Nature and transaction of Certified Emission Reduction (CER) units

The Clean Development Mechanism (CDM) under the Kyoto Protocol is the only mechanism with dual objectives in which Non-Annex B Countries of the protocol، particular developing countries، have the ability to participate in it. Certified Emission Reduction (CER) Units resulting from the activities of the CDM projects are the tradable units that usually traded by the participants in these projects. The nature and terms of these units have been offered different theories and not a consensus has been reached. Likewise، Certified Emission Reduction transactions with the high level of diversity and flexibility may be influenced by the nature of these units. In this paper، we try to delineate the nature of these units with a review of theories which are presented and then normal structures of the Certified Emission Reduction transactions with the advantages and disadvantages of each of these transactions will be stated.