the US coastline, the average risk of a 100-year flood will increase 40-fold by 2050. Such floods are statistically expected to occur only once every 100 years because of their severity, although this doesn’t mean these sort of floods never happen in consecutive years. The annual chance of such a flood is around 1%.

The research found that if emissions are not curbed, San Francisco and Seattle would both get a 100-year flood every year by 2050, while San Diego would expect 10 such events annually and Key West in Florida would be hit 11 times a year. Some of the worst affected areas would be in Hawaii, with Mokuoloe island, situated off Oahu, forecast to be deluged by 130 floods a year that are currently considered to be 100-year events.(guardian)…[+]