Abstract
This study examined three problems of credibility in offset credits issued by forest-based carbon sequestration projects under the Japan Verified Emission Reduction (J-VER) Scheme. (1) Permanence of carbon sequestration is ensured against emissions by both natural disasters and landowner behaviours, although it is ensured for only 10 years after the end of the period for issuance of credits and is shorter compared with other verified emission reductions (VERs). (2) The criteria for the acceptable level of sequestration uncertainty by the projects might become nominal because monitoring areas or stands do not need to coincide with areas where a monitoring plot is set. (3) Two methodologies for increasing CO_2 sequestration by forest management activities are methodologies R001, a thinning promotion project, and R002, a sustainable forest management promotion project. However, methodology R002 does not necessarily promote sustainable forest management.
