1185. Increasing Frequency and Impacts of Multiyear Droughts

Multiyear droughts (MYDs) are becoming more frequent due to climate change, and the threat to nature and humans is increasing. A paper published in the journal Science identified global MYDs through a time-series and spatially continuous examination of extreme weather events, and showed that MYDs are becoming drier, warmer, and less vegetated. From 1980 to 2018, the area affected by MYDs increased at a rate of 49,279±14,771 square kilometers per year.

MYDs can lead to extreme soil moisture depletion and reduced river flows, resulting in irreversible consequences for both ecosystems and human society. The impacts of MYDs include large-scale crop failures, increased tree die-off, reduced ecosystem productivity, and reduced water supply. This highlights the need for a better understanding of MYDs, including the interaction of climate anomalies and their subsequent impacts on ecosystems.

Quantitative inventories of the occurrence, severity, trends, and impacts of MYDs provide an important benchmark to promote more effective and collaborative preparedness for mitigation and adaptation to extreme events.

Reference
Liangzhi Chen, Global increase in the occurrence and impact of multiyear droughts, Science (2025). DOI: 10.1126/science.ado4245. www.science.org/doi/10.1126/science.ado4245

Contributor: IIYAMA Miyuki, Information Program