Carbon calculators and ecological footprints
These allow you to measure your personal carbon dioxide emissions – the major cause of climate change. They ask questions about your lifestyle, including heating and powering your home, transport and perhaps food. The results show you which aspects of your life result in the highest carbon emissions, so you know where to make the biggest changes.
Online carbon calculators are often quite simplified. They may not cover all aspects (such as food), and will make assumptions and generalisations to simplify the questions. Also, they often don’t include the indirect emissions from industries and services that allow you to carry out your day-to-day life. For example, not only the emissions from a car exhaust, but also a share of the carbon that results from building and maintaining roads. There is also an ‘infrastructure share’ for the emissions from providing the services we all benefit from, such as building and running schools and hospitals. To reduce these emissions you’ll need to use your influence as a citizen to encourage the government to make services more climate-friendly.
Some carbon calculators were developed by companies selling carbon offsets – particularly for plane flights, which have a very high environmental impact. Efforts to reduce home energy use, compost or recycle waste, and invest in renewable energy can all be negated by just one return flight. However, we think it’s better to invest in avoiding carbon emissions in the first place. Or to donate directly to charities & non-profit organisations working in this area, rather than via an offsetting company. See below for more on offsetting.
The ecological footprint is a way of expressing our impact on the planet more widely than with carbon emissions alone. It shows the amount of land used to provide us with everything we consume (energy, food, homes, travel, the things we buy, etc) and also to cope with the waste that we produce.
My eco-footprint can be expressed in terms of the number of planets that we’d need to absorb my impact if everyone on earth lived as I did. For example, if everyone lived like the average Briton we’d need three planets to mop up our carbon emissions, grow our food and dispose of our waste. The clear target is to become a ‘one planet’ person, and nation. An individual ecological footprint can be expressed in global hectares. An individual’s fair share is less than 2 hectares, but the average ecological footprint in the UK is over 5 global hectares per person.
The eco-footprint doesn’t measure everything. It can’t give us figures for the impact of some types of pollution, for the use of finite resources or aesthetic or social impacts. But it provides another way of seeing the relative impact of our actions, so that we can prioritise what we do to reduce our impact.
Eco-footprinting for education
The ecological footprint is a powerful educational tool. It lends itself to games, theatre, practical workshops and creativity. It can help young people to understand global environmental and social issues. CAT has created activities using the eco-footprint for school pupils and youth groups aged from 7 to 18. Our “Where’s the Impact?” resource pack contains materials for eco-footprinting activities. The activity can be run at a variety of levels, from KS2 to A-level.
Examples of Calculators
CAT’s own Laura’s Larder is a detailed calculator for emissions from our diets. It gives you feedback on nutritional qualities and deficits as well as greenhouse gas emissions, and makes suggestions for improvements
A simple carbon calculator from the National Energy Foundation uses recent data for emissions from energy use and transport.
The EcoPassenger calculator compares the energy consumption, carbon emissions and other environmental impacts for passenger travel by plane, car, or train.
Related QuestionsShould I buy carbon offsets?
Because a plane flight is a single big carbon impact, many companies promote methods of neutralising the impact of those emissions, such as investing in renewable energy or planting trees.
One flight is responsible for roughly 0.17 kilograms (kg) of carbon dioxide (CO2) per passenger-kilometre. These emissions should be multiplied by a factor of 2.5 due to the increased warming effect of upper atmosphere emissions. However, some calculators don’t include this factor when evaluating offsets. A return flight from London to Malaga (2,300 km) would emit almost 1 tonne of CO2 equivalent.
However, we are very wary of offsetting in principle because what we really need to be doing is reducing our own emissions as much as possible. There is the danger that carbon offsetting schemes leave people feeling that it is fine to fly as they can just buy their way out of the consequences. It is far better to reduce your emissions at source by travelling by train rather than plane and taking holidays closer to home.
If you have to fly, you could invest in carbon saving measures closer to home instead of offsetting. You could insulate your home to a very high standard (if you are a homeowner). Or invest in an electric car or bike to reduce the impacts of car travel, or in a community renewable energy scheme. Or you could just donate directly to charities & non-profit organisations working in this area, rather than via an offsetting company.
If your own options are limited and you do want to investigate offsetting, then Ethical Consumer have more advice on avoiding bad offsetting schemes. As they mention, schemes that plant trees are not as common now, as there were many problems with how these were managed. We do need to address deforestation, but poorly sited tree plantations can have negative effects on habitats, water supplies and local people. Young trees use lots of water, so if many are planted they can reduce the water available to farmers downstream. When a tree rots or is burned, any carbon absorbed is released again. The trees need to be allowed to grow for many years, and the forest then needs to stay in place for centuries to come.