Climate simulations reveal that Day Zero Drought conditions are approaching rapidly worldwide, putting vast populations at risk of severe water scarcity.
A new study finds that global warming is speeding up the likelihood of multi-year droughts. These prolonged dry periods can push regions toward severe water shortages, putting pressure on drinking water supplies, agriculture, and communities around the world within the next few decades.
To investigate this risk, the team used state-of-the-art climate model simulations to estimate when local water demand will surpass the available supply from rainfall, rivers, and reservoirs. This tipping point is known as the Day Zero Drought (DZD). Recent close calls in Cape Town (South Africa) in 2018 and Chennai (India) in 2019 have already demonstrated how vulnerable cities are to running out of water.
Identifying when and where these thresholds will occur is essential for planning effective water management for both urban and rural regions. According to the study, DZD events are projected to rise rapidly in the coming years, happening far earlier than once expected.
Climate model projections reveal accelerating Day Zero Drought events
The team relied on climate simulations based on the SSP3-7.0 and SSP2-4.5 greenhouse gas scenarios. By examining prolonged rainfall shortages, declines in river flow, and growing water use, the researchers identified clear DZD hotspots across the Mediterranean, southern Africa, and sections of North America. The analysis shows that cities in these regions are especially at risk.
