Carbon offsettingWhich? carbon offsetting investigation

Problems with carbon offsetting websites

Look for a carbon offsetting company that publishes full details of its activities

When we asked 2,214 members of the Which? online panel for their views on carbon offsetting in April 2009, they said they would feel more confident about paying for an offsetting scheme if the provider gave more details of where the money went (36%) and the projects supported (30%). Around a quarter would feel more confident with a government carbon offset quality mark.

With this in mind, we analysed the websites of 17 carbon offset companies to find out how informative they were – and how pricey. We found major differences and some serious problems.

Problems with carbon offsetting websites

• Several of the sites failed, in our view, to give enough information about where your money goes.
• Most failed to reveal how much of your payment goes on administration fees and company profits.
• The emissions calculated for our scenario varied hugely between the different sites.

Most and least informative carbon offsetting websites

The companies that we felt gave the most relevant information were Climate Care, Pure and World Land Trust. 

Others appeared less open about their operations on their websites and many – including Carbon Footprint, Carbon Offsets, Flying Forest and RBS/NatWest – published, in our view, insufficient financial information.

Cost of carbon offsetting schemes

The prices charged to offset a tonne of carbon dioxide (CO2) varied widely in our study. For example, Carbon Clear charges £7.50 per tonne, compared with more than £20 per tonne for Carbon Offset Scotland’s tree-planting project. However, cheaper schemes are not automatically the best, as the projects supported vary and can’t be compared like-for-like.

Calculating carbon emissions

We also tested the sites’ carbon emission calculators – and found significant variations. On each site we attempted to calculate the same sum – the amount of CO2 produced by a couple living in a two-bedroom semi in West London, driving a Honda Civic 8,000 miles a year, and taking a return flight from London to Barcelona each year. The calculated emissions ranged from 7.73 tonnes with Carbon Offset Scotland to 11.5 tonnes with RBS/NatWest – a difference of almost 50%. The government's ActOnCO2 calculator gave a figure of 10.48 tonnes.

These variations seem to suggest that sites use different methods and data; some may be more accurate than others. The companies that have signed up to the government quality assurance scheme, including Carbon Footprint, Carbon Passport, Clear and Pure, have all had their calculators checked and approved by the government as part of the accreditation process. For other sites, if you're not sure how accurate the companies' calculations are, you could use the government’s carbon calculator. Then enter this figure into your chosen offset company’s website to calculate how much you should pay.