Neither the UNFCCC nor the g[Kyoto Protocol ](which includes most of the binding commitments to reduce greenhouse gases) specifies a compliance mechanism, although Article 18 of the Protocol refers to a compliance mechanism.
Discussions regarding how non-compliance with Protocol obligations should be handled have been contentious. For example at COP-6, some States argued for binding consequences (either in the form of additional obligations or financial penalties — and there was considerable disagreement over which consequences were appropriate). Other States argued that non-binding consequences were preferable, in part because binding consequences would require an amendment process (with its own negotiating, signature, and ratification processes).
COP-7 adopted the Marrakech Accords which included a “rulebook for compliance” with the Protocol, establishing a Compliance Committee with two separate but complementary branches: a facilitative branch and an enforcement branch. The facilitative branch is primarily for developing countries, and it seeks to facilitate and assist countries to come into compliance. This is particularly relevant where non-compliance results primarily from a lack of capacity and not necessarily a lack of political will. In contrast, the enforcement branch has the power to review allegations of non-compliance and to impose a range of sanctions including financial penalties, forfeiting access to mechanisms such as emissions trading, and/or reductions in future allocations of allowable emissions. The Compliance Committee met first in 2006.
For more information, see http://unfccc.int/resource/docs/cop7/l21.pdf or contact secretariat@unfccc.int