Do you take a “normal” number of return flights every year? A skiing week in the winter, perhaps, and a longer villa holiday in the summer? Plus a couple of long weekends to the Continent? Maybe a shopping trip to New York? Then, whether you like it or not, you’re a carbon criminal.

There is no getting away from it: one of the biggest carbon polluters is flying. The airline industry has long cited reassuring statistics that the sector accounts for as little as 1.6 per cent of global emissions. But the recent Stern report on the Economics of Climate Change stressed that “the impact of aviation is two to four times higher”, largely because emissions at altitude enter the most sensitive part of the atmosphere. It also describes flying as “among the fastest-growing sectors, rising threefold by 2030”.

The statistics are scarier, however, when they get personal: visit the emissions calculator at the website of Climate Care, the carbon-offsetting organisation, and you will see that one passenger flying to New York and back creates 1.5 tonnes of emissions. That’s roughly the same as the domestic emissions (heating, hot water and cooking) that the average British individual is responsible for in a year. Flying Heathrow-Auckland return, meanwhile, equates to a year’s emissions from a medium-sized household.

The Stern Report pulls no punches — if we carry on polluting at current levels, we are headed for economic, social and environmental disaster. But Sir Nicholas Stern, the economist who wrote it, was careful to underline that, if action is taken swiftly to reduce our carbon emissions, there is still time to avoid catastrophe. Gordon Brown, who commissioned the report, has said that this would mean cutting European-wide emissions by 30 per cent by 2020 and 60 per cent by 2050.

So, what to do? Lobby for increased taxes on flying and jet fuel? Resist airport expansion plans? Sign up for popular carbon-offset schemes and pay a supplement to support reforestation or sustainable energy projects — such as low- energy lighting to South Africa, fuel-efficient stoves to Honduras, wind turbines to India — to become “carbon-neutral”? Or should we, as Mark Ellingham, founder of Rough Guides, and Tony Wheeler, founder of Lonely Planet, recently urged: “Fly less often, stay longer.”

This advice from two men who have helped to turn travel into an international religion attracted inevitable accusations of hypocrisy, and never got the airing it deserved. The travel-guide gurus’ simple prescription offers the most direct route, short of stopping flying altogether, to reducing the impact of your carbon footprint.

Bundle together several of those short holidays that you took last year into a single, longer holiday entailing one return flight, and you dramatically reduce your carbon emissions without cutting into your time abroad. Combine, for example, two one-week breaks and two short breaks into one three-week holiday and you reduce, assuming a comparable destination in terms of distance, your holiday-flight emissions by 75 per cent.

Tony Bosworth, transport campaigner for Friends of the Earth, believes that people have become more aware of flying’s harmful effects. A London stonemason, John Valentine, felt concerned enough to launch a website, www.flight pledge.org.uk, earlier this year, where environmentally minded citizens, almost 1,000 so far, can voluntarily commit to reduce their flying habit or cut it out altogether.

Ethical tourism, which covers community stays, working holidays and eco-hotels, now features regularly in operators’ brochures. The irony is that the operators are busy offering the opposite of the “fly less often, stay longer” formula when it comes to flights. Short trips to distant destinations, including weekends in St Petersburg (Thomson), Istanbul (easyJet), and short breaks to Morocco (Audley Travel), are popular. Cox & Kings even offers a four-night tiger-watching Wildlife Weekend in India. Five pounds per night, per client, is donated to the Travel Operators for Tigers campaign, but more than two tonnes of atmospheric emissions have been spent getting there.

Philip Grierson, marketing director at Cox & Kings, says: “These short journeys are a fringe element of what we do, and are aimed at people who don’t have time to go for longer. If they encouraged people to travel farther, for shorter periods, then we wouldn’t offer them, but there is no evidence of this. How people travel is very much an individual choice.”

Rough Guides is among a growing number of companies that direct concerned clients to carbon-offsetting schemes. Critics say these merely soothe frequent flyers’ consciences. The director of Climate Care, David Wellington, says that the best approach “is to reduce and offset — getting the benefits of offsets as soon as possible while reducing the need to offset in the future”. In other words, there is no substitute for cutting back on flying.

Longer, fewer holidays may make environmental sense, but Bosworth says that it must be an exact science to work: “There’s a danger of people trading in shorter return flights, say to Málaga, Prague and Orlando, for a longer one to Australia, for example, which would double their emissions. It’s got to be like for like.”

Even so, I could find no operators using the environmental argument to tout longer holidays — which is the dream, incidentally, of almost every operator in the business.

The managing director of Sunvil Holidays, Noel Josephides, has agreed to carry the “fly less often, stay longer” message in his next brochures. But no hotel or lodge has acknowledged that their impressive energy savings — such as solar heating and lighting, locally sourced building materials and locally produced food — were undermined by a long-haul, short-break clientele.

Justin Francis, of Responsibletravel.com, a travel agency dedicated to environmental and ethical holidays, thinks that longer holidays offer another significant advantage. “Short breaks give you a breathing space,” he says, “but I know from experience that longer breaks are more like a magic pill which rejuvenate, reinvigorate and give you a fresh perspective. You don’t get that from three days in Prague.”

And with everything that climate change could entail, a fresh perspective may be just what we need.

Details: www.climatecare.org; www.flightpledge.org.uk

Download the full Stern Report at www.hm-treasury.gov.uk.

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