Global warming has implications for the extent of the planet’s great ice sheets – and the loss of those ice sheets will have significant implications itself for the future – our future.
But we don’t yet understand the full extent of the effects, which we need in order to achieve an understanding of both current and future processes within the ice sheets.
That’s where new research, published in the Journal of Glaciology, comes in.
By creating a computer model which uses past information from Greenland’s glaciers and applies them to possible future climate scenarios, researchers are able to gain a greater insight into the rates and patterns of melting and, thus, any future inputs to sea level change from the Greenland Ice Sheet (GrIS).
The Importance of the Greenland Ice Sheet
So why does it matter what happens to the ice sheets? Well, estimates from the National Snow and Ice Data centre (NSIDC) suggest that total melting of the Greenland and Antarctic ice sheets would, between them, release enough fresh water to increase global sea level by approximately 66m, of which Greenland’s contribution would be around 6m (other estimates vary).
That isn’t all: the loss of such a large area of ice has potential impacts for climate (as less heat is reflected from ice-covered surfaces and as the cooling influence of the ice sheets is removed) and ocean circulation (by injecting large quantities of fresh water into areas where the deep water flow which drives ocean currents and, consequently, heat transport is formed).
Modelling and Ice Sheet Dynamics
The problem is that the dynamics of ice sheets are complex and, in many aspects, not fully understood. Glaciers move at different speeds at different locations, according to factors which include their size, length and thickness, as well as the type of rock they move across and whether melting is on the surface or at the base of the glacier.
Melting introduces so-called positive feedbacks (where melting promotes further melting) and negative feedbacks (where a change can inhibit melting.