I ALMOST choked on my sweet-chestnut roast when I read J Beisley's letter about his non-veggie Christmas (Readers' Letters, December 24).

I would like to think that his quip about carbon monoxide pollution was a typographical error, but I feel in retrospect he was actually sadly displaying his ignorance about atmospheric science.

Why does he presume that the poultry we eat are "raised and processed locally"?

Actually, it is just as likely that his bird was farmed in the Far East or mainland Europe than from Norfolk or nearer.

And as for my vegetable-only festive feast, the chestnuts came from Poppleton Road, carrots and spuds from York, sprouts from near Pocklington and the only long-distance ingredients were brazil nuts which are one of the only sustainable harvests from South American rainforests.

Vegetarians who choose their diet for ethical reasons will also consider the food miles impact and are more likely to buy local, or Fair-trade if buying something from afar.

But one of the main reasons to be a vegetarian is to do with reducing one's climate change impact by cutting out emissions of two of the main culprits, carbon dioxide and methane, which has 23 times the warming power of CO2.

Livestock farming uses far more land and other resources than the equivalent vegetarian option.

To rear a beef animal, or a turkey, needs a lot of crops such as grain, which itself uses fertilisers, fuel for ploughing and harvesting and transport... and then the animal makes quantities of methane and manure which has to be processed and disposed of.

Transport is only a tiny part of the environmental impact of food production.

Happy New Year J Beisley and all other future vegetarians! New Year resolution anyone?

John Cossham, Hull Road, York.