THIS week I saw something which deeply affected me personally and re-enforced my commitment to the environment.

I was at a meeting about green issues when we were shown a video by Al Gore, former vice-president of the US and now a committed campaigner on global warming.

I know I bang on about this subject, but I offer no apology because climate change is the single biggest issue facing us all, whether you are a world leader, a local politician or a private individual.

Al Gore is passionate and compelling on his subject and the science he uses to back up his arguments is profoundly convincing.

Climate, even in Middlesbrough, is controlled by the ocean currents. The Gulf Stream brings warmth from the equator to Europe and keeps our weather pleasant and bearable.

As this warm water meets cold air from the north it cools, sinks, and flows back south in a system known as the North Atlantic Conveyor. At the end of the last ice age a huge lake of cold, fresh water from North America spilled into the Atlantic, cooling the currents and diluting the salt in the water, which makes it sink.

As a result, the conveyor turned off and Europe spent another thousand years in the grip of the ice.

Today, Greenland is covered in ice which could, if it melted, have a similar effect. Images of an ice island ten miles long have hit our news media this week. Pictures that fascinated and scared me equally. It is hard to believe something that size could be floating about out there, but it is.

This huge chunk of ice used to be a part of the Ayles Ice Shelf and had been for 3,000 years. Now it is floating free 400 miles from the North Pole. Could this be part of what Al Gore was talking about? Even if it is a lesser symptom it is part of the same disease.

Experts predict Middlesbrough will be five times more likely to experience flooding, suffer more from storms and have seriously changed weather patterns as the Earth warms.

In November 2002 I signed a commitment to reduce Middlesbrough's greenhouse gas emissions. We committed ourselves, as a council, to a minimum reduction of one per cent a year and I am delighted that we have achieved more than that every year since, for the whole of the town.

But that is not enough. Every one of us has to do more, painful as it will be to change our lifestyles. Recycling, home insulation, better public transport and composting are all fine and dandy, they make a serious contribution to cutting emissions.

Walking to work, or catching the bus; buying food grown locally, or even growing your own; not printing out that e-mail - all these things are small changes which we will all have to make, voluntarily now or perforce in the future.

I know that I need to do more, personally, in these areas. I have to be seen to walk the walk, because talking the talk is no problem for me. That is my challenge.

I recently watched a film starring Dennis Quaid called The Day After Tomorrow, in which he tries to persuade the White House that we are on the brink of another ice age. It was compelling drama, but I thought it was fiction. Now I know it could come true.

Global warming causing an ice age is a difficult idea to grasp and, according to Gore, the transition from our pleasant climate to Siberian temperatures could take only ten years. Ten years from now we could need snow shoes to walk the dog!

If the choice was between giving up my car and life in the deep freeze I know which I would choose. See you at the bus stop!