The seven worst years for polar ice sheets melting and losing ice have occurred during the past decade, according to new research, with 2019 being the worst year on record. The seven worst years for polar ice sheets melting and losing ice have occurred during the past decade, according to new research, with 2019 being the worst year on record. The melting ice sheets now account for a quarter of all sea level rise — a fivefold increase since the 1990’s — according to researchers who have combined 50 satellite surveys of Antarctica and Greenland taken between 1992 and 2020, funded by NASA and the European Space Agency.