Droughts are emerging as one of the most complex and significant environmental challenges of the 21st century. While periodic drought conditions are a natural occurrence in many regions, the nature of droughts is undergoing dramatic changes globally. What were once episodic events are becoming more frequent, prolonged, and severe (see Chapter 2), posing a growing challenge to societies across the globe. These unprecedented challenges exacerbate existing risks, particularly in arid and semi-arid regions that are already grappling with chronic water scarcity.
Recent scientific evidence underscores the alarming acceleration in drought trends. According to the Intergovernmental Panel on Climate Change (IPCC), global warming of 1.1°C above pre-industrial levels has already intensified hydrological extremes such as droughts (IPCC, 2023[1]). The global land area affected by dry conditions has more than doubled since 1900, and many regions have experienced more frequent extreme drought events in recent decades (see Chapter 2). Yet, unlike rapid-onset disasters such as storms or floods, droughts unfold gradually, silently eroding resilience and often catching communities, ecosystems, and economies unprepared.
The worsening of drought conditions is intrinsically linked to climate change. Rising global temperatures accelerate evaporation rates, reducing soil moisture and depleting freshwater resources, while shifting atmospheric circulation patterns are leading to irregular precipitation (IPCC, 2023[1]). As a result, some regions are now faced with increasingly prolonged dry spells while others experience extreme rainfall and flooding. Recent studies show that climate change made the ongoing megadrought1 in North America 42% more intense and the 2022 drought in Western Europe up to six times more likely (Williams, Cook and Smerdon, 2022[2]; Schumacher et al., 2022[3]). In addition to these climatic factors, other drivers such as land-use changes, urbanisation, and unsustainable water use further exacerbate these challenges (see Chapter 2).
Drought impacts are cross-sectoral and ripple across boundaries, affecting the livelihoods and well-being of millions of people. The largest economic costs of droughts occur in the agricultural sector. In particularly dry years, crop volumes may drop by more than 20% compared to normal conditions (see Chapter 3). Even moderate drought episodes can substantially affect the income of agricultural areas. Yet, the economic impacts of drought extend much beyond the agricultural sector to affect energy production, industrial operations, and essential municipal services. For instance, extreme droughts in central Europe have recently reduced fluvial trade volumes by up to 40%, while hydroelectric production might suffer reductions of more than 25% during severe droughts (Rossi et al., 2023[4]; Tikoudis, Gabriel and Oueslati, 2025[5]).
The economic costs of droughts are projected to increase. Globally, economic losses and damages due to droughts are increasing with an annual rate of 3-7.5% (see Chapter 3). This implies that, with the most conservative estimates, a drought episode in 2025 could be at least twice as costly than it was in 2000, and that an episode in 2035 will be at least 35% more costly than it is today. The social impacts of drought are equally profound and disproportionately affect disadvantaged communities. Low-income populations and agricultural workers in water-scarce regions often lack the resources to adapt to prolonged dry spells and water shortages. In some cases, prolonged drought conditions may force families to migrate in search of water and livelihoods, destabilising entire communities and fuelling social unrest, political instability, and cross-border tensions over dwindling resources (see Chapter 3).
Beyond its socio-economic dimensions, droughts also have major ecological impacts. Since 1980, 37% of global land has experienced significant soil moisture loss, while declining river flows and groundwater levels have been reported in many regions (see Chapter 2). These shifts in water availability exacerbate soil degradation, affect vegetation productivity, and disrupt critical ecosystem services, such as water purification, creating feedback loops that may intensify future drought risks (see Chapter 3).
The impacts of droughts are not evenly distributed. Vulnerable regions such as sub-Saharan Africa, South Asia, and parts of Latin America bear a disproportionate burden, as they often lack the resources and infrastructure to cope with increasingly extreme drought events. Highly industrialised nations are also increasingly affected by growing drought risk. For instance, recent extreme droughts in Europe, North America, and Australia have severely strained water supplies, disrupted food systems, and inflicted billions of dollars in economic losses (see Chapter 3).
As the global climate continues to warm, the frequency and intensity2 of drought are expected to further escalate, intensifying impacts and costs across most regions of the world. Rising temperatures, shifting precipitation patterns, reduced snowpack, and more frequent extreme weather events will exacerbate drought conditions. Projections suggest that, under future climate change, droughts could become up to seven times more frequent and intense compared to pre-industrial times (IPCC, 2021[6]). This growing risk threatens not only regions already vulnerable to water scarcity but also areas historically less prone to drought, amplifying the complexity and scale of future impacts.