Global drylands to cover 40.28% of land by 2100, study projects

September 8, 2026 at 09:26 AM2 min

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A study led by the Chinese Academy of Forestry projects that global drylands will expand from 38.58% of land in 1994-2023 to between 39.31% and 40.28% by 2071-2100. The increase equals 2.37 million square kilometers of newly arid land, comparable to Algeria's area. The projection accounts for carbon dioxide's effect on plant water loss, which slows aridification compared to earlier estimates of 56%.

Key Facts

The study, led by the Chinese Academy of Forestry, used updated climate models and the aridity index to map current and future dryland distribution.
Drylands covered 38.58% of global land excluding Antarctica from 1994 to 2023.
By 2071–2100, drylands are projected to reach 39.31% to 40.28% of land depending on greenhouse gas emission scenarios.
The highest scenario of 40.28% corresponds to 2.37 million square kilometers of new dryland, equal to Algeria's area or about 30% of Australia.
Australia, Brazil, and parts of Africa are expected to experience the most pronounced aridification during the century.

Study Methodology

Scientists led by the Chinese Academy of Forestry mapped current global dryland distribution and projected future spread using updated climate models. The analysis applied the aridity index, calculated as a region's precipitation divided by potential water loss through evaporation and transpiration. Researchers found that elevated atmospheric carbon dioxide levels cause plants to close their pores and lose less water, slowing dryland expansion. Without accounting for this carbon dioxide effect, earlier studies estimated drylands could reach 56% of land by 2100.

Regional Projections

Australia is projected to undergo the most significant aridification over the century, followed by Brazil and certain regions of Africa. Current data show semi-arid regions dominate global drylands, while arid zones are prominent in China and Australia. Hyper-arid areas are concentrated in countries such as Algeria, Libya, and Saudi Arabia. Future scenarios indicate the largest increase will occur in hyper-arid areas.