Debunking the Biological Myth of the Ocean Carbon Cycle
Source PublicationScience Advances
Primary AuthorsResplandy, Lévy, Bopp

Researchers have synthesised global marine carbon data to show that physical and chemical processes, rather than marine life, drive the ocean carbon cycle. Historically, tracking these dynamics was exceptionally difficult because data remained fragmented across vastly different scales, from microscopic plankton to blue whales.
These results were observed under controlled laboratory conditions, so real-world performance may differ.
The Physics of the Ocean Carbon Cycle
The ocean serves as a vital sink for human carbon dioxide emissions. While public narratives suggest that restoring coastal ecosystems or protecting whales could significantly boost carbon sequestration, this analysis compares these biological claims against physical baselines. The data indicates that biological carbon storage is minor compared to solubility-driven ocean sinks.
Quantifying the True Carbon Sinks
By auditing both living and nonliving carbon reservoirs, the researchers clarified the limits of biological sequestration:
- Whales and fish sequester negligible fractions of global carbon.
- Coastal ecosystems like mangroves offer localised but globally limited climate mitigation.
- Physical ocean currents and chemical dissolution remain the primary drivers of carbon storage.
This synthesis suggests that while marine biology is vital for biodiversity, its role in climate regulation has been overstated. By transitioning from fragmented, scale-specific narratives to an integrated global audit, this review brilliantly unifies disparate data. Nonetheless, its scope is constrained by the inherent uncertainties of existing global flux models, meaning highly localised dynamics require further empirical validation.
Conservation Beyond Carbon
These findings imply that marine conservation policies should be decoupled from carbon-offset metrics. Preserving biodiversity is valuable in its own right, and funding should not depend on inflated carbon sequestration claims.