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BC emissions inventories

Action 2.2: Mobilise voluntary compilation and reporting of black carbon inventories beyond EU, AC and UNECE

BC emissions from countries outside the EU, AC and UNECE have an impact in the Arctic as well. Furthermore, with black carbon being a significant SLCF, it can be argued that beyond international air pollution agreements, black carbon should be embedded within the UNFCCC/Paris Agreement. Potential inclusion of black carbon in NDCs submitted under the Paris Agreement is considered in Component 2.2a. Component 2.2b highlights need for continued scientific synthesis of climate impacts of BC.


Area of Action
BC emissions inventories
Mobilise voluntary compilation and reporting of black carbon inventories beyond EU, AC and UNECE
2.2a Inclusion of black carbon in NDCs submitted under PA
2.2b Scientific synthesis on climate impacts of BC
Type of intervention
2.2a Regulation/legislative proposals (National climate policy)
2.2b Funding of research, independent analysis and innovation Establishment and improvements of monitoring and inventories
Time perspective
2.2a Short- to long-term: 2020, 2025 and 2030 are the next rounds of submission
2.2b Ongoing and future assessment cycles of IPCC
Structural change
Jurisdictional scope
2.2a National
2.2b International
Policy forum
2.2a National authorities, UNFCCC-PA, CCAC
2.2b IPCC

Component 2.2a. Inclusion of black carbon in NDCs submitted under the Paris Agreement

Within the UNFCCC, the landmark agreement on combating climate change is the Paris Agreement, reached at Conference of the Parties COP 21 in 2015. At COP 24 in 2018 in Katowice, a decision on the modalities, procedures and guidelines (MPGs) for the transparency framework for action and support referred to in Article 13 of the Paris Agreement was agreed. This decision with a purpose to establish a robust reporting and review system, made no mention of black carbon; thus, potential reporting of black carbon under the Paris Agreement is currently not foreseen. However, the Paris Agreement and the so-called enhanced transparency framework will develop over time, and therefore this component may lay foundations to enable formal black carbon emissions reporting under the Paris Agreement in the future (after 2030).

As an international agreement, the Paris Agreement is built as a bottom-up system in certain important aspects. The submission of the NDCs reflects this, as the agreement does not prescribe these contributions for each Party in a top-down approach. NDCs, where Parties describe the effort, they offer to contribute to the collective response to climate change, are prepared, communicated and maintained by the Parties themselves. A small number of countries included black carbon to different extents in their first NDCs. Countries may continue and further elaborate black carbon issues in upcoming NDCs.* If indeed a substantial number of countries are seeking to make their climate change mitigation contribution through black carbon emissions reductions and communicate this action in their NDCs, these countries may exercise the potential option of including black carbon emission trends in their Biennial Transparency Reports.

Since recently agreed MPGs made no mention of BC, it is not possible for the Parties to include black carbon emissions data in their annually/biennially** submitted National Inventory Documents or accompanying Common Reporting Tables. However, there will probably be scope for Parties to report trends in national total black carbon emissions within so-called tracking of progress tables foreseen as part of Biennial Transparency Reports (to be submitted every two years starting at the latest at the end of 2024). Some further clarity can be expected with a COP decision on the Common Tabular Format tables for tracking progress in implementing and achieving NDCs. Such a decision is anticipated in November 2021 at COP 26. Any potential voluntary reporting of black carbon mitigation action and emissions in NDCs as well as Biennial Transparency Reports will be driven by the Parties to the Paris Agreement themselves. Support and coordinated impetus to this process could be provided by international networks of governments and organisations such as CCAC. Within the UNFCCC-PA forum, CCAC has become an influential voice advocating the inclusion of action on SLCFs in NDCs. CCAC undertakes capacity-building missions and has helped several countries to develop national black carbon inventories.

In the UNFCCC negotiations, the details for reporting in the enhanced transparency framework are currently being discussed. In the new transparency framework, all Parties will have to use the 2006 IPCC Guidelines for estimation of their emissions in the inventories. In 2019 the IPCC approved a refinement of the guidelines. Neither of these two documents provides guidance for estimation of black carbon emissions. In the negotiations of the reporting tables, possible inclusion of the 2019 IPCC Refinement is getting pushed back by some Parties. It seems unlikely that there will be great enthusiasm among Developing Country Parties for expanding reporting requirements, even if non-mandatory, to other climate-relevant air pollutants in the near future. The first review of the MPGs (including the reporting tables and methodology) will happen in 2028, and no regular MPG review schedule is agreed so far.

In the methodological support of black carbon emission reporting within UNFCCC, IPCC work is crucial. The IPCC's Task Force on National Greenhouse Gas Inventories was in 2020 about to commence preparatory work to develop an IPCC Methodology Report on SLCFs. Due to the COVID19 pandemic, the expert meetings had to be rescheduled to 2021. The establishment of the expert group on SLCFs and its work on SLCF inventory methodologies over the coming years is very important in terms of providing methodological guidelines for Parties. Necessity of such guidelines will be more obvious if reporting of black carbon emissions becomes an issue of negotiations and is encouraged to be reported under the Paris Agreement transparency framework. As the SCLF expert group is still in the process of being established, drafting of inventory guidelines will not commence until the next IPCC cycle (after 2022). Depending on the IPCC internal elections and on the risk of further delay caused by COVID-19, the Methodology Report can cautiously be estimated to be approved in 2025/2026.

There are several steps and preparatory work before even negotiating the inclusion of black carbon under the reporting of the UNFCCC. The IPCCs Assessment Report 629 and Methodology report on SLCF are important cornerstones on this way in the coming years.

Component 2.2b. Scientific synthesis of climate impacts of BC

In the quest to mobilise voluntary compilation and reporting of black carbon inventories beyond EU, AC and UNECE, the importance of the IPCC work should be highlighted. The IPCC assessment reports have provided the guiding science on which climate policy is based, and the subsequent assessment reports (e.g. AR6 Synthesis Report due in 2022) will continue to quantify inter alia the radiative forcing of SLCFs including BC. Here it is possible to improve the knowledge base through funding of research.

*NDCs have to be updated every five years and have to represent a progression over time, as specified in Decision 1/CP.21. Parties with a time horizon until 2025 (2021-2025) in their first NDCs are requested to communicate a new NDC by 2020 and to do so every 5 years thereafter. Parties with a time horizon until 2030 (2021-2030) are requested to communicate a new or updated NDC by 2020 and to do so every 5 years thereafter.

**Annex I Parties under the UNFCCC and the Kyoto Protocol have the obligation to continue to submit annual GHG inventories, regardless if they are Parties or non-Parties to the Paris Agreement. Parties to the PA must use the MPGs for reporting. Developing country Parties submit their inventory together with their BTR biennially. Several flexibilities are granted to those developing countries that need it in the light of their capacities. Furthermore, least developed countries and small island developing states are offered additional discretion in reporting.