New York's 'once-a-century' storms to become common

Massive storm surges that statistically threaten New York City once a century could occur at intervals from three to 20 years by 2100, according to estimates by US scientists published Tuesday. Researchers from the Massachusetts Institute of Technology (MIT) and Princeton University built a computer model that simulated tens of thousands of storms under different scenarios for global warming. In the model, intense storms become more frequent by the period from 2081 to 2100, a finding that backs previous research, they found. Warmer temperatures drive up sea levels through thermal expansion and also provide the raw fuel for hurricanes. Today a "100-year" land-falling storm causes a flood surge of about two metres (more than six feet) in New York. By 2100, this could occur at intervals of just three to 20 years, according to the paper. An apocalyptic flood, bringing a surge of three metres (10 feet), that today has a risk of occurring once every five centuries would occur statistically every 25 to 240 years. Both kinds of events would easily top Manhattan's present sea walls, which stand 1.5 metres (nearly five feet), the investigators noted. The highest surge flood recorded in New York was in 1821 and measured 3.2 metres (10.4 feet), according to the probe, published in the journal Nature Climate Change.