Green issues are taking centre-stage in the wine industry at the moment, with producers across the world working to develop more environmentally friendly products and practices, and find ways to communicate their green credentials to consumers. Chris Losh believes they are on the right track.

For drinks, especially wine, right now green is big. It's the hot-button issue that's setting the wires alight from Napa to New South Wales. And the talk is not just about organic or biodynamic. The eco-debate has moved beyond the vineyard and into the issue of carbon emissions, which takes in the entire production, packaging and shipping process.

Some wineries trumpet the carbon-neutrality of their production process; others laud their new plastic pouches because they're lighter and therefore burn up less fuel in shipping. These are not issues that were exercising too many brains even five years ago.

Slower-moving members of the drinks trade (and the wine industry has more than its fair share of the head-in-the-sand brigade) might think that cavilling over bottle weights and arguing about carbon footprinting are just so much (pardon the pun) hot air, and that given time the industry will move on to something else.

This, though, would be a disastrous misreading of the situation.

Already, the Kiwis (always at the forefront of anything green) are working with big companies and the Californians to try and come up with a reliable formula that gives each product a kind of carbon index. Direction from this is coming from the highest level within the New Zealand government, and will run across many more product areas than wine. If all goes to plan, they will by next March have a consistent measure of each product's sustainability.

"We don't have all the answers, but we're very committed to the environmental issue," says Warren Adamson of Wines of New Zealand. "The country is very much aiming for carbon neutrality and sustainability in all sectors."

This should not incidentally be viewed as a case of a small country deciding to score a few green credibility points. Several European supermarkets are already examining the possibility of introducing some form of carbon labelling in the medium term. This is no one-off.

The trouble with carbon indexing, of course, is that it relies on coming up with a definitive number, and this figure is incredibly complex to calculate. Moreover, since all things green tend to get lumped into a fuzzy basket labelled "feelgood" it can lead to a number of apparent paradoxes. A South African fairtrade wine or a Chilean organic wine, for example, could gain a lower score than an undistinguished mass-produced wine that is shipped in bulk and bottled at market.

Not so much a paradox, though, as an example of comparing apples and pears.

"Carbon emissions are an altogether different matter from, say, organic viticulture,' says journalist Joe Fattorini, who has done more work on this than just about anyone else. "To attempt to link them is doomed to failure. Carbon emissions is about establishing a standardised quantitative measure of the carbon dioxide (or equivalents) emitted in the production of a product. Organic is about the way grapes are grown; fairtrade is about correcting imbalances in power. They're all completely different."

Taken in unsentimental isolation, a carbon index, it seems, is calculable, albeit with significant effort. An internationally agreed standard, however, is almost certainly too much to hope for. It's more likely that we'll end up (as with organic wines) with a situation where there are various regional calculations that all broadly do the same thing, but make allowances for local peculiarities of self-interest.

Establishing such formulae - and getting them accepted overseas - doesn't promise to be either pretty or edifying, but those in the know seem fairly confident that in as little as ten years' time, some form of carbon score could be as standard on labels as alcohol levels.

All of which raises two further points: firstly, whether consumers will tend to gravitate towards lower-emission bottles; and secondly whether those products with a high rating risk being either delisted by retailers desperate to trumpet green credentials, or hit with some form of carbon charge as a punishment.

"My own sense is that relying on voluntary action by consumers just won't bring the emissions reductions required," says Fattorini. "Ultimately we're more likely to see carbon charging of some type or imposing requirements on products."

The key to success, it seems, will be in selling the concept to a consumer who already finds wine, in particular, largely baffling.

"There are so many variables it's going to be a struggle to communicate it,' Adamson admits. "But once we have the facts it is at least something we can start to address."

And a carbon score where, for instance, low is good and high is bad, is certainly far easier for consumers to understand than biodynamic viticulture.

In fact, there's a good case for saying that the industry could do itself no harm by taking the lead on this issue. Producers were far too slow in embracing the whole 'responsible drinking' idea in the UK, and gave the government a handy stick with which to beat them. They can't afford to do the same with the environment.