Methods for assessment of inventory data quality: issues for an IPCC expert meeting

The quality of greenhouse gas inventories has been a long-standing issue among the scientific community and its importance has more recently risen on the policy agenda. This is because national inventories are now the basis of legally-binding commitments under the United Nations Framework Convention for Climate Change. The quality of inventories will also affect the effective implementation of the Kyoto Protocol through its flexible mechanisms, such as emissions trading. In 1997, the Intergovernmental Panel on Climate Change (IPCC) brought together a group of experts to consider approaches for assessing the quality of inventory data. This meeting considered three key issues. First, how do we define inventory quality? Second, what approaches can we use to assure the quality of inventories? Third, given the policy needs of Climate Convention, what are the next steps for quality assurance? There are several approaches for assessing inventory quality. This paper summarises them for carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Many of these approaches are routinely performed by inventory experts, others are novel.