El Niño intensifies Amazon rainforest fires, threatens biodiversity and carbon storage

El Niño is already in full swing and scientists say it may be the strongest on record, putting the Amazon rainforest on the brink of irreversible change. The warm phase of this natural cycle has been amplified by global warming, raising temperatures worldwide and tightening the drought that follows each El Niño. In Brazil’s vast forest, the heat and dry winds are already cracking the canopy and setting the stage for widespread fires.

The Amazon has struggled for decades. Deforestation, illegal logging and mining have weakened the forest’s resilience, making it more vulnerable when the climate swings. Dr. Bernardo Flores, a Brazilian ecologist based in Spain, warns that a severe El Niño could trigger a drought so intense that it pushes the forest past a tipping point. “When the forest dries, it becomes flammable,” Flores says. “We’ve seen past El Niños produce thousands of kilometres of burned area that were previously untouched.” In the last few El Niño events, the Amazon lost 3 % of its canopy in a single season, a figure that could rise sharply this year.

Fires in the Amazon are not just surface blazes. The dry conditions allow flames to penetrate deep into the forest, destroying the moist interior that usually keeps the ecosystem intact. The fire damage can grow exponentially as more trees die, reducing the forest’s ability to recover. Indigenous peoples and local communities have long protected the land, but organized crime syndicates are encroaching. They bring ignition sources, compete for territory, and add violence that forces people off the land. This loss of stewardship increases the risk that the forest will turn into savannah, releasing huge amounts of carbon and further warming the planet.

The stakes are global. The Amazon stores 1.6 billion tonnes of carbon, and its loss would accelerate climate change and reduce biodiversity. Scientists call for urgent action: stricter enforcement against illegal activity, support for indigenous stewardship, and climate mitigation to temper future El Niños. If the forest crosses the tipping point, the change will be irreversible, and the world will face a much hotter, drier future.