Sound Science Bite: December 26. Al Gore Vindicated?

Recent evidence implies the West Antarctic ice sheet might have disappeared during the last warm, interglacial period called the Eemian that was extant 129 000 to 116 000 years ago. This period was only one degree Celsius warmer than the present. A news report in the journal Science (21 Dec 2018 p. 1339) describes evidence collected by Anders Carlson at Oregon State University and his team from archived ice cores that implies erosional debris from the West Antarctic ice sheet disappeared during the Eemian. This could mean the ice sheet was no longer present, but it could also be due to, for example, a change in ocean currents.

At any rate sea level rose six to nine meters (20 to 30 feet) during that period, flooding much of the world's coastal plains. It had been thought this rise was due to the complete melting of the Greenland ice sheet, but research performed by Carlson and colleagues in 2011 contradicts that idea. As glaciers on the edge of the West Antarctic ice sheet are retreating quickly, there are now serious questions about its stability during our current warming period. In the past I have poked fun at people like former Vice President Al Gore for raising the alarm of a collapse of the West Antarctic ice sheet due to the lack of evidence it disappeared during previous interglacial periods, but maybe old Al could turn out to be right after all. Happy New Year!