Another geoengineering scheme that has received some coverage in recent years is artificial ocean upwelling, whereas flap-valve operated ocean pipes are used to upwell nutrient-rich deeper waters to fertilize surface oceans, with the objective of ultimately increasing carbon sequestration. An excellent potential reading in this context is a new study in GRL, A. Oschlies, et al., Climate Engineering by Artificial Ocean Upwelling: Channelling the Socerer’s Apprentice, 37 Geoephysical Research Letters L04701 (2010) (subscription required).
Key take-aways from a simulation conducted by the researchers include the following:
- The cumulative projected oceanic carbon sequestration would be only 18 PgC by the year 2100, a mere 7% of the cumulative increase in export production; however, the reduction in atmospheric carbon dioxide would be much mroe substantial,a bout 83 PgC; this would correspond to one of the “stabilization wedges” of Pacala & Socolow’s projections of what would be necessary to avoid a doubling of atmospheric concentrations of carbon dioxide over the next 50 years. As a consequence, simulated global surface temperatures could drop by up to 1C within the first decreases up the pipes’ operation;
- However, should the scheme’s operation cease, conditions would not simply revert to the control run, in contrast to some other climate engineering schemes. Rather, temperatures would rise by 0.07C in 20 years because ocean upwelling would additional heat uptake of the planet, with the extra heat stored predominantly in the ocean’s low-latitude subsurface waters, where it would make its way back to the sea surface once upwelling stopped.
Some potential discussion questions could include:
- What potential adverse side-effects do you envision could result from ocean upwelling? How do you envision this risk would be addressed in a governance regime?
- Does the potential increase in temperatures that could result from ceasing ocean upwelling operations counsel against even consideration of the method?
- What legal regimes would potentially have jurisdiction over ocean upwelling operations?