Historical glacier change on Svalbard predicts doubling of mass loss by 2100

Can we use spatial patterns of historical glacier and climate change to predict the future fate of glaciers? A new study in Nature led by Emily Geyman (Caltech) and co-authored by among others Ward van Pelt, quantifies both past and future glacier change in the High Arctic archipelago of Svalbard. The study uses a unique combination of historical aerial imagery, structure-from-motion photogrammetry, and an inventive ‘space-for-time substitution’ approach.

Globally, the melting of glaciers and ice caps is greater than mass loss from the much more voluminous Greenland and Antarctic ice sheets, and contributes about one-third to current sea level rise. Since 1991, the archipelago of Svalbard, home to almost 2,000 glaciers, has experienced warming at a rate of 1.7 ^oC  per decade, which is seven times the global average. This has induced accelerating glacier mass loss, but estimates of past mass loss show a large spread, primarily due to a lack of observations.

The new study makes use of >5,000 aerial images from the 1930s covering most of Svalbard and uses structure-from-motion photogrammetry to construct a historical digital elevation model of nearly all Svalbard’s glaciers. When compared with a more recent topographic map, glacier thinning from 1936 to 2010 is calculated, showing a loss of around 600 Gt of glacier mass, equivalent to 1.6 mm of sea level rise (1.4% of the global mean sea level signal).

A comparison of spatial maps of glacier thinning and summer temperature across Svalbard reveals a strong correlation, which is then used in a so-called ‘space-for-time substitution’ to construct a simple model to predict future glacier mass loss. With this model and future projections for temperature and precipitation up to 2100 under three emission scenarios, the rate of glacier mass loss in Svalbard is expected to more than double in the remainder of the 21^st century compared to 1936-2010.

Read the article in Nature here; "Historical glacier change on Svalbard predicts doubling of mass loss by 2100". 

For more information contact: Associate Professor Ward van Pelt
Email: ward.van.pelt@geo.uu.se
Telephone: +4618-471 7180