Modelling SRM and global warming’s impact on water storage in the MENA region

Envisat image of a sandstorm blowing across the Persian Gulf toward Iran. Photo: ESA, CC BY-SA 3.0 IGO

Water storage is vital for people living in the Middle East and North Africa (MENA) region, as it is among the most water-stressed areas in the world. Climate change is worsening this situation, and the region is expected to have the largest economic losses from climate change-related water scarcity.  

A former DECIMALS team from Iran*, co-led by Dr Khalil Karami and Dr Abolfazl Rezaei from Iran’s Institute for Advanced Studies in Basic Sciences (IASBS), set out to analyse how terrestrial water storage in the MENA region might change in the future. The team compared an extreme scenario of accelerating greenhouse gas emissions with an SRM deployment scenario designed to counteract this high level of warming.    

The research findings suggest that SRM could potentially improve water storage in dry regions like Iran, Iraq, the Arabian Peninsula, and parts of North Africa relative to the projected impacts of climate change in the extreme warming scenario. However, SRM may still exacerbate a decline in water storage in wetter and cooler regions, particularly around the Mediterranean coasts, compared to historical levels. However, the team finds the area would still be relatively better off with the deployment of SRM to offset the warming of the high emissions scenarios modelled in this study.   

Despite the potential relative benefits of SRM, the study also highlights challenges. While SRM could help mitigate extreme changes in water storage across most of the area in the study, dry regions like Iran, Iraq, and the Arabian Peninsula might be exposed to increased flood risks due to greater terrestrial water storage when compared to a high emissions climate change scenario. The authors underline the need for careful planning and adaptation measures, such as building or modifying infrastructure like dams, to manage the risks effectively, should SRM be considered to counteract global warming.   

While the study provides valuable insights into the potential effects of SRM and climate change on water storage in the MENA region, it is important to recognise that the chosen extreme warming scenarios are unlikely to reflect future real-world conditions. The authors recommend that subsequent studies assess SRM deployment against lower emissions scenarios that account for current mitigation targets. This would generate results which would inform about a wider range of future climate pathways. 

* The Iran team was contracted and funded by the World Academy of Sciences (TWAS), a unit of UNESCO, as part of the DECIMALS fund – the precursor to the Degrees Modelling fund, managed by TWAS.

Future water storage changes over the Mediterranean, Middle East, and North Africa in response to global warming and stratospheric aerosol intervention in Earth System Dynamics by Abolfazl Rezaei, Khalil Karami, Simone Tilmes, and John C. Moore