The MRI recently co-sponsored the conference “Climate Change: Organizing the Science for the American Cordillera (CONCORD).” This conference summarized current research and identified scientific gaps and research needs to support adaptation to global change along the Cordillera from Alaska to Tierra del Fuego. Immediately after the conference the MRI sponsored the “Cordillera Transect Workshop” in order to design concrete projects to fill these research gaps.

CONCORD: the first inter-American conference on global change research along the American Cordillera

Mendoza, Argentina, is the home of IANIGLA, the Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales (Argentine Institute for Snow Studies, Glaciology and Environmental Sciences). From 4–6 April 2006 IANIGLA's director, Ricardo Villalba, hosted CONCORD with its 150 participants as well as 3 side events (a meeting of the Working Group on Snow and Ice of the UNESCO Latin American Hydrological Program, an IHDP Networking in the Andes meeting chaired by Fausto Sarmiento, and the Cordillera Transect Workshop organized by the MRI). The MRI was part of the Organizing Committee (co-chaired by Henry F. Diaz of NOAA and Ricardo Villalba), and the manager of program development and invitations.

Mountain regions of the western American Cordillera may be especially vulnerable to changes in climate, to the ensuing changes in snowpack, streamflow, and ecosystem functioning, and to a host of impacts on human and natural systems. In these mountain regions small perturbations in global processes can cascade to produce large changes in both highlands and lowlands, ultimately affecting the health, safety, and prosperity of people throughout the region.

Outcomes of the conference

Excellent presentations over 3 days yielded insights into topics, methods, and findings of current global change research along the American Cordillera. Some of the urgent topics identified with respect to earth system functions were:

Some of the urgent topics identified with respect to impacts on people and resources were:

The program and the presentations (as webcasts) are available at the MRI website:  http://mri.scnatweb.ch/content/category/7/44/66/. The abstracts volume, the meeting summary and the list of participants can also be found here.

Example of current research

Climate Change in the Tropical Andes—Observations, Models, and Simulated Future Impacts on Glaciers and Streamflow

The tropical Andes are one of the regions where recent climate change is most evident. As a result, glaciers are receding, with potentially severe consequences for the availability of drinking water, and water for irrigation, mining, and hydropower production.

General Circulation Models (GCMs) run with a 2 ×CO₂ scenario predict additional warming of more than 2.5°C by the end of the century. However, great uncertainties exist about these projections: the coarse resolution of GCMs is inadequate to resolve the meso- and local-scale circulation features associated with steep Andean topography.

We have started a new project aimed at simulating climate variability and change in the Andes under both present-day conditions and different IPCC-SRES emission scenarios (2071–2100) with 2 regional climate models (PRECIS and RegCM). With this project we will, for the first time, establish robust projections of how glaciation, runoff, and downstream water availability will change in this region by the end of the 21st century.

The following research framework was proposed (Figure 1):

FIGURE 1

Flow chart of proposed modeling and validation studies, and participation of members during the stages of the project.

1. Two regional climate models (RCMs), PRECIS and RegCM3, will be used to simulate present-day climate.

2. The simulations will be validated with observational data. Since many parts of the tropical Andes are devoid of in-situ data, we will complement surface data with observations from space from different sensors (TRMM, TOVS, ISCCP, MODIS). We will focus on glacier-relevant variables: precipitation, cloud cover, temperature, water vapor.

3. Output from the RCMs will be used to feed a tropical glacier-climate model (ITGG 2.0). This model will yield estimates of glacier mass balance and streamflow in selected catchments.

4. The results from the glacier-climate model will be validated with observational mass balance and streamflow records.

5. To assess the potential impact of climate change on glaciation and streamflow from glacierized catchments, we will repeat the analysis with the ITGG 2.0, this time using simulated climate for 2071–2100 under IPCC Special Report on Emissions Scenarios (SRES) A2 and B2 conditions as an input into our glacier-climate model. We will thus be able to present robust projections of the impacts of climate change on tropical Andean glaciers and water resources at the end of this century.

Mathias Vuille, University of Massachusetts (mathias@geo.umass.edu)

The American Cordillera Transect Workshop

This workshop offered an opportunity to sign up for concrete collaboration addressing the issues raised in the CONCORD conference through the development of specific research projects in sites along the American Cordillera.

The long-term goal of the Cordillera Transect is to establish a transect of pole–equator–pole global change research sites and to integrate their researchers in a trans-American network working with comparable methods. Data and results can thus be shared and compared. In addition, the MRI is aiming for interdisciplinary projects, ie projects that examine the basic functioning of the earth systems and the impacts, as well as transdisciplinary work, to promote stakeholder involvement in project development.

The workshop launched the American Cordillera Transect with 6 international working groups established at the end of the day. The groups have 6 months to develop project descriptions to be used by the participants in the development of funding proposals. A successful project description will specify the precise research themes and methods, the timetable, the institutions and researchers involved, and the sources of funding.

The contact persons and participants in the working groups on Science and Stakeholders, Hydrological Modeling, Forests, Biodiversity, Land Use and Land Cover Change, and Climate Data can be found at:  http://mri.scnatweb.ch/content/category/3/45/67/.

The American Cordillera Transect is the first instance of MRI's Real Projects in Real Places

The GLOCHAMORE Research Strategy laid out a global template for global change research in mountain regions. The MRI's Dr. Astrid Björnsen Gurung took the scientific lead of the “Global Change in Mountain Regions” (GLOCHAMORE) project, of which the major product was the GLOCHAMORE Research Strategy (see also Mountain Research and Development 26(1), pp 282–283; for the Research Strategy go to  http://mri.scnatweb.ch/content/view/74/31).

It is now the MRI's task to initiate and support regional networks of global change research. Regional foci are the American Cordillera, the European Mountains, North and Central Asia, Southeast Asia, and Africa.