Fanned by El Niño, megafires in Brazil threaten Amazon’s preserved areas

Record-breaking fires have flared up across the Amazonian state of Roraima, in northern Brazil, amid one of the worst droughts in 25 years. The number of hotspots in the state this past February alone hit an all-time high of 2,057, according to the Queimadas program run by INPE, Brazil’s space agency. Roraima is one of the smallest of the nine states that make up the Brazilian Amazon, but has already recorded more than half of the Amazon’s fires in the first two months of 2024.

Fires at this time of the year aren’t unexpected in Roraima, Brazil’s northernmost state, whose location north of the equator gives it an inverted climate compared to other Amazonian states. The dry season here peaks in the first three months of the year. But with the current drought intensified and prolonged by El Niño, the abnormal warming of the surface waters of the equatorial Pacific Ocean, there’s been less rain than usual over the Amazon Rainforest. This climate pattern, still active and strong, contributed to historic droughts and calamitous fires in the Brazilian Amazon last year.

In Roraima, El Niño abruptly stopped the 2023 rains, anticipating the onset of the dry season and intensifying its effects. Experts say this natural phenomenon favored the fire boom currently underway. “We are facing a series of megafires,” Haron Xaud, a researcher at Embrapa, Brazil’s agricultural research agency,and a professor of natural resources at the Federal University of Roraima (UFRR), told Mongabay by phone. “The situation is delicate because forecasts indicate another 30 days until the start of the rainy season in Roraima.”

According to IBAMA, the federal environmental agency, 23% of the outbreaks recorded in Roraima are in Indigenous areas, affecting at least 13 territories. Several communities reported houses and crops burned down and animals killed. The worst situation is in the Yanomami and Raposa Serra do Sol Indigenous lands, which have the highest number of fires inside protected areas.

News outlet Amazônia Real released a video showing the devastating advance of a fire on a community in the São Marcos Indigenous Territory, in the municipality of Paracaima, in February. Fires also devastated Indigenous communities in Cantá and Amajari municipalities, according to news outlet G1. Some 50,000 Indigenous people now face a water shortage, according to the Instituto Socioambiental (ISA), a nonprofit that advocates for environmental and Indigenous rights.

In recent weeks, Boa Vista, the capital of Roraima, has been smothered in a suffocating layer of smoke, with air quality hitting alarming levels. The drought has also seen water levels in the Branco River, which passes through the capital, fall to critically low levels, affecting the water supply. In inland areas of the state, farmers and ranchers have reported “incalculable” damage to crops because of the lack of water.

According to the Roraima civil defense office, 11 of the state’s 15 municipalities declared a state of emergency because of the drought and fires. Brazil’s Ministry of the Environment and Climate Change has declared a state of environmental emergency in Roraima until April 2025 and reinforced firefighting strategies.

Human factor

While climatic conditions have allowed the fires to spread, there’s also a human hand behind them. According to IBAMA, 60% of the fires recorded in Roraima in 2024 were started on private lands, almost all located in savanna areas, which account for 17% of the state’s total area. Many fires grow out of control, intentionally or otherwise, and tear their way through this type of vegetation, usually at the beginning of the dry season, boosted by the local “fire culture.”

“Burning in rural areas to clear land for crops and pasture is allowed with a permit, but this large number of fires indicates criminal actions by people who did not seek authorization,” Mário Terra Leite, an official with the state fire department, told Mongabay by phone. “With the severe drought, the situation has become uncontrollable.”

The prolonging of the drought by El Niño has prompted concerns about preserved areas of the Amazon Rainforest, which are becoming increasingly dry. “The fires are still concentrated in rural properties, but the prolonged drought makes dense rainforest areas less humid and more vulnerable. There are great concerns about conservation units,” Terra said.

Xaud said the vegetation in Roraima is becoming less resilient to fire, a warning echoed by other scientists. According to Xaud, who has been active in implementing strategies to prevent and combat fires in Roraima, repeated droughts and fires associated with the effects of climate change are making the rainforest vulnerable, especially in degraded and fragmented areas.

“Human activities are reaching more distant points, where protection agencies have less control. Previously cleared rainforest, which is very common near roads, stops working as a generator of humidity and regulator of high temperatures, losing its protective function,” he said. “Many people were waiting for these dry conditions to set fire in these areas.”

Researchers are also investigating another factor that may be fanning the fires. For the past 20 years, the Amazon Basin has seen a drastic reduction in its total water surface area. A study published in 2022 by MapBiomas, a collaborative network that produces mapping of land cover and freshwater, showed that Roraima was the worst-affected Brazilian state, having losing 53% of its water surface, mainly due to a huge increase in agricultural activity.

While Roraima faces megafires driven by drought, Acre state, at the far west of the Brazilian Amazon, is suffering historic flooding of its rivers and igarapés, the shallow streams that wind through the dense rainforest. According to the state government, more than 100,000 people have been affected by the floods in 19 of Acre’s 22 municipalities, including the state capital, Rio Branco. In the municipality of Brasiléia, 80% of the territory is underwater, an all-time high.

Banner image: Fires in municipalities such as Amajari, in the state of Roraima, are troubling firefighters and authorities. Image courtesy of Jader Souza / Roraima State Legislative Assembly.

With half its surface water area lost, an Amazonian state runs dry

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