A new study published in the journal Earth's Future has found that El Niño and warming in the tropical Atlantic Ocean could serve as early-warning indicators of extreme heat events in the Amazon Basin, with some predictive signals detectable as many as seven months in advance. The finding could have significant implications for disaster preparedness across one of the world's most ecologically critical regions.

How the Research Was Conducted

The study was carried out by researchers from the Australian Research Council Centre of Excellence for the Weather of the 21st Century and Brazil's National Institute of Space Research. The team examined how major patterns of natural climate variability — particularly those in the tropical Pacific and Atlantic oceans — influence temperature and rainfall extremes across the Amazon Basin. Researchers also employed machine learning techniques to study compound extreme events, which are harder to model through conventional methods.

Key Findings on Heat Extremes

According to the study, Amazon heat extremes were more likely to occur following unusually warm conditions linked to El Niño in the tropical Pacific and warming in parts of the tropical Atlantic. The strongest long-range signal was identified during the March to May window, when extreme heat across much of the Amazon was associated with climate conditions recorded up to seven months earlier. Early-warning potential was also found for compound hot-dry events, particularly in the northern and lower central Amazon, though predictability was reportedly weaker in other sub-regions.

Why This Matters for the Amazon

Compound hot-dry events pose a serious threat to the Amazon ecosystem and the communities that depend on it. According to the researchers, such events can increase wildfire risk, damage ecosystems, and threaten human health, food security, and water supplies. Critically, they also weaken the Amazon's capacity to absorb carbon dioxide — a function central to global climate regulation. The researchers noted that hot-dry events have grown more frequent and intense in recent years, making early warning systems increasingly urgent.

Limitations and Next Steps

While the study identifies specific regions and seasons where Pacific and Atlantic climate signals could serve as predictors, the authors cautioned that further research is needed to translate these relationships into practical, operational warning systems. The use of machine learning opens new avenues for examining compound extremes, but the researchers acknowledged that predictability remains considerably weaker in certain parts of the basin. Collaborative efforts between climate scientists, governments, and local communities will be essential to convert these findings into on-the-ground preparedness tools.