Growing vegetation, especially in forest
s, absorbs carbon dioxide
, one the major greenhouse gases
. Some nations have proposed planting new forests, or protecting old ones, as measures to help them meet their commitments in terms of the Kyoto Protocol
to reduce greenhouse gas emissions.
While reforestation is probably a good idea, carbon sinks are controversial. Firstly, carbon sequestration through sinks isn’t permanent: forests burn or die, someday. Secondly, while using sinks might defer the need actually to reduce emissions, real reductions will have to happen sooner or later. Thirdly, it is difficult to measure and account for the impact of sinks: how much carbon absorption can be credited to human action and how much would have happened anyway? Finally, some people feel there isn’t enough data available to support the use of forests as carbon sinks.