Otley Science Fair

Fancy weighing your carbon footprint?

On Saturday 14th November the branch hit the road and headed to Otley, with a ‘carbon footprint scale’ which was designed and built by Jo Robinson, Fundraising Officer of the branch.

This scale meant that kids could ‘weigh out’ the carbon footprint of various day to day activities, commodities and activities.

What is CO2 and why is it important?

‘CO2’ stands for carbon dioxide, which is a gas made from one carbon atom and two oxygen atoms. Carbon dioxide is a ‘greenhouse gas’, which means that when it is present in the atmosphere it heats up the earth.

Other gases, such as methane, also heat up the earth in the same way. So that we can compare, the term CO2 equivalent (CO2e) is often used.

A major way we get energy is from burning fossil fuels, and this produces CO2. We can calculate carbon footprint of an item by calculating how much carbon dioxide would be burnt to release the energy needed to produce an item such as a book.There are also hidden CO2 emissions, for example the energy needed to transport it once it is made.

Let’s weigh it out!

To give a physical meaning to the relative proportions of CO2e we filled cardboard boxes with rice, in proportion to that item’s carbon dioxide equivalent. Jo then built a set of scales so that kids could come and weigh out everyday items.

Scales all ready to go! Photo credit: Ruth Amey

How much CO2 are we using day to day?

For example, those 6 eggs you had for breakfast? That’s 1.8 kg CO2e. And don’t forget your 15 minutes shower – better add on another 1.7kg CO2e.

And think about your leisure activities – a book will ‘cost’ just 1kg CO2e and last you a lifetime, whereas the Lord of the Rings trilogy on a 42 inch TV will be 2.5kg CO2e.

It may surprise you to know that a pair of jeans weighs in at 6kg CO2e, whereas a pair of leather shoes weighs in at a huge 15kg CO2e! This is because of the cost of energy to raise cows and produce the leather, as well as the methane that cows produce in their lifetime.

However, the ‘heaviest’ item we had for our scales was a train from London to Leeds, with 30kg CO2e.

Jannick answers a lot of questions about carbon dioxide emissions! Photo credit: Ruth Amey

All figures are from the book ‘How Bad Are Bananas? The Carbon Footprint of Everything’ by Mike Berners-Lee.