Thresholds and Closing Windows: Risks of Irreversible Cryosphere Climate Change at Current INDCs Georg Kaser Mountain Glaciers: First Irreversible Signs IPCC AR5 WG1 SPM (2013) ,0 m 0,0 m Sea Level Projections Levermann et al. PNAS (2013) RCP8.5 RCP2.6 Observes sea level rise : 3.2 mm/year Data from Table 13.1 IPCC AR5 WG1 Ch.13 (2013) Thermal expansion: 38% Glaciers: 28% Greenl. Ice Sheet: 10% Antarct. Ice Sheet: 10% Land water stor.: 14% Total :100% Obs. GMSLR: 110% Gardner et al. Science 2013 IPCC AR5 WG1 Ch.4 (2013) Glacier shrinkage [Gt/yr]: appr. 200,000 glaciers 726,258 km 2 38,5 % TW 412 mm SLE appr. 200,000 glaciers 726,258 km 2 38,5 % TW 412 mm SLE Data: ACINN, BAdW Glacier loss rates increase 3 glaciers in Austria Alps (small glaciers): 100 % anthropogenic drivers Global (large glaciers) : 70 % anthropogenic drivers, 30 % recovery from Little Ice Age. Marzeion et al. Science (2014) Glacier shrinkage: The drivers Natural forcing Natural + anthropogenicObservations Glacier mass loss until 2300 RCP8.5 = 4.5C in 2100 RCP2.6 = 1.6C in 2100 RCP4.5 = 2.4C in 2100 Marzeion et al. TC (2012) The glaciers future contribution to sea level rise Kaser et al. PNAS (2010) Present glaciers contribution to water availability (steady state) Foto: B. Marzeion