The Amazon rainforest is facing a pressure barrage that could lead to a large-scale ecosystem collapse as early as 2050, according to a new study out Wednesday that warns of dire consequences for the region and the world. Home to more than 10 percent of the world’s biodiversity, the Amazon helps stabilize the global climate by storing the equivalent of carbon dioxide emissions that have been warming the planet for nearly two decades.

But stress from deforestation, drought, fires and rising temperatures has weakened the ability of the Amazon forest to withstand shocks, and scientists warn this could trigger a so-called “tipping point” that would lead to irreversible change in a key ecosystem of the world. the coming decades.

A new study published in the journal NatureAn international group of scientists predicts that by 2050, 10 to 47 percent of the Amazon will be under stress that could lead to large-scale ecosystem changes. This could cause a critical ecosystem to stop absorbing or even releasing the carbon it has stored, further contributing to global warming and exacerbating its effects.

“We are potentially approaching a large-scale tipping point, and we may be closer (both locally and system-wide) than we previously thought,” said lead author Bernardo Flores, of the Federal University of Santa Catarina in Florianopolis, Brazil.

white sand savannah

Researchers used information from computer models, observations, and evidence of past changes going back thousands of years to map the complexity of forest systems and identify the root causes of stress.

They then analyzed these stressors, such as global warming, annual rainfall, length of the dry season, and deforestation, to see how they might act individually or together to trigger feedback loops that could trigger a major collapse. According to them, there may be an unprecedented water shortage in the Amazon by 2050.

Previous studies have shown that global warming, which warms the Earth’s surface by an average of 1.2°C above pre-industrial levels, could push the Amazon into a much drier savanna state. A recent study has shown that its fate may be more complicated.

Following fires, some areas in the Amazon may already turn into sprawling “white sand savannahs,” while other parts of the Amazon may be partially covered by fire-resistant trees interspersed with invasive grasses. Wet areas may remain degraded forests with fewer tree species and a greater proportion of fast-growing plants such as bamboo.

“We have evidence that rising temperatures, extreme droughts and fires can affect forest functioning and change the tree species that can integrate the forest system,” said co-author Adrian Esquivel-Mulbert, from the Birmingham Forest Research Institute in the UK.

A global concern

In recent months, much of the Amazon region has been gripped by a severe drought that has dried up key waterways, dried out crops and fueled wildfires. Scientists from the World Weather Attribution Group said the historic drought period was mainly caused by climate change rather than the natural El Niño weather phenomenon. Flores said the severe drought is a harbinger of the climate conditions expected in the region in the early 2030s.

“The huge rivers have dried up completely; Due to food and water shortages, locals and indigenous people remained isolated for months. I never thought that people in the Amazon could face water shortages,” he told AFP.

Because vegetation and soil absorb large amounts of carbon, terrestrial ecosystems around the world have become an important ally as the world tries to limit CO2 emissions. But this is under threat, and scientists have already expressed fears that parts of the Amazon are turning from a “sink” to a “source” of CO2. It is expected that this issue will come to the fore even more clearly next year, when a grand round of international climate negotiations will be held in Brazil.

Flores emphasized that the fate of tropical forests and the consequences of forest loss are a global concern: “Even if Amazon countries commit to zero deforestation and achieve this goal in the coming decades, these monumental efforts may be in vain if the whole world does not do so. We are committed to greatly reducing greenhouse gas emissions.” said.