What is a Carbon Footprint?
Carbon is one of the building blocks of life. Humans, animals and plants are made up of organic compounds. We burn wood and fossil fuels to produce energy and power transport, inadvertently releasing the greenhouse gas, CO2 into the atmosphere.
We will look at a series of calculations that represent the carbon cycle and how CO2 production is related to energy. You will start to see the energy implications of various fuels and technologies and their CO2 footprint.
The associated information sheet will provide the data you need to answer the questions below.
How much CO2 is emitted by the following activities? (calculate them in kg of CO2)
- Driving 100 miles?
(Using 13 litres of petrol or 10 litres diesel)
- Using your LED TV for 5 hours a day during a week?
(A 50” LED TV uses 100 watts, to convert to kWh, multiply kW by number of hours)
- Boiling water in the electric kettle for a family for a week?
(A kettle uses 1200 W and it takes 3 minutes to boil water and this is done 10 times a day – or does your household drink more hot drinks?)
- Heating the water with natural gas for a week of daily 5 minute showers?
(Heating 30 litre of water to 40°C uses 1.1 kWh in the form of gas, where emissions from natural gas are 0.2 kg CO2/ kWh burned)
- Charging mobile phones for the family for a week. With an average of two full charges a day.
(Typical phone charges at 0.015 kWh and takes 2 hours to charge fully)
- Play station for 20 hours a week
(A Playstation 4 Pro uses 139 W)
2. How to quantify CO2 emissions in terms of volume and mass?
- How many cubic metres of CO2 would 5000 kg CO2 occupy?
- A factory states that it releases 10 tons C per year (as greenhouse gas emissions). How many m3 of CO2e is this?
- If UK car emissions released 3 GtC in a year and all the CO2 remained in the atmosphere, by how much would the CO2 concentration increase?
- Go to see last year´s UK Carbon emissions published by the government (Provisional GHG emissions). In 2019 it was 351.5 Mt CO2 Considering the UK population is 63 million and the world population is 8.3 billion, are our carbon emissions representative of global average emissions? ((World emissions in 2017 were 36 Bt)
- What is today´s CO2 concentration at Mauna Loa (https://www.esrl.noaa.gov/gmd/ccgg/trends/)? How much has it increased since 1950? How much has it increased since the same month in 2018?
- Why has CO2 not decreased in 2020 if CO2 emissions have dropped? Is there still last years and the decade before´s emissions in the air or are we still emitting more despite the drop in transport and industry in 2020?
3. Steps towards reaching carbon neutrality
- Do you think the UK is on its way to becoming a low carbon economy? Why do you think some countries like Estonia are way behind the UK and countries like Sweden are way ahead?
- The UK has a goal of reaching Carbon neutrality by 2050- do you think we are on our way to reaching that?
- What percentage of our man-made CO2 emissions are absorbed by the oceans?
- If a fully grown tree absorbs 22 kg of CO2 per year and an acre of forests 2.5 tons of Carbon, if we wanted to neutralize our country-wide annual emissions of 351.5Mt* CO2, how many more trees or acres of forest would we need?**
*The latest government statistics on UK annual CO2 emissions (for 2019) was 351.5 Mt CO2 equivalent
**UK forests absorbed 21 million tonnes CO2 in total in 2020, so they are working away continuously at helping to neutralise our emissions!
