Modeling studies suggest that Amazon Rainforest is more resilient than expected

The imminent loss of Amazon rainforests due to deforestation has been linked to scientists, activists and citizens around the world. The region’s unparalleled biodiversity and natural habitats that maintain important carbon stores are at risk, and the global climate is far-reaching.

Previous research warned that Amazon was moving towards a tipping point, but beyond that the forest would retain itself, thereby losing its ability to turn into a savanna. However, new research suggests that this may not be the case.

Scientists at the Max Planck Institute for Meteorology (MPI-M) have revealed that the Amazon region remains precipitated, even if it is completely deforested. This work has been featured in the journal Geophysical Research Letters.

The arguments for the tipping point were based on a simplified model

The reason scientists fear a turning point was the importance of vegetation to make the rain. Plants transport water from the soil through the leaves to the atmosphere, thereby creating moisture that maintains precipitation in the Amazon region. The combined ability of soil and plants to water the atmosphere is known among experts as evapotranspiration.

There was a conceptual argument that deforestation leads to a decrease in evapotranspiration and therefore precipitation is supported by numerous modeling studies.

But they all had important limitations. The study was based on a global climate model using a simplified representation of convection, a major atmospheric process that converts water into rain in the Amazon, or a regional model that does not allow it. Large-scale atmospheric circulation to adapt to deforestation.

Now, MPI-M scientists Arim Yoon and Cathy Hohenegger have used the global storm-removal icon model to overcome both of these limitations. They performed global simulations of the atmosphere with a horizontal resolution of 5 km and a period of 3 years. Instead of using simplified rules of thumb, convection was explicitly resolved in the model.

The wind transports moisture to the area

The results show that Amazon precipitation is less dependent on evapotranspiration than previously thought. Rather, the loss of evapotranspiration due to deforestation is compensated by large-scale cycle changes.

“The winds at an altitude of about 3km carry ample moisture from the ocean to the area to compensate for the reduction in evapotranspiration,” Yoon says. The calculation shows that average annual rainfall on Amazon does not change significantly after complete deforestation. This contrasts with previous findings.

“When compared to the state-of-the-art climate models currently used in IPCC assessment reports, it is more than the evaporation of global storm-removal simulations than the evaporation of global storm-removal simulations, compared to the large-scale circulations that are currently used in the IPCC assessment report. It seems tightly coupled, and this fact is exciting. We ask for a reexamination of some of the things we thought we knew about precipitation and its sensitivity over the land,” says Hohenegger.

However, although the total rainfall in the Amazon over the year is not predicted to change, the distribution of rainfall throughout the year is the case. “Using one indicator to assess the future of Amazon rainforests is not enough,” says Yoon. “Details of rainfall patterns can make a huge difference.”

As a next step, researchers would like to use the same simulation to investigate whether extreme rainfall and extreme droughts are becoming more frequent or severe.

Therefore, this study is good news, but not entirely clear. Deforestation does not significantly reduce average annual rainfall, but it still changes the climate of the region and the world, negatively affecting ecosystems and negatively affecting those who rely on them. that.