Arid Land Expansion from Warming—Graph : Climate Interactive

Overview for the En-ROADS graph “Arid Land Expansion from Warming.”

Big Messages:

Climate change is driving the expansion of arid lands, leading to biodiversity loss, ecological degradation, and threats to food security for people dependent on dryland ecosystems.
Strong climate policies that limit global temperature rise to 2ºC by 2100 could reduce arid land expansion by approximately 40% compared to the Baseline Scenario (3.3ºC by 2100).

Warming alters precipitation patterns and causes more water to evaporate from soil and plants, leading to more frequent and severe droughts like those shown in the “Likelihood of Prolonged Drought” map and damaging ecosystems.
Delayed response to action. Even with strong climate policies, reductions in arid land expansion will not become noticeable until the 2040s due to the time lag in how temperature responds to emissions reductions.

This graph shows the increase in arid and hyper-arid lands, areas sometimes referred to as “semi-desert” and “desert” (UNDDD). Arid and hyper-arid lands currently comprise 17% of global land and are home to 6% of the world’s population, about 500 million people. Drylands overall currently make up around 40% of the global land and support 35% of the world’s population.
Increased aridity can lead to desertification. Climate change drives aridity through reduced rainfall and higher evapotranspiration. Desertification happens when land can no longer support vegetation, influenced by both aridity and human activities like overgrazing and deforestation, which speed up land degradation.
Over 50% of the arid land expansion shown in this graph may be desertification. Our calculations, based on Zhang et al. (2024), suggest that at least 50% of expanding arid land in En-ROADS will undergo severe degradation and desertification. The rest will become drier but still support vegetation, thanks to the CO₂ fertilization effect, which may help plants grow and use water more efficiently. However, there is high uncertainty about the strength of this effect by 2100. Most of the desertification is projected to occur in northeast Brazil, Namibia, the Horn of Africa, and Central Asia (Zhang et al., 2024).

Desertification and climate variability are expected to worsen poverty, food insecurity, and disease burden in dryland regions by intensifying droughts and reducing farmable land.
In communities reliant on agriculture, women face disproportionate challenges from environmental degradation, as they often have limited access to resources, economic opportunities, and land ownership (IPCC SRCCL, 2019).