Climate Change Could Expand Drylands to Cover 40% of Earth's Land by Century's End

Projected Growth of Global Drylands

According to НВ — Техно: A recent study conducted by the Chinese Academy of Forestry projects that by the late 21st century, drylands will occupy between 39.31% and 40.28% of the Earth's land surface. Published in Environmental Research Letters, the forecast period spans from 2071 to 2100. This expansion represents an increase of approximately 2.37 million square kilometers-equivalent to 237 million hectares. For context, during the baseline period from 1994 to 2023, drylands covered about 38.58% of global land area, excluding Antarctica.

Impact on Ecosystems and Natural Resources

The research further details that semi-arid regions currently account for 14.72% of the land, while arid zones-predominant in Australia and China-make up 11.24%. Extremely arid areas, mainly found in Algeria, Libya, and Saudi Arabia, cover 6.27% of the Earth's surface. Drylands are defined by an aridity index where the ratio of precipitation to potential evaporation falls below 0.65.

Earlier climate models, which did not consider how plants reduce water loss under elevated CO₂ levels, anticipated drylands expanding to cover as much as 56% of land by 2100. However, updated findings suggest these estimates were too high. The most pronounced shifts and dryland expansion are expected in Australia, Brazil, and certain African regions.

The growth of dryland areas poses significant challenges to sustainable development, particularly through increased water scarcity and ecosystem degradation. The projected 2.37 million square kilometers increase is roughly equivalent to the size of Algeria or nearly one-third of the Australian continent, highlighting the scale of ecological stress that climate change could impose globally.

"The expansion of drylands carries profound implications for global ecology and economies, influencing agriculture, water availability, and ecosystem resilience." - Source: Environmental Research Letters

Regions facing the largest transformations are likely to experience heightened drought risks, threatening food security and public health. These insights underscore the urgent need for proactive climate adaptation efforts and improved natural resource management strategies worldwide. Understanding and preparing for these shifts is crucial as drylands play a vital role in supporting biodiversity and human livelihoods across diverse landscapes.