Amazon Rainforest Trees Show Significant Growth Due to Increased CO₂ Levels, Study Finds

A recent study published in Nature Plants on September 25, 2025, reveals that trees in the Amazon rainforest have been increasing in size over the past few decades, a trend attributed to rising atmospheric carbon dioxide (CO₂) levels. Researchers monitored 188 permanent plots across the Amazon from 1971 to 2015, finding that the average tree size increased by approximately 3.2% per decade. This growth was observed in both large and small trees, suggesting a widespread response to elevated CO₂. The study involved nearly 100 scientists from over 60 universities worldwide, including the Universities of Birmingham, Bristol, and Leeds. While the findings indicate a potential resilience of Amazonian forests to climate change, researchers caution that other factors like heat stress, drought, and deforestation could offset these growth benefits in the future.

The Amazon rainforest, spanning nine countries and covering approximately 5.5 million square kilometers, is a critical component of the Earth's climate system. It accounts for about 10% of the world's terrestrial primary productivity and stores a significant portion of global carbon. Understanding the dynamics of tree growth in this region is essential for predicting the future of global carbon cycles and climate change.

The study's findings suggest that Amazonian forests may be more resilient to climate change than previously assumed, as even large trees—usually more vulnerable to drought and lightning—are thriving in intact forest areas. However, the researchers caution that other factors such as heat stress, drought, and deforestation could offset these benefits in the future. Dr. Rebecca Banbury Morgan from the University of Bristol highlighted the irreplaceable value of large, old trees, noting that planting new trees cannot immediately replicate the carbon and biodiversity benefits provided by mature forests.

The increase in tree size across the Amazon has significant implications for global carbon storage and climate regulation. However, the potential offsetting effects of climate-induced stressors and human activities like deforestation highlight the need for comprehensive conservation strategies. Preserving intact forests is essential to maintain their role as carbon sinks and biodiversity reservoirs.

While the increase in tree size across the Amazon offers a glimmer of hope in the fight against climate change, it is essential to address other environmental stressors such as deforestation, drought, and heat stress to ensure the long-term health and resilience of these vital ecosystems.