Tech Earth’s oceans could rise over 6 feet by 2100 as polar ice melts, swamping coastal cities such as NYC May 20, 2019May 21, 2019Doyle Rice, USA TODAYComments Off on Earth’s oceans could rise over 6 feet by 2100 as polar ice melts, swamping coastal cities such as NYC Portions of many U.S. coastal cities could be lost to the sea by the end of the century because of global warming, a study says.