``How come,'' an editor asked me the other day, ``that you are still so enthusiastic about what you do at your age?''

The question came as something of a shock. Part of it, of course, was the impact of the last two words. The truth is that - in blissful contradiction of my expanding waistline, sparse grey hair, and fast growing-up children - I still think of myself as a rather young 26.

This gets me into strange situations where I find myself giving the respect due to age to people who turn out to be no older, or even younger, than me. Better than being born middle-aged like some people, I suppose, but perhaps not entirely appropriate for a journalist of 51 who increasingly finds the disconcerting word ``veteran'' attached to his description in the public prints.

But it's more than that. Despite - or I would say because of - nearly 30 years at the grindstone, I really am still enthusiastic both about journalism and about the particular speciality I cover.

I know there are a lot of people who think I shouldn't be. A recent survey of young people found that journalists easily came top of a list of those they least respected, even outdistancing MPs (the fact that the survey concluded that the young it questioned were ``materialistic'' and ``self-centred'' makes me feel a bit better). And an invitation from a group of respected columnists has just landed on my desk inviting me to a conference on the Media and Public Confidence.

``There is widespread and legitimate concern,'' says the invite, ``that the press and television are increasingly directed towards the lowest of human interests and that editors and journalists are more than happy to lay aside ethical considerations in the interests of an increased audience.''

This, I have to say, is not my experience. True, I have worked with some people who I would not trust as far as I can throw them. But the great majority of my colleagues on the three papers I have worked for - The Yorkshire Post, The Observer and The Independent on Sunday - have exhibited a truthfulness, idealism and capacity for hard work that, if applied in industry or politics, would have made Britain a very different place. It's not at all what I expected when I entered journalism, and I have found it humbling.

Now, I know I have been lucky - no, that's not true, I have taken considerable care - to work for papers that encourage such standards. Others do so too, but a fair few do not. Though newspapers are, indeed, far more concerned about circulation than they used to be, I can honestly say that I have never been put under pressure to distort or sensationalise a story to put on sales.

So I remain passionate about the importance of a free and awkward press, without which there can be no democracy. At its best - and Britain has some of the best, as well as some of the worst, newspapers in the world - the press is one of the few defences the individual has against the powerful. It can give an honest, objective account to the people of what its leaders are doing, and in return represent their concerns to those in power.

I also remain enthusiastic about specialising in the environment and world development. Again, I never expected to be. I fell into it by complete accident. I was told to cover it just shortly after joining The Yorkshire Post as a graduate trainee in late 1969 by a farsighted editor who spotted a coming issue and reached for the nearest uncommitted body. I was far from keen - I had seen myself, in my dreams, as a high-profile political or foreign correspondent, or something of the sort - but, as the newest kid on the block, I was in no position to refuse.

But I slowly realised that my luck had been in, not out. These were clearly emerging issues of great importance that caught the public imagination long before they attracted serious political attention. And, as one of the first in the field, I was being given the chance - which comes to only a few journalists in each generation - to help define a new speciality.

For years after I joined The Observer, I was the only environment correspondent in what used to be Fleet Street. Now all quality, and some popular, papers have them and there is an excellent collection of environment and development specialists, not just in Britain, but worldwide. As with anything new, they often have to work harder and with more imagination than those covering better established specialities to get space in their papers, but they develop such fascination for the area that few leave to do other jobs.

Being enthusiastic about covering an area properly and honestly is of course very different from espousing a particular cause, or aligning oneself with one side of an argument. The environment and development pressure groups, for example, need to be watched just as critically as industry or government. They are now big organisations, wielding considerable influence, fuelled by a great deal of money entrusted to them by ordinary people - and just as prone to partiality, half truths and occasional sharp practice as any other protagonist.

But if half what the scientists tell us is true, we stand on the brink - as we enter the new millennium - of one of those times when the tectonic plates of world society shift, creating a new landscape. We appear to be approaching both the `outer limits' of the pollution that the planet's systems (such as the climate) can take without cracking , and the `inner limits' of the build-up of poverty and deprivation that human society can take without breaking down. And yet solutions are increasingly emerging. Covering this monumental change in human affairs, and perhaps contributing to elucidating some of the solutions, is indeed something to get enthusiastic about, even at my age...