Impacts of sea level rise in the New York City metropolitan area

Abstract

The greater New York City region, with over 2400 km of shoreline, will be vulnerable to accelerated sea level rise (SLR) due to anticipated climate warming. Accelerated SLR would exacerbate historic trends of beach erosion and attrition of highly productive coastal salt marshes. Coastal populations in the region have swelled by around 17% (av.) and over 100% in some localities between 1960 and 1995. The coastal zone will thus be increasingly at risk to episodic flood events superimposed on a more gradual rise in mean sea level. Projections of sea level rise based on a suite of climate change scenarios suggest that sea levels will rise by 18–60 cm by the 2050s, and 24–108 cm by the 2080s over late 20th century levels. The return period of the 100-yr storm flood could be reduced to 19–68 years, on average, by the 2050s, and 4–60 years by the 2080s. Around 50% of the land surface of salt marsh islands have disappeared in Jamaica Bay since 1900. While losses prior to stricter environmental protection starting in 1972 can largely be attributed to anthropogenic activities, such as landfilling, dredging, and urbanization, further investigation is needed to explain more recent shrinkage. Given projected rates of SLR, and plausible accretion rates, these wetlands may not keep pace with SLR beyond several decades, resulting in severe loss.