National and international water policy must adapt to ongoing, accelerated changes in the global water cycle and respond to them quickly and comprehensively. This is the key message of the WBGU report 'Water in a heated world', which the German Advisory Council on Global Change (WBGU) today presented to Federal Environment Minister Steffi Lemke and the Parliamentary State Secretary in the Federal Ministry of Education and Research, Mario Brandenburg.
Water emergencies are becoming more frequent worldwide
The effects of climate change, the overexploitation of water resources, the unequal distribution of water, the loss of ecosystem services, and related health risks are increasingly leading to water emergencies. Recent examples include the declaration of a water emergency in Catalonia due to water shortages in spring 2024, large-scale catastrophic flooding events such as those which occurred a few weeks ago in Eastern Europe, or the increasing pollution of water resources in many parts of Africa. "We expect such regional water emergencies to occur more and more frequently, so we can now speak of a global pattern. We see this as a threat with a global dimension," warns WBGU member Jörg Drewes. In extreme cases, situations arise that are beyond the limits of controllability. They can lead to the destabilization of political, societal and ecological systems. Climate-change mitigation, the protection of ecosystems and a climate-resilient, socially balanced water management are the most important measures for preventing water emergencies.
Place water higher on the international political agenda
"An international water-mapping initiative is needed to identify potential crises at an early stage and avert regional water emergencies with a planetary dimension," emphasizes WBGU co-chair Sabine Schlacke. The aim of this initiative would be to recognize critical developments at an early stage, exchange effective solutions and improve the transfer to policy-makers of scientific findings on dealing with water emergencies and threatening situations.
The upcoming UN Water Conferences in 2026 and 2028 offer a window of opportunity to negotiate an International Water Strategy that recognizes the protection of water resources as a common concern of humankind, and strengthens and interlinks existing processes and conventions. In addition to 'blue' water (e.g. streams, rivers, lakes, reservoirs, groundwater), 'green' water (i.e. soil moisture that enables plant growth) should also be given greater consideration in the strategy and taken into account worldwide in the implementation of climate-resilient water management. The international strategy should be incorporated into intergovernmental economic and trade relations, also to make the most of synergies between the protection of water resources and strengthening climate-neutral development and food security. Implementing the goals of the three Rio Conventions on climate, biodiversity and desertification is essential for this. Overall, the topic of water should be placed higher on the international agenda.
Establish climate-resilient water management
It is of key importance, locally and regionally, to establish a climate-resilient, socially balanced water-management system in which infrastructures and procedures can adapt to the increasing changes in the water balance. Well-functioning self-organized structures, e. g. water-user associations, should be strengthened and supported. The protection of water quality requires consistent implementation of the zero-pollution approach and an efficient circular water economy, incorporating ecosystems and the active management of green water in the form of soil moisture. "However, this will not succeed without credible long-term funding for the necessary measures from both public and private sources," says WBGU co-chair Karen Pittel.
Strengthen science for climate-resilient water management
The science system has a key role to play in dealing with exacerbated water-related challenges. Climate change is increasingly altering precipitation patterns, runoff volumes, and the scale and frequency of flooding events and extended dry periods involving extreme heatwaves. This reduces the reliability of water-availability forecasts as a basis for planning processes. More precise data on water availability and water requirements are needed to better take these changes into account. This can only be achieved by a digitalization campaign that provides real-time data as well as scenarios on expected future, long-term developments of the local water balance. Here, science is called upon to continuously collect and evaluate data, and provide planning-relevant and solution-orientated knowledge.
The WBGU: science for a sustainable future
The German Federal Government set up the German Advisory Council on Global Change (WBGU) as an independent, scientific advisory body in 1992 in the run-up to the United Nations Conference on Environment and Development (Rio Earth Summit). The WBGU's task is to analyse global environmental and development problems and to develop recommendations for action and research in the quest for solutions to these problems. Karen Pittel and Sabine Schlacke are currently the two chairs of the WBGU.
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