An assigned amount unit was a tradable "Kyoto unit" or "carbon credit" representing an allowance to emit greenhouse gases comprising "one metric tonne of carbon dioxide equivalent, calculated using global warming potentials".
[5] Article 17 of the Kyoto Protocol allowed emissions trading between Annex B Parties (countries).
Parties that had "assigned amount units" to spare because of reductions in emissions below their Kyoto commitment set out in Article 3 and Annex B could sell those units to countries that had emissions exceeding their targets.
[6] Article 17 also required that any such emissions trading must be supplemental to domestic action for the purpose of meeting quantified emission limitation and reduction commitments.
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