Low rainfall and, with them, the drought is once again on the warpath against nature. And is that, the sensitivity of tropical forests to irregular rain, for prolonged periods, could cause 40% of the Amazon evolve into a savanna state.

The conclusions of the study published by Nature Communications are worrying, as some parts of the Amazon region are receiving less rain than before and this trend is expected to worsen as the region warms up with rising Emissions of greenhouse gases.

The consequences of this climate change are obvious: If the rain falls below a certain threshold, these areas may change to a savanna state, as explained by the main author of this research, Arie Staal.

NASA’s troubling map of active fires: Africa and the Amazon burn quietly

To explore how tropical forests respond to changing rains and thereby achieve these results, the scientific team focused the study on the stability of tropical forests in America, Africa, Asia and Oceania. In this way, the resilience of tropical forests was explored by analyzing two questions: If all the forests of the tropics disappeared, Where would they grow again? And, conversely, What if rainforests covered the entire tropical region of the Earth?

With the first simulations, focused on hypothetical forest-free areas in the tropics of Africa, America, Asia and Australia, it was concluded that “as forests grow and spread over a region, this affects rainfall: forests create their own rain because the leaves emit water vapor and this falls like rain more downwind. Rain means fewer fires leading to more forests. “

The latter, by contrast, were based on a world where rainforests completely covered the tropical regions of the Earth. This is an unstable scenario because in many places there is not enough rain to sustain a rainforest. So this time in many places forests receded due to lack of moisture.

To conclude this cycle of research, we explored what would happen if emissions continue to increase during this century. In this case, it was concluded that as emissions increase, more parts of the Amazon lose their natural resilience, become unstable, and are more likely to dry out and change to become a savanna-like ecosystem. A really worrying fact, which puts the health of our ecosystem in the spotlight.