Study projects up to 40% of Earth's land could become dry by century's end

A team headed by Yifei Cai of the Chinese Academy of Forestry modeled future changes in global drylands, defining them by an aridity index below 0.65. Their results indicate that dryland coverage could grow to between 39.31% and 40.28% of non-Antarctic land by 2071-2100, with the high-emission SSP5-8.5 scenario adding about 2.37 million km². Incorporating the physiological response of vegetation to rising atmospheric CO₂—namely reduced stomatal opening and transpiration—lowers the projected extent; without this effect, the same scenario would yield roughly 42.11% coverage.

Regional shifts are uneven, with notable drying projected for Australia, eastern Brazil and northern Africa, while parts of northern China may become wetter. Approximately 13% of the planet’s surface could experience significant aridity changes, though this does not equate to desert expansion.