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Carbon Sinks 101

A carbon sink is anything that absorbs more carbon that it releases whilst a carbon source is anything that releases more carbon than they absorb. Forests, soils, oceans and the atmosphere all store carbon and this carbon moves between them in a continuous cycle. Consequently, forests can act as sources or sinks at different times.

The most important carbon sinks however are fossil fuel deposits as they have the unique benefit of being buried deep inside the earth, naturally separated from the carbon cycling in the atmosphere. This separation ended when humans began burning coal, oil and natural gas, causing greenhouse gas concentrations in the atmosphere to soar to levels more than 30 per cent higher than at the beginning of the industrial revolution. We are still adding roughly 6 billion tonnes of carbon per year to the atmospheric carbon cycle, significantly altering the intricate web of carbon fluxes, and as a consequence, altering the global climate.

Because of this, a lot of emphasis and hope has been put into the ability of trees, other plants and the soil to temporarily sink the carbon. Indeed, the Kyoto Protocol, the international communities’ main instrument for halting global warming suggests that the absorption of carbon dioxide by trees and the soil is just as valid a means to achieve emission reduction commitments as cutting carbon dioxide emissions from fossil fuels.

The fatal flaws

FERN profoundly disagrees with the assumption that fossil fuel use can be justified by sinks because it overlooks some important facts:

  • If used to offset fossil fuel emissions, carbon sinks justify an emission that would not otherwise have happened as it would have put the fossil fuel user over its emissions allowance under the Kyoto Protocol.
  • All carbon is not the same. Fossil carbon is generally static whereas that which is in the active carbon pool (the atmosphere and the biosphere) can be easily released through activities beyond government control such as forest fires, insect outbreaks, decay, logging, land use changes or even the decline of forest ecosystems as a result of climate change.
  • Afforestation - especially afforestation in northern boreal regions - may accelerate global warming. Climate change is expected to shift Canada's boreal forest borders northward and boreal forests are expected to expand into the southern parts of the tundra. While this will mean that carbon is removed from the atmosphere as trees grow, it may not benefit the climate: One of the key factors affecting the global climate is the 'albedo effect', a process which determines how much sunlight is reflected back into space and how much warms the Earth's surface. Dark green forests absorb more sunlight than tundra or farmland, adding to the warming trend in the boreal if large non-forested areas that are now covered in highly reflective snow were planted with trees.
  • It is not possible to accurately measure the damaging effect of fossil fuel (airplanes for example are more damaging depending on how high they fly) or the “sink” effect of a forest (trees will take in different amounts of carbon depending on the weather).

Negative effects on peoples

Besides the major shortcomings of sinks from a scientific perspective, FERN’s analysis has shown that many sinks have had and continue to have negative impacts on forests and forest peoples:

  • The Kyoto Protcol makes no difference between forests and plantations, meaning that a substantial percentage of afforestation and reforestation projects would result in large-scale tree plantations. The first carbon sinks project seeking registration with the Kyoto Protocol’s Clean Development Mechanism (CDM) was a plantation in Brazil.
  • Many carbon sinks are, or will be, located on lands where forest peoples' rights to customary land use have not been recognised or have been violated (see Forests of Fear). The Kyoto Protocol cannot hope to improve this situation as it includes no reference to indigenous peoples or forest dwellers.
  • Lands dedicated to carbon sink projects require contractual agreements that lock the land up for years. Effectively grabbing the best land for emission rights for the most polluting countries rather than contributing to meeting the needs of people in the Global South.

SinksWatch aims to dispel the myth that 'carbon is carbon', as that assumption ignores the interactions of different carbons with the atmosphere. In addition to this basic fallacy, there are further flaws once with regards to the carbon accounting framework and the environmental and social shortcomings of the Kyoto Protocol itself.

The following reports also provide additional information about the problems associated with carbon sinks accounting:

Full Carbon Account for Russia
IIASA Interim Report IR-00-02.

Taking Credit.

Sinks in the Kyoto Protocol: A dirty deal for forests, forest peoples and the climate

The Carbon Shop: Planting new problems


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