A fit for purpose approach for reporting and review under UNFCCC’s Enhanced Transparency Framework

Abstract Parties, expert review teams and the secretariat have worked diligently over the past decades to implement a transparency system that responds to the decisions of Parties. The existing system has enhanced the transparency of Party’s reporting of climate information and has been successful in assessing Parties’ compliance with their Kyoto Protocol obligations. But that system is operating at a very high, possibly unsustainable, workload for all involved. With the ensuing demands from the enhanced transparency framework requiring more Parties to report more information more frequently, it is important to take stock of what has been learned and apply that knowledge to implement a system that adheres to the Parties’ decisions and achieves the goals of the Paris Agreement. This paper proposes implementation of a reporting and review process that is “fit-for-purpose”, with a view to ensuring that the objectives of the Paris Agreement are met in the most efficient, cost-effective and sustainable manner. Key elements in the design of a “fit for purpose” approach include: ensuring national submissions made by Parties are fit for purpose, organizing reviews in a manner that is most appropriate for the circumstances of the country under review, and preparing focused review reports that are conducive to Parties’ needs. The proposed approach starts from the basic premise that within the cyclic reporting and review process the previous review team did their job and the present review team therefore focuses on changes in the submission.


Background
One of the important processes under the United Nations Framework Convention on Climate Change (UNFCCC) is its system of reporting and review, requiring Parties to the UNFCCC to regularly report their progress towards achieving the agreed upon objectives and quantitative greenhouse gas (GHG) emission reductions needed to meet the objective of the Convention: avoidance of dangerous climate change.To this end, Parties have agreed to inform each other in various formats on their policies and actions towards meeting this objective, as reflected in a series of decisions of successive annual Conferences of the Parties (COPs): All countries (or Parties, as referred to in the UNFCCC) have been required or encouraged to report information on national efforts related to climate mitigation, adaptation, and financial, technological development and transfer, and capacity building support provided or received by the country to meet the objective of the Convention.
These so-called National Communications have been submitted on a periodic basis since the adoption of the UNFCCC in 1992; In addition, Annex I Parties 1 have reported annual inventories of national GHG emissions by sources and removals by sinks since the mid-1990's, subject to increasing requirements with the adoption of the Kyoto Protocol in 1997 and its subsequent first commitment period (2008-2012) and second commitment period (2013-2020); In 2013, Parties agreed to a framework for reducing emissions from deforestation and forest degradation, as well as the sustainable management of forests and the conservation and enhancement of forest carbon stocks in non-Annex I Parties (i.e.developing countries), referred to as "REDDþ".Participation in these activities is voluntary, but those developing country Parties who choose to do so report on these activities to receive results-based finance for actions that are measured, reported and verified.Since 2014, Annex I and non-Annex I Parties have also been required to submit updated climate information on a more frequent basis through Biennial Reports (BRs) and Biennial Update Reports (BURs), respectively.
At the COPs in Paris [1] and Katowice [2], Parties agreed to embark on a transition from the present measurement, reporting and verification (MRV) system under the Convention and the Kyoto Protocol towards an Enhanced Transparency Framework (ETF) under the Paris Agreement.This transition will lead to a system where all Parties (developed and developing countries) report all information in a common Biennial Transparency Report (BTR).
The rulebook outlining what information "shall" and "should" be reported under the Paris Agreement has been agreed by all Parties through the Modalities, Procedures and Guidelines (MPGs) for the transparency framework for action and support referred to in Article 13 of the Paris Agreement (decision 18/CMA.1),as has the overall scope and procedures for the review of that information by technical expert review teams.Further operational guidance was agreed in subsequent decisions by Parties, particularly decision 5/CMA.3,which instructs Parties how to report that information in various tabular and narrative formats and outlines.
Experience from implementing the current MRV system under the Convention has demonstrated that effective and efficient operation of the reporting and review process in a manner that is consistent with Parties' decisions, requires careful and continuous consideration by the UNFCCC secretariat, Parties and technical experts.On the reporting side, the Consultative Group of Experts (CGE), a group providing technical assistance and support to developing countries to help them fulfil their reporting requirements, periodically assesses the constraints, lessons learned and capacity-building needs in preparing climate reports.Regarding review, lead reviewers from two of the processes (the review of GHG Inventories and review of biennial reports) meet on an annual basis to discuss lessons learned in implementing Parties' decisions and make recommendations to the UNFCCC secretariat on ways to improve the effectiveness and efficiency of the review process.The conclusions from these annual meetings are made publicly available 2 , and when read in conjunction with the periodic technical papers prepared by the CGE 3 , provide a window into the successes and challenges faced in implementing the current reporting and review system under the Convention.
We seek to draw from the collective wisdom of these actors, as well as our own experience 4 , to highlight some key challenges identified in the current reporting and review process under the Convention and the Kyoto Protocol and offer possible suggestions to address these challenges for those charged with preparing for implementation of the ETF under the Paris Agreement.Specifically, we propose to apply a quality criterion to the reporting and review process under the ETF that is "fit for purpose" rather than one that always strives to be perfect.
We explore this concept of "fit for purpose" from the perspective of promoting an effective reporting and review process that provides Parties with timely information on Parties' status of implementation of the Paris Agreement.A BTR does not have to be perfect in order to provide information on whether a Party is on track to meet its Nationally Determined Contribution (NDC) under the Paris Agreement.Rather, sufficient information needs to be made available in a timely manner.

Purpose of ETF reporting and review
The overall purpose of the framework for transparency of action is to provide a clear understanding of climate change action in light of the objective of the Convention, while the overall purpose of the framework for transparency of support is to provide clarity on support provided and received by the relevant Parties (paras. 1 and 2 of the annex to decision 18/CMA.1 [2]. The UNFCCC reporting and review processes are fundamental in building trust amongst Parties that all Parties transparently report their responses to all obligations and decisions agreed at the successive COPs, including reporting of emissions by sources and removals by sinks of GHGs.The reporting of the BTR, and its subsequent review and facilitative multilateral consideration of progress (FMCP), is the vehicle for delivering to other Parties transparent information on national climate actions and support.
We focus in this paper on making the review process fit for purpose, and by extension helping to guide countries how to improve their reporting.The review process is what establishes whether a Party's reporting complies with the relevant decisions and a consideration of whether the Party is on track to achieve its NDC and is meeting its obligations under Article 9, if appropriate (see Table 1).This paper does not focus on suggestions to make the FMCP more "fit for purpose", in part because in our experience this stage runs efficiently within the expected timeframes and resources.
We acknowledge that Parties often seek to use their climate submissions to achieve multiple domestic and international goals, beyond simply meeting international reporting obligations.We also know that BTRs will provide a wealth of information, opportunity and lessons learned that will benefit from wide dissemination.While these outcomes are welcomed, in fact necessary to address the climate challenge, we suggest that these activities are in addition to and complement the implementation of the review process outlined in the MPGs.

Key challenges implementing the current MRV system
The MRV/transparency system has been evolving since the early years of the twenty first century, very much as a learning on the job activity.Key observations on this evolution based on our experience and consideration of the conclusions of lead reviewers are: Countries have improved in the transparency, completeness, consistency and accuracy of reporting over time while reviews have ensured comparability between Parties' submissions 5 ; While the quality of submissions have improved, perhaps counter-intuitively, the review process, particularly for developed countries, has grown more complex and time consuming, focusing on smaller details.The experience with "review" of developing country submissions has a shorter tradition as the introduction of the technical analysis of biennial update reports submitted by developing countries started only in 2015; Review reports have gotten longer, with a larger fraction of recommendations in the report related to more minor issues (e.g.requests for more details as opposed to completeness) resulting in efforts by lead reviewers to limit the review reports to the main substantive findings; 6 We see more reviewers asking Parties to reorganize their submissions, noting there is so much information, the submission is no longer transparent.
This "complification" has resulted in an increasingly heavy workload to Parties, expert review teams and the UNFCCC secretariat [3] and may partially explain why reviewers decline UNFCCC invitations to participate in these important processes (for example, for the review of GHG Inventories in 2022, of the 262 experts invited to participated in reviews, 96 declined due to other obligations, a heavy workload, lack of financial resources or other reasons [4]).
The observed evolution may not be surprising.As major reporting issues are resolved over time, reviewers start looking into finer details.For example, reviewers may seek more and more information for inclusion in the report, aligned with their views of what is required to be transparent.The notion of what is "transparent" can be inherently subjectivewhat information needs to be presented to describe a country's suite of policies and measures and their relationship to any national target?In the case of support provided, how much detail is needed to explain a Party's support for the development and enhancement of endogenous capacities and technologies?What is considered transparent by one individual may not be seen as transparent by another.
It leads to the question, when can a review team determine that the Party's submission is good enough for the purposes of determining the Party's compliance with its obligations under the Paris Agreement?If this point is reached, review teams could just continue to monitor the Party's submission for changes that may impact this determination.The objective of these questions is not to enable the Party and the international system to relax and abdicate their responsibilities, in fact the opposite is true.The goal is to avoid operationalizing a reporting and review process that gets so mired into the details that it cannot deliver in a timely manner, or worse, allows all to lose sight of the bigger picture and the most effective means to address the climate challenge.In fact, it has been shown by [3], once a certain level of development of the national systems, data flows and reporting procedures has been reached, significant issues and problems found during the reviews decrease in numbers and in importance.Despite these remarks and comments by successive review teams and the Party's responses to it, we saw that at the end of the first commitment period of the Kyoto Protocol all inventories were good enough to establish whether each Party met the targets as set in the Kyoto Protocol.Although one would expect that both the preparation of submissions by Parties and the reviews by expert review teams would become easier and would require less effort the more mature Parties' national systems become, this was not the case.Despite successive review teams' recommendations for improvements, the submissions were fit to use in monitoring each Party's progress towards, and success in, meeting the agreed upon targets.
In other words: these submissions were fit for purpose.

New challenges with the ETF
Expanding from the current system that demands reporting and formal review of submissions from 44 Parties every 1-2 years, along with periodic assessments of submissions from a subset of developing countries, to one that requires reporting and review of BTRs from 194 Parties within that same time frame, risks overloading an already constrained system, jeopardizing Parties' ability to meet their climate goals.The UNFCCC secretariat, extrapolating from present practice, estimates the need for experts participations to double in the coming few years and to increase by a factor of 5 in the longer term (Figure 1) in order to support this growing process.
These experts will also be operating in a different regime; not one in which all developed countries are assessed against one set of guidelines, while all developing countries are assessed against a different set of guidelines, but rather one in which all countries are reviewed for adherence to a single rulebook.And that single rulebook offers flexibility to those countries that need it in light of their capacity and requires that technical expert review pay particular attention to the respective national capabilities and circumstances of developing country Parties.

Developing procedures that are fit for purpose
As Parties, the UNFCCC secretariat and technical expert reviewers prepare for and develop their procedures to implement the ETF, we offer suggestions for how to implement these procedures in a way that is fit for purpose.We focus on three key stages in implementing the ETF: reporting the national submissions, organizing the reviews, and conducting the review.

National submissions
The contents of a Party's submission under the ETF are described in paragraph 10 of the annex to decision 18/CMA.1 [2] (Table 2).
The MPGs provide specific provisions on what the Party shall (i.e.must) and should (i.e. is encouraged to) report in each of these sections of the BTR.The elevated importance of shall provisions results in recommendations to a Party to address an issue; while non-shall provisions lead to encouragements.
At the COP in Glasgow [5] the Parties operationalized these requirements into detailed descriptions of how to report this information in the BTR submissions.These include: encouraging Parties to use the outlines of the BTR itself, the national inventory document; and adoption of three sets of tables to present the required information in a comparable manner.
Together, these guidelines provide a welldefined structure for the contents of the national submissions in combination with the understanding of what and when Parties shall and/or should report.
The fit for purpose national submission A first step by a Party to prepare a national submission within the ETF system that is fit for purpose is to, at a minimum, provide a response to each shall provision.If a Party is not able to comply with a should provision the relevant table or report section could be marked as Not Applicable or Not Reported, or a similar notation as used in the GHG inventories.
The second step is to compile all required information in a transparent way, within the available resources and present it using the agreed reporting outlines tables and formats (Table 3).As resources will always be limited, the following could help to prioritise and economise on the work to be done to comply with the ETF requirements: Where resources are limited, focus first on shall provisions (noting the GHG inventory reporting guidelines direct countries to focus on key categories) and the necessary institutional arrangements to support this reporting.Follow the report outlines, facilitating the reporting and review process.Efficient use of referencing -not all information must be included in the submission, but rather can be referenced.Parties need not provide all information to allow external groups to replicate their submission, but rather they need provide sufficient information and references so others may understand what has been reported (refer to the definition of transparency from the 2006 IPCC Guidelines (Volume 1, chapter 1), as referenced in paragraph 17 of the MPGs).To facilitate review, and consistent with the MPGs, submit the report in a UN language; if references are not in a UN language, include a short summary in the report in a UN language.

Organizing the review process
This paper advocates to apply the experience and knowledge gained from conducting reviews under the Convention and develop procedures for the review process that implements Parties' decisions in a manner that is ever mindful of the purpose of that process.Two key areas where processes can Table 2. Required contents of the Biennial transparency report; from paragraph 10 of the annex to decision 18/CMA.1 [2].
In the biennial transparency report: be made more "fit for purpose" when organizing the reviews are in selecting the review format and composing the teams.

Selecting the review format
Technical expert reviews may be conducted in three different formats, defining different levels of intensity (Table 4).A fourth formata simplified review-is carried out by the UNFCCC secretariat and not a review team.Decision 18/CMA.1 [2] provides guidance on the frequency of applicability of these various formats for each Party in paragraphs 156 to 161.From this it is clear that Parties consider in-country review as the most elaborate format, as it must be applied for the first BTR submitted and at least twice within a ten-year period, of which one is the BTR that contains information on the Party's achievement of its NDC.In addition, both the review team and the Party may request the next review be in-country.
On the other hand, one could infer that desk reviews are envisioned to be of a more limited scope.This can be interpreted from the provision that a desk review should not be conducted more often than once every five years and is not deemed of sufficient rigor to support the review of the first BTR submitted following a Party's communication of its NDC or for the BTR that contains information on the Party's achievement of its NDC (para.160).
The rigor of the centralized review lies somewhere between the in-country and the desk review.
The fit for purpose review format Consistent with the implicit importance given by Parties to each type of review format, we propose to introduce a clear distinction in the expected effort needed for each of these formats: an incountry review would represent the most demanding review format, whereas the desk review could be quite simple and straightforward.The "rules" outlining when an in-country review must take place, resulting in a scenario that in-country reviews must take place for essentially every other BTR submission, ensures that the overall quality and integrity of the process is not compromised by such an approach.An in-country review is when the members of a technical expert review team conduct the review in the country of the Party undergoing review.In-country visits will be scheduled, be planned and take place with the consent of, and in close coordination with, the Party subject to review DR: desk review A desk review is when the members of a technical expert review team conduct the review remotely from their respective countries SR: simplified review A simplified review of a Party's national inventory report involves the secretariat undertaking an initial assessment of completeness and consistency with the MPGs, consistent with the initial assessment procedures.A review of the findings of this initial assessment will form part of the consequent technical expert review of the Party's national inventory report In-country reviews would provide the maximum opportunities for capacity building during the initial phases of the development of the national systems responsible for the reporting.Centralized reviews and desk reviews may have only limited capacity building opportunities for reporting Parties but given the frequency of in-country reviews this will not be an impediment to improvement.
Linking the expected effort to the outcomes of earlier review cycles may lead to the following logic when assigning a review format to countries, consistent with the requirements in para.156-161 of the MPGs: Review of the first submission from any Party will typically be subject to an in-country review.During the in-country review, the review teams will have the opportunity to look in-depth at the submission, including policies and measures, methods, models for GHG inventory and projections and national arrangements.Depending on the number and nature of the issues identified in the in-country review, the next review would be a centralized review (more issues, relatively more complex issues) or a desk review (relatively fewer issues).During the following centralized or desk review, the review teams would focus on assessing if Parties were able to address the findings of the in-country review team, and, in centralized reviews, highlight any new major issues identified.For developed countries, these reviews would also address any issues identified in the simplified review of the previous GHG inventory.These teams would not necessarily focus on resolving the issues given the more limited interaction in these formats, but alerting the Party to outstanding problems, and highlight issues for further consideration in the subsequent in-country review.When a team has identified outstanding issues, the subsequent review would take place in-country, allowing for necessary in-depth discussions.
This approach has the additional benefit that the most in-depth conversations on technical issues related to the submission are taking place face-to-face, avoiding miscommunication between the Party and the review team and ensuring the Party knows how to correct an issue.This approach could also minimize cases where sequential review teams have different understanding of a Party's reporting, leading to proliferation of (possibly inconsistent) recommendations to the Party from one year to the next.
Table 5 outlines the proposed tasks of the review team, consistent with the review format.

Composing the review team
Paragraphs 175 -182 of the MPGs outline the requirements for composing a review team [2].Overall, the team must contain the necessary expertise to review the contents of a Party's submissionmeaning covering all relevant sectors of the GHG inventory, the ability to consider the Party's mitigation actions and progress towards its NDC target, and for developed countries, support provided and mobilized.The UNFCCC secretariat has the task of selecting a team, which can be quite challenging given their need to ensure geographic and gender balance in the teams, language capabilities for those submissions in UN languages other than English and arriving at a balance of experts from developed and developing countries.
The fit for purpose review team A review team will be fit for purpose if it is independent (i.e.experts do not have any conflicts of interest) and comprises all expertise that enables it to establish whether or not a Party's submission is fit for purpose.A "fit for purpose" team would mean there is not a standard pre-defined size of the team, rather it would be established based on the national circumstances of the Party under review and the format in which the review will take place.
Reviewing small economies could allow for smaller review teams.On the contrary, a larger economy with a complex NDC or multiple types of targets in their NDC may demand a larger, more experienced team.Given the intensity of the review of the GHG inventory, and the personnel resources required, careful consideration of the team reviewing the inventory and possibly GHG projections should be considered.For smaller countries, a single expert could review multiple sectors.Countries that do not have a large industrial sector may not need an expert in the GHG inventory of industrial processes; conversely countries with a large agricultural sector may require more experienced review experts.
An in-country review may require more experienced reviewers than centralized reviews and desk reviews.Centralised reviews may offer better training and coaching possibilities for inexperienced and "new" reviewers.
Some may argue that smaller economies who are relatively new to reporting, may demand a larger review team to enable the team to spend the time supporting capacity building and training in-country.While it is true the need for capacity building and support will be great, technical expert review resources are limited, there are only so many experts to support the process.Implementing a system that results in expert reviewers identifying the challenges with the Parties' reporting and clearly outlining recommendations for improvements, could then go hand in hand with international support to spend the necessary time and resources to help that country implement those recommendations.Table 6 presents a proposal.
A fit for purpose review team would also take advantage of the various skills that each expert on the team, as well as the UNFCCC secretariat, brings to the process.Technical experts are assigned their role on the team based on their demonstrated competence in a functional area of the BTR.The UNFCCC secretariat is tasked to support the process logistically and administratively, but also plays a key role in provision of tools and materials to support the experts.Through use of these tools the secretariat is able to run statistical checks on submissions and identify possible issues for the review team's consideration.Designing a system that allows the secretariat to identify possible initial issues in the Party's submission based on the use of automated review tools, while reserving the review team's time to technically assess which issues are of importance, and to consider the adherence of the Party's submission with the MPGs, can best make use of the valuable technical expertise of the expert.
A fit for purpose review team will work from the assumption that a previous review team, which conducted the review in a more rigorous format, has done a fit for purpose job and that this team has identified all recommendations and encouragements and has made a comprehensive consideration of the progress of the Party towards its target and the provision of support based on the in-depth review.Only in an in-country review can the review team perform this full review and consideration and have time to identify any issues that may have been missed in earlier reviews.Whenever a review team of a less rigorous review format suspects that an earlier in-country review may have overlooked an issue with a shall requirement, it could elaborate the issue in the review report to alert the Party as well as the subsequent review team that the issue needs to be considered further in the next in-country review for this Party at the next reporting cycle.This approach would result in a working mode that would build on results from earlier reviews and not be inclined towards executing every successive review from scratch.

Conducting the review
The actual conduct of the review by the review team involves pre-review week preparations, an intensive week during which the team closely collaborates and agrees to the recommendations and encouragements to be included in the review report, and post-review week where the report is finalized, subject to quality control activities and commented on by the Party, prior to finalization.Applying fit-for-purpose procedures throughout the conduct of the review involves careful reflection of "who is the audience for the review report", "what is the scope of the report" and "what is the level of detail needed in the report" to achieve the overall purpose of the ETF as outlined in paragraphs 1, 5 and 6 of Article 13 of the Paris Agreement.

Review report intended audience
Review reports are fit for purpose when they first and foremost inform all Parties whether the Party under review complied with all mandatory requirements (no recommendations) and continues to be, or not be, on track to meets its NDC target(s).Still important, but to a lesser degree is the Party's adherence to non-shall provisions.
Thus, it is important to consider the appropriate audience for the review report, given its scope, per paragraph 146 of the annex to decision 18/CMA.1 [2].All elements of the scope of the review focus on the consistency of the Party's reporting with that which is required in the MPGs and assisting Parties to implement the areas of improvement identified.As outlined in annex VI to decision 5/CMA.3[5], the review teams are also expected to provide their written consideration of the Party's implementation and achievement of its NDC and support provided (if applicable) in the final review report, important information for the Party under review, but also other Parties.The audience for this report is, therefore, Parties.
Reports fit for the intended audience Review reports that are fit for purpose acknowledge and respond to the needs of the intended audience.There are means of communicating suggestions to the Party formally during the review (through questions and answers and the preliminary findings) that do not necessarily have to be included in the final review report.
It is important to emphasize here that this discussion is focusing on the audience of the technical expert review report, to be drafted in accordance with the requirements of the MPGs and decision 5/CMA.3.While this report will be largely technical in nature, and provide the review team's technical assessment and consideration of the consistency of the Party's reporting with the MPGs, there are other important avenues outside of the review process that can, and should be, explored to further build trust among Parties.Alternative channels outside of the process (e.g.dedicated teams savvy in communications; systems established as part of, or in line with the FMCP process; or partnerships among organizations or institutes) may be made available for summarizing Party submissions, promoting climate initiatives or highlighting lessons learned.

Review report scope
Considering the various levels of rigor and effort for the different review formats (Table 4, Table 5), it is reasonable to assume that review report contents may vary in detail based on the review format, while still adhering to the overall agreed review report outline contained in annex VI to decision 5/CMA.3[5].Table 7 proposes a possible line of thought that could help review teams in the various review formats to prioritise their work and draft their reports.
Following this line of thought, one may conclude that the most important contents of the report will be the review team's assessment on whether the Party's submission is consistent with the MPGs and whether the review team considers that the Party is on track to meet its NDC target(s) and obligations under Article 9 of the Paris Agreement, if appropriate.If the Party's submission meets all the mandatory requirements, it suggests that reporting is sufficiently transparent for the review team and other Parties to make this assessment.Review reports that are concise, focusing on the findings and key messages the review team wants to convey to the Party will be most effective at communicating the outcomes of the review to the Party.The review report need not summarize the Party's submission.The Party itself knows well its submission while any other interested stakeholders are better directed to read the Party's submission itself to understand its contents.
Historically, all recommendations and encouragements to the Party for possible improvements have been included in the final review report.It could be said that the detailed suggestions by the review team on how improvements are to be made are more beneficial to the Party under review, than the global community.This is necessary as part of capacity building activities during the early stages of development of a Party's procedures and data flows but might be less important when the Party's reporting system is well established.
As the main objective of the review report is to provide trust with the Parties that the Party under review has complied with all shall requirements in the relevant decisions, one could argue that the review report should concentrate on, or even be limited to, assessing whether the Party has fulfilled all these shall requirements.As a consequence, if the report were limited to reporting the results of Table 7. Fit for purpose review report contents.

Format
Fit for purpose review report

In-country Review
As the review will be the most rigorous one possible within the ETF system, including focusing on institutional arrangements and data collection and more complex GHG emissions calculation and models, the review team will be able to look into anything they may feel necessary or unclear.
The report therefore can be quite elaborate and detailed.It would include: recognition of all shall and should requirements being met; recommendations for any shall requirement that is not being met; encouragements for any should requirement that the team considers as important to improve the usability of the report for the processes under the Convention and the Paris Agreement.follow up on any issues identified in the previous simplified review report (for developed countries only) comprehensive documentation of its consideration of the Party's progress towards its target and, if applicable, support provided; whenever the review team identifies issues that could lead to improvement of the Party's report, this could: either be mentioned in the report but not be labelled as an encouragement or be communicated to the Party during the review, but need not be included in the review report.
The report of the latest in-country review will be regarded as complete and covering all issues that need attention from the Party during successive review(s).

Centralised Review
A review team for a centralized review will work from the assumption that the latest in-country review was well performed and has identified all instances where the Party under review was not complying with one or more shall and should requirements.
The report therefore would concentrate on checking whether or not any major changes have occurred in any shall requirement that was sufficiently met in the earlier report; checking whether or not the Party has followed up on and solved all recommendations as identified in the latest incountry review report; have a brief look at the encouragements identified in the earlier in-country review report and recognize all instances where such encouragements have resulted in an improved report; follow up on any issues identified in the previous simplified review report (for developed countries only) In the exceptional cases where a team suspects that the Party has not met one or more shall requirements that was overlooked by a previous review team, the current team could either; simply mention this, noting the next review would likely be an in-country review, or if in doubt, recommend to the UNFCCC to apply an in-country review for this Party in the next review cycle; or include in the report a recommendation for the Party to consider this shall requirement further, which in turn highlights to the next review team that this shall requirement must be considered during the next in-country review.
Provide its assessment if any changes in the submission impact the Party's progress towards its target, and if applicable, support provided; and if so, how?Desk Review A review team for a desk review will only check whether or not all shall requirements have been met.For the review of the GHG inventory component of the BTR, focusing on recalculations since the previous submission will help the team to focus their work and determine whether there have been any changes to the Party's adherence to shall provisions.
The report therefore would concentrate on highlighting whether any major changes have occurred in any shall requirement that was sufficiently met in the earlier report; follow up on any issues identified in the previous simplified review report (for developed countries only); In the rare case that an issue is identified while reviewing previous shall requirements, this could be noted for the next in-country review team's consideration; If identified, raise any possible concerns with the Party's progress towards its target for consideration by the next review team.

Simplified Review
Since a simplified review would only be applied to the annual GHG inventory submission by developed countries in years that a BTR is not due, the review report could be modelled on the automatically generated initial assessments currently performed by the UNFCCC secretariat for reviews under the Convention and the Kyoto Protocol.
the review of shall requirements (i.e. by including only recommendations), encouragements could still be communicated to the Party (e.g. through direct written communication between the team and the Party experts in the preliminary findings at the end of the review week, or other means) and with copies in each review's archive.Whenever the review team concludes that the submission fulfils all shall provisions defined in the relevant decisions, it could conclude that the submission is fit for purpose.The initial focus on shall provisions would be commensurate with the elevated importance of these provisions in the MPGs, and guide Parties to prioritize these issues in their subsequent BTR submissions.
A possible presentation of this assessment could be maintained in two parts in the technical expert review report: a main report summarizing the findings and the overall consideration by the review team on the Party's progress towards its target, and if applicable, support provided and an annex containing a technical assessment for consistency.
The findings could be included in the annex to the report in a standard table listing all shalls and a column with OK marks for shalls that are fulfilled, to ensure that the review team has assessed the Party's response to each and every shall in the decisions.Or, the review report could identify only those shall provisions not implemented in the Party's reporting (i.e. the report would contain only the problems identified).
If one or more shalls are not satisfactorily fulfilled, the review team is required to include a recommendation for each of these issues, noting that this Party's submission is not yet fit for purpose.The review team could also provide guidance to the Party on how to address these issues, in line with paragraph 146(e) of the MPGs [2].The review of subsequent submissions must check whether the Party has solved each recommendation.

Review report contents
Whether review reports focus only on recommendations or include both recommendations and encouragements, a last challenge to address is the increasing level of detail observed in current review reports.Here we turn back to the question whether "all this information is necessary" to be included in the final report.
The IPCC definition of transparency does not require every piece of data and information used to develop a GHG inventory or prepare projections to be included in the BTR, rather the audience should be able to "understand" what has been done.This can be achieved when a Party make uses of references to underlying reports and data sets in their submission, and upon request makes this information accessible to review teams.Proper use of references avoids the necessity of the Party to copy reams of data and information from underlying reports and data sets into the submission.Where review teams have questions about the Party's use of methods and data, this is a topic of discussion during the review.In the current review processes under the Convention, most of these questions lead to a Party receiving a recommendation to include the missing information in the next submission.However, another approach, consistent with the IPCC definition of transparency, would be for the review team to make an assessment based on the information provided by the Party during the review, as to whether what the Party has done is consistent with the quality principles.If it is, the review team could conclude positively, with no corresponding finding in the report.It is only when the discussions identify there is an underlying problem with the Party's approach would there a need for a recommendation or encouragement in the review report.A positive review then would result from "understanding and knowing how the Party compiled the submission" (the definition of transparency referenced in the MPGs) rather than "being able to reproduce the submission" (the requirement for transparency under the current system as outlined in decision 24/CP.19).
Once a review has concluded that the Party provides all necessary references to background reports and data sets, and the review team is satisfied that based on any discussion during the review that the Party's submission adheres to the relevant UNFCCC and IPCC Guidelines, subsequent review teams would not need to dive into these details again, unless they identify an unexplainable change in an Party's submission as compared with the previous one.

Conclusions
Our proposals would lead to a fundamental change to the current review process.While under all review processes currently, review teams are considering previous issues, they are also essentially re-examining the submission from scratch every year to see if there are any issues.The proposed approach starts from the basic premise that the last review team did their job and the current review team therefore focuses on changes in the submission.This would not prevent a review team from identifying a new issue if necessary, but would avoid re-examining the same issues year after year and arriving at different conclusions.Our proposal explicitly uses the cyclic character of the reporting and review processes under the UNFCCC.
Parties, expert review teams and the secretariat have worked diligently over the past decades to implement a transparency system that responds to the decisions of Parties.It was demonstrated that the existing system was successful in assessing Parties' compliance with their Kyoto Protocol obligations.But that system is operating at a very high, possibly unsustainable, workload for all involved.With the ensuing demands from the ETF requiring more Parties to report more information more frequently, it is important to take stock of what has been learned and apply that knowledge to develop a system that achieves the goals of the Paris Agreement.
This paper proposes application of the principle "fit-for-purpose" to the reporting and review process, with a view to ensuring that the objectives of the Paris Agreement are met in the most efficient, cost-effective and sustainable manner.A "fit for purpose" system recognizes the fundamental role of the technical expert review teams and the review of Parties' BTR submissions in enhancing the cycle of ambition of Parties' NDCs, but also acknowledges that the review process is one component of the larger international response to climate change both inside and outside of the Paris Agreement.There will be a continued need to promote key initiatives across countries to enhance engagement, to build capacity in-country for climate change mitigation and adaptation, and generate financial flows that will help countries realize their goals.
While much could be written in a review report to highlight the policies and efforts of Parties related to climate change, or to showcase new and innovative ideas, expanding on these types of narratives goes beyond the mandated task of the review team, leading to extended periods of time to draft reports.Similarly, asking the review team to summarize information presented by the Party in its own submission diverts the review team's attention from their mandated task and does not provide new and additional information to other Parties about whether the Party under review is meeting its climate obligations.Designing an ETF that tries to "do it all" rather than one that is "fit for purpose", risks jeopardizing the success of the very international system we are trying to implement.
As was experienced during the early years of the review process under the Convention, there will be a "training" phase when Parties start submitting their first BTRs.During this training phase the reviews of submitted BTRs should prioritize the development of adequate systems, data flows, methods and institutional arrangements to ensure that subsequent submissions will as soon as possible evolve to a quality level that is fit for purpose.In other words, are of sufficient quality to show all Parties that the reporting Party met the agreed upon obligations and targets.Including numerous smaller recommendations and encouragements in review reports in the early years risks overwhelming Parties and preventing them from seeing the forest for the trees.
Frequent in-country reviews during this time period will be particularly beneficial to Parties as this review format provides the best opportunities to provide any capacity building needed.At the same time, the international community will clearly see from the published reports where further capacity building and support may be needed to help countries meet both their reporting goals, as well as their NDC.
The high number of in-country reviews will demand a large number of technical experts qualified to participate on a review team.This proposal assumes that expert review teams working incountry are competent in their tasks to identify whether a Party's reporting is consistent with the MPGs.It is essential that countries nominate experienced experts to the Roster of Experts, that these experts become fully qualified by taking the necessary training and exams, and that they be given the opportunity to gain experience through participating in the various types of reviews.
Based on current experience, the reporting and review of BTRs will improve over time.Parties will review, and if necessary, update the MPGs in 2028 and the implementation, frequency and scope of undertaking the various review formats could be evaluated with the experience gained at that time.
Capacity building has been and will continue to be an important aspect of the review process, especially in the early stages of development of a Party's institutional arrangements, data flow systems and quality control approaches.Obviously, capacity building works best when direct face to face contacts are possible.Hence, in-country reviews will provide the best circumstances for a review team to support the Party's experts in developing their understanding of what is needed and what is possible and the systems, processes and procedures that ensure their BTR will meet all shall requirements in the relevant decisions.
The ETF is the backbone of the Paris Agreement, building trust among Parties that all are doing their part.It is therefore essential that we examine the implementation of the processes supporting the ETF to ensure they deliver as intended.Preparing BTR submissions that are fit for purpose, organizing reviews in a manner that is appropriate for the circumstances of the country under review, and preparing review reports that are conducive to Parties' needs; will help ensure the ETF is fit for its purpose.Available at https://unfccc.int/sites/default/files/resource/CGE%20TP%20Distilled%202021%20 final.pdf 4. The authors have been participating in the UNFCCC reporting and review processes in various roles for more than 15 years.

Disclosure statement
No potential conflict of interest was reported by the author(s).

Figure 1 .
Figure 1.Estimated number of expert participations in national submission reviews in the coming decade (from https:// unfccc.int/documents/626533).
shall provide a national inventory report of anthropogenic emissions by sources and removals by sinks of greenhouse gases (GHGs), in accordance with the MPGs; (b) Each Party shall provide the information necessary to track progress in implementing and achieving its NDC under Article 4 of the Paris Agreement, in accordance with the MPGs; (c) Each Party should provide information on climate change impacts and adaptation under Article 7 of the Paris Agreement, in accordance with the MPGs; (d) Developed country Parties shall provide information pursuant to Article 13, paragraph 9, in accordance with the MPGs.Other Parties that provide support should provide such information and, in doing so, are encouraged to use the MPGs; (e) Developing country Parties should provide information on financial, technology transfer and capacity-building support needed and received under Articles 9, 10 and 11 of the Paris Agreement, in accordance with the MPGs.

Notes 1 .
"Annex I" and "non-Annex I" Parties refer to those Parties that either are, or are not, listed in Annex I to the Convention.The Paris Agreement uses the terms developed and developing country Parties.2. These reports can be found at the UNFCCC website: -Annual reports on the technical review of greenhouse gas inventories from Parties included in Annex I to the Convention: annual report, the 2022 issue available at FCCC/SBSTA/2022/INF.3 -Technical review of information reported under the Convention by Parties included in Annex I to the Convention in their biennial reports and national communications: annual report.The 2022 issue available at FCCC/SBSTA/2022/INF.2 3. CGE 2021.Technical Paper 2021 Distilled.

Table 1 .
The scope of a technical review as defined in the annex to Decision 18/CMA.1[2].

Table 3 .
Operationalizing the modalities, procedures and guidelines (MPGs) as defined in decision 18/CMA.1 for submissions under the enhanced transparency framework[5].
CR: centralized reviewA centralized review is when the members of a technical expert review team conduct the review from a single, centralized location.During a centralized review, a single technical expert review team could review several Parties ICR: in-country review

Table 5 .
Fit for purpose review tasks depending on review format. of the Party's submission, including an in-depth review of the Party's policies and measures, progress towards the target, selection of methods and applied models for GHG inventory and projections, data sources, support provided and mobilized, country-specific circumstances, etc. (Once reviewed in depth, in subsequent reviews focus on changes to this information); A full consideration of the institutional arrangements, and the relationship with reporting, and the evolvement of the transparency system; Check the Party's response to all recommendations and encouragements from the previous review report, if any; Check for any changes in the Party's approach, data flows and methods, where relevant; Identify any unexpected changes in the submission as compared with the previous one; Check for any changes in the Party's approach, data flows and methods, where relevant; Identify any unexpected changes in the submission as compared with the previous one.Discuss with the Party whether any of the changes identified in the Party's latest BTR submission impacts the consideration made by the previous review team on the Party's progress towards its target or support provided.Changes related to the suite of policies and measures reported, GHG inventory and projections, and changes in support provided could be of particular relevance.DR Desk Review Check the Party's response to all recommendations in the previous review report, if any; Identify any unexpected changes in the submission as compared with the previous one for consideration in the subsequent centralised or in-country review.SR Simplified Review Automatic review of the Party's NIR submission by the secretariat CARBON MANAGEMENT

Table 6 .
Fit for purpose review team.
5. For example, see: UNFCCC 2020.International Consultation and Analysis: Facilitating Climate Action through Transparency.Available at: https:// unfccc.int/sites/default/files/resource/53756_UNFCCC_ICA_Brochure.pdfand the Conclusions from Lead Reviewers Meetings for the review of Biennial Reports and National Communications available at https://unfccc.int/lrs-brs-ncs,which started assessing improvements in completeness and transparency starting in 2019.6.For example, see UNFCCC 2022.Technical review of greenhouse gas inventories of Parties included in Annex I to the Convention available at FCCC/SBSTA/2022/INF.3 (unfccc.int).