Satellite image of sea-surface chlorophyll concentrations with our bloom encircled. Note much larger natural bloom on the upper right and the generally higher values in the southeast than elsewhere. Graphic: NASA (http://oceancolor.gsfc.nasa.gov)
The verdict from one of the first real world geoengineering experiments? It didn’t work (but they learned a lot).
A team of scientists from the German National Institute of Oceaonography and the Alfred Wegener Institute recently attempted one of the first large scale experiments in oceanic geoengineering.
The team fertilized a 300 square kilometre patch of ocean with six tonnes of dissolved iron in an effort to sequester excess CO2. The idea was that certain kinds of plankton eat the iron, die, then sink to the bottom of the ocean, taking tonnes of CO2 with them. Unfortunately it didn’t work as expected.
From the press release:
The cooperative project Lohafex has yielded new insights on how ocean ecosystems function. But it has dampened hopes on the potential of the Southern Ocean to sequester significant amounts of carbon dioxide (CO2) and thus mitigate global warming.
Why did it dampen hopes? Christine Lepisto has an excellent summary over at Treehugger. She writes:
The experiment started out following scientists’ predictions. After the addition of the iron source to the swirling current, phytoplankton biomass doubled, as can be seen by the orange-reddish swirl in the NASA image above. But the growth was mainly a soft and tasty algae called Phaeocystis. Other little creatures, known as copepods, moved in quickly to gobble up the algae, soon followed by shrimp-like amphipods which lunched on the copepods. Ultimately, these amphipods end up in the bellies of squid and fin whales, so maybe iron fertilization could be a geo-engineering solution for supporting these top-of-the-food-chain species. But certainly, the experiment did not result in tons of CO2 safely sequestered on the ocean floor, proving the iron fertilization hypothesis not yet ripe for geo-engineering scale games with mother nature.
The experiments were not a failure from a scientific point of view, the press release notes that a tremendous amount of new data and information was gained. But it does suggest that iron fertilisation is unlikely to be a solution to our climate change concerns.
This experimental data confirms many of the anxieties of commentators writing about geoengineering, which we have previously covered here (“Irreversible Climate Change, Meet Unstoppable Political Force”).