Enhancing New York City's resilience to sea level rise and increased coastal flooding

• Published in: Urban climate 2020-09, Vol.33, p.100654, Article 100654
• Main Authors: Gornitz, Vivien, Oppenheimer, Michael, Kopp, Robert, Horton, Radley, Orton, Philip, Rosenzweig, Cynthia, Solecki, William, Patrick, Lesley
• Format: Article
• Language: English
• Subjects: Coastal flooding; Flood adaptation; Meteorology And Climatology; New York City; Resiliency planning; Sea level rise
• ISSN: 2212-0955; 2212-0955
• DOI: 10.1016/j.uclim.2020.100654

Accelerating Greenland and Antarctic Ice Sheet ice mass losses and potential West Antarctic Ice Sheet instability may lead to higher than previously anticipated future sea levels. The New York City Panel on Climate Change Antarctic Rapid Ice Melt (ARIM) upper-end, low probability sea level rise (SLR) scenario, which incorporates recent ice loss trends, improved ice sheet-ocean-atmosphere modeling, and potential ice sheet destabilization, projects SLR of up to 2.1 m by the 2080s and up to 2.9 m by 2100, at high greenhouse gas emissions (NPCC, 2019). These results exceed previous high-end SLR projections (90th percentile) of 1.5 m by the 2080s and 1.9 m by 2100, relative to 2000–2004 (NPCC, 2015). By 2100, the 1% annual chance (100-year) floodplain could cover 1/3 of the city's total area under ARIM; around 1/5 of the area could be flooded during monthly high tides. Some low-lying locations could become permanently inundated by late century. Will New York City coastal resiliency initiatives, guided, in part by NPCC findings, suffice for very high sea levels? Additional research is needed to determine technological, environmental, or economic limitations to coastal protection and to decide when and where strategic relocation may become necessary. •Accelerating ice losses, advanced modeling, and potential WAIS destabilization may lead to upper-bound sea level rise (SLR).•Upper-end, low probability SLR scenarios such as ARIM should be considered•ARIM projects a NYC SLR of 2.1 m by the 2080s and 2.9 m by 2100 at high CO2 levels.•Low-lying communities around Jamaica Bay, NYC will be at very high risk to increasing coastal hazards•Existing, planned coastal defenses will need strengthening; managed relocation and buyout may become necessary.