A UK environmental pressure group has urged the British government to force businesses to standardise on the way they report their carbon footprint.

The Aldersgate Group says companies can currently report their carbon footprint in any way they choose, making comparisons next to impossible. It has written to two government secretaries of state: Hilary Benn (environment) and John Hutton (business and enterprise), stating that in the world of business financial reports, businesses have to report in the same way.

It thinks businesses can do what they like when reporting their carbon footprints, and that a standardised carbon footprint report format would allow valid comparisons between companies and lead to faster change, as well as enabling measurement of progress to carbon budget goals in the coming Climate Change bill.

The letter says: "Current reporting levels are still too low, and what is disclosed is not comparable because of the use of different calculation methods. ... few FTSE 350 companies have credible carbon reporting in place, and it is extremely difficult for investors to make sensible comparisons between those that do."

The Aldersgate Group describes itself as a broad coalition of environment agencies, non-governmental organisations (NGOs or quangos), think tanks and industry representatives, including BT. It believes that high environmental standards are essential for the UK's future economic well-being and competitiveness.

Adrian Wilkes, the group's chairman, said: "The current lack of comparable, standardised measures means that companies that are reducing their carbon emissions are unable to demonstrate their success, while those that are not reducing emissions cannot be effectively challenged."

The group asserts that high environmental standards will be a major part of future economic growth and international competitiveness. This argument is set out in its 2006 report: Green Foundations: Better Regulation and a Healthy Environment for Growth and Jobs.

Although the Aldersgate Group member's roster is impressive, it does not list many businesses, or business organisations such as the CBI or chambers of commerce. Critics may feel that it is duplicating the work of the Carbon Disclosure Project, which has a vastly greater business membership.