New research warns that the Amazon rainforest might face several pressures that could result in a large-scale ecosystem collapse by 2050, with dire consequences for the region and the world. The Amazon is home to more than 10 percent of the world’s biodiversity, and it plays a crucial role in stabilizing the global climate by storing the equivalent of around two decades of planet-warming carbon dioxide emissions. However, due to deforestation, drought, fire, and rising temperatures, the Amazon’s forests have lost their ability to withstand shocks, and this could trigger a tipping point, leading to an irreversible transition in the ecosystem in the coming decades. The latest study published in the journal Nature shows that between 10 and 47 percent of the Amazon will be exposed to stress by 2050, which could lead to widespread ecosystem change. If this happens, the critical ecosystem may stop absorbing or even release the carbon it stores, further exacerbating global warming and intensifying its effects.
“We are approaching a potential large-scale tipping point, and we may be closer (both at local scales and across the whole system) than we previously thought,” said lead author Bernardo Flores, of the Federal University of Santa Catarina, in Florianopolis, Brazil.
The researchers used computer models, observations, and evidence of past changes to map out the complexity of forest systems and identify key causes of stress. They analyzed stressors like global warming, annual rainfall, the length of the dry season, and deforestation to see how they could trigger feedback loops that might cause a major collapse. They predict that by 2050, the Amazon could be exposed to unprecedented levels of water stress.
Previous research has indicated that global heating alone could push the Amazon into a drier savannah-like state. However, the latest study suggests that the Amazon’s fate could be more complex than that. Some areas could transition into “white-sand savannas,” which are already expanding in the Amazon following wildfires. Other areas of the Amazon could see patchy coverage of fire-tolerant trees interspersed with invasive grasses. Meanwhile, wetter areas could remain as degraded forests, with fewer tree species and a greater proportion of fast-growing plants like bamboo.
“We have evidence showing that rising temperatures, extreme droughts and fires can affect how the forest functions and change which tree species can integrate the forest system,” said co-author Adriane Esquivel-Muelbert from Britain’s Birmingham Institute of Forest Research.
The Amazon region has been hit hard by a harsh drought that occurred in recent months. This drought resulted in the drying up of important waterways, damaged crops, and caused an increase in wildfires.
According to the World Weather Attribution group, this historic drought was primarily caused by climate change, rather than the natural El Nino weather phenomenon.
Flores has warned that the extreme drought is a sign of the climatic conditions that the region is likely to face in the early 2030s.
“Immense rivers went completely dry, keeping local and Indigenous peoples isolated for months, with scarce food and water. I never imagined that people could experience a lack of water in the Amazon,” he told AFP.
Terrestrial ecosystems around the world play a vital role in reducing carbon dioxide emissions. The vegetation and soil absorb a significant amount of carbon which helps in combating climate change. However, there is a threat to these ecosystems and scientists have warned that parts of the Amazon have shifted from being a “sink” to a “source” of CO2.
This could have serious implications for the world’s efforts to tackle climate change. Brazil will host an important round of international climate negotiations next year, which will bring the issue into sharp focus. It is important to remember that the fate of the rainforest is a global concern, and forest loss could have far-reaching consequences.
“Even if Amazonian countries commit to net-zero deforestation and reach this goal in the next decades, this huge effort may be useless if the whole world does not commit to sharply reducing greenhouse gas emissions,” he said.
