6 ONE-hundred-and-thirty-six years ago, a far-sighted person predicted that if we carried on using fossil fuels, carbon dioxide would cause the greenhouse effect.

At that time, only a few hot-air balloons and rockets had taken to the skies. No aeroplanes no petrol or diesel engines, no jet engines. All heat generated was at ground-level.

It looks as if he may have been right. But stop and look how we are heating his greenhouse. A jet taking off pulls through its four engines a massive 540 cubic metres of air per second, (more or less the air in three houses) or 32,000 cubic metres a minute (180 houses).

The air is pulled in at, say, 15C and heats it up to 200C. This is carried into the sky until it reaches up to six miles above the earth. Far different to 1864.

Is it any wonder when jets took to the skies, our air temperatures took off as well? For every 10 gallons of fuel, one gallon of water is injected to give extra thrust. In 1997, some 290 billion tons of water was used for this purpose (240 gallons per ton).

There is an old saying what goes must come down. A far as I can see none of this is put into our computers models for global warming. I wonder why.

M SIMPKINS,

Droitwich Road,

Worcester.