Cacti are built for harsh conditions, but a new study suggests even these desert specialists may be badly exposed to climate change. Researchers modeling nearly 1,000 cactus species across the Americas found that extreme drought could sharply increase projected habitat losses beyond what conventional climate forecasts predict.
Published in Nature under the title Severe drought and warming increase the extinction risk of cacti, the research combined 648,316 occurrence records with species-distribution models covering 993 Cactaceae species. The international team included scientists from the University of Arizona, University of South Florida, the International Union for Conservation of Nature’s cactus specialist group, and institutions across Latin America, Europe, and the United States.
The central problem is how climate models define a species’ future environment. Many rely heavily on long-term averages for temperature and precipitation, which can conceal the biological damage caused by short, intense droughts. In 91% of the researchers’ comparisons, models that included severe drought were better supported than models based on average climate alone. Under scenarios allowing 100 kilometers of dispersal, the share of cactus species projected to lose suitable climatic area rose from 58–61% to 69–72% when extreme drought was included.
The most severe projections are particularly stark. Without the drought factor, 1–15% of species were expected to lose more than four-fifths of their suitable area, depending on the emissions scenario. Adding severe drought raised that range to 25–35%. If species cannot move into newly suitable territory, projected losses increase further: 84–85% of species lose suitable area in the study’s zero-dispersal scenarios. Five bioregions could lose more than a quarter of their cactus species.
That vulnerability may surprise people who think of cacti as nearly indestructible. The family occupies far more than iconic desert landscapes, ranging through ecosystems from Canada and the American Southwest to Florida and the southern reaches of South America. Earlier research has also found that cactus diversification is favored by moderate rather than extreme conditions, reinforcing the idea that drought tolerance does not mean immunity to increasingly severe climate swings.
The consequences extend beyond individual plants. More than 30% of cactus species are already considered threatened, with habitat destruction and illegal collection among the major pressures. The new projections suggest that some additional species could meet criteria associated with critically endangered status if severe drought is incorporated into assessments. The authors argue that conservation planning must account for climate extremes—not just average future conditions—when identifying refuges, protecting connected habitat, and evaluating extinction risk.
The study does not predict a single fate for every cactus, and its results vary with emissions pathways, dispersal assumptions, climate models, and other modeling choices. But its broader warning is clear: a species can appear resilient when viewed through historical averages while still being vulnerable to the increasingly intense events that those averages hide. The researchers have made their analytical code available through GitHub, offering conservation scientists a way to examine and build on the forecasts.
