In any crisis, someone can be relied on to invoke the old wartime spirit, but is the threat of climate change great enough to persuade people to join a carbon rationing scheme? Oxfordshire web design company Torchbox, based in Charlbury, believes it is.

Its 25 staff keep tabs on their out-of-work carbon emissions by signing up for the Pact (Personal Allowance Carbon Tracking) scheme and recording their activities in a computer system.

Some companies using the scheme, such as London environmental consultancy WSP, pay a fine' of 5p for each kilogram they exceed of their yearly six-tonne limit of carbon dioxide.

The money goes into a fund to be used to buy energy efficiency devices. If an employee's annual carbon emissions are less than six tonnes, they can choose either a direct cash payment, or for the money to be invested in the fund.

So far, Torchbox has not implemented the fines' at its own headquarters at Cornbury Park, but it hopes companies wanting to improve their green credentials will set up inter-departmental competitions for employees, perhaps with prizes for those who use the least carbon.

Torchbox co-founder Olly Willans, who set up the company in 2000 with Tom Dyson, said: "We created a carbon-tracking program where you can enter your electricity and gas bills and your flights and journey to work.

"It's about letting people know what their carbon use really is, and it's ongoing, unlike many other systems, which give you a snapshot. This lets you track your performance over time.

"We are trying to get people to keep themselves up to date and encourage them to input their readings from their car, etc, each month, so that people will choose to walk or cycle, because they are constantly being reminded of their carbon use.

"One of the things that is highlighted is what a big difference flights make. In fact, it's such a big contribution that you have to use a different graph for it, otherwise you wouldn't be able to see the electricity use."

For example, the average personal electricity use produces 617kg of carbon per year, while one cheap flight to Granada equates to about 543kg.

Mr Willans said: "It doesn't include indirect emissions like clothing and food, which are extremely difficult to calculate. That makes it much simpler to operate."

Torchbox's founders are certainly not run-of-the-mill techies and their staff have a wide range of scientific qualifications, which helped with research on carbon emissions.

The founders met while working for the charity OneWorld Online in the 1990s and set up Torchbox to provide Internet sites for charities and voluntary groups.

Having worked hard to establish the company, which has a wide range of clients in the non-profit making sector, the pair's green' awakening was relatively recent, said Mr Willans.

"We were both touched by the issue after reading a couple of books - Mayer Hillman's How we Can Save the Planet and George Monbiot's Heat - and seeing the Al Gore film, An Inconvenient Truth.

"Now we are personally motivated to do what we can about climate change. The fact that we both have young children is another factor."

Since using the carbon-tracking system, both bosses and one employee decided to live without air travel.

Mr Willans said: "If you travel to Bilbao by boat or train, it's still a big carbon consumption, but if you tell people you are not flying, it makes a difference because it makes them think.

"For instance, I'm going to a meeting in Dublin and I have to get to Euston at 6am for a 3pm meeting. It would be a lot easer to go on an EasyJet, but I feel strongly about this. You learn to turn the lights off, because it makes the figures better."

Mr Dyson said: "We don't want to be too hard-line. We are looking for practical ways that people can make the necessary changes."

Having set up a Footprint Calculator for the Worldwide Fund for Nature WWF's website, they are keen to see their tracking system used by other organisations.

"It's a very powerful tool. If you have to record everything you are doing, it does change your behaviour," said Mr Dyson.

Residents of Oxford will soon get the chance to try the system, which is due to be used in the Oxford Is My World website, run by Oxford City Council.

Torchbox hopes that commercial sales of the system will subsidise its use by voluntary groups. Mr Dyson added: "At the moment, we are donating it, and we would like to make it free to members of Carbon Rationing Action Groups (Crags) and transition towns'."

The My World website, supported by Midcounties Co-operative, is part of Oxford's bid to become a transition town', joining hundreds of other communites in a worldwide initiative aimed at increasing resilience to climate change, as well as cutting carbon emissions.

Businesses will be asked to sign a pledge that they will examine their own emissions.

Mr Dyson is one of the founding members of a Wychwoods area Crag, set up last month in Charlbury.

As well as acting together to reduce their individual and collective carbon footprints, at the end of the year, members will pay their carbon debts' into the group's "carbon fund", for good causes which result in a net absorption of carbon.

He said: "If you do it with other people, you can encourage each other to make changes in your life. If you use it in a business, some employees will be more committed than others, but everyone can contribute."

o Contacts: Torchbox: 01608 811870, www.torchbox.com o Carbon Rationing Action Groups (CRAGS) www.carbonrationing.org.uk