El Niño Triggers Severe Fire Season Across the Amazon Rainforest
Severe drought conditions fuel uncontrolled forest fires, disrupting urban life and regional ecosystems.
1El Niño Climate Impact
The 2026 El Niño event has introduced severe drought conditions across the Amazon, priming the region for an intense fire season. Scientists note that this climate phenomenon disrupts rainfall patterns, creating a cascade effect that began in Indonesia and has now reached the central and eastern Amazonian regions of Brazil.
2Urban Air Quality Crisis
By October 12, 2026, heavy smoke from surrounding fires severely impacted Manaus, a city of over 2 million residents. Fine particulate matter reached 135 micrograms per cubic meter, forcing the closure of schools and the cancellation of sports leagues as officials declared the air quality hazardous for the entire local population.
3Human-Driven Fire Origins
While lightning causes less than 1 percent of fires in the naturally wet Brazilian Amazon, human activity remains the primary ignition source. Many fires began as controlled management efforts to clear shrubs or crops but escaped containment, spreading rapidly through the parched understory of the rainforest due to extreme drought conditions.
4Satellite Detection Challenges
NASA satellites, including MODIS and VIIRS, often struggle to detect lower-intensity fires due to dense smoke, cloud cover, and thick tree canopies. Research indicates that official FIRMS data may undercount fires by up to 40 percent in regions like Santarém, necessitating advanced mining of satellite observations to track true activity.
5Ecological Degradation Risks
Rainforest species are not adapted to fire, making these events particularly destructive to the local ecosystem. Many areas currently burning were previously scorched during the 2015 and 2023 El Niño events. This repeated exposure degrades the forest structure, leaving remaining trees more susceptible to intense burning during subsequent drought cycles.
6Predicting Future Fire Waves
Scientists anticipate the fire cascade will move northward throughout November and December 2026, affecting Roraima, northern Pará, Amapá, Venezuela, Guyana, and Suriname. The risk is expected to peak in the southern Amazon regions of Brazil and Paraguay by August and September 2027, following the established pan-tropical pattern identified by researchers.
7Collaborative Monitoring Efforts
NASA Earth Action projects are currently working with MapBiomas to improve fire tracking accuracy. By sharing candidate fire locations that fall below standard detection thresholds, these institutions aim to provide better data for regional authorities. This multi-institutional network combines university research and NGO resources to map land-use changes in real-time.
8Urgent Mitigation Requirements
With rainfall levels in Manaus dropping 95 percent below normal in August, the situation remains critical until the rainy season arrives in early 2027. Experts emphasize that avoiding all burning is essential to prevent further catastrophe. The current intensity of the El Niño necessitates immediate caution to protect the remaining forest.
Original article: NASA — El Niño Triggers Severe Fire Season Across the Amazon Rainforest