Extreme droughts lasting several years have become increasingly frequent and severe over the past four decades, leading to significant disruptions in agriculture, energy production, and natural ecosystems. These prolonged dry periods have covered larger areas each year, as highlighted by recent meteorological assessments. The findings underscore the rising threats posed by climate change, with regions like northern Chile enduring a 14-year drought and southern Australia and parts of the United States also experiencing extensive dry spells. This intensification of droughts presents a growing challenge for environmental and economic sustainability worldwide.

Drought Trends and Contributing Factors

According to a study published in Science by the Swiss Federal Institute for Forest, Snow and Landscape Research, drought-affected areas have expanded by 50,000 square kilometres annually since 1979. This change is attributed to increased temperatures and shifting precipitation patterns. As reported by WSL News, Lead researcher Dirk Karger,, has emphasised that multi-year droughts inflict substantial economic losses, particularly in agriculture and power generation, as reported by WSL News. The study also analyzed vegetation changes during these events using satellite data, revealing that grasslands show quick recovery, while forests may face prolonged damage due to severe water shortages.

Ecological and Global Impacts

Observations detailed in the study suggest that tropical forests and colder-climate woodlands exhibit some resilience to short-term droughts but suffer irreversible effects under extreme conditions. Field evaluations in Chile’s Aconcagua region have revealed abandoned farmland and damaged plantations. Postdoctoral researcher Liangzhi Chen from WSL described the drought inventory, developed using high-resolution CHELSA climate data, as the most detailed compilation of drought events over the last 40 years. Philipp Brun, a co-author of the study, has pointed to rising global temperatures as a key factor exacerbating these droughts by increasing evaporation rates and altering rainfall distribution.

The research provides crucial insights for policymakers and environmental planners to prepare for and mitigate the effects of long-term droughts in vulnerable regions.