How the calculations work

Our calculator is based on research done by the UK Government’s Department for Environment, Food and Rural Affairs (DEFRA). We take the facts you supply about your energy consumption and use conversion factors supplied by DEFRA to convert that into the amount of CO2 you produce.

Inevitably some of these calculations are approximations: for example, we take the average fuel consumption of cars with a given engine size. The actual fuel consumption of an air passenger depends on a whole range of factors – the weather, the length of journey, the type of aircraft, how heavily loaded it is, and so on. You can find conversion factors for all our calculations on the DEFRA website.

Once we know how much CO2 you produce, we ask you to pay £10 per tonne. The cost per tonne of CO2 sequestered varies greatly between projects. As we grow we expect that some projects will plant large numbers of low-cost, fast-growing trees, while in others we will invest in more expensive, slower-growing trees that bring additional benefits, such as an improved environment for wildlife or for people. On average, £8 per tonne goes directly to the projects which are offsetting your emissions. The other £2 helps towards the essential running costs of the organization, such as setting up new projects, managing the website and finances, and advertising the services we offer.

Why should you use Climate Stewards when more commercial organisations sell carbon offsets more cheaply per tonne of CO2 emissions? Climate Stewards has committed to choose projects that have benefits other than just offsetting your CO2 emissions. Whenever we plant trees we ensure that we use a wide variety of native species which improve the biodiversity of the eco-system they are grown in. We always involve the local community and by ensuring that they experience some benefits from the planting we gain their long term commitment to the projects and give the trees the best chance of long term survival.

Thank you for offsetting your emissions with Climate Stewards. Every offset helps reduce the impact of climate change on us all.