The first officially-recognized Clean Development Mechanism projects, in Honduras and India, have finally their carbon credits. One reason why the pace of CDM project certification is slow turns out to be a lack of standardization of greenhouse gas accounting processes. Although counting the greenhouse gases mitigated by clean development projects is well-understood in principle, just how the details are counted can vary from organization to organization. This lack of consistency -- and, occasionally, transparency -- prompted the World Resource Institute, working with the World Business Council for Sustainable Development, to assemble a standardized methodology for climate change mitigation accounting.

The GHG Protocol for Project Accounting (PDF) may sound like boring wonkery, but it provides a useful insight into the practical aspects of figuring out how to reduce our carbon footprints, and (just as importantly) to know for certain that we've done so.

The Project Protocol’s procedures are compatible with existing Clean Development Mechanism methodologies. However, the Project Protocol brings together in one place the key concepts, principles, and methods to account for GHG emission reductions from any type of GHG project. It provides detailed instructions for developing a GHG emission “baseline” using the two major approaches developed by climate policy experts [...]. It also explains how to account for the unintended changes in GHG emissions a project might cause, and how to report GHG emission reductions for maximum transparency.

The Project Protocol (which has its own website at GHGProtocol.org) is not intended to replace existing accounting mechanisms, but to supplement and translate between them, so that everyone is on the same figurative page regarding each project.

None of the six key principles embodied by the Project Protocol are terribly surprising, as each (relevance, completeness, consistency, transparency, accuracy, conservativeness) is typical of good accounting practices in general. What's notable is the effort the Project Protocol goes to in order to ensure the testable reliability of the results. This strikes me as enormously encouraging; the last thing an international effort to combine climate mitigation and global development needs is an accusation of fraud or accounting malfeasance.