Some 272 billion tonnes more snow were being dumped on the White Continent annually in the decade 2001-2010 compared with 1801-1810. Put another way, it is the amount of water you would need to cover the state of Colorado to a depth of 1m.
Dr. Liz Thomas presented the results of the study at the European Geosciences Union (EGU) General Assembly in Vienna, Austria. The British Antarctic Survey (BAS) researcher said the work was undertaken to try to put current ice losses into a broader context. “The idea was to get as comprehensive a view of the continent as possible,” she told BBC News.
“There’s been a lot of focus on the recent era with satellites and how much mass we’ve been losing from big glaciers such as Pine Island and Thwaites. But, actually, we don’t have a very good understanding of how the snowfall has been changing. The general assumption up until now is that it hasn’t really changed at all – that it’s just stayed stable. Well, this study shows that’s not the case.”
It found the greater precipitation delivered additional mass to the Antarctic ice sheet at a rate of 7 billion tonnes per decade between 1800 and 2010 and by 14 billion tonnes per decade when only the period from 1900 is considered. Most of this extra snow has fallen on the Antarctic Peninsula, which saw significant increases in temperature during the 20th Century.
“Theory predicts that, as Antarctica warms, the atmosphere should hold more moisture and that this should lead therefore to more snowfall. And what we’re showing in this study is that this has already been happening,” Dr. Thomas said.
The BAS researcher is keen to stress that the increases in snowfall do not contradict the observations of glacial retreat and thinning observed by satellites over the last 25 years. Although the extra snow since 1900 has worked to lower global sea level by about 0.04mm per decade, this is more than being countered by the ice lost to the oceans at Antarctica’s margins, where warm water is melting the undersides of glaciers.