Mining disturbs 172 tonnes of stored carbon per km2 but sequesters only 14 kg

Abyssal sediments in the Clarion-Clipperton Zone are a long-term carbon sink, having accumulated organic carbon over millions of years. Research published by Planet Tracker shows that deep-sea mining collector vehicles would disturb approximately 172.5 tonnes of carbon per year for every km2 mined. By contrast, the natural carbon sequestration rate in the CCZ is only 13.9 kg of carbon per km2 per year. This means mining releases carbon stores roughly 12,400 times faster than nature can replace them. The disturbed carbon enters the water column as dissolved and particulate organic carbon, where it can be remineralized by bacteria and ultimately released as CO2. Additionally, sediment plumes from mining machinery reduce light penetration in the upper water column, inhibiting phytoplankton photosynthesis -- the very process that drives biological carbon sequestration in the first place. This creates a double hit: releasing stored carbon while simultaneously reducing the ocean's capacity to sequester new carbon. The problem is structurally irreducible because the carbon is physically stored in the same sediment layer that must be disturbed to access the nodules sitting on top of it.