IOC Releases Ocean Fertilization Policy Guide

The Intergovernmental Oceanographic Commission (IOC) has released a report titled Ocean Fertilization: A Scientific Summary for Policy Makers. The guide is brief, impartial, and remains agnostic on the question of ocean fertilization. Two of its conclusions are noteworthy:

• "Whilst models can be developed to improve predictions of both benefits and impacts, the totality of effects will be extremely difficult − and costly − to directly verify, with implications for the confidence and cost-effectiveness of commercial-scale applications." Tradeable carbon credits require credible measurement and verification in order to maintain the integrity of any trading system. Technical and cost factors make measurement and verification difficult to carry out for ocean fertilization activities, and thus call into question the very proposition of commercial ocean fertilization.
• "Estimates of the overall efficiency of atmospheric CO2 uptake in response to iron-based ocean fertilization have decreased greatly (by 5 – 20 times) over the past 20 years. Although uncertainties still remain, the amount of carbon that might be taken out of circulation through this technique on a long-term basis (decades to centuries) would seem small in comparison to fossil-fuel emissions." The promise of ocean iron fertilization as a CDR strategy is less than first thought, and continuing assessments show progressive declines in estimates of carbon removal potential. Ocean fertilization may play an important role as part of a geoengineering policy portfolio, but it is increasingly unlikely to serve as the principal tool of climate intervention.

These conclusions reinforce a growing perception that ocean fertilization is both more complicated and less effective than originally imagined, and that commercial, scientific, and policy interest may have already peaked.