The UK’s carbon footprint is measured in different ways for different purposes. Each basis of measurement is published by the government. The different bases should be viewed as complementary ways of accounting for carbon emissions. Territorial basis Emission estimates are based on the UK greenhouse gas inventory and published by the Department for Energy Security and Net Zero (DESNZ) – this is used as the basis for our reporting to the EC (European Commission) and United Nations Framework Convention on Climate Change (UNFCCC) and forms the basis for reporting on progress towards our domestic and international emissions reduction targets. The inventory measures emissions on a territorial basis, so only includes emissions which occur within the UK’s borders. GHG emissions emitted in international territory, i.e. from international aviation and shipping, are reported as memorandum items. Production basis Emissions estimates are reported in the UK Environmental Accounts, published by the Office for National Statistics (ONS) - these measure GHG emissions on what is referred to as a “residents” basis, which means that the figures represent emissions produced by UK residents and industry whether in the UK or abroad but exclude emissions within the UK which can be attributed to overseas residents and businesses. International aviation and shipping emissions are allocated to countries based on the operator of the vessel. Figure 7: Relationship of different measures of the UK’s GHG emissions 1996 to 2021 Download the data for this figure Figure 7 shows the relationship between three different measures of GHG emissions relating to the UK. Whilst the carbon footprint has decreased 15 per cent over the time period, emissions on a territorial basis have decreased 46 per cent whilst emissions on a production or residents basis have decreased 39 per cent. The larger reduction in territorial emissions may be due to the UK economy further moving from a manufacturing base to a service base with a greater dependence upon imports and their associated embedded emissions. For further details on the different measures, please see measuring uk greenhouse gas emissions