Aridity extends over three-quarters of the planet. 77% of the Earth's surface has experienced drier than usual conditions in the last three decades, mainly due to rising temperatures from climate change, according to a scientific report sponsored by the UN and presented at the COP16 on desertification held in Riyadh until December 13.
The Mediterranean region, the eastern US, southern Australia, and much of southern Africa are some of the areas at greatest risk of desertification. South Sudan and Tanzania have the highest percentage of lands considered in "transition" to arid, and China has the largest total extension.
"For the first time, the aridity crisis has been clearly documented revealing an existential threat affecting billions of inhabitants," warned Ibrahim Thiaw, Secretary-General of the United Nations Convention to Combat Desertification (UNCCD).
"Droughts come and go, but when the climate becomes drier, with long periods without rain, the ability to return to previous conditions is lost," Thiaw added. "Aridity represents a permanent transformation and this analysis shows it is a global trend."
22% of the Earth's surface, wetter
The report The Global Threat of Drylands concludes that, conversely, 22% of the Earth's surface is experiencing wetter than usual conditions, with the US interior and various points in Southeast Asia as the most prominent geographical areas.
The report estimates that 2.3 billion inhabitants live in lands that are drying up and will require adaptation efforts to water scarcity in the coming decades. The report warns that with the current trend of emissions and planet warming, the threat could reach 5 billion inhabitants by the end of the century. Deforestation, erosion, and demographic pressure are other factors contributing to the "aridity crisis," which underlies climate migrations.
Aridity already affects 40% of agricultural land and is one of the main causes of soil degradation. It is estimated that 100 million hectares are degraded each year, an area equivalent to twice the land area of Spain.
"This report underscores the critical need to address aridity as one of the global challenges of our time," said Sergio Vicente-Serrano, co-author of the report and expert at the Pyrenean Institute of Ecology. "We are not just measuring change, but charting the path to resilience, with a collaborative vision that integrates adaptation and innovation to ensure a better future for all."
Improving land use, experimenting with drought-resistant crops, investing in water efficiency, building aridity-resilient communities, and developing a global cooperation framework are some of the proposals from the report that have marked the midpoint of the COP16 on desertification in Riyadh.
Restoring 1.5 billion hectares
The summit, which concludes a year also marked by the COP16 on Biodiversity in Cali and COP29 on climate change in Baku, aims to achieve a commitment among nearly 200 countries to restore 1.5 billion hectares of land by 2030 and achieve the so-called Land Degradation Neutrality.
Saudi Arabia, with 95% of its territory desertified or threatened by aridity, has set the path as the host country with the Green Middle East Initiative, aiming to plant 50 billion trees and restore 200 million hectares of degraded land. The country, which usually plays the role of the "black sheep" in climate summits, is leading the global fight against desertification and driving the G20 Global Initiative, which aims to reduce soil degradation by 50% by 2040.