significantly during the past century, with temperatures increasing more than twice the global average. This makes alpine mountains especially vulnerable to changes in the hydrological cycle and decreases in snow and glacier cover, which are already occurring.
Global climate change threatens to continue altering the alpine hydrological system drastically. Projected changes in precipitation, snow-cover patterns and glacier storage will further alter run‑off regimes, leading to more droughts in summer, floods and landslides in winter and higher inter-annual variability. Projected water shortages and more frequent extreme events, combined with increasing water demand (for irrigating agriculture or tourist influxes, for example), are likely to have severe adverse effects on ecosystem services, such as the provision of drinking water.
Furthermore 60 % of mountain plant species may face extinction by 2100 if unable to adapt by moving northward or uphill. Economic sectors, including households, agriculture, energy production, forestry, tourism, and river navigation, are already now vulnerable to water shortages. Climate change may worsen current water resource issues and lead to increased risk of conflicts between users in the alpine region (particularly the south) but also outside the Alps where droughts are also expected to become more frequent. Observed and projected reductions in permafrost are also expected to increase natural hazards and damage to high altitude infrastructure.