Key points
- Less than 4% of the carbon sequestered in the ocean is stored on the seafloor, with most held in the water column, according to Dr. Michael Clarke, TMC’s Environmental Manager.
- TMC says there is no known pathway for carbon disturbed at 4,000 meters to reach the surface and be released into the atmosphere; the only measured pathway, CO2 from the riser pipe during operations, is described as negligible.
- The video argues that most sequestered carbon is held in shallow-water sediments, not abyssal sediments, and that benthic trawling in shallow waters disturbs more sequestered carbon than polymetallic nodule collection at depth.
- TMC cites life-cycle studies showing that sourcing metals from the seabed produces a fraction of the carbon emissions of land-based mining, which involves deforestation and soil disturbance that release stored carbon.
