Amazon rainforest:

Amazon Rainforest Trees Bigger: New Study Report

A new study has revealed that trees in the Amazon rainforest have steadily increased in size due to the rising levels of carbon dioxide (CO2) in the atmosphere, according to a study published on September 25. The trees are increasing in size by more than three percent every 10 years, the analysis said.

The study, increasing tree size across Amazonia, was published in the journal The An tropica on September 25. It was carried out by a team of around 100 scientists from more than 60 universities around the world.

What Did the Study Say?

• Scientists monitored trees across 188 permanent forest plots, with an average area of 12,000 square metres across the Amazon basin, to build the long-term dataset. Although monitoring periods varied, some were as long as 30 years.
• During this time, the researchers found that, on average, trees increased in diameter by about 3 percent each decade. Usually, the average diameter of trees in undisturbed old-growth forest stays roughly the same, as saplings take the place of fallen big trees and grow.
• Scientists believe that in the case of the Amazon rainforests, trees did not follow this trend due to a rise in atmospheric CO2, which increased nearly a fifth in the last 30 years.
• The rise of CO2 levels can benefit tree growth because of a phenomenon known as the carbon fertilisation effect. More CO2 in the atmosphere increases the rate of photosynthesis, leading to increased growth in some plants.

About Amazon rainforest:

• The Amazon rainforest, often called the “lungs of the Earth,” is the world’s largest tropical rainforest, spanning approximately 5.5 million square kilometers across nine countries, with Brazil holding the majority.
• It is home to an estimated 400 billion individual trees from 16,000 species, supporting unparalleled biodiversity, including millions of insect, plant, and animal species, many yet undiscovered. The rainforest plays a critical role in global climate regulation by absorbing vast amounts of carbon dioxide and producing about 20% of the world’s oxygen.
• Recent studies, including one from September 2025, indicate that trees in the Amazon are growing larger due to rising CO2 levels, increasing in size by over 3% every decade.
• However, the region faces threats from deforestation, with around 11,088 km² lost in 2022 alone due to logging, agriculture, and mining. This habitat loss impacts indigenous communities and accelerates climate change. Efforts to protect the Amazon include international agreements and reforestation projects, though challenges persist.