This is great news. A carbon labelling scheme is being launched. I really hope it catches on as I've been scratching my head trying to guess which products in the shops have the lowest carbon impact.

http://news.independent.co.uk/environment/climate_change/article2362754.ece

The only real rule of thumb I've managed to come up with is "Buy British".

When in doubt, buy the product that has travelled the least distance. (It isn't infallible, out of season tomatoes grown in a heated greenhouse might have a higher carbon footprint than those imported from a warmer country, so buying fruit in season is also a good rule).

Buying British (if you live in Britain) also makes good economic sense. Money that goes to someone in your own country means that tax paid on that money is being used in your own country. Not only that, but the odds are good that much of the money that goes to the seller will be spent in your own country.

What goes around comes around. The more locally you spend your money, the more likely it is that some of it will come back to you.

The money you give to a local farmer may be spend on locally grown fodder by a man who spends his money in a local shop which gives wages to a local parent who spends some of it with a local photographer, etc.