2019年9月号 [Vol.30 No.6] 通巻第345号 201909_345001-en

IPCC guidelines on national greenhouse gas inventories — brief history and 2019 Refinement

  • Shamil Maksyutov
    Specialist, Satellite Observation Center

1. Introduction

Reporting the national greenhouse gas emissions started as a measure to evaluate progress towards limiting climate change. In 1988, an Intergovernmental Panel on Climate Change (IPCC) was established by the United Nations, with a task to prepare a comprehensive review and recommendations with respect to the state of knowledge of the science of climate change; the social and economic impact of climate change, and potential response strategies and elements for inclusion in a possible future international convention on climate. In 1990, the IPCC produced its First Assessment Report. In response to scientific evidence, as summarized in the IPCC report, world nations agreed on a United Nations Framework Convention on Climate Change (UNFCCC) aiming at limiting “greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system” (article 2). The Convention was prepared for signature before the United Nations Conference on Environment and Development in Rio de Janeiro in 1992. Under UNFCCC, parties accepted an obligation to submit their national communications, that include the national greenhouse gas inventory reports. To improve transparency of reporting the emissions, the IPCC produced 1996 and 2006 Guidelines on greenhouse gas inventories (IPCC Methodology Reports), which provide a comprehensive set of recommended procedures for national inventory compilation. The national GHG inventories are based on activity data by national statistics (such as industrial, agricultural, municipal), and emission factors, either taken from the Guidelines or using country-specific ones, but in some cases also from the IPCC emission factor database. Under the UNFCCC, the parties in Annex I are now reporting the emissions every year, and others (Non-Annex I) are reporting emissions every 2 years or less frequently.

2. Paris agreement and changes to reporting

The UNFCCC established a Conference of the Parties (COP), which held its sessions every year from 1995 and worked on preparing an international agreement, adopted as a Protocol to UNFCCC at COP in Kyoto in 1997. The Paris agreement, concluded at COP in 2015, was joined by a large number of parties, set an ambitious target on limiting climate change to 2 deg warming and proposed changes to the national communications and greenhouse gas inventory reporting. The rulebook for Paris agreement was then approved at COP meeting in 2018. According to the Paris rulebook, the parties submit their GHG emission reduction goals in form of Nationally Determined Contributions (NDC) and submit biannual transparency reports, that provides information on the progress of the NDCs. For reporting on the national emissions, the parties are now requested to use 2006 IPCC inventory guidelines and any updates and refinements to it. Also, there is no distinction between developed and developing countries in reporting frequency. Those changes are demanded by a need to better know the progress of climate change control measures, both at the national level and globally. To monitor the change of emissions globally, a Global Stock Take (GST) cycle of 5 years (starting in year 2023) is proposed. At the end of each GST cycle, the inventory reports by countries can be summarized and compared to the observed GHG content changes in the atmosphere and the rest of the Earth system.

3. 2019 Refinement to 2006 IPCC Guidelines for National Greenhouse Gas Inventories

The 2019 Refinement to 2006 IPCC inventory guidelines has been prepared by a group of more than 190 inventory experts with a goal to keep the Guidelines scientifically valid to serve the needs of accurate emission accounting under Paris agreement framework. The content of the 2019 Refinement was discussed at Minsk scoping meeting 2016, that defined required changes to the 2006 Guidelines, listing the issues to be addressed by the volume and chapter. The authors started working on the Refinement draft in 2017, attended four Lead Author meetings, prepared 4 draft versions which went to expert and government reviews. The Refinement was adopted by IPCC at the 49th session in Kyoto in 2019.

Overview Chapter in the Refinement explains the difference between the 2006 Guidelines and 2019 Refinement as: “2019 Refinement:

  • Provides supplementary methodologies for sources and sinks of greenhouse gases only where currently there are gaps or where new technologies and production processes have emerged requiring elaborated methodologies or for sources and sinks that were not well covered by the 2006 IPCC Guidelines;
  • Provides updated default values of emission factors and other parameters based on the latest available scientific information only where significant differences from the default values presented in the 2006 IPCC Guidelines are identified;
  • Provides additional or alternative up-to-date information and guidance, where possible, as clarification or elaboration of existing guidance in the 2006 IPCC Guidelines.

The 2019 Refinement does not revise the 2006 IPCC Guidelines, but updates, supplements and/or elaborates the 2006 IPCC Guidelines where gaps or out-of-date science have been identified. It does not replace the 2006 IPCC Guidelines, but should be used in conjunction with the 2006 IPCC Guidelines…”

The Guidelines and Refinement are composed of 5 volumes, and 2019 Refinement outline can be summarized as follows:

Volume 1, ‘General Guidance and Reporting’ updates on: national greenhouse gas inventory arrangements and management tools, data collection strategy, use of facility-level data in inventories, uncertainty analysis, key category analysis, comparison of greenhouse gas emission estimates with atmospheric measurements, use and reporting of models and several other issues.

Other sector-specific volumes, provide updates on emission factors and elaborate on inventory procedures.

Volume 2, ‘Energy’ covers fugitive emissions (does not update guidance on stationary combustion, mobile combustion, or other sources), including emissions from mining, processing, storage and transportation of coal; oil and natural gas systems; fuel transformation.

Volume 3, ‘Industrial Processes and Product Use’ covers new categories and gases, such as additional hydrofluorocarbons, perfluorocarbons, and halogenated ethers; guidance for production of nitric acid, fluorochemicals, iron and steel, aluminium, and electronics, and for the production and use of refrigeration and air-conditioning equipment; revision of reporting categories.

Volume 4, ‘Agriculture, Forestry and Other Land Use’ provides an update on use of emission models, accounting for interannual variability of emissions (including natural disturbances), also on biomass estimates, soil carbon, rice cultivation, flooded lands, livestock and manure management, soil nitrous oxide, and harvested wood products.

Volume 5, ‘Waste’ covers updates on waste generation, composition, and management; emissions from landfill; incineration and open burning of waste; emissions from wastewater treatment and discharge into aquatic environments.

4. Comparison of greenhouse gas emission estimates with atmospheric measurements

It is worth mentioning an update to guidance on “Comparison of greenhouse gas emission estimates with atmospheric measurements”, that overlaps with areas of expertise of our Center for Global Environment Research, NIES. The Refinement mentions good practice examples of countries like the UK and Switzerland, where atmospheric concentration measurements of non-CO2 GHG are used to estimate country total emissions of those gases and to compare with emission estimates. In both countries, networks of continuous observations include several tall towers and one background monitoring site. The observations are used in tracer transport modeling for estimating the emissions of methane and N2O. Emissions of several other gases such as HFCs are estimated using correlation to better-known tracers such as carbon monoxide. These estimates are used to provide additional scientific verification of inputs and results for some of the emission categories and gases and assist in reducing uncertainty, identifying possible sources of errors and improving inventory procedures. The guidance describes key components and steps that are applied when using atmospheric measurements and inverse models for comparison with inventory emission estimates as part of inventory quality assurance and quality control procedures.

View of the session chairs during the TFI Plenary of the 49th Session of the IPCC, in Kyoto (Photo by IISD/ENB | Sean Wu, http://enb.iisd.org/climate/ipcc49/11may.html

ご意見、ご感想をお待ちしています。メール、またはFAXでお送りください。

地球環境研究センター ニュース編集局
www-cger(at)nies(dot)go(dot)jp
FAX: 029-858-2645

個人情報の取り扱いについては 国立環境研究所のプライバシーポリシー に従います。

TOP