A new study using historical images of glaciers in southeast Greenland to investigate glacier response to climate changes suggests that the recently observed acceleration of ice loss from Greenland may not be a long-term phenomenon. Instead, as marine terminating glaciers reach their grounding line and as the termini of land-terminating glaciers migrate upwards in elevation, ice loss rates from glacial discharge may slacken. According to Anders Bjørk and co-researchers:
[T]he recent high rate of retreat may come to a slowdown when retreating marine-terminating glaciers reach their grounding line and become less sensitive to the influence of ocean temperature, or through positive or negative feedback mechanisms relating to the cold East Greenland Coastal Current.
Our results have implications for future estimations of sea-level rise as retreat rates for marine-terminating glaciers are likely to increase as temperature rises until glacier fronts reach the grounding line, or when cold ocean currents re-establish, whereas retreat rates for land-terminating glaciers are not likely to rise in the same order of magnitude.
Such results throw a bit of cold water on alarmist ideas that rising temperatures will lead to ever-accelerating ice loss from Greenland and accelerating sea level rise.
For example, Eric Rignot and colleagues (2011) last year documented an acceleration in the rate of ice loss from Greenland (and Antarctica) over the past two decades. They extrapolated this acceleration into the future, to arrive at potential future sea level contributions from the loss of ice sheets:
At the current rate of acceleration in ice sheet loss, starting at 500 Gt/yr in 2008 and increasing at 36.5 Gt/yr2, the contribution of ice sheets alone scales up to 56 cm [22 in.] by 2100.