Clean Development Mechanism
Credits generated under the Clean Development Mechanism are called Certified
Emission Reductions (CERs). A company can earn CERs in the same way
as ERUs with the difference that CERs only can be earned by realising
emission-reduction projects in developing countries.
Since January 2005 large companies in the EU are bound to emission ceilings.
If they cannot reduce their emission sufficiently, they can buy ERUs
(after 2008) and CERs, or emission rights from other companies. Also
governments with emission targets under the Kyoto Protocol can buy
or sell carbon credits.