Tax is an old-fashioned blunt instrument and none of the money raised would be spent on the environment. We already pay £1bn a year in air passenger duty, which the Treasury claims is an environmental tax, but none of it is used for environmental improvements. Emissions trading is a much better system, because the money goes directly into emissions reductions. Chris Goater, London

If a tax on aviation fuel is to be introduced it must be on a worldwide scale and reflect the size and fuel efficiency of the aircraft. We are all encouraged to use public transport more, but why use the train to go to Newcastle from Stansted when it costs over £100 and you can fly there for a few pounds. The Government must look at its transport policy as a whole and not fragments. Tax on aviation fuel will have to be introduced to cut down on pollution. Sadie Carmichael, Stanstead

Taxing fuel would deter people from making frivolous journeys on so-called no frills airlines, which are subsidised by government. The Government's claims that there are numerous treaties involved cuts little ice. They don't bother about that when there is a war to start. Malcolm Willis, Farnham, Essex

The fact that aviation fuel isn't taxed means - in effect - that airlines are getting a huge hidden subsidy by not having to pay for their environmental damage. Yes, we urgently need to tax aviation fuel, but it shouldn't be seen as a tax, more as a requirement for airlines to pay for their pollution. To those who say the UK can't do it because airlines will simply refuel elsewhere: simple. You tax aviation fuel and require that all commercial flights to/from the UK source at least - say – 40 per cent of their fuel in the UK. Simon Robinson, Lancaster

There is an urgent need to halt the growth in aviation for many reasons, not least of which are to protect the planet from climate change, to preserve some of the fast-depleting oil reserves for our grandchildren and, more parochially, to rein back the damage to the UK economy from the annual £14 billion air tourism trade deficit. The potential negative impact on UK airlines from the imposition of a fuel tax is small beer compared with these matters. Ken McDonald, Stansted Mountfitchet

The suggestion is simplistictic and virtually unworkable. A worldwide solution is needed, and anything more than a small gesture of a UK-only tax would lower the proportion of air passenger and cargo-tonne miles from UK airports, as opposed to those from non-UK airports. This would damage UK-based airlines and other businesses vis-a-vis their foreign competitors. Because a worldwide solution is needed, this should begin by a government-led campaign to win the hearts and minds of US citizens in general and George W Bush in particular, as the US is in this matter the biggest rogue state in the world. Don Pitman, Orpington, Kent

I am not in favour of using taxation for petrol, aviation fuel or utilities for reducing pollution as I do not see that they reduce consumption. The only way to reduce pollution is to either reduce consumption of that product or provide a more environmentaly friendly alternative. You need to provide cheap and efficent alternatives. The taxation level should be such that the road tax pays for the bus and rail networks. By doing this, domestic air travel would be reduced and the objective of reducing pollution met. Nadia Pastouna, Hoboken, New Jersey

In principle all use of fossil fuels should be taxed. However, aviation fuel tax could only work if all countries agreed to levy it, as otherwise airlines would just plan to re-fuel where there was least tax. The only direct and easy way for the UK to tax aviation fuel would be to impose a passenger landing/take-off levy, possibly a variable amount depending on the type of aircraft and its fuel efficiency rating. Stuart Walker, Great Dunmow, Essex

It's good that cheap flights let poor people go abroad occasionally, but it sickens me when people fly from Edinburgh to Manchester because it's slightly cheaper and quicker than the train. UK internal flights should be heavily taxed because they are a selfish luxury. Ultimately the best system might be to assign every person a number of allowed air miles per year, and allow them to buy or sell these (emission trading). This will cut flying and redistribute wealth. Richard Milne, Edinburgh

Why tax other forms of transport and not aviation fuel? The connsequences are the same. Yes, the poor would suffer, but most of the people using budget airlines are middle class. Most people are ignorant to the fact that they do not pay a tax on aviation fuel, perhaps they would be happy to do so if they were better informed. Chris Read, Islington, London

Taxing aviation fuel in the UK will have as much impact on the environment as the Kyoto Treaty without the signatures of China, India, the US and Russia. The net result of taxing fuel would be UK consumers paying more, successful UK airlines going to the wall (along with their staff) and foreign airlines filling the slots. If people are so concerned about aviation exhaust pollution, they should exercise their free will and refuse to travel by air. Can't think of many "greens" who would deprive themselves of a good holiday, though. Jonathan Jones, London

It should be taxed but not to the patently ridiculous level that petrol for cars is taxed. It does seem to me that many people fly, simply because it is cheap. I have been involved in many business meetings over the years in Europe, the US and South Africa, where the small number of delegates have travelled from all over the world. At the end of the meetings I am always left with the feeling that we could have achieved just as much, if not more, over the phone, through e-mail or by video link. Derek Sinclair, Dundee