evidence: Records broken for ocean heat, sea level rise, Antarctic sea ice loss and glacier retreat [...] A new report from the World Meteorological Organization (WMO) shows that records were once again broken, and in some cases smashed, for greenhouse gas levels, surface temperatures, ocean heat and acidification, sea level rise, Antarctic sea ice cover and glacier retreat. [...] Ice sheets: There are two principal ice sheets, the Greenland Ice Sheet and the Antarctic ice Sheet. Combining the two ice sheets, the seven highest melt years on record are all since 2010, and average rates of mass loss increased from 105 Gigatonnes per year from 1992–1996 to 372 Gigatonnes per year from 2016–2020. This is equivalent to about 1 mm per year of global sea level rise attributed to the ice sheets in the latter period.