A recent study conducted by the Swiss Federal Research Institute for Forest, Snow and Landscape (WSL) and the Institute of Science and Technology Austria (ISTA) reveals a significant rise in the frequency and intensity of multi-year droughts over the past four decades. The research indicates that the area affected by droughts has expanded by approximately 50,000 square kilometers annually, surpassing the size of Switzerland.
Dirk Karger, the lead researcher from WSL, states, "Multi-year droughts cause substantial economic damage, particularly in agriculture and energy production." The study also highlights increasing societal and ecological impacts, including water scarcity, crop failures, tree mortality, and heightened wildfire risks.
The research team developed a drought index by analyzing precipitation and evaporation deviations over the last 40 years, supplemented by satellite observations of plant growth changes. Findings were published in the journal Science.
The experts attribute these trends to climate change, which has led to rising temperatures and alterations in the water cycle. This results in extreme weather patterns, including prolonged dry spells and intense rainfall, as well as increased evaporation from soil. Consequently, droughts are developing rapidly and lasting longer.
Examples cited include the ongoing drought in parts of Chile for the past 15 years, the drought in the western United States (2008-2014), Australia (2017-2019), and Mongolia (2000-2011), along with less documented drought occurrences in the Congo rainforest (2010-2018).
Co-author Philipp Brun from WSL warns, "The severity of multi-year droughts will intensify with climate change." Prolonged droughts not only exacerbate existing issues but may also lead to irreversible consequences for both nature and humanity. The long-term effects remain largely unknown.
Severe water shortages could result in tree die-offs in tropical and boreal regions, causing enduring damage to these ecosystems. Karger notes that boreal vegetation is likely to take the longest to recover from such climate disasters.
The researchers stress the necessity for a better understanding of these drought events to enable countries to prepare more effectively for future droughts, particularly focusing on prolonged dry periods and developing strategies for damage control that extend beyond a single season or year.
The impacts of climate change are rendering larger portions of the Earth uninhabitable for humans, often resulting in migration to other regions. While individuals in wealthier nations may relocate within their country, those in poorer regions frequently seek refuge beyond national borders to escape poverty-related threats. The number of climate refugees is projected to rise significantly, with estimates suggesting over 140 million climate refugees by 2050, according to the Global Hunger Alliance. There are increasing calls to recognize climate displacement as a valid ground for asylum.