In a market mechanism such as emission trading, emission permits have to be shared (or allocated) among the different actors.
The most widespread allocation methodologies are:
In the UNFCCC, the reduction effort has been negotiated and calculated for each industrialized country (Annex I to the UNFCCC) according to the differentiate responsibility and capacity principles.
The European Union (EU15) has negotiated a global reduction objective of -8% of CO2-eq. emissions in comparison with the 1990 level (= the "European bubble"), that has been shared among the Member States on the basis of the triptych approach.
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