The Daily Telegraph, 3 November 2005 - Perhaps those two deadly sisters, Hurricanes Katrina and Rita, will have finally persuaded President Bush to take a fresh look at climate change. But it is not just the anecdotal evidence -of natural disasters, and longer, warmer summers followed by milder winters - that counts. Worldwide, a consensus is emerging among scientists that climate change is real, and is quite possibly intensifying.

Businesses can respond to these circumstances in a number of ways. They can ignore it all and hope that the problem will go away - but it won't. They can sign a Corporate Social Responsibility statement while leaving their core operations unaltered, and hope to be able to deal with any future legislation with the minimum of action. Or they can try to gain competitive advantage by reassessing their environmental impact and changing their behaviour now.

Who will move first? A survey for the CarbonNeutral company (formerly known as Future Forests) earlier this autumn revealed that 75pc of FTSE500 directors will only take the question of carbon emissions seriously when forced to do so by taxes or regulation. Less than 40pc of businesses surveyed had a target for reducing their emissions of carbon dioxide.

There is political stand-off here which might appear to give companies a little breathing space. The Kyoto protocol of 1997, weak though it was, has hardly produced a great surge in activity around the developed world to reduce the production of greenhouse gases. Yet if CO2 emissions are not cut by 60pc in the next 30 years, scientists estimate that climate change will become irreversible, and produce devastating outcomes.

"The question is, can you decouple growth from carbon?" asks Jonathan Shopley, chief executive of CarbonNeutral. "Less than 25pc of the firms we surveyed say that they have a plan even to keep their emissions stable. We need to find some answers to this question." Mr Shopley's team of around 20 consultants works with businesses to identify their carbon "footprint" - the amount of CO2 they produce in a year - and then helps them find ways of reducing unnecessary emissions and off-setting what remains with other activities around the world - supporting sustainable energy projects or planting new forests. It is a rigorous, all-round assessment of everything the company does. This analysis is validated by the independent Edinburgh centre for carbon management. Clients have ranged from global corporations such as HSBC and Avis to international pop stars Dido and Coldplay.

But if climate change is to be slowed down and even halted, it will take more than a few multinational businesses and celebrities to do something about it. Businesses of all sizes will have to be involved. The Radio Taxis Group, the employee-owned London taxi business, is one such company. In February this year Radio Taxis became "the world's first carbon neutral" taxi company. Even though its 3,000 taxis and 80 executive cars produce 24,000 tonnes of CO2 a year, around the world the company's net effect on the planet is neutral as far as carbon emissions are concerned. The company worked with the team from CarbonNeutral in assessing its carbon position and finding ways to deal with it. For managing director Andrew Herbert, going carbon neutral has the twin benefit of establishing a distinct brand identity for the firm, as well as making staff feel good about the work they do. In the past few months alone the company says its carbon neutral status was a significant factor in winning five new accounts worth over pounds 1.2m, ten times the pounds 120,000 invested by the business in environmental schemes around the world.

"Ten years ago if you tendered for work there would be one question - 'do you have an environmental policy?' and of course everyone would tick that," Mr Herbert says. "Five years ago, people started asking for more details of that policy. Now we can not only tell prospective clients about our approach, we can show them what we are doing." Radio Taxis have chosen to offset their CO2 emission via three initiatives around the world. They have helped some villages in Sri Lanka get rid of dangerous kerosene lamps, that were being used to light people's homes, and replace them with solar panels. Not only did the lamps produce CO2, but they caused respiratory problems.

A second investment was in a micro-hydro power station in Bulgaria. This helped avoid the unnecessary damming of a whole area, allowing renewable electricity to be generated simply from the flow of water in a river. The third element of off-setting, accounting for the final 20pc of the company's CO2 footprint, is a commitment to planting new trees in Germany.

"Some people have said to me, 'why aren't you doing some of these things in London, which is where the pollution is being created?', Mr Herbert says. "But the point is there isn't just a little pocket in London where our emissions cause a problem. Co2 is a global issue, and we have to find global responses to it."

Berkeley Homes, a division of the Berkeley group, a FTSE250 company, has an annual turnover of pounds 500m. It has committed to being carbon neutral in its latest major development, the West 3 apartments in Acton, west London.

Paul Vallone, divisional operations director, says the company is trying to make its long-standing commitment to sustainability more meaningful. "But this is not just about us wanting to do the right thing, for moral reasons" he says. "It has to stack up financially. A lot of contracts today, with government bodies for example, call for 'sustainability'. It's not always clear what they mean by that. But they will ask us questions about our approach, and we have to be able to answer them." The firm has also worked with CarbonNeutral consultants on this project.

Berkeley Homes converted to a "green" electricity supplier for the West 3 project, saving 20pc on its CO2 emissions. It has offset the rest of its carbon through forestry and by supporting a hydro-electric plant. The investment has cost nearly pounds 150,000.

"I'm sure it is worth it," Mr Vallone says. "In the context of 500 units [apartments], it is not a big number. But this does keep us at the leading edge of the industry. I'd compare it with the way attitudes to health and safety have changed over the years," he adds. "In the past, you saw people working without goggles, boots, hard hats - not any more. I think sustainability will go the same way.

"This is quite an onerous task. We will stick with it, and in the future make it easier to get information from sub-contractors about their use of energy - it will make it easier to calculate the position on carbon," Mr Vallone says. "But the main thing for us is that we don't want to be in a position in 10 years' time when we drive past a major project and hang our heads - 'yes, we made money there but at what cost?'. This is really about having a different management philosophy."

Small and medium size irms also have a role to play in reducing net production of carbon. Slough-based Elite Couriers, "the UK's first carbon neutral transport and logistics firm", is one such. With 35 employees, its carbon "footprint", says the CarbonNeutral team, is tiny - 220 tonnes, offset by pounds 5,000 worth of investment.

But managing director Mark Dean is serious about the commitment to being carbon neutral. "For me,it is a way of making our vision a reality," he says.

The Management Consultancies Association has awarded Stefan Stern its interviewer of the year award.