THERE I was buying my food locally and in season to cut down on food miles.
The food didn't have to travel as far, therefore less carbon dioxide was emitted and therefore I would be helping slow human-induced global warming.
I spend hours checking food labels for their country of origin and buy Australian when I can.
Some countries, concerned about the carbon emissions of air transport, have gone so far as to put air-freighted stickers on food.
The trendy UK supermarket chains, Tesco and Marks and Spencer, did this.
Turns out I was presumptuous, and Tesco and Marks and Spencer were perhaps too quick to exploit the concept.
Indeed a study at New Zealand's Lincoln University in 2006 found it made more sense (based on food miles) for someone in England to buy lamb shipped from New Zealand than to buy locally raised lamb.
The study crashed the theory that food miles, alone, are a fair measure for buying food based on its carbon dioxide emissions output.
It's not rocket science really. After all, there's much more to food than simply transporting it.
At the very least you have to plant, water, fertilise, harvest and pack it, and the carbon dioxide emitted in these steps are not taken into account by food miles.
The study found that lamb raised on natural pastures in NZ was less carbon-intensive than lamb raised in intensive-farming (ie. feedlots).
Ditto with dairy products.
NZ also produced more energy-efficient and less carbon-intensive apples than the UK, thanks largely to high storage emissions in the UK but when it comes to onions, the UK beat the NZ version hands down on energy efficiency and carbon intensiveness.
The study was funded by the NZ Government which, like Australia, has a vested interest in protecting its export markets upon which both countries depend.
Still, it threw a spanner in the works and got economists salivating at the prospect of developing theories and methods for calculating the true "carbon cost" of food.
That, as you'd expect, is proving challenging in the extreme.
Other countries have already examined and tested carbon labels, according to a recent report published by the Australian Bureau of Agriculture and Resource Economics, which examines the issues in food miles and carbon labelling.
The UK Government, through its publicly funded Carbon Trust, came up with a method to measure a product's carbon footprint and tested a carbon-reduction label on some products.
A label on a washing powder product, for example, lists the amount of CO2 emitted per wash based on the emission produced in the powder's production, transport and use.
Some supermarkets in France have a carbon label and Switzerland, the US and Canada each have some form of labelled carbon accounting on some products.
ABARE's report raises all sorts of risk associated with carbon labelling, but suggests Australia is sniffing out something equivalent.
But how would it work? And what might it mean for our food producers? And what about food that has a low carbon foot print but is nutritionally useless.
How do we fairly label that?
One thing's for sure: as consumers we're going to have to get even smarter at reading and understanding the labels on our food if we want to be discriminating, environment and climate-conscious shoppers.
