In a new study, Professor of Earth Sciences Dr. István Kovács emphasizes that climate models fail to account for CO2 emissions linked to tectonic processes or widespread mantle degassing.

Instead, the modern carbon budget accountants primarily consider CO2 emissions from the tiny number of Earth’s active volcanoes and ignore the non-negligible mantle-derived emission quantities of from continental regions where no active volcanism exists.

So while on one hand it is true that “the natural geological flux from Earth’s interior continues to play an essential role in regulating atmospheric CO2 over geological timescales,” on the other hand “our understanding is heavily biased towards areas of active volcanism.”

This active-volcanism-only bias serves to severely underestimate natural contributions to the carbon cycle and consequently leads to inaccurate flux measurements.

Image Source: Kovács, 2026