National consumption-based emissions of households are typically disaggregated using consumption and expenditure microdata. This data collection contains neighbourhood- and product-level per capita household emissions for the year 2016 estimated using an input-output methodology and three such consumption and expenditure datasets for subnational disaggregation. These datasets include the Output Area Classification (a publicly available geodemographic classification), the Living Costs and Food Survey (an openly available expenditure survey), and a commercial household expenditure dataset by TransUnion. Data are available for Lower and Middle Layer Super Output Areas in England and Wales, to Data Zones and Intermediate Geographies in Scotland and to Super Output Areas and Wards in Northern Ireland. Product-level data are available at Classification of Individual Consumption by Purpose (COICOP) 2 and 3 levels.In light of an increased involvement of local actors in climate change mitigation, understanding local greenhouse gas emission trends is vital. Particularly in countries and cities with high consumption-based footprints, recognising how local consumption contributes to global and national emissions is key for effective emission reduction. Typically, national emissions are disaggregated using consumption and expenditure microdata. To assess the reliability of such an approach, this research generates emission estimates using three UK microdata datasets from the year 2016 and compares their emission outputs, when levels of spatial and product details are high. These datasets include the Output Area Classification (a publicly available geodemographic classification), the Living Costs and Food Survey (an openly available expenditure survey), and a commercial household expenditure dataset by TransUnion. Per capita greenhouse has emissions are estimated for UK Lower and Middle Super Output Areas using all three datasets, in order to assess the impact microdata selection can have on emission estimates.

To generate these data geographic data, census data, expenditure data, and input-output data are used. The expenditure datasets used to disaggregate national emission estimates are the Living Costs and Food Survey (LCFS) (ONS and Defra, 2020), Output Area Classification (OAC) Group Level (Gale et al., 2016), and a rarely used commercial consumer expenditure dataset by TransUnion from the year 2016. To calculate the GHG emissions associated with the consumption-patterns of UK neighbourhoods we need a set of product-based conversion factors that can be used to convert household activity into emissions. Conversion factors consider both the direct emissions associated with burning fuel to heat homes and drive cars and the indirect emissions associated with the full production supply-chain of the goods and services bought by the household. This includes both emissions from domestic production and those emissions released abroad which are used in the production of imports. The UK’s MRIO (UKMRIO) is used to calculate the conversion factors: GHG per unit spend (£) by COICOP product (ONS, 2019; United Nations: Statistics Division, 2019; Defra, 2020; ONS, 2020). The UKMRIO is a national statistic constructed annually by the University of Leeds following methodology outlined by Tukker et al. (2018) and Edens et al. (2015). Greenhouse gases reported in the UKMRIO are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulphur hexafluoride (SF6) and nitrogen trifluoride (NF3), these are converted into their carbon equivalent and are reported as tCO2e. A more detailed description of the UKMRIO can be found in Owen and Barrett (2020).