Vulnerability of the Alps to climate change
Spanning the centre of continental Europe, the Alps play a crucial role in accumulating and supplying water to the continent. Recognised as the 'water towers of Europe', the mountains host most of the headwaters of the rivers Danube, Rhine, Po and Rhone; as such, they deliver vital ecosystem services both within and beyond the region, underpinning social and economic wellbeing in vast lowland areas.
Troublingly, the alpine climate has changed 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.
The global climate is forecast to keep changing unless global greenhouse gas emissions are reduced substantially to keep global temperature increases below 2 °C (above pre-industrial levels), which is the EU target. This target is guiding the negotiations on a global post-2012 climate agreement to be discussed at the UNFCCC climate change conference in Copenhagen (December 2009). However, even a global increase of 2 °C will still result in major impacts to which the world and Europe (primarily mountain regions, coastal areas, river floods-prone areas, the Mediterranean and the Arctic) will need to adapt.
The heatwave of summer 2003 demonstrated the potentially severe impacts of higher temperatures and drought on human wellbeing, ecosystems and water‑reliant economic sectors (such as power generation). Such extreme events have raised the
national and community awareness of the need to develop adaptation strategies. Some initial adaptation measures are already in place, partly as a response to extreme events. These initial measures can provide governments and citizens elsewhere
guidance on which approaches are likely to be successful and which less so, and also provide a preview of the challenges ahead.
The EU Adaptation White Paper together with the National Adaptation Strategies and the Action Plan on Climate Change of the Alpine Convention provide key steps towards European frameworks for adaptation measures and policies to increase resilience to climate change impacts. The knowledge base, governance structures and implemented actions are important issues to consider for developing effective adaptation measures. Hence, drawing on the most recent knowledge of climate change impacts in the Alps and experiences across the region, this report analyses the risks that climate change presents to the region's water supply and quality, identifying needs, constraints, opportunities, policy levers and options for adaptation. It extracts policy guidance on adaptation practice and aims to assist regional and local stakeholders in developing robust adaptation strategies. The focus of the report is on water resources and related adaptation, rather than water-related extreme events like floods, avalanches, landslides or mudflows, which are already well covered by existing studies of climate change impacts in the Alps.