Ice Loss Accelerating and Sea Level Rising

A study recently published in Science concluded that the Greenland ice sheet is losing mass at a quicker pace than previously. Consequently, it is making an increasing contribution to sea level rise.

Lead researcher Michiel van den Broeke from Utrecht University in the Netherlands and his team used weather data, satellite readings and models of ice sheet behavior. They want to understand the mechanics of the annual loss of 273 thousand million tonnes of ice, why it is accelerating, and what can be prognosticated about the consequences for sea levels.Van den Broeke told the BBC, "Since 2000, there's clearly been an accelerating loss of mass..." Advances in satellite technology have been particularly important to this latest study. A new NASA satellite, the Icesat mission, now allows scientists to measure glacier thickness in detail. According to the BBC this is a result of new technology:

The US space agency satellite uses a laser altimeter to measure the elevation of the ice sheets. It can acquire high-resolution data, especially in the steeply sloping coastal areas, where the radar altimeters flown on many other Earth observation satellites struggle to see important details.

Between 2000 and 2008 the melting Greenland ice sheet was contributing 0.46mm annually to sea level rise, Currently, it is contributing 0.75mm annually. This represents a 63 percent increase in two years. This accelerating rate of ice loss can be traced to many factors. Warming oceans; increased surface melt absorbing more solar energy than ice; and, glacial thinning, that acts to accelerate gravitational/oceanic flow all increase the rate of ice loss. Dr. van den Broeke told BBC News, "Over the last 10 years, it's quite simple; warming over Greenland has caused the melting to increase, and that's set off this albedo feedback process."