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.

格陵兰岛和南极冰原的加速流失以及潜在的南极西部冰原的不稳定可能导致比以前预期的未来海平面更高的水平。纽约市气候变化专门委员会南极快速冰融化（ARIM）高端，低概率海平面上升（SLR）方案，该方案结合了近期的冰流失趋势，改进的冰原-海洋-大气模型以及潜在的冰原失稳，预计到2080年代SLR最高可达210万，到2100年SLR最高可达290万（NPCC，2019）。与2000-2004年相比，这些结果超出了2080年代之前的单反高端预测（第90个百分位）和2100年的1.9M（NPCC，2015年）。

到2100年，每年1％的机会（100年）洪泛区将覆盖ARIM下该市总面积的1/3；在每月的涨潮期间，大约1/5的地区可能被洪水淹没。一些地势低洼的地区到本世纪末可能会被永久淹没。在NPCC调查结果的指导下，纽约市的沿海防灾举措是否足以满足非常高的海平面？需要进行其他研究以确定沿海保护的技术，环境或经济限制，并确定何时和何地可能需要进行战略迁移。