As the climate warms and sea levels rise, the frequency of local extremes in storm surges will increase along much of the US coastline.
To assess changes in local flood risk, Claudia Tebaldi at Climate Central in Princeton, New Jersey, and her colleagues combined projections from a model of global sea-level rise with long-term records from 55 tidal gauges around the United States. The team estimates that by 2050, one-third of gauge locations will see an increase in the frequency of extreme high-water levels that are currently expected to occur only about once a century. Some locations can expect to see these extremes, on average, every ten years, others even annually.
In a separate study, Benjamin Strauss, also at Climate Central, and his colleagues assessed US communities' topographic vulnerability to sea-level rise. Given that sea level could increase by one metre or more during this century, the team estimates that 3.7 million people live within one vertical metre of local mean high tide.