ISN'T it great the way shops are falling over themselves to go green these days? There's Marks & Spencer's Plan A (Because there is no Plan B'); New Look is selling organic jeans, and Tesco is out to flog ten million low-energy light bulbs within the year. My work here is done.

Well, almost.

There are still some people who cling determinedly to the notion that climate change is nothing to do with us.

I chaired a debate recently in which a fervent global warming sceptic made just this argument. He won the DVD of Al Gore's compelling film, An Inconvenient Truth, in the raffle. How's that for karma?

I suspect there are those with fixed opinions one can never reach, even when Bangladesh has disappeared completely under water and clothing retailers are forced to source cheap labour from higher ground. However, they are in the minority.

The Pope and Rupert Murdoch have come on side now and George Bush is apparently making a belated U-turn.

Maybe we're not as doomed as we thought.

I was chatting to someone at a party the other day, telling them about my newly green lifestyle, and they asked me whether I was optimistic about the future.

I admit the question set me back a bit.

Whatever you do as an individual can feel rather futile, but I wouldn't be bothering if I didn't think there was hope.

I can't say I trust governments to act out of altruism (especially the US, which, for all Bush's rhetoric, has been scuppering climate talks in Bonn recently and may delay next week's G8 initiatives by another two years).

Or large corporations, come to that. They act out of self-interest.

The good news is, that self-interest is fed by us. If we want it, they will do it, or sell it, whether it's policies or organic pork sausages.

It's World Environment Day on Tuesday, so on a personal note this seems a good time to take stock of the 100 eco-challenges I set myself last year.

Going down the list, I've ticked off 85 of them to date, although I can't say I've succeeded with all of those.

Growing vegetables never happened - life's just too busy - but I have managed to pot up some herbs. And in my own compost, produced by recycling our kitchen waste, too.

I haven't entirely been weaned off expensive beauty products, either. On the other hand, I have ditched fashion chains in favour of buying from charity shops. Recent purchases include a wicker chair, a crate of crockery, a Christian Lacroix top and a hamster cage, even though we don't have a hamster to go in it.

Trying out environmentally-friendly laundry products has been interesting, too. I'm a big fan of soap nuts, which are very economical, leave clothes clean and exceptionally soft and don't dull colours, either.

The water butt has finally arrived and been connected up and we have three different flush options on the loo. Oh, and we've adopted a tiger and bought up four hectares of Brazilian rain forest for good measure.

What of the bigger challenges?

I've stopped eating red meat, something I feel much better for, and I'm going to carry it on even though the husband and daughter haven't been converted. I've got back on a bike, albeit tentatively, and I hardly use the car these days.

We've had three UK holidays, shop locally and use a veggie-box scheme, taken up composting, turned down the heating, draught-proofed the front door, switched to green electricity and done a home energy audit.

Nothing earth-shattering about all that, is there? I agreed to make a Video Nation film for the BBC recently, but when it came to it, I thought, "Well, what is there to show people?"

We haven't got a wind turbine on the roof (yet) or chickens in the back garden, although we do have free-range guinea pigs that play a voracious part in the recycling process.

But, you know, that's really my point. It's about making lots of little changes, rather than expensive fancy stuff (what my friend Cath calls Eco Swank').

You'll be able to view the film on the BBC North website eventually, so long as I don't drop the camera again. I've also got a book about green living coming out next year.

Will all this stop the polar ice caps melting? No.

We need presidents and prime ministers to help do that. But they answer to us, and that's what keeps me motivated because all around me I see and hear people asking questions, people starting to make changes, people demanding alternatives.

What started out as a ripple became a groundswell, and that groundswell is rapidly becoming a tidal roar.

If I have faith in anything, it is human nature.