A recent study has revealed that climate change-induced extreme temperatures and humidity could significantly reduce the Amazon rainforest’s ability to absorb methane, a key greenhouse gas. The research, conducted by scientists at the University of São Paulo, Brazil, showed that methane absorption in upland forests could drop by 70% under warmer and drier conditions, while increased rainfall would boost methane emissions in flooded areas. The Amazon, often called the lungs of the planet, is critical for global greenhouse gas balance, but these findings suggest its role may be severely impacted by future climate change.

The Amazon’s flooded regions, which cover 20% of the area, already emit significant methane, contributing up to 30% of global methane emissions from wetlands. The study, published in Environmental Microbiome, emphasises how sensitive the region’s upland soils are to temperature increases, reducing methane absorption under dry conditions, and showing an uptick in methane production when exposed to heavy rainfall.

Researchers collected soil samples from flooded and upland areas of the Amazon and subjected them to extreme conditions: 27°C and 30°C with varying humidity levels. In the elevated forests, the ability to absorb methane dropped drastically in dry conditions, while in floodplains, an increase in methane-producing microbes was observed, though no immediate increase in emissions was detected.

Lead researcher Julia Gontijo of the University of California, Davis, stressed that this shift in microbial behavior due to climate change could severely disrupt the Amazon’s role in mitigating greenhouse gas emissions, highlighting the broader global implications for climate regulation.

The findings underscore the critical vulnerability of the Amazon’s ecosystem to climate change, where rising temperatures and extreme weather could alter the balance between methane absorption and release, potentially turning this vital “greenhouse gas sink” into a significant source of emissions in the future.