Under the Convention, all Parties must report on the steps they are taking to implement the Convention (Articles 4.1 and 12). Most Annex I Parties submitted their first report (known as a "national communication") in 1994 or 1995 and their second in 1997, except for most Parties with economies in transition, who submitted their second communications in 1998 (according to the longer timeframe granted to them).

Since 1996, Annex I Parties must also submit an annual greenhouse gas inventory (GHG), beginning with data for their base year (in most cases 1990), and up to the last but one year prior to the year of submission (inventories for 2001, for example, include data up to 1999).

Reporting guidelines

In preparing their national communications and GHG inventories, Annex I Parties must follow reporting guidelines. These guidelines have now been revised twice, at COP 2 (Geneva, July 1996) for the preparation of the second round of communications, and again at COP 5 (Bonn, October/November 1999), where revised reporting guidelines were adopted for the preparation of third national communications. At COP 5, Parties also adopted separate reporting guidelines for annual inventories, including a common reporting format, as well as guidelines for reporting on global climate observing systems.

At SBSTA 12 (June, 2000), Parties considered the IPCC report entitled Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories. The SBSTA concluded that the good practice guidance contained in the report should be applied by Annex I Parties to the extent possible when preparing their inventories due in 2001 and 2002 and should be used for inventories due in 2003 and beyond. Annex I Parties with economies in transition may phase in the good practice guidance two years later than other Annex I Parties. As the good practice guidance did not include specific guidance for the land use, land-use change and forestry sector, the SBSTA invited the IPCC to conduct further work on good practice guidance for that sector.

The Convention states that the information provided by Annex I Parties is to be reviewed by the COP (Article 4.2(b)). In-depth reviews of the first and second national communications of Annex I Parties, including inventory data, have taken place based on procedures established by COP 1. As part of the review process, the secretariat has prepared compilation and synthesis documents of national communications.

The in-depth review of each national communication results in the publication of an in-depth review report, which expands on, and complements, the information already given and provides more up-to-date information that has become available since the publication of the national communication. The in-depth review reports aim to facilitate the work of the COP in assessing the implementation of commitments by Annex I Parties. The reports also allow easier comparison of information between the national communications of Parties, although no common indicators are employed.

At COP 5, Parties adopted separate guidelines for the technical review of greenhouse gas inventories by Annex I Parties, to be used during a two-year trial period beginning in 2000. The results of the various stages of the technical review so far completed have been published on the secretariat's web site: initial check of annual inventories (2000 & 2001); synthesis and assessment of GHG inventories (2000); and reviews of individual GHG inventories (2000).

At SBI 13 part II (meeting together with COP 6 in The Hague, November 2000), Parties considered a compilation prepared by the secretariat of the latest available annual inventory data (1990-1998) submitted by Annex I Parties. The SBI expressed concern over the increase in emissions in many Annex I Parties indicated by the latest data (emissions in Annex II Parties rose 7% over the period) and reaffirmed the need for further action to reverse this trend.

Also at SBI 13 part II, Parties reviewed progress made by the secretariat in conducting in-depth reviews of national communications and in implementing the trial period for the technical review of greenhouse gas inventories launched at COP 5. The COP took note of the SBI’s conclusions.

There was no substantive discussion on issues related to national communications from Annex I Parties at either SBSTA/SBI 14 or COP 6 part II (meeting during the same period in Bonn, July 2001).

A workshop on the preparation and review of third national communications, which had been requested by SBI 12 (June, 2000), took place in Bonn in February/March 2001.

SBSTA 15 (meeting together with COP 7 in Marrakesh, October/November 2001) is expected to hold a preliminary discussion on the experiences of Parties, the secretariat and experts in using the reporting guidelines for inventories and the guidelines for the technical review of inventories adopted at COP 5, along with the IPCC good practice guidance.

The SBSTA will also consider information provided by the IPCC on its work in developing good practice guidance for the land use, land-use change and forestry sector.

The SBSTA, however, may defer in-depth consideration of possible revisions to the GHG inventory guidelines until its next session (June 2002), with a view to recommending revised guidelines for adoption at COP 8. To prepare for this work, an expert meeting on the methodological and operational aspects of the GHG reporting and review guidelines will be held in Bonn, on 4-6 December 2001.

At SBI 15, meeting during the same sessional period, Parties will continue their discussions, initiated at SBI 12, on the feasibility of developing detailed guidelines for the in-depth review of national communications. The SBI will also discuss the timing of in-depth reviews of third national communications and make a recommendation on this matter to COP 7. In addition, the SBI is expected to invite Parties to nominate experts to the roster to serve on in-depth review teams.

The SBI will also consider a status report on the in-depth review of second national communications, as well as the latest inventory data submitted for the period 1990-1999.

The third national communications of Annex I Parties are due on 30 November 2001.