CARBON CALCULATORS AND ECOLOGICAL FOOTPRINTS

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Carbon calculators

These allow you to measure your personal carbon dioxide (CO₂) emissions - the major cause of climate change. They ask questions about your lifestyle, including heating and powering your home, transport and food. Carbon calculators show you which aspects of your life result in the highest carbon emissions, so you know where you need to make the biggest changes. Most calculators also provide advice on reducing your emissions.

Some calculators include the indirect emissions from industries and services that allow you to carry out your day-to-day life. For example, if you drive a lot then you are responsible not only for emissions from your car, but also for a larger share of the CO₂ that results from building and maintaining roads. There is also an ‘infrastructure share’: emissions from providing the services we all benefit from, e.g. building and running schools and hospitals. Reducing your infrastructure share means using your influence as a citizen to encourage the government to make services more climate-friendly.

CAT has designed climate:mobile, a personal carbon calculator that runs on WAP mobile phones. To download it (on standard network rates), point a WAP phone at: www.cat.org.uk/climatemobile

The Resurgence calculator is very detailed (www.resurgence.org/carboncalculator). You need a year's fuel bills to complete the questions and it is a time consuming process. However, the accuracy means you'll be able to see the effect of even small lifestyle changes. Your indirect share is estimated based on your annual income.

The Climate Outreach and Information Network (COIN) carried out a review in 2007 of 19 online carbon calculators, which can be found at: http://coinet.org.uk/materials/carboncalculations

Ecological footprinting

The ecological footprint is an alternative way of expressing our impact on the planet. It shows the amount of land that is used to provide us with everything that we consume (energy, food, homes, travelling around, the things we buy) and also to cope with the waste that we produce.

Your eco-footprint can be expressed in terms of the number of planets that would be needed to absorb your impact if everyone on earth lived as you did. For example, if everyone lived like the average Brit we would need three planets to mop up our CO₂ emissions, grow our food and dispose of our waste. The clear target is to become a 'one planet' person.

The ecological footprint can also be expressed in global hectares. 1.9 hectares is an individual's fair share. The average ecological footprint in the UK is 5.3 global hectares per person. This graph (using WWF figures) shows how it breaks down.

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 a way of seeing the relative impact of our actions, so that we can prioritise what we do to reduce our impact.

You can measure your own ecological footprint online. www.myfootprint.org asks 15 questions to work out your footprint in global hectares relative to other people in the country you live in. The site also provides advice to individuals, schools and businesses on reducing their ecological footprint.

Flights and carbon offsetting

Many online carbon calculators have been developed by companies selling carbon offsets, particularly for plane flights. Flights have a very high environmental impact. Carbon calculators can demonstrate how an individual's regular eco-efforts - composting, recycling, energy efficiency measures, even investing in renewable energy - are instantly negated by a return flight.

One flight is responsible for roughly 0.17kg of CO₂ per passenger-kilometre. These emissions should be multiplied by a factor of 2.5 due to the increased warming effect of emissions in the upper atmosphere (some carbon calculators don't include this factor). For example, a return flight from London to Malaga (about 2,300 km) would emit almost a tonne of carbon dioxide equivalent - 40% of your total annual carbon allowance.

Various schemes exist which plant trees (to absorb carbon emissions) or invest in renewable energy for every air mile travelled. You can use a carbon calculator to calculate your share of the emissions created during your journey and the cost of neutralising the impact of those emissions. We do not see this as a viable solution to climate change for the following reasons:

Firstly, most offsets do not include the increased warming effect of greenhouse gases in the upper atmosphere where planes fly.

Secondly, trees absorb and store carbon. When the tree rots or is burnt, the carbon is released to the atmosphere. So trees only take carbon out of the atmosphere temporarily. There is also a long time delay between the planting of the tree sapling and the absorption of carbon by the fully grown tree, so it will take a very long time for the tree to absorb the carbon emissions emitted by the plane. There is no guarantee that these trees will make it to this stage. Poorly sited tree plantations can also have negative effects on habitats, water supplies and local people. Young trees use a lot of water, so if many are planted they can reduce the water available to farmers downstream.

Finally, 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 always give your money to an environmental charity rather than a carbon offset company.

Eco-footprints of cities, regions and countries

Specific footprint studies have been done for particular cities, regions and countries. This helps governments to assess where the biggest impacts are and where to make changes.

York, Liverpool and London have all had specific footprinting studies done. A detailed study of Wales, Cardiff and Gwynedd is being undertaken by the Stockholm Environment Institute (SEI), working with Bangor and Cardiff Universities.

Several footprinting studies carried out by SEI, including the one of York, can be accessed at www.sei.se/programmes/future-sustainability/projects.html

A detailed study of London can be found at www.citylimitslondon.com

WWF’s Living Planet Report (www.panda.org/livingplanet) uses the ecological footprint to show the impact of human demands on the world ecosystems.

The Global Footprint Network (www.footprintnetwork.org) gives information about global and national ecological footprints.

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 a variety of activities building on the eco-footprint for pupils from 7 to 18, as well as teachers and youth groups. Our Where's the Impact? resource pack contains photocopiable materials for eco-footprinting activities. The activity can be run at a variety of levels, from KS2 to A level, and is available from CAT by Mail Order.

Publications

Sharing Nature's Interest (Chambers, Simmons & Wackernagel)
Excellent book on the method of eco-footprinting analysis.

Collins Gem Carbon Counter (Lynas)
Pocket sized book to measure your own Carbon Footprint on all aspects of your life from food shopping to work, holidays and clothes.

These books, and the Where's the Impact? pack, are available from CAT Mail Order: http://store.cat.org.uk.