Academic journal article Duke Environmental Law & Policy Forum

Sinks and the Climate Change Regime: The State of Play

Academic journal article Duke Environmental Law & Policy Forum

Sinks and the Climate Change Regime: The State of Play

Article excerpt


The sequestration of carbon by ecosystems, particularly terrestrial environments, has been the subject of much discussion since 1990, when the method was first recognized as a way to combat climate change. Since that point, ferocious debate has surrounded the evolving proposals, eventually leading to the collapse of one of the Conference of the Parties (COP) to the Framework Convention on Climate Change (FCCC), and the United States walking out on the Kyoto regime. This article intends to show why this collapse occurred, discuss the bewildering array of concerns over carbon sinks, and reflect on the current state of play with regard to the sink question in the overall climate regime.


It is possible to sequester (suck up) carbon from the atmosphere and store it in "reservoirs." A "reservoir" is a component of a climate system where a greenhouse gas or a precursor of a greenhouse gas may be stored. (1) The term "sink" is used to describe the process, activity or mechanism that removes a greenhouse gas, aerosol, or precursor of a greenhouse gas from the atmosphere. (2) Theoretically, sinks may either be oceanic or terrestrial in nature. The following sections describe these processes and explain their importance to the global climate change debate.

A. Sequestration in the Ocean

It is hypothesized that huge growths of plankton formed in the oceans 55 million years ago shortly after massive volcanic eruptions flooded the atmosphere with carbon dioxide. Arguably, this plankton played a key role in removing carbon dioxide from the atmosphere and helping the Earth return to a more hospitable temperature. Moreover, contemporary studies suggest that the phytoplankton may currently be incorporating 45-50 billion metric tons of inorganic carbon into their cells every year. (3) This possibility has caused a number of scientists to suggest that plankton populations should be increased. (4) It has been shown that adding iron to the ocean can make plankton bloom temporarily. (5) This bloom may accelerate the reduction of carbon dioxide buildup in the atmosphere; the microscopic organisms suck up dissolved carbon dioxide from the water, which in turn is replaced by carbon dioxide from the air. (6) As plankton die and settle on the ocean floor, their cells decompose and carbon is locked up in the seabed, and is thereby removed from circulation. (7) This cycle causes the ocean to act as a carbon sink. In theory, adding one ton of iron to the ocean could lead to a bloom of plankton that could absorb up to 10,000 tons of carbon from the atmosphere. (8) Such possibilities also suggest that "seeding the ocean" could be a relatively cheap option for reducing carbon dioxide buildup as compared to other reduction strategies. (9)

Despite these possibilities, the limitations of this approach have become apparent. There was originally "considerable quantitative uncertainty" in this area, and it has now been shown that massive amounts of seeding would be required to make relatively small reductions in carbon dioxide build-up. (10) Further, dumping extra iron into the oceans may also disrupt ecological cycles. (11) In fact, seeding the oceans may actually encourage bacteria that produce methane and nitrous oxide. (12) It may also disrupt the nutrient patterns near the surface of the ocean and detrimentally affect biological activity in areas such as with fisheries. (13) Finally, rather than causing an explosion of algae that would sequester carbon in the long term, seeding may simply give planktonic animals that feed on algae a massive free lunch in the short term. (14) Due to such limitations, sequestration in the ocean has received little attention within the formal climate change regimes. Moreover, the Kyoto Protocol has limited emissions by sources and removals by sinks to land-use change and forestry activities, specifically "afforestation, reforestation and deforestation. …

Search by... Author
Show... All Results Primary Sources Peer-reviewed


An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.