Uncertain water resources in a changing world

Join webinar: https://stockholmuniversity.zoom.us/j/845471560
Webinar ID: 845 471 560

Speaker: Peter Greve, Research Scholar – Water Program IIASA – International Institute for Applied Systems Analysis


Sand dune with a water pond under
Photo: Private

The sufficient availability of freshwater is vital to humans, economies, and ecosystems. However, water availability is threatened both by overexploitation of water resources and anticipated climate change. Even nations with abundant water resources may experience water shortages in the future. Sustainable water planning, therefore, requires reliable assessments of water resources availability – both within the near and far future. Anticipated changes in water availability will pose substantial risks to households, farmers, industries, and water-dependent ecosystems - challenging the secure and sufficient supply of water in the coming decades. To facilitate adequate policy-making that addresses mounting water scarcity problems, a thorough assessment of uncertainties and characteristics of projected changes in water scarcity is of great interest to decision-makers and stakeholders in the water sector. The assessment of global water model projections following feasible combinations of Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) for the first half of the 21st century shows that average water scarcity and the associated range of uncertainty are generally on the increase worldwide. Hence, long-term water resources planning and decision-making need to account for conditions of severe water scarcity in the face of uncertain projections of future water availability and aridity. It is, therefore, important to develop a decision-making framework accounting for water-policy challenges in the context of scarce water resources by explicitly taking into account the associated uncertainties in impacted regions. Also, to enable adequate water resources planning, it needs to be acknowledged that changing water scarcity is both driven by increasing water demand and anticipated climate change. Water scarcity changes are indeed more likely driven by substantial increases in water demand especially in those regions showing highest water scarcity risks. Such results are needed to design and faciltate targeted adaptation strategies in the most impacted regions.




Man with beard
Photo: Private

Peter Greve joined IIASA’s Water (WAT) program as a Research Scholar in November 2016. He contributes to the program’s activities by providing a climate-focused perspective both on the use and the development of the Community Water Model (CWatM) specifically, and the integrated assessments at IIASA in general. He received his PhD from ETH Zurich in 2015, for his work on the topic of understanding and characterizing past, present and future hydroclimatological change. He also holds a diploma in Meteorology from Christian-Albrechts-University Kiel, Germany.


His main research interest is at the interface of climate and hydrological science. During his time at ETH Zurich (Switzerland) as a Postdoctoral Researcher/PhD student, he aimed to identify and quantify historical and projected trends of water availability and aridity and their associated uncertainties by using a comprehensive collection of datasets and climate models. He is also interested in the further development and use of the popular conceptual Budyko framework in the context of hydroclimatological assessments. Peter was a contributing author for the IPCC special report on the impacts of global warming of 1.5°C and is currently involved within four different chapters (concerning drought and hydrological impacts) in WGI and WGII of the upcoming IPCC 6th Assessment Report.