Guiding cities under increased droughts: The limits to sustainable urban futures

Climate change is likely to increase droughts. The vulnerability of cities to droughts is increasing worldwide. Policy responses from cities to droughts lack consideration of long-term climatic and socio-economic scenarios, and focus on short-term emergency actions that disregard sustainability in the connected regional and river basin systems. We aim to explore the dynamics of the water-energy-land nexus in urban systems suffering increased climate change-related droughts, and their implications for sustainability. We complement a case study with a literature review providing cross-regional insights, and detail pervasive knowledge, policy and ambition gaps in the interaction between cities and droughts. We show that water availability with low emissions, without compromising ecosystems and with low costs to society, poses a local-scale limit to sustainable urban growth, a new concept delineating the limits to growth in cities. We conclude that urban and river basin planners need to institutionalize transparency and cross-sectoral integration in multi-sector partnerships, to consider long-term land use planning together with water and energy, and to apply integrated climate services to cities. Our study reveals the importance of including land, water and energy in long-term urban planning, and to connect them with the county, region, river basin and global scales. © 2021 The Author(s)
The authors would like to express their gratitude for limited contributions, comments and discussions that helped to improve the manuscript to Muhamad Bahri, Jörg Cortekar, Mirabela Marin, Serban Octavian Davidescu, Iñaki Torres Cobián, and to two anonymous reviewers that helped to substantially improve the manuscript. Valuable feedback obtained in two conference sessions co‑lead by some of the authors (at Adaptation Futures 2018 in Cape Town, and at the 4th European Climate Change Adaptation conference, in Lisbon in 2019) is acknowledged. The authors acknowledge financial support from the project CLISWELN funded by ERA4CS. ERA4CS is an ERA-NET initiated by JPI Climate, and CLISWELN is funded by BMBF (DE), UEFISCDI (RO), BMBWF and FFG (AT), and MINECO (ES), with co-funding from the European Union (Grant 690462 ). This paper and the content included in it do not represent the opinion of the European Union, and the European Union is not responsible for any use that might be made of its content. Marta Olazabal