With the growing awareness about global warming has come an increasing pressure on the travel industry, in particular aviation, to take steps towards the off setting of carbon emissions. According to figures from the Stern Review the contribution of aircraft to global warming is 3% today and could rise to 5% by 2050. And although aircraft emissions are the fastest growing source of greenhouse gases, cracking down on flights isn't going to save the world. In comparison road transport accounts for 10%, electricity generation 24% and deforestation 18% (half of this last figure is due to deforestation in just two countries alone, Brazil and Indonesia).



People, however, ignore these facts. Many feel that holiday travel is a luxury and therefore discretionary. In effect, if we are serious about saving the planet then it is something which we can cut without too many far reaching consequences. Rather than people campaigning for cleaner nuclear energy or the preservation of forests they prefer the moralistic feeling of raging against the jetsetters and western consumerism.

This is where the moral pressure to plant trees, buy carbon credits and offset our carbon footprint comes from. But the very idea that we can plant our way out of climate change is faintly ridiculous. There's recent research to suggest that planting trees in Northern climes may actually trap heat leading to an increase in global warming. Trees suck up CO2 but in temperate latitudes absorb a lot of heat without losing much moisture; and when the trees burn or decompose the carbon is released back into the atmosphere. And, it would take a forest the size of Dorset to be planted each year, ad infinitum, to offset the UKs carbon emissions - any benefits of which would take years to materialise.

Other offset schemes, such as buying energy efficient light bulbs and stoves for the developing world, may be better. However, there is an underlying problem with the concept of carbon offsets. Rather than seeking ever more ingenious ways to offset pollution we should be trying to produce less of it in the first place.

But there is now a burgeoning industry of offsetting firms, mostly in the US and UK, each happy to calculate our carbon debt and each offering a bewildering array of away to neutralise it from planting trees in Dorset to building wind farms in India. ABTA, which represents 70% of British travel agents; has recently announced offsetting schemes and last minute.com has an offsetting option on its booking page. But do these schemes actually accomplish much? According to a study by the respected US charity, Clean Air-Cool Planet, the answer is, perhaps surprisingly, often no. The study gave a mere eight out of thirty companies a score of more than five out of ten.

Many of the schemes - be they planting trees, using bio fuels, or installing solar power - would have occurred anyway and so don't offset anything. It's also extremely difficult to know whether the offsets you have purchased have been sold more than once as there is no record of what has already been done. And, more cynical, consumer guilt over the environmental cost of flying represents huge dividends for those peddling the offset schemes. Another problem is that calculations for CO2 offset often vary widely. A report in the magazine Nature showed calculations for the CO2 emissions per person on a return flight from Bangkok to London varying between 2.1 to 9.9 tons of CO2.

Wind farms, solar panels, installing energy efficient light bulbs, low flow showers and energy efficient wood burning stoves are just some of the options available. But even green groups such as Friends Of The Earth remain sceptical. Given scale of the problem which faces us today we might as well try ?stopping sea levels rising by drinking a glass of water?. Indeed, UK consumers only offset 1% of Britain's annual emissions.

Certainly greater clarity is needed in the offset industry and people need to realise that it isn't the answer to climate change. The reduction of emissions is far more effective than compensating for those already released. This does seem to be the growing consensus, that carbon offsets are just a way for the comfortable off to salve their consciences without actually making any sacrifices. Perhaps the future lies not in carbon offsets but in rigorous carbon allowances for businesses and individuals and allowing the trading in such allowances to develop.

The most environmentally friendly thing would be to stop flying and stop going on holidays. This is not realistically going to happen, so people need to take their holidays in the most environmentally friendly way possible. So from now think about your carbon footprint before you jet off on holiday and check to see whether your travel company or tour operator has an environmental policy; then you'll be on your way to becoming an eco-friendly traveller.