Reducing the atmospheric concentration of carbon dioxide to pre-industrial levels would require removing approximately 1,000 gigatons of carbon dioxide. Work is underway to remove carbon dioxide at the needed speed and scale with ocean iron fertilization.

Reducing the atmospheric concentration of carbon dioxide down to pre-industrial levels will require removing and sequestering approximately 1,000 gigatons of carbon dioxide. This requires scaling up removal to about 60 Gt/yr by 2030 and maintaining that rate through 2050. The only method demonstrated to remove carbon dioxide at the needed speed and scale is ocean iron fertilization (OIF). Work is underway to refine monitoring, reporting, and verification (MRV) for marine carbon dioxide removal. This requires measuring the carbon dioxide removed and any carbon dioxide that returns to the atmosphere. 

OIF requires continuous monitoring during process development and during full-scale production. The effectiveness of this method, which replicates a natural process, needs to be measured across large areas where the application of iron dust stimulates phytoplankton growth, providing carbon dioxide removal through photosynthesis and sequestration in the ocean depths as biomass sinks. 

Ocean-going buoys measure carbon dioxide in the water and air, both upwind and downwind of the project area, and across a grid of sectors within the project area. This provides direct evidence of effectiveness. Measurements from NASA’s OCO-2 satellite monitor changes in carbon dioxide concentration above OIF project areas so that, in addition to observing reductions, possible re-emissions can also be detected. 

IEEE and other organizations are continuing to explore the science and engineering needed for MRV.