A team of scientists from Argentina, Chile, Denmark, the Netherlands, Sweden, the United Kingdom, and the United States, with the participation of Juan Rivera (CONICET Mendoza, IANIGLA), analyzed how climate change induced by human activities worsened the conditions that favored the fires that occurred in Argentinian Patagonia and central Chile in early 2026.
The work focused on two regions:
- Chile: between the coast and the Andean foothills of Ñuble, Biobío, and La Araucanía.
- Argentinian Patagonia: Los Alerces National Park, northwest of Chubut.
Meteorological Conditions
To assess the risk, the heat-dryness-wind index (HDWI) was used, which combines high temperatures, low humidity, and strong winds.
- In Chile, the maximum HDWI over 2 days was analyzed.
- In Patagonia, the maximum HDWI over 5 days.
The results showed that weather conditions conducive to fires were much more likely in the current climate than in the pre-industrial period.
Climate Influence and Reduction of Precipitation
The study identified the influence of La Niña and the Southern Annular Mode, which generated anticyclonic anomalies and favored warm and dry conditions.
- Very low precipitation was recorded from November 2025 to January 2026.
- The reduction compared to the pre-industrial period was close to 20% in Patagonia and 25% in central Chile.
- This caused soil moisture deficit and stress on vegetation, key for the development of fires.
Increased Probability Due to Climate Change
The specialists concluded that:
- In central Chile, events like the one analyzed are 3 times more likely than in the pre-industrial period.
- In Argentinian Patagonia, the increase is 2.5 times.
- Global warming due to greenhouse gas emissions increases the recurrence of extreme conditions.
Propagation Factors
The study also noted that non-native conifers, especially radiata pine plantations, which are highly flammable, contributed to the spread of the fire. The fires destroyed vast areas of native forest and grasslands, putting pressure on biodiversity.
The team emphasized the need for:
- Effective land-use planning.
- Management of forest plantations, especially in the urban-rural interface.
- Early removal of invasive pines to reduce fire hazard.
- Advancing towards longer-term risk forecasts, beyond the current 72 hours, to anticipate dangerous conditions.
Future Perspectives
Rivera warned that forecasts for February–April 2026 show higher probabilities of above-normal temperatures and below-normal precipitation, which could lead to a high risk of fires. He noted that risk monitoring should be conducted over short periods, from days to weeks, to improve prevention.
The study confirms that climate change worsened the conditions that fueled the fires in Patagonia and central Chile, increasing their probability and severity. The combination of water deficit, high temperatures, intense winds, and flammable forest species created a critical scenario that demands land management, prevention policies, and climate adaptation.
