KOSEN 한인과학기술자네트워크

As evidence for the link between atmospheric greenhouse gases and climate change has increase, international efforts have focused on ways in which anthropogenic emissions of greenhouse gases, particularly carbon dioxide (CO₂), can be reduced. Knowledge that CO₂ is stored within and exchanged between the atmosphere and vegetation and soils has led to the suggestion that soils and vegetation could be managed to increase their uptake and storage of CO₂, and thus become land carbon sinks'. Under the terms of the 1997 Kyoto protocol, signatores can meet part of their obligations to reduce greenhouse gas emissions from fossil fuel consumption by increasing these land carbon sinks. However there have been concerns about the permanece of land carbon sinks and the accuracy with which they can be quantified and verified. This report focuses on the scientific issues underpinning land carbon sinks, particularly in the context of their inclusion in the Kyoto Protocol. Terrestrial vegetation and soils are currently absorbing approximately 40% of global CO₂ emissions from human activities. Changes in agricultural and forestry practices and slowing deforestation could increase this, potentially achieving a maximum of 25% of the reductions in CO₂ that are projected to be required globally by 2050 to avoid large increases in temperature. This would however require considerable political will and there is little potential for increasing the land carbon sink thereafter. . . . . . There is still considerable uncertainty in the scientific understanding of the causes, magnitude and permanence of the land carbon sink through changes in land management practices is finite in size and duration. The amount of CO₂ that can be sequestered in these sinks in small in comparison to the ever-increasing global emissions of greenhouse gases. Projects designed to enhance land carbon sinks must therfore not be allowed to divert financial and political resources away from the restructuring of energy generation and use (e.g. increased use of renewable energy), technological innovation (e.g.increased fuel efficiency, sequestration of CO₂ at source) and technology transfer to less developed countries. It is these that must provide the ultimate solution to the problem of reducing the concentration of greenhouse gases in the atmosphere.