photo: Christine Zenino/Creative Commons
New satellite research shows that not only are both the Greenland and Antarctic ice sheets melting more rapidly than climate models have shown, but have now overtaken ice loss from mountain glaciers as the largest contributor to sea level rise.
Eric Rigot, the study's lead author from NASA's Jet Propulsion Laboratory notes, "What is surprising is this increased contribution by the ice sheets is already happening. If present trends continue, sea level is likely to be significantly higher that level project by the United Nations Intergovernmental Panel on Climate Change in 2007."Drawing on data from the past 20 years, the study found,
The pace at which the polar ice sheets are losing mass was found to be accelerating rapidly. Each year over the course of the study, the two ice sheets lost a combined average of 36.3 gigatonnes more than they did the year before. In comparison, the 2006 study of mountain glaciers and ice caps estimated their loss at 402 gigatonnes a year on average, with a year-over-year acceleration rate three times smaller than that of the ice sheets. (Science Daily)
Drawing on 2006 as an example again, the Greenland and Antarctic ice sheets lost a combined 475 gigatonnes of mass, enough to raise global sea level 1.3 millimeters each year.
Over the time period the study examined, the Greenland ice sheet lost mass faster than did the Antarctic: In Greenland mass lost year over year averaged 21.9 gigatonnes; in Antarctica 14.5 gigatonnes was lost.
All of that ice loss, plus ice loss from mountain glaciers and ocean thermal expansion, means that sea level rise by 2050 could reach 32 centimeters (12.6 inches).
Recently eminent climatologist-activist Dr James Hansen published research confirming that under a business as usual greenhouse gas emissions scenario multi-meter sea level rise by 2100 will happen.