Worldwide glacier retreat and associated future runoff changes raise major concerns over the sustainability of global water resources, but global-scale assessments of glacier decline and the resulting hydrological consequences are scarce. Here we compute global glacier runoff changes for 56 large-scale glacierized drainage basins to 2100 and analyse the glacial impact on streamflow.

Changes in the hydrology of high-altitude catchments may have major consequences for downstream water supply. Based on model projections with a higher spatiotemporal resolution and degree of process complexity than any previous intercontinental comparative study, we show that the impacts of climate change cannot be generalized. These impacts range from a high climatic sensitivity, decreasing runoff, and significant seasonal changes in the Central Andes of Chile to increasing future runoff, limited seasonal shifts, but increases in peak flows in the Nepalese Himalaya.

Since the recognition that allopatric speciation can be induced by large-scale reconfigurations of the landscape that isolate formerly continuous populations, such as the separation of continents by plate tectonics, the uplift of mountains or the formation of large rivers, landscape change has been viewed as a primary driver of biological diversification. This process is referred to in biogeography as vicariance. In the most species-rich region of the world, the Neotropics, the sundering of populations associated with the Andean uplift is ascribed this principal role in speciation.

Bridging the gap between the predictions of coarse-scale climate models and the fine-scale climatic reality of species is a key issue of climate change biology research. While it is now well known that most organisms do not experience the climatic conditions recorded at weather stations, there is little information on the discrepancies between microclimates and global interpolated temperatures used in species distribution models, and their consequences for organisms’ performance.

Mountain regions have played a significant role in the history of biodiversity conservation, and promise to play an even larger part in future efforts to respond to climate change. After an historical overview of scientific research into mountain ecosystems, biodiversity conservation in mountain regions is examined in light of the ever-expanding research agenda on landscape connectivity and corridor ecology.

Researchers are racing to determine how shrinking glaciers in the Andes will affect the water supply of millions of people.