Significant areas of the Amazon rainforest may be degraded to a savanna-like ecosystem in a scenario of below 2°C warming due to continued deforestation, according to research published in Nature.

Scientists from PIK discovered that increasing temperature, together with deforestation, can cause degradation of the Amazon rainforest before previously predicted temperatures. They stated that a combination of warming by up to 1.9°C and deforestation of the rainforest of 22% to 28% may cause the degradation of more than half of the rainforest.

The scientists predict that a change in the ecosystem will not happen before temperatures reach 3.7°C to 4°C in a scenario where no deforestation occurs. They added that deforestation leads to disruption of atmospheric moisture circulation patterns in the Amazon Basin and makes the ecosystem less capable of generating rain.

They claim that 17% to 18% of the Amazon has already been deforested, putting the ecosystem at risk close to the threshold. Scientists based their research on climate modeling, hydrology analysis, and atmospheric moisture transportation modeling in the Amazon Basin.

Deforestation in one area can lead to drought effects in another place by altering moisture recycling. This study showed that the Amazon forest is crucial in supporting rainfall patterns over extensive regions in South America.

In a different report released earlier in the year, deforested parts of the Amazon had higher surface temperatures, less precipitation, and decreased evapotranspiration than those with dense vegetation.

Another group of researchers has shown that deforestation in the Amazon leads to increased occurrences of droughts, floods, and heat waves. In another study, researchers have looked into the influence of deforestation on carbon sequestration and rainfall systems in South America.