Only the more mature will remember the way shopping was paid for in old department stores. The money and the bill were put in a small canister and then vacuum-whooshed through tubes to a central cashier.

A related method - compressed air - is found these days driving a dentist's drill or a pneumatic hammer ripping up the tarmac.

Compressing air is just a way of transferring the energy to where it is needed and while the dentist's drill uses electricity, the pneumatic one is connected by a hose to the diesel-driven compressor.

Compressed air by itself does not produce CO2, but the method of compressing it certainly can.

If the electricity comes from a coal or gas power station then CO2 is released, but there would be very little from electricity produced by wind turbines, solar panels, HEP or nuclear power. Unfortunately, building site compressors are usually diesel powered and so produce CO2.

It would be very helpful if air could be compressed to produce movement, particularly if the compression was CO2 free. It already occurs in torpedoes, and in locomotives in mines where sparks are dangerous.

It just so happens that the first vehicles powered in this fashion, using an engine type developed in Argentina and France, are to be manufactured in India next year, when the Tata company will produce various versions using CAT - Compressed Air Technology. Other companies have plans for buses and trucks.

They are, in effect, electric cars without an electric motor. They have a number of advantages over internal combustion engines and hybrid electric models and will be developed decades earlier than hydrogen vehicles.

They are expected to cost about £2,000, use light carbon fibre tanks with the air compressed to 4,500 psi, and do 150 miles on one tank with a top speed of around 70mph. They can be filled in four minutes at a compressor station, or plugged in at home where the tank can be filled in four hours.

There are many benefits, in addition to really upsetting Jeremy Clarkson. Because no heat is involved in the engine it can be simple and robust and only needs one litre of vegetable oil lubricant every 30,000 miles. Just imagine a car without a radiator or spark plugs! They are simple to maintain with no cooling or ignition system, they are a lot safer and the only exhaust gas is air.

However, the cold engine means passenger heating needs providing, perhaps from the braking system, but the cooling air from the tank can be used for air conditioning.

The real advantage will be compressing air using renewable electricity, without CO2, and schools and businesses could have wind turbines or use green tariffs for their staff cars.

Compressing air could keep us on the road while we tackle climate change.