In a world where water scarcity is becoming an increasingly pressing issue, a new study published in the journal *Environmental Research Letters* (translated from English as “Letters on Environmental Research”) sheds light on the future of irrigation under climate change scenarios. Led by Andrea Citrini from the Biosphere Sciences & Engineering division at the Carnegie Institution for Science in Stanford, California, the research delves into the long-term sustainability of irrigation, a critical component of global agriculture.
The study utilizes an ensemble of simulations to project changes in unsustainable irrigation water consumption (UIWC) through each decade until 2100, under two distinct scenarios: a sustainable development pathway (SSP1-2.6) and a high-emissions pathway (SSP5-8.5). The baseline estimate of global UIWC is currently at 458 cubic kilometers per year. However, the projections reveal a stark contrast in future outcomes depending on the emissions pathway and model assumptions.
Under the low-emission scenario, global UIWC is projected to range from 458 to 546 cubic kilometers per year by 2100. In contrast, the high-emission scenario paints a more alarming picture, with estimates ranging from 456 to 638 cubic kilometers per year. These projections underscore the urgent need for climate change adaptation strategies in agriculture.
“Our findings highlight the divergent future outcomes depending on emissions pathways and model assumptions,” Citrini explains. “This underscores the critical need for robust climate change adaptation strategies in agriculture to mitigate the impacts of unsustainable irrigation water consumption.”
The study also identifies regional hotspots of irrigation pressure, particularly in South Asia and the Nile Delta, where per-area UIWC exceeds 50 millimeters per year and is projected to rise further under both scenarios. The Ganges, Sabarmati, and Indus basins are identified as areas with the highest UIWC under baseline conditions, with the SSP5-8.5 scenario projecting larger increases in these regions compared to SSP1-2.6.
The commercial impacts of these findings are significant for the energy sector, which is closely intertwined with agriculture through the water-energy nexus. As water scarcity intensifies, the energy required for water extraction, treatment, and distribution will likely increase, potentially leading to higher operational costs and reduced profitability.
Moreover, the study’s assessment of multi-model water scarcity risks in irrigated croplands provides crucial insights for guiding climate change adaptation strategies in agriculture. By understanding the potential future trajectories of UIWC, stakeholders in the energy sector can better prepare for and mitigate the impacts of water scarcity on their operations.
As the world grapples with the challenges of climate change, this research serves as a timely reminder of the urgent need for sustainable water management practices. By highlighting the divergent future outcomes under different emissions pathways, the study underscores the importance of proactive adaptation strategies in agriculture and the energy sector.
In the words of Citrini, “Our research provides a critical foundation for developing targeted adaptation strategies that can enhance the resilience of agricultural systems and the energy sector to the impacts of climate change.”