Sometime between now and mid-March, the German research vessel Polarstern will head out into the southwest Atlantic with a load of iron sulfate that it will disperse into the southern ocean. the goal is to test the feasibility of sequestering carbon by triggering phytoplankton blooms with trace iron introduced into the surface layer.
This despite the fact that a similar effort by the now-bankrupt Planktos was abruptly canceled last year, and researchers published a study in Nature last week that concludes the potential of iron-induced carbon sequestration is greatly overstated. Based on the 2004 CROZEX experiment, the study discovered that carbon sequestration can vary dramatically in different regions of the ocean, and that capturing even a fraction of the carbon released every year would require disruption of vast stretches of ocean.
But I’ll bet this doesn’t dissuade the Polarstern’s Indian and German sponsors, LOHAFEX. as this is a classic example of engineering optimism in the face of messy reality. This is one more instance of the growing debate between two camps: “Engineers” — people convinced we must engineer our way out of the climate crisis with bold, planetary-scale interventions–, and “Druids” — individuals equally convinced that the only sensible option is to reduce our human planetary footprint. As I have already written, I believe the answer lies somewhere in the middle with a mix of restraint and intervention. But I fear that the engineers-druids debate will continue to slow our collective response to climate change. In the meantime, it would be a good thing if Polarstern’s sponsors took a moment to read the CROZEX results before littering the Antarctic Ocean with iron filings.