Cutting down the Amazon will bring extreme rain, wind and heat

Imagining life in the Amazon post-total deforestation doesn’t evoke images of tranquility; rather, it conjures visions of droughts interrupted by torrential downpours, harsh winds thwarting any and all regrowth, and sweltering temperatures pushing both the human and wildlife populace to their limits. This startling depiction challenges the longstanding belief that tree removal will simply sap moisture from the earth, leading to a drier climate.

While most prior assessments have forecasted a significant decline in rainfall following the eradication of the Amazon rainforest, these conclusions often relied on rough models failing to capture the nuanced convection dynamics inherent to the tropical ecosystem.

In response, a team led by Arim Yoon from the Max Planck Institute for Meteorology has implemented a refined climate model that more accurately simulates rainfall and convection in the rainforest. This innovative approach has garnered praise from specialists like Dominick Spracklen at the University of Leeds, who finds it “really impressive” for its capacity to simulate the climate’s response to deforestation more effectively.

In previously reported findings, Yoon suggested that despite total deforestation, the mean annual rainfall surprisingly remained stable. In her most recent study, she dives deeper into how hourly fluctuations in rainfall, temperature, and wind velocity will alter in a fully deforested Amazon.

The results are alarming: the region is projected to experience prolonged periods of dryness and a staggering 54% rise in intense rain events—defined as over 50 millimeters falling within an hour. Furthermore, minimum and maximum daily temperatures are expected to rise by 2.7°C (4.9°F) and 5.4°C (9.7°F), intensifying heat stress for millions. Additionally, the likelihood of strong winds will significantly increase.

With over 30 million residents in the Amazon, including approximately 2.7 million Indigenous peoples, these forecasts paint a dire picture. As Luis Cattelan from the University of Leeds points out, “You’re going to have more extreme rainfall and more extreme temperatures. That is basically horrible for everyone who is there.”

However, Cattelan urges caution, suggesting that further validation of this modeling approach is essential. He emphasizes the need for additional research into the regional climatic effects of partial deforestation, which aligns more closely with anticipated future conditions. “These extreme scenarios are more for scientists to try to decipher the signal. But we know they’re not realistic,” he notes.