But this modeling exercise is not nearly the most interesting part of this new Nature study.
A new study published in Nature claims that:
Mass loss from ice-covered land areas contributed around 1.5 mm per year to sea-level rise between 2003 and 2010, according to a study in Nature. The new estimates, based on satellite observations of gravity change, place a tighter constraint of the contribution of global ice loss to sea level rise and reveal surprising regional patterns.
Previously, the overall influence of glaciers, ice caps and ice sheets on sea-level changes had been unclear owing to methodological limitations and non-global geographical coverage. John Wahr and colleagues now assess ice mass loss by applying a consistent methodology to all ice-covered regions greater than 100 km2. From these data, the authors calculate that the total contribution to sea level rise was 1.48 ± 0.26 mm per year over the assessed period. They note that mass loss from Asian glaciers was notably smaller than previous estimates, and conclude that Asian glaciers have a minimal impact on sea-level rise.
Whatever, but the most interesting info was in the accompanying Nature News article:
Yet significant controversy2 and uncertainty surround the recent past and future behaviour of glaciers in this region. This is not so surprising when one considers the problem in hand. There are more than 160,000 glaciers and ice caps worldwide. Fewer than 120 (0.075%) have had their mass balance (the sum of the annual mass gains and losses of the glacier or ice cap) directly measured, and for only 37 of these are there records extending beyond 30 years. Extrapolating this tiny sample of observations to all glaciers and ice caps is a challenging task that inevitably leads to large uncertainties.
So… of the Earth’s 160,000 glaciers, only 120 have been studied and only 37 have records extending beyond 30 years.