New research finds that a warming climate could flip globally abundant microbial communities from carbon sinks to carbon emitters, potentially triggering climate change tipping points. The findings are published in Functional Ecology.

Mixotrophic microbes are organisms that can switch between photosynthesizing like plants (absorbing carbon dioxide) and eating like animals (releasing carbon dioxide). They are globally abundant, commonly found in freshwater and marine environments, and estimated to make up the majority of marine plankton.

By developing a computer simulation that modeled how mixotrophic microbes acquire energy in response to warming, researchers at Duke University and the University of California Santa Barbara, have found that under warming conditions, mixotrophic microbes shift from being carbon sinks to carbon emitters.