Despite 2005 seeing UK householders cut domestic carbon emissions, the overall rate still rose, and at least a good part of it seems to be due to travel.

Every time we step on a plane we negate our six months of schlepping to the recycling bins.

In short, all our good deeds are pearls before swine unless we can find a cleaner way to get off our island.

Short haul
If you had a finger of blame and you wanted to point it at something - low-cost, short-haul flights would be a tempting target.

Popping over to Prague for a night and getting change from £50 is a tantalising proposition, unthinkable for all but the wealthiest up until quite recently. Now it's cheaper than a round-trip ticket from London to Glasgow.

But we're not all about the pounds and pence here. There is an environmental cost, and, looking at the figures: it's considerable.

A plane trip to Paris will spew around 10 times more CO2 into the atmosphere than a train (8800kgs of CO2, as opposed to 880kgs according to www.climatecare.org).

Destinations are also not as limited as one might think. Exotic Morocco can be reached overland in as little as 48 hours. Just take the Eurostar to Paris; then on to Madrid via the 'trainhotel' sleeper; spend some time enjoying the capital before boarding the afternoon express to Algerciras; jump on a ferry; and bish, bash, bosh.

Tuscany too is a breeze. Hop on the Eurostar and head for gay Paris, then board the 'Palatino' overnight sleeper (departs Paris 7pm) and 12 hours later you'll be sipping Chianti and preparing a fava-bean stew.

Long haul
Journeying to exotic distant lands, without threatening the long-term prospects of the polar bear, is a little more difficult. You could take the QE2 to New York to begin your grand tour of the new world, but not if your salary is anywhere close to the national average.

Alternatives are, however, emerging. Oz-Bus (www.oz-bus.com) for instance can get you all the way from London to Sydney without your feet leaving the ground. It takes twelve weeks, 20 countries and a few ferries and costs £3,750.

Intrepid Travel (www.intrepidtravel.com) organize a similar trip from Singapore to Paris. It takes 130 days, costs £6,520 and uses buses, trains, boats, rickshaws and even elephants.

The Trans Siberian is another way to go or the Silk Route (re-opened) via Kazakhstan by train to Beijing, both will get you to the Far East.

These are clearly not an option for the average holidaymaker and therein lies the problem. Our expectations are higher than ever before because air travel is cheaper and more abundant than ever before.

The easiest answer is to change the way we think about long-haul holidays. If you've always wanted to see Australia and the South Pacific, do it properly, take a couple of months off work, and see the whole thing in one grand tour rather than two or three separate visits.

After all, a once-in-lifetime holiday doesn't happen twice.