Earth’s Drylands Expand, Threatening Billions By 2100

With rising global temperatures, huge parts of the world are drying out, putting ecosystems and human communities at risk. A 2024 UN report found that during the last 30 years, over three-fourths of the Earth's land surface has dried out considerably compared to the last 30 years. Drylands now cover 40.6% of the land area of the Earth (not including Antarctica), and the population in these dry areas has doubled to 2.3 billion. Under a worst-case climate scenario, the population could grow to 5 billion by 2100.

Areas undergoing extensive drying are the western United States, Brazil, much of Europe, Asia, and central Africa. If greenhouse gas emissions remain at existing levels, yet another 3% of the globe's wet areas could convert to dryland by the close of the present century. U.S. Midwestern, central Mexican, Venezuelan, Brazilian, Argentinean, Mediterranean, Black Sea, and southern African coastal regions as well as southern Australian regions are found to face intensifying drylands. More important, none are projected to be converted from drylands into even wetter places in the foreseeable future.

Desertification, a condition under which formerly productive land becomes dry and desolate as a result of land degradation and climate change, is increasing. Unlike droughts, desertification can often be permanent. Already, 25–35% of the drylands are undergoing some form of desertification. Climate change is accelerating the crisis by escalating the occurrence and intensity of droughts. Since 2000, the incidents of drought have increased by 29%, and by 2050, three-quarters of global citizens may be impacted. Without moisture, vegetation withers away, as do soil microbes needed to ensure a balanced ecosystem. Overgrazing, excessive tillage, deforestation, and uncontrolled irrigation lower the land further, causing desertification to become irreversible.

The effects of desertification are devastating. Desertification causes erosion, reduced farm produce, and hunger. Agricultural production can decline by 50% by 2050 if land degradation is left unabated. Drying up of aquifers due to over-extraction exacerbates water scarcity, while loss of biodiversity jeopardizes ecosystems and local livelihoods. Desertification also fuels dust storms, which can lead to respiratory problems and cardiovascular diseases. In certain areas, dust storms account for 15–50% of total cardiopulmonary mortality. Wildfires increase as parched vegetation is used as fuel for fires. Furthermore, desertification compels large-scale migration as individuals abandon barren lands in pursuit of improved living standards, leading to social and political unrest in areas already facing resource shortages.

In spite of the bleak picture, there have been some encouraging attempts at curbing desertification. In China, the Loess Plateau, which was once a rich agricultural region, was severely degraded. With a mix of government initiatives and public participation, extensive ecological restoration work was initiated. Methods like terracing hillsides, re-vegetation with grasses and trees, and building check dams successfully undone desertification, enhanced water retention, and boosted farm productivity. The area has since become a huge carbon sink, mitigating climate change. Still, others claim that introducing non-native trees will have unforeseen effects like excessive water use.

Africa's Great Green Wall project, initiated in 2007, seeks to fight desertification by rehabilitating 100 million hectares of degraded land in the Sahel region. Although some progress has been made, with 30 million hectares rehabilitated, the project has not been without challenges, such as shortages of funds and challenges in choosing the most appropriate tree species. Initial attempts involved planting large quantities of trees, but most did not survive after irrigation stopped. Consequently, the project changed its strategy to focus on local community participation and multiple land restoration approaches instead of extensive tree plantations. In 2021, international leaders committed $14 billion to fast-track the completion of the project by 2030.

Other efforts have been applied in other places. In Bolivia, land degradation occurred on the Altiplano plateau because of overgrazing and management issues. Locally initiated projects, such as rotational grazing, check dams, and indigenous grass planting, effectively rejuvenated the region's productivity as well as the livelihoods of local people through sustainable agriculture and tourism. Urban centers, such as Dakar, Senegal, are utilizing nature-based measures to avert desertification through the promotion of urban forest planting. The Trees in Dry Cities Coalition and similar projects promote the planting of miniforests—high-density plantings of indigenous vegetation—to enhance soil health, moderate temperatures, and boost biodiversity.

Stopping desertification involves a multi-pronged strategy. Nature-based solutions like growing native tree species that are well-suited to arid environments can restore ecosystems without excessive water use. Efficient water use strategies like rainwater harvesting, drip irrigation, and eliminating alien invasive species are vital for conserving water. Regenerative agriculture, focusing on no-till cultivation, crop rotation, and organic manure, can improve soil health and avoid further land deterioration.

Indigenous knowledge is also important in fighting desertification. People in arid areas have traditionally used methods such as rock dams and half-moon depressions to reduce water runoff and improve the soil. In Burkina Faso, farmers use "zai pits"—pre-plant holes that focus water and nutrients—rehabilitating degraded land. By integrating contemporary scientific progress with traditional knowledge, more efficient land management practices can be created.

Global cooperation is critical in combating desertification. Governments, NGOs, investors, and local communities need to cooperate in enacting policies to ensure sustainable land use. Organizations such as the UN Convention to Combat Desertification, the UNEP Generation Restoration initiative, and the International Union for Conservation of Nature are working around the clock to restore ecosystems and counter land degradation. There is still need for increased efforts to achieve long-term success.

As the world warms, desertification threatens food security, water resources, and biodiversity. Reversing it is not easy, but effective measures can restore lost land and halt further loss. With an optimal mix of science and technology, indigenous knowledge, and international collaboration, salvation can be found in maintaining the fragile ecosystems of the earth and ensuring a secure future for billions of people.