共同実施
The EU ETS is 'linked' to the Joint Implementation and Clean Development Mechanism projects as it allows the limited use of 'offset credits' from them. Participating firms were allowed to use some Certified Emission Reduction units (CERs) from 2005 and Emission Reduction Units (ERUs) from 2008. Each Member State's National Allocation Plan must specify a percentage of the national allocation that will be the cap on the CERs and ERUs that may be used. CERs and ERUs from nuclear facilities and from Land Use, Land-Use Change and Forestry may not be used.