A silent machine works constantly to ensure that millions of people in South America have access to water, rivers, and crops. This mechanism is called the Amazon, and it works as follows – moisture from the ocean produces rain over the forest; the water is absorbed from the soil by the trees and released back into the atmosphere as vapor; the wind then spreads this vapor across the entire continent, causing rain in various regions.

Researcher Julia Valentim Tavares explains that this is South America’s primary water infrastructure and the largest “rain machine” on the planet. A mature tree in the Amazon can release 200 to 300 liters of water into the atmosphere every day.

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“Imagine 400 billion of them working together every day. If we could visualize that moisture, we’d see giant rivers flying through the sky. That’s what we scientists call ‘flying rivers.’”

Marielos Peñaclaros, co-chair of the Scientific Panel for the Amazon – an organization that brings together more than 350 scientists dedicated to studying the biome – emphasizes that the forest is the backbone of water, nutrient, and carbon cycles at the local, regional, and global levels.

“In other words, the Amazon sustains life – not only in the Amazon region but on the planet as a whole.”

The two specialists participated in the latest edition of TEDxAmazônia, held in late August in Ecuador. TEDxAmazônia stems from a commitment to listening deeply to this region. It is the only TEDx event dedicated to a single biome. The conversations that emerge at these gatherings “cross borders, connect knowledge, and bridge the local and the global,” a text on the TEDx website reads.

Warning

In addition to emphasizing the importance of this water system, the scientists issued a warning – the devastation of the Amazon is already affecting the “rain machine,” and its breakdown would be catastrophic for the entire planet.

Activities such as mining and drug trafficking, combined with deforestation and wildfires, have directly impacted Amazonian connectivity – a key factor for the conservation of the biome, Marielos noted.

“The Amazon is a living mosaic of interconnected terrestrial and aquatic ecosystems, home to a great diversity of cultures. These communities have a deep and interdependent relationship with the ecosystems through their ways of life, management practices, and knowledge.”

The effects on the climate are already measurable, she said, with evidence that deforestation in the Brazilian Amazon results in less rainfall in regions of Brazil and Bolivia. In deforested areas, temperatures have risen, and dry seasons are becoming more intense and longer.

Julia Valentim Tavares is also measuring these effects from within the trees along the southern edge of the Amazon – a region known as “arc of deforestation” – where rainfall has already decreased and temperatures have risen over the past decade. She is investigating how long these trees can withstand droughts before their internal “ropes” are damaged.

“If the soil has water, this rope remains intact. During a dry season, the soil loses its water, and this rope becomes taut. The atmosphere pulls it upward, the soil pulls it downward, until the rope finally snaps. If this happens repeatedly in various parts of the tree, the tree literally begins to die of thirst.”

Global warming

In recent years, the region has also suffered from the effects of global warming. In 2024, the Amazon faced the worst drought in its history as a result of El Niño – a natural phenomenon involving the warming of Pacific Ocean waters that alters atmospheric circulation and has been growing in intensity.

Marielos points out that 88 percent of the Amazon basin felt the effects of this drought, which also disrupted the “rain machine.” Bogotá, the capital of Colombia, located in the Andes region, suffered from water shortages. In Quito, Ecuador – which is also outside the Amazon – water shortages led to power outages.

“The question we should all be asking is, where does the water for countless Latin American cities come from? Where does the water we use in agriculture, industry, and food production come from?” asked the co-chair of the scientific panel for the Amazon.

The drought also rendered the Amazon more vulnerable to wildfires, which reached record levels that year. Julia Valentim Tavares notes that smoke from the fires spread across the country, reaching as far as the Brazilian Southeast.

“This casts light on two key issues – first, the Amazon has never been far away. What happens in the forest does not stay in the forest. And second – millions of people depend on the Amazon, yet they still do not feel connected to it.”

The forecast that a super El Niño will occur this year has alarmed the scientists. “When these droughts occur, the forest either faces mortality due to water stress, or stops growing – plus wildfires. As a result, the Amazon ceases to function as a carbon sink and becomes a source of emissions, contributing to global warming,” she warned.

“We’re expecting it to be as strong as or stronger than in 2024, but the main difference is that last time, things happened that no one was expecting. How could a river dry up in the Amazon? Now everyone is talking about it,” Marielos noted.

In her view, a definitive solution will only be achieved through a drastic reduction in greenhouse gas emissions, which depends heavily on replacing fossil fuels with less polluting energy sources.

“We also have to invest in connectivity – restoring degraded areas, rehabilitating those that were deforested for production, and reestablishing this ecological connectivity, because the Amazon is already approaching the point of no return, and because the total loss of this connectivity would be catastrophic for the entire world.”

*The reporter attended TEDxAmazônia at the invitation of the event organizers.

More than one-third (38%) of human settlements in the Amazon were highly exposed to the effects of the 2024 El Niño, according to a study released Friday (Sep. 4) by MapBiomas – a network formed by universities, NGOs, and technology companies. Among the 5,673 inhabited areas in the region, 2,172 suffered severely from the phenomenon.

El Niño is characterized by the warming of the surface waters of the Tropical Pacific Ocean and causes changes in atmospheric circulation, leading to irregular rainfall patterns. In the Amazon, it causes drought and rising temperatures.

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In light of the weather forecast predicting that the phenomenon will be particularly strong this year – “Super El Niño” – researchers cross-referenced data on rainfall and land surface water to show how the Amazon was affected during the last occurrence of this climate event.

From September through November 2024, the water surface area in the Amazon was 1.9 million hectares below the historical average for the years 1985 through 2025. Rainfall was also lower, at 27 percent below average.

The average maximum temperature during those three months also rose significantly, reaching 2.6 °C above the historical average for the same period.

“Less rainfall and higher temperatures increase evaporative demand in the atmosphere, contributing to soil moisture loss and water stress in vegetation,” said Bruno Ferreira, a researcher at the Amazon Institute of People and the Environment (Imazon) and a member of the MapBiomas Amazon team.

Population

The study also examined the effects of the phenomenon on different types of human settlements – such as urban and rural areas, indigenous territories, quilombola communities, settlements, and other categories.

The population in these areas are said to have been severely affected by El Niño, as 93 percent of the locations surveyed – 5,273 in total – are within 5 km of areas that experienced a reduction in water surface area, the study notes.

“The drought also manifests itself in lower river levels, with consequences for transportation, access to water, fishing, and other activities that depend on river systems,” Bruno Ferreira noted.

Land cover and land use data complement the biome exposure factors, since over the 41-year historical time series of the study on this topic, 3.9 million hectares of native vegetation were lost, which is equivalent to a 14 percent reduction in the previously existing green cover.

In the study, the experts cross-referenced data on land cover and land use, water, and the atmosphere. They also used data from the statistics bureau IBGE on inhabited areas and information from the El Niño Panel of Brazil’s National Institute of Meteorology (Inmet).