The low winter sun that blinded me from behind the City buildings did look strangely like the end of the world that morning. Or the beginning of a new one? I couldn’t decide at the time.

In any case, there was something very different about that breakfast event, where a Deutsche Bank economist addressed the mostly business audience with the words “I’m here today because of my personal irritation with GDP growth.”

There in the midst of the credit crunch, Pavan Sukhdev wanted to talk to us instead about the value of the goods and services that fall between the cracks of conventional spreadsheets: the clean air, water and biodiversity that are ‘worth’ so much less than gold and diamonds in monetary terms – until you don’t have them.

He came up with the sobering calculation that while Wall Street had already lost $1-$1.5 trillion by then, we are losing natural capital worth between $2-$5 trillion every year.

But it wasn’t so much the figures in his report, ‘The Economics of Ecosystems and Biodiversity’, that struck me. Sukhdev said himself that his job wasn’t to come up with a new value for the Earth – that’s impossible. Actually, it was the way in which everything that the environmental movement has been banging on about for years – disappearing forests, dying coral reefs – was talked about with a serious business head on. As he said, the only reason to put a value on these resources is that they’d get overlooked if they weren’t given a price tag.

I’ve never been a great believer in number crunching, but he won me over to the force of economics that morning. And to believing that it’s essential to package up the solutions to our disappearing resources – you know, straightforward things like forestry projects in Costa Rica or ecotourism schemes in Uganda – into neat financial tools. ‘Wetland banking’, ‘forest securitisation’, ‘endangered species credits’, they’re all going to float an investor's boat. In the end, it’s about speaking the right language.

As I stepped out in the crisp air, with the sun now high in the sky, I think I’d answered my own question.

I don’t know how I thought a ‘sustainable fashion show’ would look... Certainly not this: An army of doleful stick-like models marching up the catwalk to a backdrop of gritty retropop, all punctuated with paparazzi-style flashes.

‘Sweat shop industry’ rang like an alarm bell in my head. If they’ve got in girls this skinny, I thought, how can it be about sustainable fashion? Aren’t we meant to be promoting healthy bodies, too?

But as the models did their serious, sultry walk, in turquoise hotpants, breathtaking black dresses, and clothes verging on works of art, I was so glad the London College of Fashion had gone for an authentic, hard-nosed event. They gave us exactly what everyone – except us greenies perhaps – expected to see on a catwalk.

Because as much as I love the earthy look of People Tree or Howies catalogues – think ruddy complexions and wholesome prints – I couldn’t think of anything worse than a fashion show along the same lines. Especially not at the heart of the capital’s high street culture.

The best thing about the students’ designs themselves were that they didn’t smack of sustainability. There was chunky jewellery, tassels, layers, those hideous 80s batwing cardigans – basically everything that’s in the magazines at the moment. Only a few pieces looked really ‘recycled’, but most were tongue in cheek anyway; one jacket had a whole load of wallets stitched on the outside as a 'statement'.

It wasn’t until I read the catalogue afterwards that I realised the chainmail-style top that had caught my eye actually was made of Forest Stewardship Council-certified wood (can you believe it?!) and that the collection featuring gorgeous pastel-coloured ruching used 90% reclaimed fabric. Just looking at Manon Flener’s collection, I wouldn’t have known that the edgy-looking brass studs were what made the pieces ‘modular’ (i.e. you can put them together in almost any combination, and not get bored of your clothes), or that Lindsay Weir’s stuff was completely carcinogen-free – so not a trace of phthalates, phenols or heavy metals...

And that’s the point. If these students are one day going to take their ideas to the high street and catch the eye of absent-minded shoppers, they can’t rely on their eco-credentials (some of which would need a pretty big label to spell out) to sell them. It sounds like they’ve got just the right attitude: You want fashion? We can do it. Leave the ethical dilemmas up to us.

It’s always a bit dangerous, opening those sumptuous clothes catalogues from the likes of Toast and Howies. Buying into the wholesome organic life of beachcombing and dog walking shown in the pictures isn’t cheap. So far, the few treasures I own bearing those coveted labels are either hand-me-downs or they were going cheap in the sales.

So when I got an email telling me about a £125 pair of organic Cornish woollen socks from James Purdey & Sons, I very nearly sent it straight to the trash can. Scrolling down, I couldn’t even afford the hand warmers at £115.

Yes, very eco-chic, very cottage industry, I thought, as I read the story behind the socks: they started life on National Trust and Duchy Original farms in Cornwall, were knitted within the county itself, the farmers were “paid properly for their fleece”, and the rustic hues of ecru, charcoal and green came from vegetable dyes… If only we could all afford to support this pastoral idyll.

What stood out, though, was a quirky little detail in the label - the date the sheep was sheared. The company is calling it the “first fully traceable organic wool”. Certainly makes a change from your average clothes label, which usually has something to hide. ‘Made in Turkey’, it says, tight-lipped. ‘And we’re not telling you how.’ What a luxury to be able to pull on a pair of socks without blanking out those sweatshop images, and to picture the warm May day they came into existence.

While the shearing date might not be an essential piece of information (unlike a use-by-date, for example), I like the way it connects a shopper to the world behind the product. We’re starting to see it on food packets – the name and picture, even, of the farmer who grew your Waitrose carrots, of the family who picked your Fruit Passion orange juice. Unlike the slightly gnomic carbon labels on packets of Walkers crisps, this isn’t just a number (that’s probably more helpful to the company doing the audit than it is to the customer) but a story.

You might think it’s verging on the ridiculous. Next thing we’ll be told is that our milk came from Daisy, a Friesian born on 25th October. But if that’s the way to appeal to us middle class ethical consumers, who like earning Brownie points through shopping, why not?

I’m not sure I’ll ever be needing a pair of ‘shooting socks and garters’ for £190, but perhaps one day all my woollens will come with a ‘sheared on’ label.

When ‘The Sun says…’ do it, we environmentalists always get excited.

Back in 2002, the newspaper wrote what was probably climate change’s most grabbing headline: ‘Where have all the tits gone?’ This week it’s engineering the biggest ever giveaway of energy saving lightbulbs – the largest single order in the history of this much-misunderstood eco-product.

Tomorrow morning, several million Sun readers will come back from the newsagents with not only their staple reading under their arm, but a twin-pack of low-energy bulbs. “No vouchers, no fuss,” the man on the end of the customer helpline told me.

The 4.5 million they’re distributing certainly promise much quicker results on the big lightbulb switch than the government’s gradual, voluntary phase out of incandescents by 2011.

Of course giveaways don't guarantee a complete turnaround in people’s habits – readers who enjoy a good freebie might not actually buy an energy-saving bulb next time round. To take an analogy, Brits can get their hands on no end of free condoms, yet that hasn’t stamped out teenage pregnancies.

But you’ve got to hand it to whoever came up with this idea – some bright spark at Southern Electric, who is providing the goods, I imagine – for actually getting these gadgets under people’s noses and showing the sceptics that they can light a room properly. The Sun itself ran a scare story on the health risks of these bulbs just two weeks ago, so boy, nothing less is needed to bring the masses round.

I know that getting them into people’s shopping baskets is only half the battle, and you might ask if anyone will bother to fit them. I mean, do we know how many Sun readers it takes to change a lightbulb?

Luckily, the organisers have got a pretty good idea, and have slipped in a bit of Charlie and the Chocolate Factory-style magic to the story: just ten special bulbs will glow green when switched on, meaning you’ve won a holiday or a Toyota Prius.

I can already picture them stacked up behind the counters at WHSmith and Tesco ready for the morning (the shop assistants must be dead pleased about that). Let’s only hope the bulbs go down as well as those chocolate bars did.