A global study has estimated that the collective metabolism of the world's population releases roughly 2 billion metric tons of carbon dioxide every year, according to Phys.org. The figure covers the CO₂ produced by human bodies as they convert food into energy, aggregated across all people.
Phys.org reported the estimate on Sunday, November 1, 2026. The outlet presented the number as an estimate from a worldwide research effort rather than a direct measurement of every individual.
The finding places everyday human biology within the broader accounting of CO₂ sources. Human metabolism is a natural process, and the study's estimate describes its total scale rather than attributing the emissions to any activity or choice.
Phys.org's report did not include further details in the summary available, such as the researchers involved, the methods used to reach the figure, or how the estimate compares with other emission sources. Those specifics would be needed to judge the number's context and its limits.
What to watch next: whether the full study is published with its methodology and regional breakdowns, which would show how the estimate was built and where the emissions are concentrated.
