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UK GHG Inventory Compilation Process & Timescales
DECC is responsible for submitting the UK's Greenhouse Gas Inventory (GHGI) to the United Nations Framework Convention on Climate Change (UNFCCC), and AEA is contracted to compile the GHGI on DECC’s behalf.
AEA is responsible for the management of the inventory compilation and reporting process including: inventory planning, data compilation, reporting, archiving and all elements of the Quality Assurance system to ensure that the UK GHGI meets international inventory reporting requirements under the Kyoto Protocol. In addition, AEA is directly responsible for producing the emission estimates for source categories, Energy (CRF sector 1), Industrial Processes (CRF sector 2), Solvent and Other Product Use (CRF sector 3), and Waste (CRF sector 6).
North Wyke Research compiles the inventory for agricultural emissions using agricultural statistics from Defra.
The Centre for Ecology and Hydrology (CEH) compiles estimates of emissions and removals from Land-use, Land-use Change and Forestry (LULUCF) using land-use data and information on forestry from the Forestry Commission (a non-departmental public body), the British Geological Survey, Defra, and from other sources.
DECC also funds research contracts to provide emission estimates for certain sources. For example, AEA is currently undertaking consultation with industry to improve UK emission estimates of HFCs, PFCs and SF6.
The GHGI is compiled according to IPCC Good Practice Guidance (IPCC, 2000). Each year the inventory is updated to include the latest data available. Improvements to the methodology are made and are backdated to ensure a consistent time series. Methodological changes are made to take account of new data sources, or new guidance from IPCC, relevant work by CORINAIR, new research, or specific research programmes sponsored by Defra or DECC.
Process of Inventory Preparation
The following activities are carried out each year as the inventory is compiled:
Step 1 Method improvement. Improvements to calculation methods are normally implemented before the inventory is compiled. These improvements are in part based on recommendations of UNFCCC (In-depth Reviews, In-country Reviews), peer reviews and relevant research sponsored by Defra/DECC or other organisations.
Step 2 Data requests. Requests for activity data and background data are issued to a wide range of data suppliers. Each request is issued with a unique code, and a database is used to track the request and the data supplied from that request.
Step 3 Data verification. Activity data received are examined. Anomalies are investigated, such as time series discrepancies or large changes in values from the previous to the current inventory year.
Step 4 Data processing. Data are prepared to allow emissions of direct and indirect GHG to be estimated.
Step 5 Emission estimation. Provisional emissions are estimated using the most recent activity data available.
Step 6 Emissions review. A series of internal reviews are carried out to detect anomalies in the estimates (time series variations and year to year changes). Errors and omissions are then rectified.
Step 7 Emissions reporting. (including background data). Estimates of emissions are prepared for the various reporting formats (e.g. IPCC, UNECE etc.).
Step 8 Report generation. Draft reports are written to satisfy the reporting criteria of the various agencies, e.g. the IPCC.
Step 9 Report review. The reports are reviewed: internally; by external contributing agencies; and by Defra. Errors and omissions are then rectified.
Step 10 Report publication. Final reports and data sets are then submitted and published in print and on publicly available web sites.
The system outlined above complies with the Tier 1 Quality Assurance and Quality Control (QA/QC) procedures, as outlined within the IPCC Good Practice Guidance (IPCC, 2000).
Note that the GHGI is compiled using the same database as the UK National Atmospheric Emissions Inventory (NAEI). The NAEI is used for reporting under other international agreements and includes emission estimates for greenhouse gases, regional pollutants leading to acid deposition and photochemical pollution, persistent organic pollutants and other toxic pollutants such as heavy metals. The NAEI is available at
Annual Cycle Schematic
The above schematic illustrates the annual cycle of inventory activities, starting with the acquisition of new data around July/August, data processing and QC activities through September/October, data finalisation and further QA activities during November and then a pre-submission inventory review of datasets in late November. The Draft Inventory data is submitted to the EU Monitoring Mechanism (EUMM) in Common Report Format (CRF) by the 15th January each year. Ongoing reviews and preparation of the National Inventory Report lead to the final delivery of inventory data and reports to the EUMM on the 15th March and the UN Framework Convention on Climate Change by April 15th each year.
An ongoing programme of inventory improvement feeds in changes to data and methodologies throughout the year as part of the inventory’s QA system with May, June and July the key periods for integrating any significant improvements to the inventory systems.
For more information about the UK's Greenhouse Gas Inventory, please contact us at:
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