Two papers released last week in the journal Nature Geoscience provide evidence that warming and melt in West Antarctica are occurring at levels that are highly unusual compared to natural variability.
The West Antarctic Ice Sheet contains about 2.2 million cubic kilometers of ice; enough to raise global sea levels by 3 to 4m. What’s making glaciologists nervous is that the ice rests on bedrock which is below sea level; this makes it vulnerable to attack from below by a warming ocean as well as attack from above by increasing air temperatures.
Whether basal and surface melt are currently exceeding natural levels, and the extent and speed at which they could destabilise the entire ice sheet are the subjects of intense research.
Warming up, melting
We already know that West Antarctica is feeling the heat. A study released late last year found that annual temperatures rose by 2.4 ± 1.2°C between 1958 and 2010. It is now ranked as one of the fastest-warming places on earth.
Thanks to satellite monitoring we also know that the ice sheet is …
