Amazon Trees Grow Larger Amid Climate Change, Study Finds

Sep 27, 2025, 3:13 AM
Image for article Amazon Trees Grow Larger Amid Climate Change, Study Finds

Hover over text to view sources

Trees across the Amazon rainforest are growing larger in response to rising carbon dioxide levels, according to a major study published in Nature Plants. Researchers found the average size of trees in the Amazon has increased by 3.2% every decade for at least the past 30 years, with both large and small trees showing growth trends . This phenomenon is attributed to the "fertilizing effect" of higher CO2 concentrations, which enhances plant growth by providing more resources for photosynthesis .
The study, led by an international team of over 100 scientists from 60 universities, analyzed data from 188 permanent forest plots across the Amazon. Monitoring began in 1971 and spanned decades, revealing that trees have thickened their trunks by 3.3% per decade since the 1970s . Professor Beatriz Marimon of Universidade do Mato Grosso noted that even the largest trees in intact forests have thrived despite climate threats, highlighting their resilience to environmental stressors .
The findings suggest that rising CO2 levels are driving a "benefits shared" response, where all tree sizes benefit from increased atmospheric carbon. This contrasts with earlier hypotheses that only larger trees would dominate under higher CO2 conditions. Dr Adriane Esquivel-Muelbert of the University of Cambridge emphasized that the results underscore the critical role of tropical rainforests in mitigating climate change, as large trees absorb significant amounts of CO2 from the atmosphere .
However, researchers caution that these benefits are not without risks. While the study shows no declines in tree basal area, the long-term effects of climate change, such as heat stress, water scarcity, and wildfires, could reverse these trends. Dr Rebecca Banbury Morgan of the University of Bristol warned that deforestation remains a major threat, as old trees provide far greater carbon and biodiversity benefits than newly planted ones . The study also highlights that fragmented forests in the Amazon have shifted from carbon sinks to sources, exacerbating the climate crisis .
The research team emphasized the importance of preserving intact forests to maintain their carbon sequestration capacity. "These results underscore just how important tropical rainforests are in our ongoing efforts to mitigate against man-made climate change," Esquivel-Muelbert said . However, the study also reveals that the Amazon's ability to absorb carbon has weakened in recent years due to deforestation, habitat degradation, and climate impacts like frequent droughts and fires .
While the findings offer hope for the Amazon's resilience, experts stress that the situation remains precarious. The study's authors call for urgent action to protect remaining pristine forests and address the root causes of climate change. As Brazil plans infrastructure projects that could further fragment the Amazon, the balance between carbon absorption and emissions remains a critical concern for scientists and policymakers alike .

Related articles

Climate Change and Cultural Heritage: Tough Choices Ahead

As climate change accelerates, cultural heritage sites worldwide face unprecedented threats. Innovative technologies are being utilized to document and preserve these sites, but the urgency raises difficult questions about what can realistically be saved before it's too late.

Beyond Carbon Offsets: 7 Charities Tackling Climate Change in 2026

As climate philanthropy grows, seven charities are leading the charge by addressing the root causes of emissions and environmental degradation. These organizations focus on behavior change, policy reform, and community empowerment to create sustainable solutions for climate challenges.

New High-Resolution Map of Antarctica's Sub-glacial Landscape Unveiled

Scientists have produced a groundbreaking high-resolution map of Antarctica's sub-glacial landscape, revealing nearly 72,000 features, including ancient valleys and mountains. This new understanding of the Antarctic bedrock could improve climate models and potentially slow sea level rise.

Meta-Analysis Reveals Self-Other Discrepancy in Climate Risk Perception

A recent meta-analysis involving over 70,000 participants across 17 countries highlights a significant self-other discrepancy in climate change-related risk perceptions. The findings indicate that individuals tend to perceive their own risk of climate impacts as lower than that of others, which may hinder climate action efforts.

Climate Change Fuels Extreme Weather: A Growing Concern

Climate change is increasingly linked to extreme weather events, making heatwaves, droughts, hurricanes, and wildfires more frequent and severe. As scientific research highlights these connections, understanding their implications is crucial for communities and policymakers.