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Despite an increase in catastrophic floods and storms in some parts of the world, more than three-quarters of the Earth's landmasses have become consistently drier in recent decades, according to a stark new analysis released by UN scientists. A report published by the United Nations Convention to Combat Desertification shows that approximately 77,6% of the Earth's land area will experience drier conditions in the three decades to 2020 compared to the previous 30-year period.
In the same three decades, drylands have expanded by about 4,3 million km² – an area almost a third larger than India – and now cover 40,6% of all land on Earth, excluding Antarctica. During this period, about 7,6% of the world's land - an area larger than Canada - exceeded aridity thresholds. Most of them have shifted from wet to arid landscapes, with profound consequences for agriculture, the ecosystems and communities that depend on them.
High emission scenarios and dryland expansion
The report warns that if the world does not limit greenhouse gas emissions, an additional 3% of today's wet areas could become drylands by the end of this century. Under the high-emissions scenarios, arid lands are expected to spread over regions including the Midwestern United States, central Mexico, northern Venezuela, northeastern Brazil, southeastern Argentina, the entire Mediterranean region, the Black Sea coast, large parts of southern Africa, and South Australia.
A study called "The Global Threat of Land Desiccation: Regional and Global Aridity Trends and Future Projections» was presented at the 16th UNCCD Conference (COP16) in Riyadh, Saudi Arabia. It was the largest land-based UN conference to date and the first in the Middle East, a region that has been hit hard by the effects of drought.
"This analysis finally dispels the uncertainty that has long surrounded global drying trends," said Ibrahim Tiaw, UNCCD Executive Secretary. "For the first time, the aridity crisis has been documented with scientific clarity, revealing an existential threat affecting billions around the world."
Climate change and drylands
According to the UNCCD Science-Policy Interface, which authored the report, human-induced climate change is the main driver of this change. Emissions from electricity generation, transportation, industry, and land-use change are warming the planet and altering precipitation patterns, evaporation rates, and plant life—conditions that contribute to increased aridity.
Data from global aridity indices, which monitor long-term changes in the environment, reveal significant drying trends. The areas most affected include almost all of Europe (95,9% of its land area), parts of the western United States, Brazil, parts of Asia (especially East Asia), and Central Africa.
Meanwhile, less than a quarter of the planet's landmass (22,4%) became wetter, with some positive trends seen in the central United States, the Atlantic coast of Angola, and parts of Southeast Asia. In general, arid areas are expanding around the world, pushing ecosystems and societies into life-threatening problems.
Increasing impact on human communities
The report identified South Sudan and Tanzania as the countries with the highest percentage of land being converted to dryland, and China as the country with the largest total area being converted from non-arid to dry land. As of 2020, 2,3 billion people – more than a quarter of the world's population – live in these expanding drylands. Aridity-related land degradation, known as desertification, poses a serious threat to human well-being and ecological stability.
The future may be even bleaker without action. Under the worst emissions scenario, up to five billion people could live in drylands by the end of the century. Such a scenario would mean soil depletion, water scarcity and ecosystem destruction for large groups of humanity.
Forced migration, already seen in some of the world's driest regions, is one of the most immediate consequences. As the land becomes inhospitable and agriculture declines, families and communities often have no choice but to relocate, exacerbating social and political problems around the world.
Cascading effects of arid lands
The cascading effects of increasing aridity go far beyond agriculture and water scarcity. The report warns that one-fifth of the entire earth could undergo drastic ecosystem transformations – from forests to grasslands and other dramatic changes – leading to the extinction of many of the world's plant and animal species. Drought is also causing a host of other problems, from falling GDP (especially in Africa) to increasing forest fires and even health crises, especially for children and women.
Global drying trend
Overcoming the threat of aridity requires not only recognition of science – it requires concerted political action and comprehensive adaptation measures. The report calls for improving aridity monitoring and integrating these indicators into drought monitoring systems, promoting sustainable land use, investing in water-efficient technologies, and increasing the resilience of vulnerable communities.
Experts also stress the need for international frameworks and cooperation, stressing that human rights, social justice and good governance must guide these collective efforts.
In essence, the global drying trend is creating a new narrative: in confronting climate change, we must recognize the irreversible transformation of once-fertile lands into dry regions. Successfully adapting to this reality will determine whether we can secure a sustainable and just future in a world increasingly defined by water scarcity and ever-expanding drylands.
