docGlacier recession in the tropical Andes – observations, model
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Glacier recession in the tropical Andes – observations, model
Glacier recession in the tropical Andes – observations, model projection and consequences for future water use Mathias Vuille Climate System Research Center, Dept. of Geosciences, Univ. of Massachusetts – Amherst NSF-EAR 0519415 IAI-CRN II 2047 The common perception of the tropics… The tropics – a different view…(I) Huayna Potosi -Bolivia Cotopaxi - Ecuador The tropics – a different view…(II) Three basic questions: • Are glaciers really retreating everywhere ? • If so, why? • Why should we care or even worry? Mountain Glacier Trends Rhonegletscher, Switzerland 2000 1856 Aletschgletscher, Swiss Alps, 1856 and 2001 Because of delayed glacier response, this glacier will retreat an additional ~2000m even if no further temperature increase would occur (unrealized response) • Antizana, Ecuador • Quelccaya, Peru • Chacaltaya, Bolivia • Villarica, Chile • Lanin, Argentina Antizana 15 Glacier, Ecuador Drinking water for Quito ! Francou et al., 2004, . J. Geophys. Res. Qori Kalis Glacier -- Quelccaya Ice Cap, Peru credit: L.G. Thompson, Ohio State Univ. Chacaltaya: formerly world’s highest ski resort and water supply for La Paz 5 M m3 in 1940 <0.4 M m3 today Coudrain et al., Hydrol. Sci. J., 2005 Francou, B., Vuille, M., Wagnon, P., Mendoza J., Sicart, J.E., 2003 J. Geophys. Res. 1945 Glaciar del Río Turbio VOLCAN VILLARRICA 2847 m RI O 1418 m RIO TU RB IO 1410 m CORRE NTOSO 1936 m Credit: G. Cassasa, CECS 1 1961 2 3 SUPERFICIE PERDIDA PERIODO 1945/61 3,4 Km2 VOLCAN VILLARRICA 2847 m RI O RIO TU RB IO 1410 m CORRE NTOSO 1936 m 1418 m 4 Km2 1 1983 2 3 SUPERFICIE PERDIDA PERIODO 1961/83 0,4 Km2 VOLCAN VILLARRICA 2847 m RI O RIO TU RB IO 1410 m CORRE NTOSO 1936 m 1418 m 4 Km2 1 1987 2 3 SUPERFICIE PERDIDA PERIODO 1983/87 0,2 Km2 VOLCAN VILLARRICA 2847 m RI O RIO TU RB IO 1410 m CORRE NTOSO 1936 m 1418 m 4 Km2 1 1998 2 3 SUPERFICIE PERDIDA PERIODO 1987/98 0,5 Km2 VOLCAN VILLARRICA 2847 m RI O RIO TU RB IO 1410 m CORRE NTOSO 1936 m 1418 m 4 Km2 1 2003 2 3 SUPERFICIE PERDIDA PERIODO 1998/2003 1,0 Km2 VOLCAN VILLARRICA 2847 m RI O RIO TU RB IO 1410 m CORRE NTOSO 1936 m 1418 m 4 Km2 The future of Andean glaciers…………. 1896 2001 Glacier on Volcán Lanin, Argentina Three basic questions: • Are glaciers really retreating everywhere ? → Yes • If so, why? • Why should we care or even worry? Glacier Mass Balance: Stability Glaciers are like bank accounts: if you want it to remain in healthy (stable) Conditions, you can not withdraw (melt in ablation zone) more, than you deposit (add through snowfall) Glacier Mass Balance: Advance Growing bank account: you deposit more than you withdraw… Glacier Mass Balance: Retreat Depleting your bank account: you withdraw more than you deposit… The record of global warming looks very similar to the rising CO2 concentrations in the atmosphere… Tropical Andes Vuille et al., 2003, Clim. Change Three basic questions: • Are glaciers really retreating everywhere ? → Yes • If so, why? → Temperature has significantly increased in the tropical Andes → higher melt rates, which are not compensated by increased accumulation → Bank account becomes negative → glacier retreats • Why should we care or even worry? • Current (2005): 380 ppmv • Projected change in mean annual temperature 2090-99 Bradley, R.S., Vuille, M., Diaz, H.F., Vergara, W., Science, [2006] PAST ELA G. Kaser pers. comm. PRESENT ELA G. Kaser pers. comm. FUTURE ELA G. Kaser pers. comm. Consequences of glacier retreat for water availability and runoff ? → Glacier on Volcán Lanin, Argentina, 1896 and 2001 Consumption vs. availability of water in the Andes in a 2*CO2 world Changes in runoff in the Llanganuco catchment for different climate change scenarios Juen et al., in press, Global Planet. Change Water means life… Agriculture Hydropower Drinking water Mining Natural habitats Ecosystem Biodiversity ….
