Scientists Project Drylands Will Cover 40.28% of Land by 2100 as CO2 Tempers Expansion
Updated
Updated · ScienceAlert · Sep 8
Scientists Project Drylands Will Cover 40.28% of Land by 2100 as CO2 Tempers Expansion
3 articles · Updated · ScienceAlert · Sep 8
Summary
40.28% of Earth’s land could qualify as dryland in 2071–2100 under the study’s highest emissions scenario, up from a 38.58% baseline in 1994–2023.
A CO2-modified aridity model drove the estimate, with researchers saying higher carbon dioxide partly closes plant stomata, reduces transpiration and lowers projected aridity versus conventional methods.
2.37 million square kilometers of additional drylands at the top-end projection would be added by 2100, with hyper-arid zones expanding the most and Australia facing the sharpest shifts, followed by Brazil.
The study warns that expanding drylands could intensify water scarcity, ecosystem degradation and desertification, even though its projections are below older estimates that put dryland coverage as high as 56% by 2100.
As hyper-arid zones silently grow, will surprising evolutionary shifts in plant survival redefine the boundaries of Earth's most vulnerable ecosystems?
Could the very carbon dioxide driving climate change actually be the invisible shield slowing the spread of global deserts?
Beyond the Aridity Index: Ecohydrological Insights and CO₂ Effects on Dryland Expansion, Food Security, and Restoration Policy
Overview
This report challenges the traditional view that rising global temperatures will cause drylands to expand rapidly. While old models using the Aridity Index predicted up to 6% expansion by 2100, new research shows that rising CO₂ levels trigger plant adaptations—like partial stomatal closure—that help vegetation use water more efficiently. This leads to more stable or even slightly contracting dryland areas, as shown by Ecohydrological Index models. However, these plant changes also alter local water cycles, and feedback loops—such as increased moisture transport into dry regions—can offset much of the expected water loss. The report also highlights how CO₂-driven greening, invasive species, and land restoration efforts interact with climate stress, water scarcity, and food security, emphasizing the need for smarter technologies and community-led solutions.