Deforestation Risk: Potential Tipping Point for the Amazon Rainforest in the 2030s

The ongoing destruction of the Amazon rainforest, primarily for cattle ranching, poses a significant threat to this vital ecosystem, increasing its vulnerability to irreversible collapse within decades if deforestation persists.

An alarming study from 2022 revealed that global warming surpassing 3.5 degrees Celsius—or even 2 degrees Celsius—could trigger widespread dieback across the Amazon. Current projections indicate the Earth may warm by approximately 2.6°C to 2.7°C above pre-industrial levels by 2100. Notably, this study did not factor in deforestation, which has already resulted in at least a 15% loss of the Amazon.

Researchers at the Potsdam Institute for Climate Impact Research, including Nico Wandering, are analyzing scenarios for the Amazon’s future, considering the combined impacts of global warming and severe deforestation by 2050. Their findings suggest that if total forest loss reaches 22%, widespread dieback may occur even with just 1.5 degrees Celsius of warming. Since the world has already warmed by approximately 1.3°C to 1.4°C, we could reach 1.5°C by the end of this decade.

While deforestation rates slowed last year, a resurgence could see the Amazon cross its critical tipping point as soon as 2031. The potential timing and scale of deforestation hinges on human carbon dioxide emissions; rates between 22% to 28% could transform 62% to 77% of the Amazon biome into grassland, savannah, or shrubland.

“We discovered that factoring in deforestation reduces the threshold for global warming by about 2 degrees,” says Wandering. “This is primarily because deforestation disrupts the crucial recycling of atmospheric moisture.”

The Amazon’s dense network of trees plays an essential role in maintaining regional moisture levels, with up to 50% of precipitation being recycled within the forests. However, deforestation hampers this process, which can result in a cascading loss of forest areas.

Despite the serious implications of these findings, they are grounded in high deforestation rates threatening currently protected areas. As pointed out by David Armstrong McKay, who contributed to the Tipping Point study at the University of Sussex, Brazil is projected to lose over 28,000 square kilometers of primary forest by 2024. However, projections suggest that by 2025, that figure will nearly halve. President Luiz Inacio Lula da Silva has committed to ending deforestation in the Amazon by 2030; if successful, this could prevent crossing the tipping point even under continued global warming.

While completely halting all deforestation may seem optimistic, Armstrong-McKay notes that even continued deforestation is unlikely to match the worst-case scenarios outlined in current research.

Nonetheless, Brazil is still expected to lose around 0.5% of its primary forest by 2025. In recent years, wildfires have contributed to two-thirds of deforestation, often starting when farmers burn vegetation and then flee into adjacent forest areas.

Once rare, wildfires have become more commonplace as conditions in rainforests grow hotter and drier, a trend likely to worsen with expected El Niño conditions later this year. As a result, the study may be underestimating the Amazon’s vulnerability, according to Dominique Spracklen from the University of Leeds.

“We are observing increasingly large fires,” he states. “Transitioning into this new regime raises significant concerns.”

The Amazon has already transitioned from being a carbon sink to a carbon source; widespread dieback may release enough carbon to increase global temperatures by up to 0.2 degrees Celsius, alongside potentially devastating impacts on terrestrial biodiversity.

“It’s imperative that we divert away from this threshold rather than inch closer to it,” urges Spracklen.