By Davide Cotti, Edward Sparkes, Saskia Werners, and Michael Hagenlocher

In recent years, it has become impossible to ignore the devastating impacts of droughts, at all latitudes. Droughts have increased in intensity, frequency, and duration, stretching our capacity to deal with them effectively. It is estimated that by 2050, droughts could affect three out of four people globally. Because droughts can cause extremely severe, long-lasting, and diverse impacts to societies and ecosystems, they can pose enormous challenges to the achievement of the SDGs.

The increase of droughts alone does not explain the growth of risks and impacts associated with them. Drought risks occur because of the complex interplay between drought hazards (such as water deficits along the hydrological cycle) and the exposure and vulnerabilities of individuals, societies, and ecosystems. This makes drought risks very complex to understand and manage.

The newly launched World Drought Atlas, produced by the UN Convention to Combat Desertification (UNCCD) and the European Commission’s Joint Research Centre (JRC) in collaboration with CIMA Research Foundation, UN University (UNU), and Vrije Universiteit Amsterdam, responds to this need, providing new insights to understand and manage drought risks.

We must expand our understanding of drought risks

Droughts have always happened, but human activities are fueling climate change, which is making droughts worse and altering crucial rainfall patterns that societies and ecosystems depend on. Droughts also result from the way we manage our water resources as poor management may result in unsustainable levels of water abstractions. When these processes interact with societies’ and ecosystems’ exposure and vulnerabilities, they create risks for key sectors and systems such as ecosystems, human health, and industrial productivity.

These risks are complex. For instance, exposure to drought can be direct, but also indirect. A drought-related decrease in agricultural production in a breadbasket region can affect dependent, but distant territories. The sectors and systems affected by drought risks present their own specific set of vulnerabilities, while at the same time being highly interconnected. This interconnectedness manifests through:

• Dependencies: industrial production can be compromised because of low flows in transportation waterways;
• Feedback loops: groundwater can be further depleted in an effort to ensure agricultural production during droughts; and
• Non-linear relationships: previous drought impacts in ecosystems can slowly build up undetected before suddenly manifesting in full ecosystem shifts.

As a consequence of this complexity, the impacts of droughts often seem to take societies by surprise, resulting in reactive management practices, while in reality they build up slowly over time through the interactions of many drivers of risks.

In consideration of these factors, there is a growing recognition that drought risks and impacts are systemic in nature. In the World Drought Atlas, this concept is used to investigate drought risks and impacts for five sectors and systems: water supply; agriculture; ecosystems; navigation; and hydropower. Underpinned by a novel conceptual framework, the main drivers of risks for each sector and system and their interconnections are unpacked in new conceptual models. The analysis highlights cross-sectoral and cascading effects on food security, human health, mobility, conflicts, and land degradation, showing how these can combine to hamper the achievement of multiple SDGs.  

New approaches to solutions are urgently needed

When looking at solutions, the World Drought Atlas offers new insights on how to tackle and manage the systemic nature of drought risks. Through the use of visual aids, it shows how targeted interventions can tackle shared drivers of risks and root causes to manage multiple risks at once. This demonstrates how, just as negative impacts can cascade, so too can the positive effects of solutions.  

For example, while improved irrigation efficiency may initially be designed to reduce inefficient irrigation methods, it might lead to maladaptive consequences by encouraging shifts to more water-demanding crops. However, if implemented in combination with additional measures such as community-based water resource management and new drought-resistant cropping varieties, it can reduce pressures on water resources for other sectors and convey cross-sectoral benefits.

This is brought together in the Atlas through an adaptation pathways framework – a tool that can help decision makers navigate uncertainty in a world of increasing drought risks. The pathways demonstrate how different clusters of water resource management, land use management, and governance measures can be combined to create synergies. Pathways also support the timing of when measures should be implemented, which avoids locking in decisions until enough information is available to facilitate the best possible outcomes.

In presenting these tools and perspectives in the World Drought Atlas, we encourage and support a shift from reactive (responding to impacts) – towards proactive (acting before the onset) and prospective (reducing future systemic risks) approaches in drought risk management.

Tackling drought risks require global actions

Through this wide-ranging overview, the Atlas functions as a call to action. Its launch at the 16th session of the UNCCD Conference of the Parties (COP 16) in Riyadh, Saudi Arabia, in December 2024, supports the efforts to achieve significant international agreement on common actions to reduce drought risks globally, such as the establishment of the Global Framework on Drought Resilience.

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Davide Cotti is a Senior Research Associate and drought risk expert at UNU Institute for Environment and Human Security (UNU-EHS).

Edward Sparkes is a Research Associate and adaptation expert at UNU-EHS.

Saskia Werners is Academic Officer, Head of the Vulnerability Assessment, Risk Management and Adaptive Planning Division, and adaptation expert at UNU-EHS.

Michael Hagenlocher is Academic Officer, Deputy Head of the Vulnerability Assessment, Risk Management and Adaptive Planning Division, and systemic risk expert at UNU-EHS.