Extreme global water shortages may occur by 2100
The risk of extreme water shortages due to climate change is predicted to affect almost 74% of drought-prone regions by 2100, according to new research in Nature Communications. In the first known published estimation of its kind, the authors report that hotspots of water scarcity will likely emerge across the Mediterranean, southern Africa, and parts of North America by the 2020s and 2030s.
The risk of extreme water shortages due to climate change is predicted to affect almost three-quarters (74%) of drought-prone regions by 2100, according to research published in Nature Communications. In the first known published estimation of its kind, the authors report that hotspots of water scarcity will likely emerge across the Mediterranean, southern Africa, and parts of North America by the 2020s and 2030s.
A prolonged lack of rainfall, reduced river flow and reservoir levels, and increased water usage all contribute to extreme water scarcity events, also known as ‘Day Zero Drought’ (DZD) events. Although it is well established that climate change will affect water systems across many regions, it is currently unknown when and where severe water shortages will occur and therefore the ability to plan for water scarcity is limited.
Christian Franzke, Vecchia Ravinandrasana, and colleague assess the characteristics of global water scarcity using a probabilistic framework based on a large ensemble of climate models to attribute the timing and likelihood of DZD events due to human-induced climate change. By the end of the 21st Century, 74% of drought-prone regions, including those with major reservoirs, globally face a high risk of severe and persistent droughts under a high emissions scenario. Almost 35% of these regions may face severe water scarcity between 2020 and 2030. The authors also predict that 753 million people, including 467 million in urban areas such as the Mediterranean, could be vulnerable to extreme water scarcity under 1.5°C of warming above pre-industrial levels. Additionally, they warn that the gap between future DZD events may be shorter than the duration of the events, which will exacerbate water scarcity risks by limiting the ability of regions to recover from drought.
Although the authors do not account for the role of groundwater as a buffer during droughts, these findings stress the urgent need for integrated water management. The authors call for the development of proactive policies to address the risks of climate change and unsustainable water use.
