Loss of trees in the Amazon can worsen floods and droughts: study March 8, 2025

Amazon Rainforest Credit: Pixabay/CC0 Public Domain

By AFP - Agence France Presse

Loss of trees in the Amazon can worsen floods and droughts: study

Deforestation in the Amazon causes more rain in the wet season and less rain in the dry season, according to new research published on Wednesday, highlighting the rainforest's “fundamental” role in regulating local and global climate.

The rapid loss of trees in the Amazon region, driven mainly by unsustainable agriculture, mining, and logging, undermines the rainforest's ability to absorb planet-warming carbon dioxide.

This has also affected regional climate patterns, with previous research showing that the reduction in vegetation has decreased the uptake of water in the atmosphere and led to generally drier conditions.

The new study, published in the journal Nature, sought to get a more detailed picture using regional climate simulations and satellite forest data from 2000 to 2020.

The researchers, based in China and Thailand, found that the impacts on the Amazon change with the seasons.

They found that more rain falls on areas where trees have been felled in the rainy season (December to February), with the exposed land becoming warmer and causing an upward flow of air that acts to attract moisture.

In the dry season (June to August), when plants need water the most, the deforested area suffered a reduction in evaporation from the vegetation, causing less rain to fall over a wider region.

“Due to its fundamental role in regulating regional and global climate, continued efforts are needed to protect the remaining forest in the Amazon, as well as to rehabilitate degraded lands,” the authors concluded.

The authors emphasized that the loss of trees in the Amazon, which is often caused by the illegal expansion of agricultural land, is a particular threat to plantations.

Increased rainfall “could exacerbate wet season flooding in certain deforested regions, damaging regional agriculture and the social economy,” they said.

Overall, they found that continued deforestation in the Amazon “could lead to a decrease in total rainfall”, which would threaten wildlife, intensify drought and aggravate forest fires, as well as reducing CO2 absorption capacity.

Reduced regional rainfall could also result in “substantial economic losses in agriculture”.

'Turning point'

In a linked commentary published in Nature, Wim Thiery, associate professor at the Vrije Universiteit in Brussels, said that the study was “groundbreaking” and that research of this kind is important for understanding the complex interactions between deforestation, climate change and plant health.

It could help researchers assess whether the rainforest is approaching a so-called “tipping point”, which would lead the crucial ecosystem to become a savannah, said Thiery, who was not involved in the research.

In a study last year, published in Nature, an international group of scientists estimated that between 10% and 47% of the Amazon will be exposed to the combined stress of warming and forest loss by 2050, which could lead to widespread change in the ecosystem.

This could cause the critical ecosystem to release the carbon it stores, further driving global warming and intensifying its effects.

The drought dried up the Amazon region from mid-2023 to 2024, driven by man-made climate change and the El Niño warming phenomenon, helping to create conditions for record forest fires.

Globally, the trend of tropical forest destruction continues, despite promises to end the practice by 2030, according to last year's “Forest Declaration Assessment” report by research organizations, NGOs, and advocacy groups.

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