The Amazon: 390 billion trees, several million species of insects, an incalculable number of birds, mammals and reptiles, some still unknown to humans. A treasure of biodiversity which, unfortunately, is collapsing. According a report published on September 6 by a group of Amazonian environmental organizations (RAISG) and the Coordination of Indigenous Organizations of the Amazon Basin (Coica), the rainforest has reached its “ tipping point ». Some areas are already beginning to turn into savannah.
The issue of “ tipping point » of the Amazon has been a concern for many years specialists in the region. By this term, scientists designate the moment when the forest, under the battering of the climate change and deforestation, would no longer be able to maintain its own rains, as is the case today. It would then evolve towards another ecosystem, drier, comparable to that of a savannah. The trees would be lower, the animals fewer in number, and the carbon absorption capacities of the forest greatly reduced.
Alerts on the imminence of this phenomenon have multiplied in recent years: in April 2021, an article published in the journal Nature revealed that the “ green lung » of the planet began to emit CO2 in the air. A year later, a team of scientists showed that 76.2 % of the Amazon rainforest had lost resilience since the early 2000s — suggesting, they said, that it had come dangerously close to its tipping point.
26 % of the Amazon heavily degraded
According to the report of RAISG and Coica, this point of no return has finally been reached. To reach this conclusion, its authors looked at a dataset relating to the state of forest cover, collected between 1985 and 2020. Their analysis shows that 26 % of the Amazon is in a state of advanced deforestation or degradation. However, in a publication of 2018, two of the best specialists in the Amazon, Thomas Lovejoy and Carlos Nobre, had estimated that the forest would topple when 20 to 25 % of its surface would have been destroyed.
This range had been designed by Lovejoy and Nobre for the specific case of eastern, southern and central Amazonia. The data analyzed by the RAISG and the Coica cover a wider area of forest. The authors of the report nevertheless believe that the tipping point of the Amazon is not “ plus a future scenario ». 24 % of Bolivian rainforest is already transformed or heavily degraded, they explain ; in Brazil, this percentage rises to 34 %. In these two countries, the “ savannization » of the forest is already “ a reality ». In the columns of New ScientistCarlos Nobre judged the results of this study “ very, very, very worrying ».
- The degraded Amazonian regions: intact areas (dark green), slightly degraded areas (light green), very degraded areas (pink), transformed areas (red). © RAISG
It is currently difficult to predict how much the rest of the Amazon could be affected by the transformation of these areas. Could a domino effect be taking place? ? “ It’s possiblesays Valéry Gond, researcher at the Center for International Cooperation in Agricultural Research for Development (CIRAD). There will probably be retro-effects on the whole of the Amazon basin, with drops in precipitation and significant mortalities. » More resilient islands, such as the Guiana Shield or the western Amazon, could “ resist longer ». “ But the forest is in danger of breaking up »according to the tropical forest specialist.
The good intentions swept away by political choices »
Can we still hope that this lush forest, its howler monkeys and its colorful frogs survive human beings? ? According to this report, 80 % of the Amazon by 2025 to prevent its drying out. A tall order: 74 % of forest today classified as “ intact » Where “ little degraded ». Achieving this objective would involve restoring in just three years 6 % of forest, or 54 million hectares of land. It would also require a very rapid increase in the area of protected areas and territories managed by indigenous communities. The majority (52 %) of the Amazon does not currently benefit from any protection. Only two of the nine countries over which the Amazon extends, Suriname and French Guiana, have been able to keep more than half of their forests intact.
A large part of the activities responsible for the deterioration of the ecosystem should also cease. First: agriculture, responsible for 84 % of deforestation in the Amazon. The mining and oil industries, which affect 17 and 9.4 respectively % of the territory, they also prevent the recovery of the forest. 483 hydroelectric plants and 11 roads are also planned: so many threats “ serious » to the integrity of the ecosystem, according to the authors of the report. Slowing the expansion of these activities could be “ very difficult » politically, warns Valéry Gond. The Amazon states are among the most indebted in the world. These lucrative activities are often seen as a way to repay their debts.
For the moment, nothing seems to indicate that they are backing down. Between 2001 and 2018, the agricultural footprint increased by 220 % within protected areas, and 160 % within indigenous territories. In Brazil, deforestation has surged since the election of former far-right soldier Jair Bolsonaro in 2019. “ It’s truly sadconcludes Valéry Gond. All good intentions are swept away by political choices. » The only glimmer of hope, the presidential election in Brazil, on October 2 and 30: the current president, Jair Bolsonaro, could be undone by Lula, more inclined to defend the rainforest.