Academics from the School of Chemical Engineering and Analytical Science at Manchester University investigated the carbon emissions that result from a traditional Christmas feast of roast turkey with stuffing, roast potatoes and vegetables, bread sauce, cranberry sauce and other trimmings. Drinks were excluded.
Their startling results show that one meal for eight generates the equivalent of 20kg of carbon dioxide emissions. When this is multiplied throughout the UK population (assuming a third of the population eats the traditional meal), the impact is a massive 51000 tonnes.
Project leader Professor Adisa Azapagic said: "Food production and processing are responsible for three quarters of the total carbon footprint."
The main culprit is the turkey, which has a particularly large carbon footprint (60 per cent of the total) throughout its lifecycle.
The researchers looked at all stages of the supply chain, including raising the turkey. Indeed, all the turkeys to be eaten in the UK will have, between them, gobbled down some 12000 tonnes of wheat, 3000 tonnes of barley, 4000 tonnes of rape seeds and 800 tonnes of fish meal.
But it would be wholly unfair to place the bulk of the blame on turkeys (and leave vegetarians smugly tucking into their meat-free roasts).
"Vegetables contribute 10 per cent to the carbon footprint, preparation of the meal at home seven per cent, and the total transport accounts for 4.5 per cent," said Professor Azapagic.
The worst offender when it came to transportation, said the researchers, is the humble cranberry.
While most of the ingredients used for Christmas dinner hail from the UK, the cranberries normal make a 5000 km trip across the Atlantic, from their native patch in the United States.
The research formed part of Manchester's Carbon Calculations over the Life Cycle of Industrial Activities (CCaLC) project, which recently received a grant to develop a comprehensive methodology and software tools to estimate carbon dioxide and other greenhouse gas emissions from different industrial sectors in the UK.
It will be looking at the food and drink industries in a broad context, as well as chemicals, biofuels and bio-feedstocks.