"During that period, global mean surface temperatures were 2–3°C warmer than today, ice sheets in Greenland and West Antarctica melted and even parts of East Antarctica’s ice retreated, causing the sea level to rise 10–20 m higher than that today," the WMO bulletin said.
Since 1990, the global warming effect of CO2 and other long-lived greenhouse gases has risen by 40 percent. The two other main gases—methane and nitrous oxide—also grew to record concentrations last year, although at a slower rate of increase than carbon dioxide.
This article was provided by Reuters.