Abstract
The large uncertainty in future global glacier
volume projections partly results from a substantial range
in future climate conditions projected by global climate
models. This study addresses the effect of global and
regional differences in climate input data on the projected
twenty-first century glacier contribution to sea-level rise.
Glacier volume changes are calculated with a surface mass
balance model combined with volume-area scaling, applied
to 89 glaciers in different climatic regions. The mass balance
model is based on a simplified energy balance
approach, with separated contributions by net solar radiation
and the combined other fluxes. Future mass balance is
calculated from anomalies in air temperature, precipitation
and atmospheric transmissivity, taken from eight global
climate models forced with the A1B emission scenario.
Regional and global sea-level contributions are obtained by
scaling the volume changes at the modelled glaciers to all
glaciers larger than 0.1 km2 outside the Greenland and
Antarctic ice sheets. This results in a global value
of 0.102 ± 0.028 m (multi-model mean and standard
deviation) relative sea-level equivalent for the period
2012–2099, corresponding to 18 ± 5 % of the estimated
total volume of glaciers. Glaciers in the Antarctic, Alaska,
Central Asia and Greenland together account for 65 ± 4 %
of the total multi-model mean projected sea-level rise. The
projected sea-level contribution is 35 ± 17 % larger when
only anomalies in air temperature are taken into account,
demonstrating an important compensating effect by
increased precipitation and possibly reduced atmospheric
transmissivity. The variability in projected precipitation and atmospheric transmissivity changes is especially large
in the Arctic regions, making the sea-level contribution for
these regions particularly sensitive to the climate model
used. Including additional uncertainties in the modelling
procedure and the input data, the total uncertainty estimate
for the future projections becomes ±0.063 m.
Original language | English |
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Pages (from-to) | 3283–3300 |
Number of pages | 18 |
Journal | Climate Dynamics |
Volume | 41 |
Issue number | 11-12 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- Glacier volume projections
- Sea-level rise
- Global climate models
- Climate change