They shall be classed 'stout'

A fat tax on airline passengers?

Seems logical, doesn't it? The more weight the aircraft has to lift off the ground, the more fuel it uses. So now global warming can all be blamed on the obese. It's not people driving single-occupant SUVs with V8 engines, nor those leaving all the aircons on full welly because they're not paying the bill. It isn't even the Chinese, opening a new coal-fired power station per week every week for the next seven years.

What's going to happen at the airport? Are we all going to be weighed in like jockeys at the Grand National? Actually, why not? Lightweight travellers must surely receive discounts, and that suits me just fine.

Solidum illegitimatum es*, as one might say following a skinful of larks' tongues and otters' noses. But I try to travel with the minimum possible amount of luggage. In fact, I'll check in no bags at all if I can possibly manage, thereby eliminating the chance of the luggage being mishandled and left festering for a week on the tarmac at Heathrow instead of arriving in Washington.

I wonder how much fuel an airline could save by not actually hauling crates of duty-free booze, fags and perfume back and forth across the Atlantic? It must surely make sense to buy the stuff at your destination. Ah, but of course a bottle of Smirnoff that costs £20 in Sainsbury's in Portsmouth and £10 in Dubai duty-free will set you back around £16 at Thiefrow just before you hit the crowd apparently protesting about 'Mr Smith' of the 'Mövenpick'. But I digress.

What is the actual difference in the fuel consumption of an airliner that's running empty rather than full to the gunwales? I did a little uninformed research. It is of course subject to E&OE.

It's possible to buy aviation kerosene for your private Learjet in and around Washington DC at around $5 per US gallon. In China, the same fuel apparently costs a broadly similar Dh2500 per tonne. So we're looking at around Dh3.50 per kilogramme for paraffin for jet engines. I assume that Sir Richard Branson could get a bulk-order discount off these prices, and I suspect Emirates and Qatar Airways get their fuel for almost no money at all, at least when they gas up at home. (I can imagine the pilot of EK029 being told by ENOC that they don't take cards, and has he got cash?) According to Lufthansa's 2005 freight haulage figures, for the past few years they've been moving freight around the world at a fleet-wide average of around 185 grammes of paraffin per tonne kilometre. I make the approximate fuel cost to transport stuff by air around Dh5.80/kilo.

Mr Ray Sing-Snek arrives at Dubai airport for a business trip to London and back again. He's carrying a laptop and a change of clothes, and weighs in at a total of 95kg. The return trip costs Dh550 in fuel only, based on the above figures. Meanwhile, Osama bin Lardarse shows up to get on the same flight with a couple of suitcases bulging with pies. He and his pies weigh 160kg, and as such his personal fuel cost is Dh930. Only Dh370 more for 65 additional kilogrammes. Less than six dirhams per kilogramme. Compare this with the outrageous excess baggage charge that I found quoted on t'internet of £18.37 per kg on Emirates one way DXB to LHR. That's equivalent to Dh275/kg in my example. KLM is around EUR12/kg each way (Dh120/kg in my example). Excess baggage charges are of course set by IATA, but are punitive; they're designed to discourage extractors of the micturition.

Having demonstrated that the actual cost implication of demonising the stout is really rather small, how would an airline discriminate between a fat passenger and a tall one? The fat already suffer from narrow seats, and tall people get persecuted by the minuscule seat pitch in cattle class. Perhaps the BMI Gestapo will have to be summoned. The idea of not charging Big Bad John ('Six foot six and two forty-five'; BMI=28.3) whilst hitting up Warwick Davis (3'6" and 77lb; BMI=30.5) for a obesity surcharge is clearly obscene and ludicrous.

* "I am a fat b^stard".