by University of Birmingham
Scientists have used clues locked into tree rings to reveal major changes in the Amazon's rainfall cycle over the last 40 years: wet seasons are getting wetter and dry seasons drier.
Oxygen isotope signals in rings from two Amazon tree species allowed the international research team to reconstruct seasonal changes in rainfall for the recent past.
Publishing their findings in Communications Earth & Environment, the researchers reveal that wet season rainfall has increased by 15–22%, and dry season rainfall has decreased by 5.8–13.5% since 1980.
The study is a result of a collaboration between the Universities of Leeds, Leicester and the National Institute for Amazon Research, in Brazil.
Co-author Dr. Bruno Cintra, now at the University of Birmingham, commented, "The Amazon is a key component of Earth's climate system. Understanding how its hydrological cycle is changing is essential for predicting future climate scenarios and developing effective conservation strategies. The upcoming COP30 in Belém, Brazil presents a critical opportunity for world leaders to take decisive action."
Researchers believe this intensified seasonal cycle is caused by changes in temperatures of the surrounding Atlantic and Pacific oceans influencing the atmospheric circulation. While these changes are partly driven by natural variability, there are also strong indications that anthropogenic climate change plays a role.
