A study published in Science, involving University of Exeter researchers, shows that the record-breaking El Niño of 2015–16 caused tropical forests across the Americas to temporarily switch from a carbon sink to a carbon source. Heat and drought together suppressed tree growth and increased mortality across the continent.
The findings highlight the vulnerability of Amazon forests to the more frequent and intense El Niño events projected under climate change — with direct implications for global carbon budgets and nationally determined contributions.
Read the full University of Exeter press release: Extreme El Niño weather saw South America’s forest carbon sink switch off
Paper: Aguirre-Gutiérrez, J., Díaz, S., Rifai, S. W. et al. (2025). Tropical forests in the Americas are changing too slowly to track climate change. Science, 387(6738). doi: 10.1126/science.adl5414