Amazon rainforest more resilient than expected?

New evidence suggests that mean annual precipitation in the Amazon region would not change significantly even if it were completely deforested, experts from the Max Planck Institute for Meteorology (MPI-M) explained in February 2025.

This is contrary to previous concerns that beyond a certain threshold, the Amazon would turn into a savannah. However, the researchers who conducted the study point out that a full picture of the consequences of deforestation requires more than one indicator.

Previous studies warned that the Amazon was moving towards a tipping point, beyond which the forest would lose the ability to sustain itself and thus turn into a savannah. But new research suggests that this might not be the case. Scientists have revealed that the Amazon region would  sustain precipitation even if it were completely deforested.

For the first time, MPI-M scientists Arim Yoon and Cathy Hohenegger used the global storm-resolving ICON model. Their results show that precipitation in the Amazon is not as dependent on evapotranspiration, the combined ability of soils and plants to release moisture into the atmosphere, as previously thought. Rather, the loss of evapotranspiration due to deforestation is compensated by changes in the large-scale circulation. 

“The wind at about three kilometres altitude carries enough moisture from the ocean into the region to make up for the decline in evapotranspiration,” says Yoon. According to the computations, mean annual precipitation in the Amazon does not change significantly even after complete deforestation. This is in contrast with previous findings. 

“Precipitation over land seems more tightly coupled to the large-scale circulation than to evapotranspiration in our global storm-resolving simulation if compared to state-of-the-art climate models currently used in the IPCC assessment reports,” Yoon explains. This fact is exciting as it asks for the re-visitation of some of the things we thought we knew about precipitation over land and its sensitivity.” 

However, while the total amount of rainfall in the Amazon during one year isn’t projected to change, the distribution of rainfall throughout the year is. “Just using one indicator to assess the future of the Amazon rainforest isn’t enough,” Yoon says. “The details of the rainfall patterns can make a big difference.” As a next step, the researchers want to use the same simulation to investigate if extreme rainfall and extreme drought are becoming more frequent or more intense. So, while the study is good news, it is not an all-clear. Even though deforestation doesn’t significantly reduce mean annual precipitation, it still changes the regional and the global climate and has adverse impacts on the ecosystem, and on the people who depend on it.

(MPI-M/ile)

Read more on the MPI-M website