Antarctica unplugged – climate change, ice dynamics and sea-level rise
Colder, windier, drier than anywhere else on the globe - Antarctica is a continent of superlatives. It is covered by a massive ice-sheet, storing water equivalent to more than 50 meters of global sea-level rise. The ice is constantly moving, flowing from the continent’s interior towards the ocean - forming, melting, re-freezing, breaking. To this day, these complex dynamics of the Antarctic Ice Sheet are the key challenge for projections of future sea-level rise under climate change. Recent observations show that part of the West Antarctic Ice Sheet is rapidly retreating, and that this retreat is likely irreversible on human timescales. Other regions are currently protected by so-called ice plugs, small volumes of ice which hinder the onset of a dynamic instability. However, man-made climate change increases the risk of triggering persistent ice discharge from the adjacent basins into the ocean. We will review the processes behind these dynamic (in)stabilities and explore the implications for future sea-level rise. Burning all of the world’s available fossil-fuel resources could eventually result in the complete melting of the Antarctic Ice Sheet and cause long-term global sea-level rise unprecedented in human history.