Tidy GHG Inventories

General description

This data file is a compilation of national greenhouse gas emissions (GHG) inventories, sourced from the Common Reporting Tables (CRTs) that countries submit to the UNFCCC. The CRTs themselves require significant manipulation before one can begin any data analysis. The objective of this dataset is therefore to put the national inventories into a tidy, consistent format that better suits user needs. I sourced the original CRT files from the UNFCCC (e.g. https://unfccc.int/ghg-inventories-annex-i-parties/2024; https://unfccc.int/first-biennial-transparency-reports) and reformatted their summary reports into a single tidy, structured data table.

Data structure

The national GHG inventories provide emissions estimates along four dimensions: countries x years x sectors x gases.

• Countries: currently only Annex I countries consistently submit CRTs each year. Non-Annex I countries submit at irregular intervals, although this may change. Recently there have also been significant delays in submissions as as countries move to the new reporting format. The full list of countries covered and associated files is in the "countries" tab of the spreadsheet.
• Years: reporting starts in 1990 and runs until two years prior to the publication of each inventory (e.g. inventories submitted in 2024 report up to 2022).
• Sectors: emissions are split into sectors as set out by the Intergovernmental Panel on Climate Change (IPCC) Task Force on National Greenhouse Gas Inventories (TFI). The six main sectors are (1) Energy, (2) Industrial processes and product use, (3) Agriculture, (4) Land use, land-use change and forestry, (5) Waste, and (6) Other. A general description of the sectors is available in the TFI guidance. In this data file the five high level sectors are split into 41 individual categories, which is the most detailed level of reporting provided in the CRT summary sheets. I have included only "leaf nodes" from the sector hierarchy in the file, which are sectors that have no further child sectors. This means that you can safely sum up all sectors for each country without double counting. The higher level sector categories are provided as variables for convenient aggregation. The "sector" tab of the spreadsheet shows which sectors are included and how they fit into the TFI hierarchy.
• Gases: countries report emissions from CO2, CH4, N2O and F-gases (HFCs, PFCs, NF3, SF6). I have converted emissions from the different gases to CO2 equivalents using global warming potentials with a 100 year time horizon from the IPCC 5th Assessment Report (GWP100 AR5). More recent GWP100 values have been published in the IPCC AR6, but I have not yet figured out if it is possible to extract F-gases from every CRT in original units, which would be necessary to update the values. CH4 and N2O can be reconverted into their original units by dividing by 28 and 265, respectively. A full list of global warming potentials can be found here.

What can I use this data for?

The national GHG inventories are a formal part of the Paris Agreement and are intended to facilitate the tracking of progress towards national and global climate objectives. As such this data can be used to evaluate whether or not countries are progressing towards their stated goals (e.g. the NDCs and long-term net zero targets). It can also be used for a wide range of other applications, such as to track the effectiveness and outcomes of different policy interventions.

The dataset is currently not complete for all countries. It is therefore not suited to tracking total global GHG emissions. For that purpose, I recommend to use one of the other 3rd party datasets such as EDGAR, PRIMAP, CEDS, or the Global Carbon Budget for CO2 emissions.

Note that there is also an ongoing debate on the differences between national inventory reporting of LULUCF emissions and removals versus estimates from global bookkeeping models. This has significant implications for national and global net zero targets. It is important to be aware of those nuances when using national inventory LULUCF data.

Issues, updates, changes

• Country coverage: I will semi-regularly check the UNFCCC submissions and include new CRTs. Once all Annex I countries have submitted theirs, I will release a first "full version" (v1).
• Validation: I have cross-validated the data by (1) calculating whether leaf node sectors sum to reported emissions at higher levels in the hiararchy; and (2) by calculating whether leaf node sectors sum to total reported GHG emissions from Table10s1 in the CRTs. So far I have observed differences with respect to #2 on the order of 0.01-0.8% of total national ghg emissions for a handful of countries (Spain, Latvia, Poland, Portugal) in certain years. There is a larger difference in Khazakstan (1.95%) in a single year (2020). For both cases I don't yet know why. Any help with validation is highly appreciated.
• Activity data: The CRTs contain underlying data on activities, fuel use and emissions factors. These are especially useful for tracking changes and attributing the impacts of policies. I may start to include these in future versions as a separate sheet.

Code availability

The Github repository is here: https://github.com/lambwf/Tidy-GHG-Inventories/

And the main script for extracting CRTs is here: https://github.com/lambwf/Tidy-GHG-Inventories/blob/main/read_crts.Rmd