Protecting the marine environment must remain central to any marine geo-engineering project, countries have warned at the International Maritime Organization.
At the recent meeting of the London Convention Contracting Parties (the London Convention as amended is the main regulatory instrument in this area) governments noted expert findings that
- marine carbon dioxide removal approaches are still in the early stages and have significant knowledge gaps
- each approach comes with trade-offs in terms of durability, energy demand, and environmental impact
- some approaches require high energy inputs, large ocean area, could be difficult to verify, and could potentially conflict with other ocean uses
The Parties declared that they will continue to advance their scientific understanding of marine geo-engineering, and will seek to develop a draft resolution to provide clarity and to address the challenges.
They will also work on the draft revised Ocean Fertilization Assessment Framework and advise on the next steps needed to promote effective implementation, and will also work on how to apply draft assessment frameworks on ocean alkalinity enhancement, biomass sinking, and marine albedo modification.
What is marine geo-engineering?
Marine geo-engineering projects hope to remove carbon dioxide from the atmosphere and put it on, or under, the sea bed.
There are different ways this could possibly be done.
Marine geo-engineering a how to… and a maybe not
One is to put nutrients on the ocean surface to encourage the growth of plankton. A large percentage of plankton will incorporate carbon into their bodies (shells are often made of calcium carbonate) and, eventually, that biomass would sink to the floor.
Another suggestion is to take large volumes of algae or crop waste, and sink it to the sea bed.
A third option could be to pump cold but nutrient-rich water from the deep to the surface so as to support bio-productivity.
Yet another option is to add a highly alkaline material (such as crushed or powdered olivine) to the sea which would boost its ability to absorb carbon dioxide.
Then there’s also the possibility of brightening marine clouds which does have rapid cooling potential, which is nice.
All of these options could potentially have some drawbacks. Causing a collapse of local or regional food webs is a foreseeable issue. Other foreseeable problems include changing the nutrient balance of the local seas, radically upsetting local ecologies, smothering the seabed, and depleting the deep sea of nutrients, and upsetting weather patterns on a global scale (well, more than they already are anyway). Oh, and, changing the chemistry of the world-ocean might also be a tad… inadvisable, y’know?
There are a lot of issues that scientists are warning about as, indeed, so has the IMO.
Demand and regulation
Dumping at sea is governed by the London Convention (1992) / London Protocol (1996) “LC/LP”.
The treaties have led to the end of at-sea incineration, the adoption of the “precautionary approach”, and the end to the dumping of industrial wastes and sludges at sea.
However, as the IMO notes, the ocean already absorbs about a quarter of current carbon dioxide emissions and marine geo-engineering has gained attention as a way to increase the ocean’s capacity to remove more carbon dioxide from the air.
The IMO also notes that there are numerous organisations that appear to be engaged in some kind of marine geo-engineering project.
In relation to marine geo-engineering, from 2007 onwards, contracting parties have decided that the LC/LP cover ocean fertilization and other projects, and there has been an ongoing, incremental, series of works calling for a halt on such matters as ocean fertilization (although this could be allowable by a permit). In relation to sea-based carbon capture and sequestration, the contracting parties to the LC / LP have since 2006 adopted amendments to create a legal basis in international environmental law to regulate carbon capture and storage in sub-sea geologies.
