Method for calculating our carbon footprint

Method for calculating our carbon footprint

The published figures represents Tesco’s carbon footprint in our full financial year 2020/21. This year, this includes 52 weeks, from 23rd February 2020 to 27th February 2021 inclusive.

In December 2020 we re-baselined our carbon figures to reflect the sales of our businesses in Thailand, Malaysia and Poland, as announced in 2020. During this process we have also incorporated data improvements since the latest assurance statement. All figures on this page are up to date and include modifications made since December 2020 to account for our acquisition of Best Foods in the UK as well as minor data improvements that have since been reported during our annual review process in line with our Carbon footprint policy. More information on our base year recalculation policy can be found here.

Our approach

We have calculated our carbon footprint according to the World Resources Institute (WRI) and World Business Council for Sustainable Development (WBCSD) Greenhouse Gas (GHG) Protocol, which is the internationally recognised standard for corporate carbon reporting. This breaks down emissions into four categories for reporting – Scope 1, 2 (market and Location based), 3, and outside of scopes.

  • Scope 1 – These are the direct GHG emissions that originate from assets that Tesco owns or controls. For example, these include emissions from gas and other fuel consumption in our stores, distribution centres and offices globally. We also include emissions from fuel consumption in Tesco owned and leased vehicles transporting the products that we sell. As well as energy, we also include emissions from refrigerant gas leakage from systems in our stores or our vehicles.
  • Scope 2 – This includes the indirect GHG emissions from the generation of electricity and district heating which Tesco uses. In accordance with the Greenhouse Gas Protocol Scope 2 Guidance we calculate our electricity emissions using both the location and market-based methods.
    • Market based - Our market-based emissions have been calculated by collecting generation data directly from our suppliers in countries where Tesco has a choice in its electricity supplier. All of the supplier-specific factors applied relate to production mixes in 2019, for the 2020/21 footprint. Our Scope 2 market-based footprint includes Tesco’s purchase of electricity backed by Renewable Energy Guarantees of Origin (REGO) or Renewable Energy Certificates (RECs).
    • Location based - We have used emission factors from BEIS’ GHG Conversion Factors for Company Reporting 2020 and have determined the Scope 2 electricity impacts for non-UK electricity from the International Energy Agency (IEA) figures (of CO2 rather than CO2e). In line with current UK Government guidance, an emissions factor of zero has been applied for renewable electricity only where this has been generated from sources owned or controlled by Tesco in our Scope 2 location-based emissions.
  • Scope 3 – This includes other indirect GHG emissions generated along our value chain. Under Scope 3 emissions we report business travel and emissions from distribution arranged by Tesco but provided by third parties (including secondary distribution globally and emissions from primary distribution in the UK). We include primary distribution for the UK only as we have a greater influence over how products are delivered to our distribution centres than in the rest of the Tesco Group. Business travel includes travel by air, rail, taxi and short-term hire car. Additionally, Scope 3 emissions include transmission and distribution impacts of electricity and heat supply and well-to-tank embodied impacts of fuel.
  • Outside of scopes – This relates to biogenic emissions that are considered to have a net zero carbon dioxide impact due to the carbon they absorb during their growth. When they are burned to produce energy this carbon is released and the associated emissions are recorded as being ‘outside of scopes’ in accordance with the GHG Protocol.

We follow the “operational control approach” to help us determine when to include emissions within our carbon footprint. Our carbon footprint boundary includes operations where we have full authority to introduce and implement operating policies. This means that we include data from our major subsidiaries such as Booker, Tesco Bank, One Stop, and Dunnhumby as well as Tesco stores and DCs where we have operational control. In cases where Tesco divests of an asset part way through a financial year, and thus relinquishes operational control, emissions from this source will not be included in Tesco annual carbon footprint.

In the case of emissions from distribution, we also include journeys which are provided by third parties but have been arranged by Tesco. These are included in our Scope 3 emissions.

Our carbon footprint is measured in carbon dioxide or CO2. Different greenhouse gases have different effects on the climate, and CO2 is a way of standardising the global warming effect of these emissions.

We present our footprint in three ways:

  • Gross emissions: Total CO2e emissions within the boundaries of our footprint.
  • Net emissions: Total CO2e emissions within the boundaries of our footprint minus the emissions credited through renewable energy we generate and provide to the national electricity grid.
  • Emissions per square foot of Tesco stores and distribution space: The intensity of our Scope 1 and Scope 2 emissions in the context of the amount of net sales area they relate to. This excludes store rooms, offices, Subsidiaries and third-party leased space.

Our carbon footprint

Global Tonnes of Carbon




Base year 2015/16

Scope 1





Scope 2 (Market-based method)





Scope 2 (Location-based method)





Scope 1 and 2 (Market-based) Total





Scope 1 and 2 carbon intensity (kg CO2e/sq. ft. of stores and DCs)





Scope 3





Emissions outside of scopes





Total gross emissions





CO2e from renewable energy exported to grid





Total net emissions





Overall net carbon intensity (total net emissions kg CO2e/sq. ft. of stores and DCs)





KPMG LLP were engaged to provide independent limited assurance over the selected greenhouse gas emissions data highlighted in this report with a * using the assurance standards ISAE (UK) 3000 and 3410. KPMG has issued an unqualified opinion over the selected data.

How we gather the necessary data

Our carbon data is collected by managers in each of the countries in which we operate and entered into an internet-based reporting tool that has been designed specifically for our carbon footprinting process. This tool has been developed to reflect the requirements of the GHG protocol. The tool calculates CO2e emissions for each country and Tesco group as a whole, as well as performance against our Key Performance Indicators (KPIs) and a number of other measures. All data is quality checked and reviewed by an analysis team.

Data estimations

Diesel Use by suppliers

Where we use 3rd party contractors to deliver goods from our DCs to stores, we estimate the amount of diesel they have used. Outside the UK we do this based on the distance travelled, (Tesco data), and average fuel performance data of the vehicles used for transport (contractor data).

Diesel used (litres) = Distance (km) x Vehicle fuel economy (litres/km)

In the UK, where we need to estimate fuel use we assume the same fuel usage per case delivered as our own vehicles. This is because we use the same types of trucks and deliver along the same routes.

Diesel used (litres) = Number of cases delivered by suppliers x Diesel use per case delivered (based on Tesco data)

Data gaps

Where data has not been provided by an area of the business included within the boundaries of carbon footprint we will estimate the relevant impacts by using the most appropriate data available (e.g. historic consumption, annual extrapolation, average emissions).

Excluded data

For a small number of areas actual data were unavailable and reasonable estimates could not be produced. The reporting and assurance processes have concluded that these areas are not of significance to the carbon footprint data overall. We will continue to improve the quality of our data and will work to obtain actual data for these sources in future.

  • Emissions from diesel used in back-up generators in the UK
  • Employee car use for business and short term hire car travel outside of UK
  • Taxis for non-UK countries
  • Emissions from asset sites – these are vacant buildings that we own but have not yet developed into stores and therefore have minimal emissions

In line with our operational control approach, emissions from the following businesses and sources are not included in our footprint:

  • Tesco Mobile services - these are delivered using O2’s mobile network infrastructure and these emissions are reported within O2’s carbon footprint.

Baseline and restatements

We use 2015/16 as the base year for our carbon footprint as that is the reference we used to set our science-based targets. In order to accurately track our progress on carbon reduction, we recalculate our base year and the prior year emissions for relevant significant changes, such as updates to emission factors. More information on our base year recalculation policy can be found here.

Method for calculating our renewable electricity consumption.

We use the below calculation for the proportion of our electricity which comes from renewable sources, i.e. from renewable Power Purchase Agreements (PPA) both onsite and offsite, renewable generation from owned assets onsite, and purchased in the form of Renewable Energy Certificates (RECs):


To calculate the proportion of electricity we procure from sources that contribute additional renewable electricity to the grid, we exclude RECs:


Renewable Power Purchase Agreements (PPAs) = contracts with a specific supplier to represent energy produced at assets off-site and on-site from an eligible renewable energy resource. These must demonstrate additionality. On-site PPAs refer to renewable energy generated from assets hosted, but not owned, by Tesco on-site.

Onsite Generation = generation of energy from assets that Tesco owns.

Renewable Energy Certificates (RECs) = Government-backed certificates that producers of renewable energy are issued with for the electricity they generate. RECs certify that the electricity comes from renewable sources.