Global Aridity Increases Permanently Across Three-Quarters of Earth’s Landmass “`

Earth, uniquely in our solar system, possesses a surface abundant with liquid water. Approximately 71% of our planet is covered by water, sustaining life for over three billion years. However, significant portions of the Earth are experiencing unprecedented dryness, primarily due to human activity.

A United Nations Convention to Combat Desertification (UNCCD) report reveals that human-induced climate change is causing permanent aridity across 77.6% of Earth’s landmass. This ongoing desiccation, observed between 1990 and 2020, resulted in a 4.3 million sq. km expansion of drylands—an area larger than India. This dryness is irreversible, according to the UNCCD.

“Unlike temporary droughts, aridity represents a permanent shift,” stated UNCCD executive secretary Ibrahim Thiaw. “Once an area’s climate dries, it’s unlikely to revert. This widespread aridity is fundamentally altering life on Earth.”

This transformation, the UNCCD notes, is causing GDP losses, forced migration, increased mortality from dust storms, worsened wildfires, land erosion, vegetation degradation, and soil and water salinization, among other issues.

“Without urgent action, billions face hunger, displacement, and economic decline,” warned Nicole Barger, chair of the UNCCD’s science-policy interface. “However, innovative solutions and global cooperation can address this challenge. The crucial question is our collective willingness to act.”

Aridity was assessed based on rainfall, plant transpiration (water transfer to the atmosphere), and evaporation. Drylands are defined as areas where potential evaporation and transpiration exceed average precipitation by 45%. These drylands now comprise 40.6% of Earth’s land (excluding Antarctica), with an additional 3% of humid areas projected to become arid by 2100.

Europe is severely affected, with 95.9% experiencing drying. Other hard-hit regions include Brazil, parts of the western U.S., the Mediterranean, central Africa, and eastern Asia. While water is conserved, not created or destroyed, the global trend is significantly towards drying, with only 22.4% experiencing increased wetness (particularly the central U.S., Angola’s Atlantic coast, and Southeast Asia). This drying comes at a substantial cost.

By 2100, up to 20% of Earth’s land could undergo abrupt ecosystem changes, such as forest-to-grassland transformations, leading to extinctions and ecosystem collapse. Agriculture will also suffer. In Africa, aridity has caused a 12% GDP decrease, largely due to degraded farmland. Sub-Saharan Africa projects a 17-22% crop loss by mid-century at the current drying rate, resulting in significant losses of maize, rice, soybeans, and wheat by 2040.

Over 2.3 billion people reside in increasingly dry areas, facing health risks from environmental changes. Reduced food supplies are expected to increase childhood stunting in sub-Saharan Africa by 55%, according to UNCCD analysis. Over 620 million people (half of Africa’s population) live in drylands, with water supplies declining by 75% in Africa and the Middle East, impacting potable water and sanitation.

In the U.S. desert southwest, a 57% increase in coarse dust and a 38% increase in fine dust are anticipated by 2100, potentially leading to a 220% rise in premature deaths from respiratory illnesses and a 160% increase in hospitalizations.

The permanence of this drying necessitates long-term solutions. While emission reductions will eventually help, the effects of aridification, such as grassland expansion and forest loss from wildfires, will persist for centuries. Adaptation is key. The UNCCD suggests wastewater recycling and efficient irrigation. The Great Green Wall initiative aims to replant 250 million acres of degraded land by 2030.

Other initiatives, such as China’s similar regreening efforts, combat desertification. Farmers should adopt drought-resistant crops (sorghum, okra, fava beans), crop rotation, and heat-resistant livestock (goats). Seawater desalination offers another option in arid regions like Saudi Arabia.

These are not complete solutions; comprehensive measures are necessary to address the environmental damage. “The consequences of inaction are severe,” stated UNCCD chief scientist Barron Orr. “Adaptation is no longer optional; it’s crucial.”