If the glacial melt water contribution to sea level is overestimated, then, the unaccounted -
for contribution to sea level rise becomes much larger than initially thought.
The warming, melting and potential
contributions to sea level rise from glaciers in Greenland and West Antarctica in the face of climate change has long since been a serious concern.
If a negative surface mass balance were sustained for millennia, that would lead to virtually complete elimination of the Greenland ice sheet and a
resulting contribution to sea level rise of about 7 m.
Near - global ocean temperature data for the last 50 years have been recently made available, allowing the first observationally based estimate of the thermal expansion
contribution to sea level rise in past decades.
@ 1 Paul S. Most assessments of ice sheet
contribution to sea level rise indicate an acceleration over the past decade, whereas altimeter - measured SLR has not been faster over the most recent decade There was a paper published within the last couple of years by some of this sites contributors that suggested part of the disparity may be due to an increase in land based water.
Study co-author Professor Andrew Shepherd, from Leeds» School of Earth and Environment, explained: «Although Western Palmer Land holds a lot of ice — enough to raise global sea levels by 20 centimetres — its glaciers can't be responsible for a
major contribution to sea level rise, because their speed has barely changed over the past 25 years.
suggests the heat into the ocean is now going into colder and fresher water, whose expansion coefficient is smaller than warmer and more saline water, resulting in
smaller contribution to sea level rise.
And, although freshwater discharge from deep aquifers may be locally insignificant relative to river runoff, deep aquifer discharge when integrated across the globe could account for the
missing contribution to the sea level rise budgets.
The United Nations Intergovernmental Panel on Climate Change (IPCC)'s worst projections for Greenland's
contribution to sea level rise top out at 68 centimeters (27 inches) by the year 2100.
And more recent estimates of the Antarctic mass
balance contribution to sea level rise has the East Antarctica ice sheet gaining mass at a more accelerated pace for 2003 - 2013 than the mere +14 Gt per year identified by Shepherd et al. (2012) for 1992 - 2011.
With glaciers thinning, accelerating and receding in response to ice shelf collapse [20, 21], more ice is directly transported into the oceans, making a
direct contribution to sea level rise.
If such a negative surface mass balance were sustained for millennia, that would lead to virtually complete elimination of the Greenland ice sheet and a
resulting contribution to sea level rise of about 7m.