Understanding CO2 emissions
Understanding the amount of carbon produced by a business is a first step in reducing the impact of climate change. The way a business uses its products and services affects its carbon emissions. It may also indirectly responsible for the emissions produced from the use and disposal of products it manufactures. A carbon calculator is used to quantify how much carbon a business is responsible for extending to its supply chain, transport and employee activities.
Once determined, CO2 emissions help individuals and organisations realise the direct effect that their activities have on climate change. After quantification, opportunities for reduction can be identified and prioritised, focusing on the areas of greatest savings potential in heating, lighting, transport and supplier choice. Carbon Sequestering has also been put forward as a way of reducing CO2 emissions.
Fact
The UK has just 1% of the world's population, but produces 2.3% of the world's CO2. (Source: Carbon Dioxide Information Analysis Centre).Calculating CO2 emissions
Greenhouse gases when released to the atmosphere contribute to climate change with CO2 being the most common. These gases can be collectively measured and converted into carbon dioxide equivalence, therefore giving a standard measure for a carbon footprint (A carbon footprint is a quantitative measure of released green house gases resulting from an activity).
All forms of energy; fuel, electricity and transport produce CO2 emissions which can be calculated by multiplying energy consumption with fuel specific emission factors.
The table below shows the emission factor for different fuel types (Source: Carbon trust/ Defra)
| Energy/fuel | Emmission Factor (CO2/kWh) |
|---|---|
| Electricity | 0.43 |
| Natural Gas | 0.19 |
| Gas/Diesel Oil | 0.25 |
| Petrol | 0.24 |
| Heavy fuel oil | 0.26 |
| Coal | 0.30 |
| Cooking oil | 0.30 |
| LPG | 0.21 |
| Renewable Energy | 0.00 |
Carbon calculators
A carbon calculator is a quick and easy way to calculate how much carbon you, your business or household produces measured as kilograms or tonnes of carbon over a period of time by quantifying basic emissions from gas, electricity and transport sources through a basic process.
Different carbon calculators use different assumptions in their calculations especially when calculating travel emissions with some taking into account ticket types and occupancy rates of the different means of transport. Others express results based on a time period basis while others are on a unit basis.
The Carbon Trust has developed a set of calculators and standards to help businesses calculate their carbon footprints.
- Carbon Footprint Calculator: This is an online calculator developed by the Carbon Trust to assist organisations calculate their basic carbon footprint covering direct and indirect emissions (e.g. electricity usage and business travel). There is also a basic footprint indicator which provides rough estimate to give an organisation's carbon emission based on energy bills and sector.
- The Carbon Trust Standard provides a spreadsheet for carbon emission calculations using the GHG Protocol or ISO 14064. It makes available a list of emissions to be included and excluded in the carbon footprint calculation. The Standard requires organisations to take direct responsibility for reducing their own carbon emissions.
- Directgov ActonCO2 calculator is a free calculator developed by Defra in partnership with other parties and government departments based on agreed underlying data and factors. It provides an estimate of CO2 emitted annually from direct emissions through use of gas, electricity and transport fuels and also highlights areas that have the greatest effect on climate change and provides advice on steps to reduce carbon impact.
- National Energy Foundation has developed a free simple and quick calculator for use by UK organisations and based upon Defra's recommended conversion factors which are part of its Environmental Reporting Guidelines.
- The Climate Care Business Calculator allows businesses to calculate their key emissions and buy carbon offsets. They also have the option of investing in emission reduction projects which replace inefficient technologies with low carbon efficient technologies in developing countries.
- Office Foot printer created by Best Foot Forward is designed to enable businesses to complete a comprehensive footprint of office based operations. Results are meant to assist develop cost effective strategies to reduce the businesses carbon footprint and explore options for reducing the environmental impact of office materials, waste utilities and travel. To access this calculator, businesses need to pay subscription costs.
