Measurement of environmental footprints and circular economy

The UK’s Net Zero (NZ) target focuses on the reduction of UK greenhouse gas emissions. However, measuring reductions in territorial emissions is only part of the picture of the UK’s global environmental impact. Firstly, we live in a global economy and the goods and services required to meet the UK’s needs cannot be completely sourced domestically. Secondly, we need to consider impacts beyond emissions – a full Environmental Footprint would also assess the changing material, energy, land and water footprint.

University of Leeds produces the UK’s CBA for Defra (Carbon Footprint, Defra 2022) and the ONS (Material Footprint, ONS 2022). As accounting from a consumption perspective moves up the political agenda, this project aims to work with the ONS to improve the underlying datasets and produce policy relevant data for UK Government.

The calculations for Defra and ONS require an Environmentally-Extended Multiregional Input-Output database. The University of Leeds has constructed the UKMRIO database using ONS Supply and Use tables (SUTs), analytical tables, the environmental accounts, and trade data from a global Multiregional Input-Output (MRIO) database.

80% of the UK’s material footprint is embodied in imports. So, it is important to understand the UK’s trade patterns and their effect on the environment. ONS SUTs report the imports to the UK but do not report which countries the UK is trading with. The UKMRIO supplements this with trade share data from another Global MRIO database: EXIOBASE. Recently, two new Global MRIO databases have been developed by the OECD (ICIO) and Eurostat (FIAGRO). The project will explore using these systems.

The UK SUTs used in the UKMRIO database are at a 112 industrial sector resolution. Material extraction sectors represent just 8 of these, with mining of metal ore being a single sector. This means we assume the same production structure for mining of iron as we do tin, leading to inaccuracies in material footprint calculations. This issue is more pronounced when we consider the emissions associated with the electricity sector. Disaggregating UK electricity generation by source (e.g. renewables, gas, coal) would see striking differences in the product-based multipliers depending on where they source electricity from in their production processes. Therefore, we explored disaggregating key sectors in the UKMRIO database using datasets held by the ONS and other sources.

Based on the new release of the 2021 Carbon footprint data, and recent research comparing global modelling approaches, we found that:

• Between 2020 and 2021, the UK’s carbon footprint is estimated to have risen by 15%. This increase reflects increases in emissions from all activities, but especially in emissions from imported goods. Imported goods are also the most uncertain component of the footprint, with differences across datasets often exceeding 30%.
• The UK carbon footprint peaked at 963 million tonnes (mt) carbon dioxide equivalents (CO₂e) in 2007. It was 27% lower than this in 2021. Similar long-term trends were consistently identified across global datasets, which typically differ by less than 6 percentage points at an aggregate level.
• GHG emissions relating to imports rose 72% from 1996 (there is a little uncertainty around the figures in the source data for 1990 – 1995) to a peak in 2007 and in 2021 were 45% higher than 1996. Emissions associated with imports from China also showed a peak in 2007. In 2021 they were more than double the 1996 level (114%). This highlights the importance of global value chains, which are a key source of variation between datasets.
• In 2021, emissions relating to the consumption of goods and services produced in the UK were 54% lower than in 1996. These are generally more consistent across datasets than imported emissions.

In addition, we improved the UKMRIO model by incorporating trade data from FIGARO. This is expected to futureproof the model and improve consistency, which is particularly important given that estimates of imported emissions can differ by more than 30–50% depending on the dataset used.

Internationally, MRIO databases are broadly reliable for calculating consumption-based emissions of large economies. In addition, major MRIO databases also identify the same key emitting industires. However, for smaller, import-heavy countries, the choice of database can substantially impact estimated emissions from imports as well as their patterns over time.

The project will allow shared learning between the ONS and other statistical offices and map out a transparent process for developing ONS statistics of material footprint.

It will create a more accurate MRIO (multi-region input-output) table to produce UK and England carbon footprint for Defra and devolved region footprints for Scottish and Welsh government and footprints for Government Office regions and Local Authorities.

The results will show the direction of travel for the UK’s environmental footprint. This will determine whether Net Zero policy is reducing both the impact of imports and other components of the footprint such as material use and water use. It will also provide a model that can be used to evaluate the effectiveness of demand side policy.

Kilian, L., Owen, A. and Hoekstra, R. ‘Quantifying the Impacts of Multi-Regional Input–Output Data on Emissions from Imports’ Economic Systems Research 05 May 2026, doi: https://doi.org/10.1080/09535314.2026.2637638

Kilian, L., Owen, A. and Hoekstra, R. ‘Improving the UKMRIO’s material footprint’ ESCoE Technical Report Series, ESCoE TR-30, August 2025.

Kilian, L., Owen, A. and Hoekstra, R. ‘Improving the UKMRIO’s trade data’ ESCoE Technical Report Series, ESCoE TR-29, August 2025.

Office for National Statistics, Material footprint in the UK, May 2025.

Department for Environment Food & Rural Affairs, Carbon footprint for the UK and England to 2021, May 2025.

Kilian, L. ‘Quantifying the impacts of MRIO data on emissions from imports‘ 10^th Conference on Input-Output Analysis, Gijon, 4-6 September 2024

Kilian, L., Owen, A., and Hoekstra, R. ‘Comparing emissions embodied in imports from four global MRIO databases’ Session 2B Productive and inclusive net zero, 38th IARIW General Conference, King’s College London, 26-30 August 2024

Local Authority Consumption Accounts Website, updated July 2024 with 2021 results.

Owen, A. ‘Calculating Carbon Footprints for UK Climate Policy’ Workshop Quantifying Carbon Footprint: Challenges and Perspectives, The University of Warwick, 16 May 2024