For decades the Amazon has been described as the lungs of the planet. It's a catchy line and it's wrong. The forest uses almost as much oxygen through respiration and decay as it produces, so its net oxygen contribution is close to zero. What the Amazon really does is store carbon, move water, and hold together a regional climate. Those jobs are the ones now at risk.
What a tipping point means here
A tipping point is the moment a system stops recovering and starts shifting into a different state. In the Amazon, the worry is that enough tree loss will switch large areas from dense rainforest to something drier and more open, closer to savanna.
The logic runs through rainfall. Trees pull water from the soil and release it as vapour, and that moisture drifts west and south as "flying rivers" that feed rain further downwind. Cut enough trees and the recycling weakens. Less rain means more stress on the remaining trees, more fire, and more tree death. The loop feeds itself.
How close are we
In 2018 the scientists Thomas Lovejoy and Carlos Nobre argued that the system could tip once roughly 20 to 25 percent of the forest is gone, and warming makes that threshold lower. About one-fifth of the original Amazon biome has already been cleared or severely degraded, so the margin is thin. Not everyone accepts a single number. Some researchers think the change will be patchy, with the southern and eastern fringes drying out first while the wet northwest holds on much longer.
A 2022 study in Nature Climate Change looked at satellite records going back to the early 2000s and found that more than three-quarters of the forest had been losing resilience, meaning it was taking longer to bounce back after dry spells. That is a warning sign, not a verdict. Resilience can be rebuilt if the pressure eases.
Drought, fire and the human hand
The 2023 to 2024 drought pushed river levels in the Amazon basin to record lows in places and left some communities cut off. Fires in 2024 burned areas of intact forest that normally resist flames, because dry conditions and degraded edges made them flammable. Most Amazon fires are set by people, for clearing pasture or farmland, and then run out of control in dry years.
Cattle ranching drives most of the clearing in Brazil. Soy, illegal mining, and road building add to it. Brazil's annual deforestation rate dropped sharply after policy changes in 2023, which shows that enforcement works. It also shows how fast the numbers can swing back when politics change.
Why people far away should care
The Amazon holds an estimated 150 to 200 billion tonnes of carbon in its trees and soil. Releasing a large share of that would add to global warming on top of whatever fossil fuels already do. Rainfall in agricultural regions of South America depends partly on the forest, so farmers in Brazil, Argentina and Paraguay have their own reasons to keep it standing.
Indigenous territories matter a great deal. Satellite studies repeatedly find lower deforestation inside formally recognised Indigenous lands than in comparable areas outside them. Securing land rights is one of the cheapest conservation tools available.
What can still be done
Stopping new clearing is the first step and the clearest. After that comes restoring degraded land, especially along the southern edge where the risk is highest, and cutting the fire that spreads from farms into forest. Supply chains also have a role. Buyers of beef and soy can demand proof that products don't come from newly cleared land, and some are starting to, with uneven results.
Nobody knows exactly where the line sits. That uncertainty cuts both ways, and it's a poor reason to wait. If the forest tips, there's no practical way to put it back.
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