Bad news for coastal cities

An international team of scientists, led by Andrew Shepherd of the University of Leeds, has put together the most comprehensive study of Arctic and Antarctic ice sheet loss to date. They also determined how much that loss of ice is affecting global sea levels. The news is not good.

The 47 authors used nineteen years of satellite data to come to their conclusions. They found that the loss of the Antarctic and Greenland ice sheets have contributed to a rise in sea level of eleven millimeters over the past two decades. While this may not sound like a lot, remember, that rise is continuing and increasing. Both poles are losing ice at a faster pace. As Erik Ivins from NASA’s Jet Propulsion Laboratory points out:

The rate of ice loss from Greenland has increased almost five-fold since the mid-1990s.

This means that the rise of the oceans due solely to polar ice sheet loss has increased to nearly a full millimeter per year. However, the bulk of the sea level rise is caused not by the added water from the melting ice but by the expanding of the ever warmer water. In other words, global warming will continue to be a problem even after the polar ice caps have already disappeared.

You can see an interview with Andrew Shepherd and Erik Ivins below. To watch an animation of the researchers' results, click here.

Shepherd, A., Ivins, E., A, G., Barletta, V., Bentley, M., Bettadpur, S., Briggs, K., Bromwich, D., Forsberg, R., Galin, N., Horwath, M., Jacobs, S., Joughin, I., King, M., Lenaerts, J., Li, J., Ligtenberg, S., Luckman, A., Luthcke, S., McMillan, M., Meister, R., Milne, G., Mouginot, J., Muir, A., Nicolas, J., Paden, J., Payne, A., Pritchard, H., Rignot, E., Rott, H., Sorensen, L., Scambos, T., Scheuchl, B., Schrama, E., Smith, B., Sundal, A., van Angelen, J., van de Berg, W., van den Broeke, M., Vaughan, D., Velicogna, I., Wahr, J., Whitehouse, P., Wingham, D., Yi, D., Young, D., & Zwally, H. (2012). A Reconciled Estimate of Ice-Sheet Mass Balance Science, 338 (6111), 1183-1189 DOI: 10.1126/science.1228102