Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

Séminaire de Mathias VUILLE, mercredi 5 juillet à 11h, salle Lliboutry, Bâtiment Glaciologie

Titre : Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead.

Résumé :
Glaciers in the tropical Andes have been retreating for the past several decades, leading to a temporary increase in dry season water supply downstream. Projected future glacier shrinkage, however, will lead to a long-term reduction in dry season river discharge from glacierized catchments. This glacier retreat is closely related to the observed increase in high-elevation, surface air temperature in the region. Future projections using a simple freezing level height- equilibrium-line altitude scaling approach suggest that glaciers in the inner tropics, such as Antizana in Ecuador, may be most vulnerable to future warming while glaciers in the more arid outer tropics, such as Zongo in Bolivia, may persist, albeit in a smaller size, throughout the 21st century regardless of emission scenario. The reduction in water supply for export-oriented agriculture, mining, hydropower production and human consumption are the most commonly discussed concerns associated with glacier retreat, but many other aspects including glacial hazards, tourism and recreation, and ecosystem integrity are also affected by glacier retreat. Comprehensive adaptation strategies, if they are to be successful, need to be based not only on future scenarios derived from physically-based numerical models, but must also consider societal needs, economic agendas, political conflicts, socioeconomic inequality and cultural values. This presentation reviews the need for adaptation as well as the challenges and constraints many adaptation projects are faced with, and lays out future directions where opportunities exist to develop successful, culturally acceptable and sustainable adaptation strategies.

Par Mathias Vuille de l’Université de New York (USA), professeur invité OSUG-UGA.
Séminaire animé par Antoine Rabatel (IGE-CYME).