Assessing Climate impacts on the Quantity and quality of WAter
A large integrating project under EU R&D Framework Programme 7 (FP7)
ACQWA Science and Policy Brief
© 2013 ACQWA Coordination Team, Geneva, Switzerland
How to cite this document Beniston, M., Stoffel, M., and Hill, M. (eds), 2013: Assessing climate impacts on the quantity and quality of water. The EU/FP7 ACQWA Project Science and Policy Brief. University of Geneva, 98 pp.
Photographs: © Martin Beniston, except for Page 10, left-hand picture (© Annina Sorg), Page 54 (© Stefano Maran), Page 64 (© David Hannah)
Assessing Climatic change impacts on the Quantity and quality of WAter
(A large integrating project under EU-FP7, 2008-2013)
A Science and Policy Brief
Document compiled by the ACQWA Coordination team University of Geneva, Switzerland August 2013
ACQWA Project Partners
37 partners, 30 academic and research organizations, 10 countries Switzerland
UNIGE: University of Geneva (Coordination + 4 teams) UNIBE: University of Bern ETHZ: Swiss Federal Institute of Technology, Zurich (3 teams) Agroscope (Federal Agricultural Research Institute), Zurich-Reckenholz IHEID: Graduate Institute of International and Development Studies, Geneva (2 teams)
CNRS: Centre National de la Recherche Scientifique (1 partner in Paris, 2 partners in Grenoble) CEN (Centre d’Etudes de la Neige), Grenoble LSCE (Laboratoire des Sciences du Climat et de l’Environnement), Paris
MPI: Max-Planck-Institute for Meteorology, Hamburg
ICTP (International Centre for Theoretical Physics), Trieste UNIAQ: University of l’Aquila ARPAPMNT (Regional Environmental Protection Agency), Piemonte ARPAVDA (Regional Environmental Protection Agency), Valle d’Aosta CVA: Compania Valdostana dell’Aqua Fondatione Montagna Sicure, Valle d’Aosta ENEL (State Electricity), Rome ISAC-CNR (Institute for Atmospheric Sciences and Climate), Turin POLIMI: Politecnico di Milano PNGP (Gran Paradiso National Park) MONTEROSASTAR (Cable-car company), Macugnaga RSE (Ricerca sul Sistema Energetico), Milan
UNIGRAZ: University of Graz BOKU: University of Vienna (Bodenkultur)
BHAM: University of Birmingham UNIVDUN: University of Dundee
CEAZA (Centre for Arid Zones Research), La Serena CECS (Centre for Scientific Investigations), Valdivia
Argentina ITDT (Instituto Torcuado di Tella), Buenos Aires Kyrgyzstan KNAS: Kyrgyz National Academy of Science, Bishkek
IPE-CSIC (Institute for Pyrenean Ecology),
The “Jet d’Eau”, one of Geneva’s famous landmarks. The University of Geneva was home to the ACQWA project coordination from 2008-2013
Table of contents
Foreword Principal objectives of the ACQWA project
PART 1: SUMMARY, METHODS/MODELS, CASE-STUDY REGIONS Summary of main results and policy implications Methods and models Case-study regions PART 2: PROJECTIONS OF CHANGE BY 2050 Regional climates Snow and ice Hydrology Extreme events and climate-driven hazards
11 12 18 24 27 28 33 41 45
PART 3: POTENTIAL IMPACTS Multiple impacts Hydropower Agriculture Aquatic ecosystems Mountain forests Tourism Lessons learned from non-European regions PART 4: POLICY, ADAPTATION, GOVERNANCE Water resource management for climate adaption Adaptive capacity, policy, and governance recommendations PART 5: CLOSING PAGES Challenges for future research Bibliography (papers with ACQWA acknowledgment) ACQWA Coordination contact details, ACQWA project web site
51 53 55 59 65 68 71 74 79 81 82 85 86 87 98
El Juncal, Chile The elevation of the summit of this glaciated mountain is 6,200 m above sea level. It is the source of the Aconcagua River, one of the ACQWA project case-study regions.
The ACQWA project was formulated in response to the first call for climate-relevant projects under the EU 7 R&D Framework Programme (FP7). The philosophy of the project was based on the need to accurately assess the vulnerability of water resources in high-elevation, mid-latitude populated mountain regions. In such regions, declining snow and ice in a warmer climate are likely to strongly affect hydrological regimes, in terms of quantity, seasonality, and also quality. As a consequence of changing water availability, both upland and populated lowland areas will be affected. Rivalries and conflicts of interest may emerge as economic sectors such as agriculture, tourism or hydropower compete for water that may no longer available in sufficient quantities or at the right time of the year for these sectors to function. The challenge for the ACQWA project was thus to estimate as accurately as possible future changes in order to prepare the way for appropriate adaptation strategies and improved water governance. The project has enabled a suite of state-of-the art models to be applied, adapted, or developed to address many of the issues related to a changing physical world and to the socio-economic impacts that these changes will inevitable generate. Model results have also been used to assess how robust current water governance strategies are and what adaptations may be needed to alleviate the most negative impacts of climate change on water resources and water use. The ACQWA project has been coordinated by the University of Geneva since its inception in October 2008, and indeed is one of the largest climate-related projects coordinated by Switzerland under FP7, both in terms of funding and the number of partner institutions (30 in 10 countries for a total of 37 different research, public, or private research entities). Such an endeavour was in itself both a scientific and an administrative challenge. However, the excellence of the consortium provided sufficient motivation for both the Coordination and the research teams to move forward collectively to produce novel results of use to both Science and Policy. It has thus been a great privilege for us at the Coordination in Switzerland to be involved scientifically and administratively in the ACQWA project, and to view at the end of the five-year funding period the tremendous progress in the knowledge base that observations and models have enabled. As this project comes to closure, it is our wish to see other projects of this nature begin, focusing on the weaker points identified in our project and on the numerous areas of uncertainty that are inherent to complex, interacting systems. It is also with keen interest that we shall follow the developments that may take place, via the European Commission and other national or local authorities, in terms of adaptation and water governance Martin Beniston, ACQWA Project Coordinator Markus Stoffel, ACQWA Project Director and the ACQWA Project Coordination Team
Climate Snow Hydrology EUROPEAN CASE STUDIES Biosphere
IMPACTS Energy Agriculture Aquatic ecosys.
Rhone, Switzerland Po, Italy Aragón, Spain Pyrenean catchments, France
NON EUROPEAN CASE STUDIES
Aconcagua, Chile Cuyo, Argentina Amu Darya, Syr Darya, Kyrgyzstan
POLICY, ADAPTATION, GOVERNANCE, OUTREACH
Overview of the principal modules of the ACQWA project
Objectives of the ACQWA project
Scientific scope of the ACQWA Project
To assess the vulnerability of water resources in mountain regions where snow and ice are a major component of the hydrological cycle Water in these regions will be vulnerable in a warmer climate because of reduced volumes of snow and ice To use, refine, and develop numerical models to help understand interlinks between climate system components: climate, hydrology, snow and ice, vegetation To predict the evolution of these systems over the next 50 years a mid-century time horizon is closer to targets that are useful for water managers and policy-makers compared to 2100 Understanding the upstream-downstream (in terms of water) and upland-lowland (in terms of economic development) implications of changing water resources originating in mountains as a key to successful adaptation options
Policy-relevant research within ACQWA
Climate change will likely modify seasonal and overall water availability and, as a result, there will be increased competition for water. As a consequence, the ACQWA project has a number of policy-relevant deliverables that are summarized in this document, based on the modelling work that enables an overall assessment of changes in water availability and the resulting impacts. The policy deliverables strive to: Present different policy options and analysis of their respective costs and benefits to individual sectors and to Society as a whole, in different regions. Determine how regulatory frameworks for water distribution among sectors and groups may be under pressure because of increased competition for water, and the changes in water governance that may be necessary. Compare water governance within the European Alps with that of other regions (Central Asia; Chile and Argentina), where political and economic structures are different from Europe. Assess the policy choices that can be envisaged within the legal environment in which such policies are implemented, through an analysis of the applicable law relating to integrated water resources management (e.g., the EU Water Framework Directive, the 92 UN ECE Helsinki Convention, as well as various national, provincial, and local legislations).
Policy-relevant issues within ACQWA
An assessment of the potential impacts on: Extreme events Energy Agriculture Aquatic ecosystems Mountain forests Tourism Identification of possible rivalries among economic actors, in the context of a resource that may become rarer in a warmer climate To assess how such conflicts could be resolved through improved governance Proposals for adaptation options in order to minimize the more adverse climategenerated risks
The rapidly-receding snout of the Rhone Glacier, In Central Switzerland.
The Eastern Aksu Glacier, Kyrgyzstan, one of the ACQWA project case-study regions.
This picture made the front cover of the October 2012 edition of Nature Climate Change, following the publication by A. Sorg et al. on the behaviour of glaciers in Central Asia
PART 1 SUMMARY, METHODS, MODELS, AND CASE-STUDY REGIONS
Summary of main Policy Implications
Comprehensive, sustainable, transformational adaptation
ACQWA has developed climate information for a set of mountain regions downscaled to temporal and spatial scales that are intended to be more useful to the challenges decision makers face. Climate change impacts in a number of basins dominated by snow and ice show that water managers and users will need to adapt to change in the quantity and timing of water resources. This is not only relevant to local and regional scales, but also to communities and economic sectors downstream who are reliant on a range of goods from mountain regions and their resources (e.g. electricity, water, water storage in the form of ice and snow). A certain level of uncertainty has always existed in water resources planning due to climate variability. Climate change represents an increase in uncertainty and the speed and magnitude of change. Water policy and management frameworks therefore must manage and cope with both existing and increasing levels of uncertainty from climate variability and climate change impacts. While principles in the management, conservation and adaptation of water resources and ecosystems abound, there remains a lack of clear policy guidance on practical governance mechanisms and actionable measures, especially in the context of mountain areas. Synergies or conflicts across different sectoral policies are particularly relevant in mountain areas, where fragile ecosystems provide valuable economic services such as energy for hydropower, water towers and natural storage systems of water,
tourism uses, etc. Existing tensions across sectors, governance scales and actor groups are likely to be further heightened by impacts from climate change, underlining the need for not only integrative but also adaptive water resources governance and management. In the highly sensitive and complex environments of mountain areas, known as ‘sentinel sites’ in their early responses to climate change, adaptation options tend to be limited in comparison to lowland areas. ACQWA policy work therefore focused on: identifying underlying water governance challenges in the mountain case regions: assessing adaptive capacity of these regions; identifying practicable governance mechanisms and actionable measures for the operationalization of adaptive and integrative water resources management and governance principles, specifically for the alpine context. Climate change in the mountain regions studied are leading to modifications in quantity and timing of water resources that have potentially significant ramifications for water governance and management. Water managers will need to adapt to potential increases in runoff in late winter and autumn and potential decreases in spring and late summer. Snow melt is likely to take place earlier, with increased melt in spring, but less change will be noticed at lower than higher elevations. One of the strongest effects is the significant reduction in glacier melt contribution expected by the middle of the century, and a constriction of the period where glacier melt is significant that will have repercussions for the management of hydropower reservoirs. At present, glaciers and snow pack provide a valuable buffer of additional water during dry summers. While increased glacial runoff from melting glaciers will at first lead to surface runoff surpluses, continued reductions in glacier volume will eventually result in a decrease of summer runoff. In some of the ACQWA case areas, this phenomenon is already occurring.
Climate change impacts in the ACQWA case-study regions
Swiss Rhone Catchment Summer & spring drying; wetter winters; temperature increases by 2050 (0.85‐0.93°C). Earlier snow-melt (5‐10 days); increased melt in April and May Significant reduction in glacier melt contribution expected by 2050 (70%) decrease in summer run-off (25%: Rhone; 50%: high elevation glaciered catchments). Lower frequency of debris flows; increase of event magnitude to stronger precipitation and larger sediment sources. Seasonal output is likely to be modified with decreasing flows in low-demand periods (Jul/Aug) and increasing flows in high demand periods (Apr/May). Total annual decrease in ice fed reservoirs is likely to negatively affect production. Increase in consumption due to crop evapotranspiration, potential water shortages for crop growth are likely. More pressure on small rivers with less supply from glaciers. Italian Po Catchment From 2001-2010 to 2041-2050Increase of temperature ranges between 15.2% and 17.5%, and variation of mean annual precipitation ranges from 1.-9.6% (mainly Jan-Mar). Accelerated melting periods; increase in evapotranspiration (summer) counteracts the influence of the larger amounts of summer precipitation on river discharge. Decrease of flow discharge is estimated to be more than 50% of the seasonal average for a large portion of the drainage network. Shifts in seasonality will affect the rules governing dam management to take into account increased availability of water in the earlier months of the year and a longer summer period with much less water left for the runoff. Despite the farmers’ observed investments to adapt to mean changes in climate at local level, unanticipated variability in climate continues to impact crop yields. Figure 1: ACQWA project case-study regions and associated climate impacts Base maps: © Demis World Map Server www2.demis.nl/mapserver/mapper.asp
Aconcagua Basin, Chile Warmer winters; Decreasing precipitation, changes in snowpack, changes in the timing of snow and glacier melt and generally increasing dry period. Shifts in seasonality and decreases in glacier melt are particularly significant in the Andean region due to the high dependence on glacier and snow melt run off for water availability during the dry summer months. Decreasing amounts of precipitation during summer are likely to be exacerbated by a decrease of glacial melt-water releases in the long-term due to reduced glacier volume impacting summer irrigation of water intensive crops (e.g. avocado, table grapes). Water transfers across the basin for water resources supply have already been undertaken. Reduced run-off in summer is likely to affect the management of run of the river hydropower plants.
Amu Darya, Syr Darya, Kyrgyzstan Decrease in summer precipitation (4-7%); increase in winter precipitation (4 to 8%) by 2050. Temperature increases are projected (+2.6-4.4°C) for all seasons. More extreme events: summers droughts and winter/spring floods. Loss of glacier volume eventually leading to decrease of glacier-fed summer runoff. Earlier and more intense snowmelt; decrease in snow cover duration. More importance placed on the buffering effect of glaciers to release additional water during dry summers in compensation for rain shortfalls for domestic, industrial and irrigation use. A tipping point is likely to be reached when glacier contributions diminish. Irrigation demand (cotton, wheat) accounts for 90% of water demand in the region, is vulnerable to drought and increased variability from climate change impacts. Total hydropower potential of the rivers may decrease by up to 14%
Enabling framework for adaptability to climate change in an Alpine context
Adaptation policy needs to be sensitive to the challenges of spatial (local-national) and temporal scales (short – long term; climate variability – climate change). This is particularly important in mountain regions where highland ecosystems provide goods and services to lowland areas, economic imbalances persist across highlandlowland scales, multiple sectors compete for water resources at different seasonal points, and the impacts of climate change are likely to be acute. Water governance and management will therefore need to minimize trade-offs across different sectoral requirements and not degrade resilience at other scales, avoiding lock-ins (rights, infrastructure, land-use planning, economic, water requirements, energy mixes) with expensive reversal costs. Water governance (systems and rules in place that affect the use, protection, delivery and development of water resources) and to be both adaptive and flexible in developing and setting rules that regulate hydropower, water rights allocations, urban growth and spatial planning for both current climate variability and climate change. An adaptable water management and governance regime must not only manage current baseline uncertainty levels of climate variability (e.g., stochasticity of precipitation) but also the more unpredictable forms of un(e.g. shifts in seasonality as glaciers melt) Water managers need to be able to make decisions under uncertainty, in their application of rules and the operationalization of policy for the practical aspects of water allocation and protection, as well as protection from and during extremes.
certainty arising from climate change Actionable measures that operationalize these principles are required in order to alleviate underlying tensions that are likely to be exacerbated by climate change impacts.
Infrastructure will need to be robust to flows of a larger range than prior climate conditions, but which in itself will be highly uncertain. Infrastructure design should therefore account for natural climate variability and change through stochastic approaches that examine multiple possible trajectories.
Technical adaptation should prioritize no-regret, reversible, flexible and iterative actions, that take a long term and ecosystem based approach (rather than purely grey infrastructure based) and integrate both adaptation and mitigation requirements. Multi-goal infrastructure should also be developed for redundancy, dynamism, uncertainty or enhanced benefit across the social and ecological system.
Identifying and alleviating exacerbation points
Governance and management challenges: common lessons drawn across the ACQWA basins Fit: The scale at which water is managed (user/management) can block longer term catchment scale planning and smoothing over shifts in seasonality creating critical local situations. Sectoral focus: The lack of integrative water and adaptation planning at catchment or basin levels. Policy goals may be integrative, but divisive in implementation/management. Lock-in: The legacy of technical and grey infrastructure and spatial planning (concreting of river reaches, removal of river bed, building zones in floodplains, commitment to single economic sectors, focus on specific species