In the past, climate modelling has indicated an approaching Amazon tipping point when global climate change, combined with increasing deforestation, could result in a rapid Amazon shift from rainforest to degraded savanna and shrubland, releasing massive amounts of carbon to the atmosphere when the world can least afford it.

Now, scientists Carlos Nobre and Thomas Lovejoy report that researchers are seeing evidence in both the atmosphere and on the ground that this tipping point has been reached and will worsen if no action is taken immediately to reverse the situation.

They reference a NASA satellite study revealing an increasingly dry Amazon over time, which space agency scientists say is one of “the first indications of positive climate feedback mechanisms.” A 2018 study found that Amazon tree species adapted to wet climates were dying at record rates while dry-adapted trees thrived.

It is urgent, the scientists say, that Brazil move away from unsustainable agribusiness monocultures of cattle, soy, and sugarcane, while launching a major reforestation project on already degraded lands in the southern and eastern Amazon, actions that could help Brazil keep its Paris Climate Agreement commitment.

The Amazon Tipping Point is here, say leading climate scientist Carlos Nobre and renowned conservation biologist Thomas Lovejoy in a new science policy editorial published today, December 20. The tipping point’s arrival could mean a rapid rainforest die-off — releasing massive amounts of carbon to the atmosphere at a time when the world most needs carbon reductions.

For more than a half century, write the researchers, scientists have known that the Amazon creates its own hydrological cycle: rainforest trees regulate the region’s evaporation, transpiration and rainfall. However, the more tree cover loss there is, the more droughts are intensified. And when the rainforest no longer receives enough rain to sustain itself, trees begin to die back into a form of degraded savanna or shrubland.

It’s the Amazon on self-destruct mode, and an event whose arrival has been quickened not only by rising deforestation rates over recent years, but by global climate change as well.

Researchers Nobre and Lovejoy have been alerting the scientific community about the Amazon tipping point for years, but now they’ve upgraded that warning: “Current deforestation is substantial and frightening: 17% across the entire Amazon basin and approaching 20% in the Brazilian Amazon,” they wrote in Science Advances. “We are scientists who have been studying the Amazon and all its wondrous assets for many decades. Today, we stand exactly in a moment of destiny: The tipping point is here, it is now.”

Ambitious reforestation, raising the quality of life in Amazonian cities, and developing a bioeconomy based on a standing forest, they say, hold the key to barring these permanent changes. That and moving away from unsustainable agribusiness monocultures of cattle, soybeans, and sugarcane.

In the past, Amazon tipping point predictions were based on mathematical climate models. But the real-life manifestations of the shifting Amazon biome are beginning to show. Recent scientific research has detected signs of the tipping point happening on the ground and in the atmosphere.

“What we predicted is now being observed in real life. It’s no longer a theoretical forecast about the future.” Carlos Nobre, one of Brazil’s top climate scientists and a researcher at the University of São Paulo, told Mongabay.

In October, NASA Scientists led by Armineh Barhordarian recorded an increasingly dry Amazon via satellite, calling it one of “the first indications of positive climate feedback mechanisms.”

Another study from 2018 combined the findings of 103 scientists, revealing that tree species adapted to wet climates were dying at record rates while dry-adapted trees thrived. “A slow shift to a more dry-affiliated Amazonia is underway,” the report stated. Fire-resistant trees with thicker bark were among the more successful species seen under current conditions, as compared to an intact Amazon in the past where trees were resistant to the spread of flames because of the region’s natural high humidity. “The forest’s vulnerability to fire is increasing. Undisturbed, it is almost impenetrable,” says Nobre.

“The periodic droughts. The longer dry season. Higher temperatures in the dry season — it’s all unprecedented,” says Lovejoy, an ecologist who has studied the Amazon since 1965 and who coined the term biodiversity, “Once there is more dry area, you get more fire, and it begins to be cumulative. Now is the time to do something, not later.”

A year ago, the pair published an update on their 2007 study, halving their previously predicted 40% deforestation estimate at which the Amazon Tipping Point would occur, reducing that to 20-25% deforestation.

The consequences of the rainforest-to-degraded-savanna shift, Lovejoy and Nobre told Mongabay, are grave: a sudden crash in biodiversity, the release of huge amounts of carbon into the atmosphere due to tree death (making the Paris Agreement goal of limiting warming to 1.5 degrees impossible), and a drastic regional upset in the natural water cycle — likely heavily impacting Brazilian aquifers, agribusiness, and the water supply of major urban areas.

Biomes have changed in the past, says Lovejoy, but changes historically happen on a lengthier timescale, occurring over hundreds of thousands, to millions of years. Species, therefore, have time to adapt as the climatic paradigm shifts. But under this tipping point scenario, if nothing is done, the shift is likely to occur over a few decades — it will be like the snap of a finger in geological time, he concludes.

As Brazilian President Jair Bolsonaro launches repeated assaults on environmental protections, hopes for the future of the Amazon are on the line. Experts now agree that Brazil is unlikely to achieve its Paris Agreement goals under this administration.

“Bolsonaro isn’t giving this any attention and is completely aligned with climate change deniers,“ says Monica deBolle, an economist at the Peterson Institute for International Economics.

According to the Climate Observatory, “the worst is yet to come” under Brazil’s current president. The NGO points to the country’s deforestation rate between 2018-19, the highest in a decade — totaling 9,762 square kilometers (3,769 square miles), with a 65% deforestation increase seen within indigenous territories.

Nobre and Lovejoy offer solutions: “The good news is we can build back a margin of safety through immediate, active, and ambitious reforestation particularly in the deforested regions that are largely abandoned cattle ranches and croplands, about 23% of destroyed forest territory.” They add that, “The only sensible way forward is to launch a major reforestation project especially in the southern and eastern Amazon, actions that could be part of Brazil’s implementing its commitments under the Paris Agreement.”

Other scientists too are calling urgently for a reversal in government policy. “We really have to ramp down [forest] clearing, start fighting fires and ramp up recovery,” says Daniel Nepstad, president of the Earth Innovation Institute. “We have everything we need to know to act now, urgently, to prevent a large-scale fire and drought driven dieback.” With fires now often going undetected beneath the Amazon tree canopy, monitoring and detection systems for Amazon fires need to improve immediately, he says.

Nepstad does worry that the tipping point forecast may send “the wrong message,” causing people to believe there is no turning back. “I don’t think there’s a point beyond which the whole Amazon collapses,” he told Mongabay. “It is all a question of how frequent and intense those really severe droughts are. And when [fires] hit, are there sources of ignition” that can be quickly located and combatted. He stressed the importance of effective firefighting in the Amazon. Under Bolsonaro and previous president Michel Temer, funding to IBAMA, Brazil’s environmental agency charged with fighting forest fires, was drastically reduced.

Having declared arrival at the tipping point, both Nobre and Lovejoy note that the future is not carved in stone: “The peoples and leaders of the Amazon countries together have the power, the science, and the tools to avoid a continental-scale, indeed, a global environmental disaster. Together, we need the will and imagination to tip the direction of change in favor of a sustainable Amazon,” they wrote.

Does the world have time enough to successfully respond? No one knows how rapidly things can change when a critical point is tipped, says Lovejoy: “Will it be a long slide, or will the kinds of changes that are already being seen start happening with greater magnitude?” he asks. “Let’s not find out by tipping it.”

Banner image caption: The Brazilian Amazon on fire in August 2019 in Candeiras do Jamari municipality, Rondônia state. Image by Victor Moriyama / Greenpeace.

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