This document discusses climate change impacts in the tropical Andes region. It notes that glaciers in the region have been retreating rapidly over the past century due to rising temperatures. This glacier melt is expected to impact water resources, with some areas expected to see up to 40% decreases in runoff by 2080. The Andean Climate Change Interamerican Observatory Network (ACCION) was created to help monitor glaciers and climate change, build local capacity, and inform policy decisions around water resource management and adaptation to these impacts.

1. Climate change, glacier retreat and water
resources in the tropical Andes
Mathias Vuille
Department of Atmospheric and Environmental Sciences
University at Albany, State University of New York
Dana McGlone & Eric Franquist
(Univ. at Albany, SUNY)
Rocio Urrutia (Univ. Oxford)
Doug Hardy, Ray Bradley (Univ. of •
Mass., Amherst)
Bernard Francou & Bolivar
Caceres (IRD, INAMHI, Quito)
ACCION –Co-PIs
Georg Kaser (Univ. Innsbruck)
Christian Huggel (Univ. Zurich)
Waldo Lavado, Ken Takahashi &
Elizabeth Silvestre (SENAMHI, IGP,
& Univ. La Molina, Lima)
Rene Garreaud & Andres Rivera
(Univ. de Chile, Santiago & CECS,
Valdivia)
Bert de Bievre & Miguel Saravia
(CONDESAN, Lima & Quito)
Wouter Buytaert (Imperial College)

2. Observations of glacier retreat
Glacier Espejo, Pico Bolivar (5002 m), Venezuela
1910 1988 2008
Jahn [1931]; Schubert [1992, 1999]

4. 2009
Photo B. Francou

5. The retreat of tropical glaciers
in Ecuador, Peru and Bolivia
Vuille, Francou, Wagnon, et al., Earth Sci. Rev., [2008]

6. 20th century temperature trends
in the tropical Andes
Near-surface temperature increase
of 0.68°C since 1939
(~0.1°C decade-1)
Vuille, Bradley, Werner, et al., Climatic Change, [2003]
Vuille, Francou, Wagnon, et al., Earth Sci. Rev., [2008]

7. Annual mean temperature change
for the end of the 21st century
B2 A2
10.4 billion people, 15 billion people,
550 ppm of CO2 by 2100 850 ppm of CO2 by 2100
Urrutia & Vuille, J. Geophys. Res., [2009]

8. The impact of glacier retreat on runoff
Relevance of this process:
- most important in regions such as
Peru (rivers draining into seasonally
arid lowlands (Kaser et al., PNAS, 2010)
- less relevant in inner tropics where
paramos can take on regulating
function and where precipitation is less
seasonally biased (Buytaert et al., 2010,
HESS)
Kaser, et al., J. Hydrol., [2003]

9. The Cordillera Blanca and
the Rio Santa Valley
Kaser, Juen, Georges et al., J. Hydrol., [2003]
Vuille, Kaser & Juen, Global Planet. Change, [2008]

10. Projected future runoff changes
in the Cordillera Blanca
Parón Llanganuco Chancos
wet dry wet dry wet dry
40
40
40
Runoff
20
20
20
delta Q [%]
delta Q [%]
delta Q [%]
change in
0
0
0
% in 2050
-20
-20
40.9% -20 31.0% 24.1% and 2080
for B1 and
-40
-40
-40
10 12 1 2 3 4 5 6 7 8 9 10 12 1 2 3 4 5 6 7 8 9 10 12 1 2 3 4 5 6 7 8 9
month (Oct - Sept) month (Oct - Sept) month (Oct - Sept) A2
Quillcay Pachacoto scenarios
wet dry wet dry
40
40
20
20
b1-2050
delta Q [%]
delta Q [%]
a2-2050
b1-2080
0
0
a2-2080
17.4%
-20
-20
9.7%
-40
-40
Juen, Ph.D Univ. Innsbruck, [2006]
10 12 1 2 3 4 5 6 7 8 9 10 12 1 2 3 4 5 6 7 8 9 Vuille, Francou, Wagnon, et al., Earth Sci. Rev., [2008]
month (Oct - Sept) month (Oct - Sept)

11. Andean Climate Change Interamerican
Observatory Network (ACCIÓN)
Adaptation requires:
- improving climate change resilience
- a strengthening of local research
institutions and enhanced capacity
building
- better networking in the region
between scientists, policy- and
decision-makers, water managers
and affected segments of the
local population
- improved capacity for glacier Photo: M. Vuille
monitoring & water resources
management
→ ACCION intends to provide a platform to promote these goals

12. Andean Climate Change Interamerican
Observatory Network (ACCIÓN)
ACCION activities include:
- regional training and capacity
building (offering workshops and
training in glaciology and climate
change science)
- fellowships for S. American
students to study in the US
- providing information and tools for
Photo: G. Kaser
policy decisions
- support outreach efforts and dialogue
in collaboration with other units (e.g.
CONDESAN, UNESCO-IHP)