Mountains are high-value features within the Earth system.

They cover a quarter of the Earth’s terrestrial surface. Their vertical extension creates great habitat over short distances, increases precipitation relative to adjacent lowlands and favors large water reservoirs in the form of glaciers, snowpack and permafrost. While often seen as resource-rich but forbidding in temperate and boreal climates, mountains are prime human habitat in tropical regions with much higher population densities than in adjacent lowland forests, plains, or deserts.

Mountain regions are experiencing profound environmental changes, which translate into serious challenges to society because of the tight coupling between social and ecological systems[1].

The reduction in water stored as snow and ice, driven by the shift from snow to rain as well as reductions in amount, reduce groundwater recharge in mountainous areas as well as the timing and amount of streamflow. These impacts are felt locally but also in cities and agricultural areas far downstream that rely on mountain water in regions as diverse as western North America, the altiplano in South America, Central Asia, and China. Increasingly destructive wildfire, degraded wildlife habitat, and wildland-urban interface conflict are additional challenges to mountain economies and communities, especially in Europe and North America. Disease vectors, invasive species, biodiversity loss and water pollution similarly afflict disparate regions around the world.

These social-ecological problems exist worldwide with a great deal of regional differentiation, but also with many common features.

Bringing science to bear on these issues requires more comprehensive, long term data on mountain systems around the world, not only to understand the nuances in each system, but also to identify the commonalities and the possible responses to management decisions.

A global network of observatories on mountain social-ecological systems is a key step toward obtaining these data and promoting these analyses.

Observatories of various types exist already in mountains around the world; the key is to bring them into communication with each other and to move toward congruent observing methodologies that reveal the complexity of these social-ecological systems.

[1] Ostrom, E. 2009. A general framework for analyzing sustainability of social-ecological systems. Science, 325 (419) DOI: 10.1126/science.1172133