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Carbon calculations

Our calculations are based on 12 months of consumption from January to December 2021.

Gas

The College’s gas consumption in 2021 was 361,380m3, which produced 735 tonnes of carbon dioxide equivalent (CO2e) (Government greenhouse gas conversion factors for company reporting, Department for Environment, Food and Rural Affairs (Defra), June 2020).

Electricity

In the same period, the College avoided the production of 366 tonnes of CO2e by using electricity generated from renewable sources (1,568,874 KwH) (Government greenhouse gas conversion factors for company reporting, Defra, June 2020).

Water

In 2021, Exeter College used 20,518m3 of mains water, which created 22 tonnes of CO2e (Government greenhouse gas conversion factors for company reporting, Defra, June 2020).

Student travel

In 2021, the majority of our taught students attended College in Trinity and Michaelmas terms, but not Hilary term (due to Covid-19 restrictions). Similarly, the majority of research students chose to stay in Oxford throughout the year. We have assumed that UK students travelled to Oxford by car, with a family member or friend dropping them in Oxford and then making the return trip home. We have therefore assumed that UK students on undergraduate and taught postgraduate courses required four return trips in 2021 (one at the start and one at the end of each term they spent in Oxford) and postgraduate research students made two return trips. For the purposes of estimating the CO2e emissions we assumed that the average return journey was 400 miles, equivalent to driving from Lancaster to Oxford and back. This equates to 174 tonnes of CO2e from our UK students travelling to and from Oxford (University of Oxford Carbon Accounting Tool 2020).

Because of Covid-19 restrictions, the majority of our international students on undergraduate and taught postgraduate courses made two return flights from their home country in 2021 and the majority of postgraduate students taking research degrees made one return flight from their country of origin. This equates to 872 tonnes of CO2e from our international students travelling to and from the UK (University of Oxford Carbon Accounting Tool 2020).

Food

The food-based carbon footprint is calculated by broad approximation and more detailed analysis in our upstream supply chain will be carried out in due course. The calculation uses the College’s 2021 catering operations and is based on the equivalent of circa 19,200 day consumers at 5.2Kg/CO2e per day (source: Food in a warming world: the changing foods on the British Plate, WWF, 2018; broadly in line with data from “Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK” by Scarborough P. et al, Nuffield Department of Population Health, Oxford, 2014). This equates to 100 tonnes of CO2e from food in 2021.

Land

Exeter owns and manages responsibly approximately 12 hectares of woodland and six hectares of grassland including a site of special scientific interest (SSSI). This absorbed approximately 74 tonnes of CO2e in 2021 (University of Oxford Carbon Accounting Tool 2020).

CO2e emitted, avoided, removed or offset for the year 2021

  Carbon emissions (expressed as tonnes of CO2e)* 
Gas  735 
Electricity  366 
Water  22 
Food  100 
Student travel  1,046 
Electricity using renewable sources of energy  -366 
Woodland  -72 
Grassland  -3 
Four verified carbon offset projects  -1,830 
Balance  -2 

 

* negative figures represent where CO2e has been removed, avoided or offset using audited and verified carbon offset projects