An international group of scientists led by Josep M. Serra-Diaz, researcher at the Botanical Institute of Barcelona (IBB, CSIC-MCNB), has developed the first global early warning system capable of forecasting when and where vertebrate species will be exposed to unprecedented heat up to nine months in advance. The study, published today in Nature Climate Change , demonstrates how operational climate prediction tools can be repurposed to anticipate biological risks in near-real time, providing the kind of foresight needed as extreme heat events intensify worldwide.
Predicting extreme heat exposure
By combining NASA’s GEOS-S2S subseasonal-to-seasonal forecasting system with long-term temperature histories for more than 30,000 mammals, birds, reptiles, and amphibians, the team identified periods between May 2024 and February 2025 in which more than 3,500 species were predicted to encounter temperatures exceeding any they had previously experienced across their known ranges. More than 1,250 of these species are already considered vulnerable, endangered, or critically endangered, underscoring how climate extremes intersect with ongoing biodiversity decline.
According to Serra-Diaz, the work addresses a critical gap in conservation planning. “Extreme heat waves are occurring faster than traditional conservation cycles can respond. Our early warning system provides the months of lead time that agencies and local communities need to prepare for impacts and act before crises unfold.”
Global hotspots
The forecasts highlight several global hotspots where exposure was both intense and extensive. Mexico stood out as one of the most affected regions, particularly in the Yucatán Peninsula and the state of Tabasco, where documented heat-stroke mortality events in howler monkeys occurred during the same period. Similar patterns of predicted exposure emerged across Sub-Saharan Africa, including the Congo Basin, and throughout the Himalayan region, where high temperatures during 2024 approached or exceeded known physiological limits for many species. Observations in India, Pakistan, and Western Australia also aligned with these predictions, with reports of birds, bats, and other wildlife succumbing to heat during the months identified by the model.
Acting before the crisis
The early warning system does more than indicate where exposure is likely. It also estimates how long species may remain under thermal stress and how far in advance the risks can be detected. Many regions around the world would have received warnings between three and five months before the onset of maximum exposure, creating an actionable window for preparing monitoring programs and deploying mitigation measures such as water provisioning, shade structures, or emergency translocations.
The framework also generates a prioritization of regions where surveillance and intervention may be most urgently required, offering conservation authorities a structured approach for allocating limited resources.
Serra-Diaz notes that adopting early-warning approaches will become increasingly important as climate extremes accelerate. “Conservation has traditionally been reactive, responding after a crisis has already caused harm. With the ability to anticipate extreme heat months in advance, we can shift toward proactive protection of biodiversity.” He adds that the system represents a new generation of predictive ecological tools—ones designed to operate on timescales relevant for emergency response and rapid decision-making, rather than distant climate scenarios.
A global collaboration
The project brings together expertise from institutions across several countries, demonstrating the value of international collaboration for developing actionable tools to safeguard biodiversity under accelerating climate extremes. According to the researchers, this system represents a new generation of predictive ecological tools—designed not for distant climate scenarios, but for urgent, near-real-time decision-making in the face of imminent threats.
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Nature Climate Change
News article
Animals
A global early warning system for predicting exposure of biodiversity to extreme heat
8-Jun-2026