Amazon's Big Trees Grow Larger, Helping Fight Climate Change

According to a study published in Nature Plants on September 26, 2025, the largest trees in the Amazon rainforest are growing in size and number, providing a welcome sign of the forest's resilience to climate change. The research, conducted by almost 100 scientists over the past 30 years, found that the mean cross-section of tree trunks in the Amazon has thickened by 3.3% per decade, with the greatest increase seen in the biggest trees.

The authors say this expansion is likely due to the rising levels of atmospheric CO2, which is fueling the growth of these dominant canopy trees. The study provides hope that the Amazon's mature, undisturbed forests can continue to act as an effective carbon sink, drawing down and storing significant amounts of carbon dioxide.

However, the researchers caution that this positive trend is under threat from deforestation, fires, and land clearance for roads and farms. Areas of the Amazon that have already been heavily fragmented have shifted from being carbon sinks to carbon sources. The authors warn that unless deforestation is stopped, the Amazon's remarkable resilience may count for little in the fight against climate change.