13 & 14 June 2015
Environment Weekend at St Chad's to celebrate “Cherishing Churchyards” week and “National Picnic” week

Click here for the Programme (opens as a pdf file)

Carbon Footprint: what is it and why is it important?

Carbon footprint is defined as the total amount of greenhouse gases emitted over a given period by an individual, a household, a building, a company or organisation as a result of day-to-day activities. It is therefore a measure of their impact on the environment. As carbon dioxide (CO2) makes up the largest proportion of greenhouse gas emissions, carbon footprint is usually expressed in terms of carbon dioxide equivalent (CO2e).

Why is carbon footprint important? The scientific evidence is now quite clear that man-made emissions of greenhouse gases are responsible for a warming climate. CO2 emissions arise from the burning of fossil fuels coal, gas and oil. For each of these fuels the amount of CO2 emitted can be calculated for each unit of energy consumed. For example the current figure for electricity is 0.537 kg CO2e per kWh and includes an element for the impact of transmission and distribution from the power station. Burning natural gas produces 0.185 kg CO2e per kWh of energy produced. Consequently by monitoring energy consumed it is possible to calculate the amount of CO2 emitted and hence estimate the size of the carbon footprint and the impact on the environment.

At Chad’s we have been monitoring electricity (lighting) and gas (heating) consumption for a few years, and particularly since the building was re-ordered. Electricity consumption over the last 3 years has largely depended on the use of the building through the week and has ranged between 13,800 and 18,000 kWh: that is roughly equivalent to a 2-bar electric fire on all day every day. These figures lead to annual emissions of CO2e of between 7 and 10 tonnes.

On the other hand gas consumption for heating depends much less on how often the building is used and greatly on the outside temperature. Generally when this drops below 15oC heating systems get switched on. The lower the temperature below 15oC the more energy is consumed to maintain the indoor temperature at the required level. Gas consumption over the last 3 years has ranged from 169,200 (2014) to 221,240 (2013) kWh, this latter figure resulting from the much colder winter of 2012/13. The increase in consumption closely mirrored how much colder it was than the warmer years. These figures give annual CO2e emissions of between 31 and 41 tonnes.

Combining the electricity and gas consumption figures gives a total annual carbon footprint of St Chad’s church building over the last three years of between 40 and 51 tonnes CO2e. This quantity of CO2 would occupy the volume of 8 to 10 Olympic-sized swimming pools, or if you prefer, 145 to 183 double-decker buses!

Mike Willison, St Chad’s Green Team

British Wildlife article
An article about St Chad's Churchyard, written by Suzanne Dalton, has been published in The British Wildlife Journal. Read it here

Suzanne Dalton