T1-5 Polar contribution to sea level rise

After a century of polar exploration, the past decade of satellite measurements has painted an altogether new picture of how Earth's ice sheets are changing. As global temperatures have risen, so have rates of snowfall, ice melting, and glacier flow. While the balance between these opposing processes has varied considerably on a regional scale, data show that Antarctica and Greenland are each losing mass overall. Much of the loss from Antarctica and Greenland is the result of the flow of ice to the ocean from ice streams and glaciers which has accelerated over the decade. In both continents there are suspected triggers for the accelerated ice discharge - surface and ocean warming, respectively - and, over the 21st century, these processes could rapidly counteract the snowfall gains predicted by present coupled climate models. This session covers advances in our understanding of both the sea level contribution due to the cryosphere and of the processes which have triggered today's imbalance.