Can Big Engineering Fix Climate Change?

David King, the Government’s former chief scientific adviser, is making the media rounds today (BBC, The Telegraph, The Daily Mail) talking about Cambridge’s planned Centre for Climate Repair which is going to investigate global scale geoengineering options to combat Climate Change.

The three examples technologies listed in most stories are ‘Ocean Spraying’, ‘Carbon Capture and Storage’ and ‘Ocean Greening’. These are all ideas with some track record — I’ve dabbled on some parts of some of these problems before myself, and they feature regularly in my classes today (as indeed, they did when I taught at Cambridge’s Centre for Sustainable Development). So I’m certainly interested in hearing about new developments on these or similar ‘big engineering’ approaches.

Of the three, I’m particularly interested in the ‘Ocean Greening’, which involves seeding the oceans with the limiting nutrient — typically iron in ” “high nutrient/low chlorophyll” (HNLC) zones. The BBC article has a nice graphic:

Like the other ideas, this proposal is by no means new (here’s a popular article from ~20 years ago proposing the same thing) but that in and of itself doesn’t mean it is a bad thing to be looking at — far from it! And I appreciate that the focus of the Centre here is on “radical solutions” to try and remedy a serious threat associated with atmospheric CO2. I don’t believe the intention is to suggest these things would be desirable interventions on their own with all other things being equal.

But we are still talking about a global intervention, and one with, by design, global effects. It’s worth then, being concerned that we not substitute one form of “dangerous and irreversible damage to the planet” with another. Rarely discussed in popular articles however, is how close the Ocean Greening proposal is to what is generally considered to be a very bad thing: Eutrophication. The Ocean Greening proposal as presented is basically an intervention to actively promote eutrophication of the oceans. So this is the kind of tradeoff that may need to be considered.

I think this makes the proposed Centre’s mandate more (not less) important and exciting, and would love to see some of these points in the coverage of it.