In the anthropocene slow carbon cycles are becoming faster. How do we know?

Prof Susan Waldron, Professor of Biogeochemistry, School of Geographical and Earth Sciences
University of Glasgow, United Kingdom

Abstract: Rivers transport carbon (C) from the land surface to the ocean. However, evasion of carbon dioxide (CO₂) from fluvial systems is now recognized as a significant component of the global carbon cycle, returning CO₂ to the atmosphere without the opportunity for sequestration in the ocean. If this rate of transfer (from the land to the river to the atmosphere / ocean) stays constant then such efflux does not exert a feedback on a changing climate.

However, if the rate of loss of C from the land changes and increases or decreases CO₂ efflux, then this exerts a feedback on the Earth warming. It is important we understand the magnitude of this efflux and what controls it. The research I will present shows how we are adding understanding here, often through fieldwork in landscapes sensitive for C storage: the Amazon, Greenland, Malaysia. Our research reveals that old C is being mobilised, and in some sites this is because of man’s activities: in the Anthropocene are we speeding up slow carbon cycles?