Verifying sinks under the Kyoto Protocol: VERTIC Briefing Paper 01/03

Article 3.4 of the 1997 Kyoto Protocol to the 1992 UN Framework Convention on Climate Change raises the possibility that activities involving agricultural soils, land-use change and forestry not dealt with under Article 3.3 might be used to help meet a party’s emission reduction targets. Article 3.4 activities can be grouped under forestry management, cropland management, grassland management and re-vegetation.
Verification refers to the activities and procedures for establishing the reliability of the data submitted by the parties for Article 3.4 activities. This usually means checking the data against empirical data or independently compiled estimates.
Whether or not Article 3.4 is verifiable depends critically on what the parties decide is acceptable in terms of verifiability.
At its most stringent, verifiability would entail the sampling of each georeferenced piece of land subject to an Article 3.4 activity at the beginning and end of a commitment period, using a sampling regime that gives adequate statistical power. Soil and vegetation samples and records would be archived and the data from each piece of land aggregated to produce a national figure. Separate methods would be required to deliver a second set of independent verification data. Such an understanding at the national level would be prohibitively expensive.
At its least stringent, verifiability would entail the reporting of areas under a given practice (without georeferencing) and the use of default values for a carbon stock change for each practice, to infer a change for all areas under that practice.
Intermediate in the range of verifiability is a scheme in which areas under a given practice are georeferenced (from remote sensing or ground survey), carbon changes are derived from controlled experiments on representative climatic regions and on representative soils (or modelled using a well-evaluated, well-documented, archived model) and intensively studied benchmark sites are available for verification.
If the parties decide on a stringent level of verifiability, Article 3.4 is at present, and is likely to remain in the future, unverifiable. If less stringent levels of verifiability are adopted, a low level of verifiability might be achieved by most parties by the beginning of the first commitment period (2008-2012).