Tanzania, South Sudan drying up faster than other countries
New report reveals that more than three-quarters of Earth’s land has become permanently drier in recent decades
What you need to know:
- Unlike droughts—temporary periods of low rainfall—aridity represents a permanent, unrelenting transformation.
- Droughts end. When an area’s climate becomes drier, however, the ability to return to previous conditions is lost.
In Riyadh, Saudi Arabia
Scientists say South Sudan and Tanzania are drying up faster than any other country in the world and have the largest percentage of land transitioning to drylands. On the other hand, China is experiencing the largest total area shifting from non-drylands into drylands.
The global aridity index (AI) data tracked aridity conditions, with figures revealing widespread change over the decades.
According to Narcisa Pricope, co-lead author of the report for Tanzania and South Sudan, the aridity situation will redefine the way of living in these two African countries.
"This will force them to now reimagine their relationship with land and water as arable land affected by aridity is the leading driver of agricultural degradation, which means more hunger and malnutrition. The key drivers of land degradation are rising aridity, land erosion, salinisation, organic carbon loss, and vegetation degradation.”
In April this year, a similar report by the Food and Agriculture Organization(FAO) highlighted that a total of 340 million hectares of woody vegetation in dryland zones of Africa have become degraded through human activities like overgrazing, agricultural expansion, overexploitation, and deforestation; with the Eastern African countries adversely affected being Kenya, Burundi, Djibouti, Ethiopia, Rwanda, Somalia, Sudan, Tanzania and Uganda.
“Kenya and Ethiopia have large areas occupied by the arid and semi-arid zones while Tanzania and Uganda have largely semi-arid and dry sub-humid dry land zones. Burundi has only five per cent of its land area covered by dry sub-humid zone while about 51 per cent of Tanzania is relatively dry.
“Over two thirds of Kenya falls within arid and semi-arid zones, where 33.3 per cent, 51.8 per cent and 12.3 per cent of this land experience slight, moderate and severe hazard levels of land degradation,” the findings then showed.
But now according to a new report titledThe Global Threat of Drying Lands: Regional and global aridity trends and future projections released on Monday in Riyadh, Saudi Arabia by the UN Convention to Combat Desertification (UNCCD) as thousands of delegates ushered in the second week of the ongoing world’s biggest UN land summit, areas particularly hard-hit by the drying trend include almost all of Europe (95.9 per cent of its land), parts of the western United States, Brazil, parts of Asia (notably eastern Asia), and central Africa.
The report also reveals significant drying trends, with water scarcity and wildfires that have become perennial hazards in parts of the Western United States and Brazil.
“Mediterranean and Southern Europe, once considered agricultural breadbaskets, are now facing a stark future as semi-arid conditions expand. This is even as Central Africa and parts of Asia, which have been biologically megadiverse areas, experience ecosystem degradation and desertification, endangering countless species,” the report observes.
Drying trends
Ibrahim Thiaw, UNCCD executive secretary, noted that this analysis finally dispels an uncertainty that has long surrounded global drying trends. “For the first time, the aridity crisis has been documented with scientific clarity, revealing an existential threat affecting billions of people around the globe.
“Unlike droughts—temporary periods of low rainfall—aridity represents a permanent, unrelenting transformation,” he added.
“Droughts end. When an area’s climate becomes drier, however, the ability to return to previous conditions is lost. The drier climates now affecting vast lands across the globe will not return to how they were and this change is redefining life on Earth,”Mr Ibrahim said.
The report by UNCCD Science-Policy Interface (SPI) — the UN body for assessing the science of landa degradation and drought — points to human-caused climate change as the primary driver of this shift.
Greenhouse gas emissions from electricity generation, transport, industry and land use changes as well as other human activities warm the planet and affect rainfall, evaporation and plant life, creating the conditions that increase aridity.
According to scientists, this means that for the 2.3 billion people – well over 25 per cent of the world’s population – living in the expanding drylands, this new normal requires lasting, adaptive solutions.
It also means that even as dramatic water-related disasters such as floods and storms intensified in some parts of the world, more than three-quarters of Earth’s land became permanently drier in recent decades.
The findings further show that some 77.6 per cent of Earth’s land experienced drier conditions during the three decades leading up to 2020 compared to the previous 30-year period.
This is why scientists highlight that aridity-related land degradation, known as desertification, represents a dire threat to human well-being and ecological stability.
“As the planet continues to warm, report projections in the worst-case scenario suggest up to five billion people could live in drylands by the century’s end, grappling with depleted soils, dwindling water resources, and the diminishment or collapse of once-thriving ecosystems.
“Forced migration is one of aridity’s most visible consequences as land becomes uninhabitable. Families and entire communities facing water scarcity and agricultural collapse often have no choice but to abandon their homes, leading to social and political challenges worldwide,” they warned.
From the Middle East to Africa and South Asia, millions of people are already on the move—a trend set to intensify in coming decades, scientists say.
“Over the same period, drylands expanded by about 4.3 million km2 – an area nearly a third larger than India, the world’s seventh largest country – and now cover 40.6 per cent of all land on Earth (excluding Antarctica),” the stark analysis highlighted, adding that in recent decades, some 7.6 per cent of global lands – an area larger than Canada – were pushed across aridity thresholds ( from non-drylands to drylands, or from less arid dryland classes to more arid classes).
Most of these areas have transitioned from humid landscapes to drylands, with dire implications for agriculture, ecosystems, and the people living there.
The research warns that if the world fails to curb greenhouse gas emissions, another three per cent of the world’s humid areas will become drylands by the end of this century.
UNCCD Chief Scientist Barron Orr explained that for decades, scientists have signalled that our growing greenhouse gas emissions are behind global warming.
“Now, for the first time, a UN scientific body is warning that burning fossil fuels is causing permanent drying across much of the world, too—with potentially catastrophic impacts affecting access to water that could push people and nature even closer to disastrous tipping points. As large tracts of the world’s land become more arid, the consequences of inaction grow increasingly dire and adaptation is no longer optional—it is imperative, “he said.
He noted that the report underscores the critical need to address aridity as a defining global challenge of our time.
“By uniting diverse expertise and leveraging breakthrough technologies, we are not just measuring change—we are crafting a roadmap for resilience. Tackling aridity demands a collaborative vision that integrates innovation, adaptive solutions, and a commitment to securing a sustainable future for all,”Narcisa Pricope, co-lead author, professor of geosciences and associate vice president for research at Mississippi State University, US noted while agreeing with the findings.
Andrea Toreti, co-lead author and senior scientist, European Commission’s Joint Research Centre, said the timeliness of this report cannot be overstated.
“Rising aridity will reshape the global landscape, challenging traditional ways of life and forcing societies to reimagine their relationship with land and water. As with climate change and biodiversity loss, addressing aridity requires coordinated international action and an unwavering commitment to sustainable development.”
The report also points out that high greenhouse gas emissions scenarios, expanding drylands are forecast across the Midwestern United States, central Mexico, northern Venezuela, north-eastern Brazil, south-eastern Argentina, the entire Mediterranean Region, the Black Sea coast, large parts of southern Africa, and southern Australia.
By contrast, less than a quarter of the planet’s land (22.4 per cent) experienced wetter conditions, with areas in the central United States, Angola’s Atlantic coast, and parts of Southeast Asia showing some gains in moisture.
The overarching trend, however, is clear: drylands are expanding, pushing ecosystems and societies to suffer from aridity's life-threatening impacts.
According to the experts, the effects of rising aridity are cascading and multifaceted, touching nearly every aspect of life and society.
This is why the findings of the report warn that one fifth of all land could experience abrupt ecosystem transformations from rising aridity by the end of the century, causing dramatic shifts (such as forests becoming grasslands and other changes) and leading to extinctions among many of the world’s plants, animals and other life.
They further stress that aridity is considered the world’s largest single driver behind the degradation of agricultural systems, affecting 40 per cent of earth’s arable lands and has been blamed for a 12 per cent decline in gross domestic product recorded for African countries between 1990–2015.
Scientists are concerned that more than two thirds of all land on the planet (excluding Greenland and Antarctica) is projected to store less water by the end of the century if greenhouse gas emissions continue to rise, even modestly, keeping in mind that aridity is one of the world’s five most important causes of land degradation (along with land erosion, salinisation, organic carbon loss and vegetation degradation).
Rising aridity’s impacts on poverty, water scarcity, land degradation and insufficient food production have been linked to increasing rates of sickness and death globally —especially among children and women.
So, which is the way forward?
The new report offers a comprehensive roadmap for tackling aridity, emphasising both mitigation and adaptation strategies. It aslo provides recommendations such as strengthening aridity monitoring by urging governments to integrate aridity metrics into existing drought monitoring systems.
This approach, the report explains, would enable early detection of changes and help guide interventions before conditions worsen.
Platforms like the new Aridity Visual Information Tool provide policymakers and researchers with valuable data, allowing for early warnings and timely interventions. Standardised assessments can enhance global cooperation and inform local adaptation strategies, experts cite.
They further recommend improved land use practices, investment in water efficiency, building resilience in vulnerable communities as well as developing international frameworks and co-operation.
“The UNCCD’s Land Degradation Neutrality framework provides a model for aligning national policies with international goals, ensuring a unified response to the crisis. The National Adaptation Plans must incorporate aridity alongside drought planning to create cohesive strategies that address water and land management challenges,” the report advises, adding that cross-sectoral collaboration at the global level, facilitated by frameworks like the UNCCD, is essential for scaling solutions.
