The urgency associated with mitigating the adverse impacts of climate change has spawned a variety of geoengineering schemes designed to promote better absorption of carbon dioxide and other greenhouse gases from the earth's atmosphere by the oceans and forests. This article examines three climate change mitigation activities which employ the ocean as a receptacle for these gases and the international law framework which applies to these activities in marine areas beyond national jurisdiction. It argues that although some guidelines have been developed by the States Parties to the London Convention and the London Protocol to regulate the environmental impact of sub-seabed sequestration of carbon dioxide, the international law framework for such activities in marine areas beyond national jurisdiction is ad hoc and far from comprehensive.
The damaging affects of anthropogenically-induced climate change on both the terrestrial and marine environment have been acknowledged by a succession of expert reports commissioned by global and national bodies. (1) This recognition has spawned heightened levels of activity by scientists, engineers and entrepreneurs to mitigate the adverse effects of climate change. Multiple schemes have been suggested to ameliorate the adverse effects of climate change on the environment caused by the burning of fossil fuels and other greenhouse gas emissions, including enhanced schemes to remove carbon dioxide from the atmosphere, The ability of the ocean to absorb rising levels of carbon dioxide in the atmosphere has been the focus of some of these schemes. The ocean is already a major sink for carbon dioxide because if its capacity to readily absorb excess atmospheric carbon and concert it to soluble form. A prominent deep sea scientist, Tony Koslow, estimates that approximately 5.5 billion tonnes (or gigatonnes) of carbon are now released into the atmosphere each year as carbon dioxide from the burning of fossil fuels, and that a third of that is taken up by the oceans. (2) Augmenting the rate at which the oceans absorb carbon dioxide, or using the oceans as a storage receptacle for excess carbon dioxide, are fundamental objectives of the climate change mitigation activities now being proposed and trialled in marine areas both within and beyond national jurisdiction. (3)
Less attention has been devoted to the environmental impacts of such climate change mitigation activities particularly where they occur in marine areas beyond national jurisdiction. While climate change mitigation activities conducted in marine areas within national jurisdiction may be subject to coastal State legislation and policy on environment, impact assessment and other environmental protection safeguards, the regulatory framework for such activities beyond national jurisdiction is fragmented and less defined. General obligations to protect the marine environment beyond national jurisdiction arc contained in Part XII of the United Nations Convention on the Law of the Sea ('1982 LOSC) (4) but these have not been supplemented in the case of marine areas beyond national jurisdiction with international law instruments applying modern environmental protection principles to the conduct of emerging activities such as climate change mitigation schemes by Flag Stares, their nationals and corporations. In the absence of systems to monitor and mitigate the adverse impacts of such activities in marine areas beyond national jurisdiction, there is a real risk of irreversible damage to the marine environment of these areas and its biodiversity (5)
This article will describe three climate change mitigation activities which involve using either the water column or sea-bed: sequestration of carbon dioxide in the water column or sea-bed; fertilisation of the open ocean with iron or other nutrients to stimulate phytoplankton blooms (which may enhance the capacity of the oceans to absorb carbon dioxide); and the use of wave-driven pumps suspended above the ocean floor to bring deeper, more nutrient-rich water closer to the ocean surface, where it may stimulate increased growth of phytoplankton to absorb carbon dioxide more efficiently, and eventually flush more carbon dioxide to the bottom of the ocean The article will analyse the applicability of the law of the sea and marine environmental law principles to these activities when they occur in marine areas beyond national jurisdiction, whether in the high seas water column or on the deep sea bed beyond national jurisdiction. …