The precarious state of the Amazon rainforest, as confirmed by the latest assessment of its deterioration, requires a collective global response if a dangerous tipping-point is to be avoided. The Amazon has been covered by rainforest for 55 million years, but a new study using satellite data suggests that the humid ecosystem of the vast region could be transformed into a dry and fire-prone savannah. This prospect is just decades away and would threaten the habitat of one-in-10 of Earth’s species and release much of the 120 billion tonnes of carbon – equivalent to several years of global emissions – bound up in its trees and soil. The climate crisis would be greatly accelerated.
Already beset by recurring drought and wildfires, the world’s largest tropical forest is losing the ability “to restore itself back to a stable state”. Critically, the Amazon has become less resilient as deforestation has continued and rising global temperatures have worsened drought. The evidence is strong that it is approaching a tipping point which would make mass dieback possible.
The greatest loss of stability is closer to farms, roads and urban areas and in regions that are becoming drier. Intensified deforestation, which is most pronounced in Brazil, has contributed to this, as many fires are deliberately lit to clear vegetation. The collapse of the Amazon rainforest is inevitable, if Jair Bolsonaro remains president of Brazil, academics and environmental activists warned last year amid a fresh government assault on protections for the forest. There are many who believe Bolsonaro's dismantling of environmental policies and violations of indigenous rights in the context of the Amazon amounts to ecocide.
The study does not enable a prediction of when the tipping point could be reached, but notes that by the time it is detectable, it would be too late to stop it. Once triggered, the rainforest would transform to grassland over a few decades at most, releasing huge amounts of carbon and further accelerating global heating.
Tipping points on a planetary scale are among the greatest fears of climate scientists, as they are irreversible on human timescales. Another recent study showed a significant part of the Greenland ice sheet is on the brink of such a tipping point, which would eventually lead to a sea level rise of seven metres.
In the case of the Amazon, study after study confirms its perilous condition; with one indicating one-fifth of the rainforest is now emitting more carbon than it absorbs – far from the healthy state it needs to be in to help stabilise Earth’s climate. Responding effectively to this singular threat to the planet – notwithstanding the all-consuming impact of war in Europe and the lasting effects of a global pandemic – would be a key indicator the world is on the right course in addressing the climate crisis.