Methodology

Updated: 19.04.2024 12:00 CEST (regular update)

The Czech national GHG inventory is performed according to the prescribed IPCC methodology (2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 1 - 5, IPCC 2006; 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories; Good Practice Guidance and Uncertainty Management in National GHG Inventories, IPCC 2000; Good Practice Guidance for Land Use, Land Use Change and Forestry, IPCC 2003; 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands, IPCC 2013; available on http://www.ipcc-nggip.iges.or.jp/). Inventory compilation is preceded by the phase of planning, which is based on assessment of results achieved in the previous period including identification of gaps and imperfections. This assessment is based both on analysis of the NIS team itself and mainly on findings and recommendations performed by the Expert review team (ERT) in the previous international review. The planning phase is coordinated by the CHMI (NIS coordinator) in cooperation with sectoral compilers who detail general instructions of the NIS coordinator.

Preparation of a QA/QC (Quality Assurance / Quality Control) plan is one of the most important parts of the NIS. Elaboration of the QA/QC plan reflects the institutional arrangements and each sectoral compiler should elaborate its own system of QA/QC procedures, incl. designation of a QA/QC expert responsible for each sector. Sectoral QA/QC plans are integral parts of the overall NIS QA/QC plan being elaborated by the NIS coordinator. QC is designed to provide routine technical checks to measure and control the quality of the inventory, to ensure consistency, integrity, correctness and completeness of the data, and to identify and address errors and omissions. Its scope covers a wide range of inventory processes, from data acquisition and handling and application of the approved procedures and methods to calculation of estimates and documentation.

QC procedures are carried out both by sectoral compilers and by the NIS coordinator. Sectoral compilers concentrate more on activity data and the sector-specific methods used; the NIS coordinator mostly checks appropriate use of methodologies, provides trend analyses and compares data from other possible sources. QA generally consists of independent third-party review activities to ensure that the inventory represents the best possible estimates of emissions and removals and to support the effectiveness of the QC program. Experts from the Slovak Hydrometeorological Institute (responsible for the GHG inventory in Slovakia) perform QA activities of the GHG estimates. Further, the team is cooperating with other experts in order to ensure appropriate QA procedures.

Thorough archiving of all data, methods used, calculation procedures and all relevant documents belong also among obligations of the CHMI as the NIS coordinator, which should be ready to submit all archived files to ERT as one of basic materials for review.

Main features and characteristics of methodology

In general, GHG are assessed by using the total (or aggregated) emission, calculated as the sum of the emissions of individual gases multiplied by the relevant values of the Global Warming Potentials (GWP). The GWP values for main gases and the 100 years time horizons are 1 for CO₂, 28 for CH₄ and 265 for N₂O. Amounts of F-gases are relatively small compared to the main gases; nevertheless their GWP values are larger by 2-4 orders of magnitude. Consequently, the total aggregated emission to be reduced pursuant to the Kyoto Protocol resp. Paris Agreement is expressed as the equivalent amount of CO2 with the same climate change effect.

Methods and emission factors used for evaluating emissions are classified into three tiers according to the level of expected accuracy (to be explained below). Tier 1 involves namely simpler approaches based on basic statistical data and default emission factors (of global or continental applicability). These emission factors are usually directly tabulated in the methodical guidelines (2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 1 - 5, IPCC 2006; 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories; Good Practice Guidance and Uncertainty Management in National GHG Inventories, IPCC 2000; Good Practice Guidance for Land Use, Land Use Change and Forestry, IPCC 2003; 2013 Supplement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories: Wetlands, IPCC 2013), which are available on IPCC website (see http://www.ipcc-nggip.iges.or.jp/).Tier 2 usually involves more sophisticated calculations and usually requires more detailed and less accessible statistical data. Emission factors (country specific and technology specific) are usually derived using calculations based on more complex studies and better knowledge of the source. Even in these cases, it is sometimes possible to find the necessary parameters for the calculations in the guidelines (for reference see previous paragraph). Tier 3 usually involves procedures based on direct measurements carried under local conditions (using site-specific and technology-specific emission factors). Methods of higher tiers should be applied mainly for key categories. Key categories (key source categories) are defined as categories that cumulatively contribute to the overall uncertainty either in level or in trend from 90 %.

Sectoral inventories

Energy sector is the most important category of the GHG inventory. In the Czech Republic approx 70% GHG emissions come from this sector, mainly CO₂. This sector includes all combustion processes and fugitive processes connected with fuel and energy treatment, production, and mining (refinery, CH₄ fugitive emissions from coal mining, etc.). CO₂ emissions calculation is based mainly on the national energy balance and on other additional data necessary for appropriate emissions allocation to individual sectors. This sector covers also emissions from transport and from other mobile sources. Part of fuel consumption is reported in other categories or it is not even included into the national inventory. It is (i) non-energy fuel use for lubricant or asphalt production, (ii) emissions from fuel use in the international (air) transport, which are reported extra in the special category (memo item) called “bunkers” and not included to the national total of GHG emissions, (iii) emissions from coke use as reduction agent for the pig iron production, which are reported in the sector “Industrial processes”, and (iv) emissions from non-energy use in chemical industry (e.g. ammonia production, see the next paragraph).

In the category “Industrial processes” the following emissions are considered: from metallurgical, chemical, mineral processes (decarbonization) and F-gases use. Specifically, sector “Metal Production” includes CO₂ emissions from coke used in pig iron production, sector “Chemical Industry“ N₂O emissions from nitric acid production and CO₂ emissions from ammonia production, “Mineral Products” CO₂ emissions from decarbonization of carbonates in cement and partly lime production (where emissions are partly compensated by removals from lime use), and also in glass production. Basic sources of activity data for emissions calculations are statistical surveys. Data on F-gases emissions are obtained by annual survey provided by importers of these gases. The most important sector of F-gases emissions is cold storage industry (refrigeration system). Solvent use is not too important source of GHG and so this category is often associated with “Industrial processes”.

GHG emissions from Agriculture in the Czech Republic consist mainly of methane and nitrous oxide. Methane emissions are derived from animal breeding. These are derived primarily from enteric fermentation (digestive processes), which is manifested most for ungulate animals (mostly cattle in this country). Other emissions are derived from fertilizer management, where methane is formed under anaerobic conditions. Nitrous oxide emissions are formed mainly from denitrification processes in soils.

Sector “Land-Use, Land-Use Change and Forestry” (known as LULUCF") has been recently completely revised to be in accordance with the new methodology [Good Practice Guidance for Land Use, Land Use Change and Forestry, IPCC 2003]. This methodology is based on monitoring of the total wood stock in forests and it should also bring new information about subcategories that were not monitored before (e.g. emissions or removals from conversions of different types of land). As for the Czech Republic until 2017, CO₂ removals have been higher than CO₂ emissions and so LULUCF could be considered as a net sink. For the years 2018-2021 different trend was reported, the emissions of CO₂ exceeded the removal. This is due to the exceptionally high sanitation harvest following an unprecedented drought and bark-beetle outbreak experienced in the Czech forestry in the recent years (since 2015).

Emissions of GHG from waste in the CR consist mainly of methane emissions from municipal waste landfills and methane emissions from wastewater treatment (industrial and municipal). This category also includes nitrous oxide emissions from wastewater and CO₂ emissions from waste incineration. In case of Tier 1 approach, it is assumed that all respective part of carbon land-filled in a given year is emitted as methane (and biogenic CO₂ which is not included). The more complex approach (Tier 2) considers the first order kinetics decay, when carbon is gradually converted to methane leaking from landfills. Tier 1 has been used so far; however, usage of Tier 2 is now under development. Emissions from land-filling and anaerobic water treatment are lowered by amount which is captured and used for energy production.