Lamb curry ready-made meals eaten in the UK amount to an annual carbon footprint equivalent to 5,500 car trips around the world or 140 million car miles.
The figures were calculated using a new carbon footprinting tool developed by researchers at The University of Manchester.
The estimates are based on the figure of 30% of adults in the UK who eat ready-made meals at least once a week. Curry is one of the nation's favourites, accounting for up to 10% of ready-made sales - which have soared during the recession.
The academics found that the fast food meal generates the equivalent of 4·3 kg of carbon dioxide emissions per person.
The meal's ingredients are responsible for 65% of the carbon footprint, with lamb contributing half of the total. Meal manufacture contributes on average 14% and packaging 4% of the total carbon footprint. The contribution of transport is small at 2%. However, storage at the retailer contributes 16%.
The £1m project is led by Adisa Azapagic, Professor of Sustainable Chemical Engineering at The University of Manchester, and funded by the Carbon Trust and the Research Councils UK Energy Programme
The previous work by the same research group showed that, surprisingly, the Christmas turkey meal prepared at home is a greener offering, coming in at only 2·5 kg of carbon dioxide emissions per person.
One of the reasons for this, they say, is that preparing food at home can help to reduce the carbon footprint.
"The same lamb curry prepared at home has a 20% lower carbon footprint, mainly because of the elimination of the refrigeration stage at retailer needed for the ready-made meals," said Professor Azapagic.
In addition to food products, the CCaLC carbon footprinting tool can be used for estimation of carbon footprints of other products, including packaging, biofuels and various chemicals.
With respect to application to the chemicals sector, the version of the tool for estimating the carbon footprints of PVC is available for free on the CCaLC website.
The CCaLC tool will be launched today (18 May) in London, where the team will introduce the tool and demonstrate on a number of case studies how it can be used and what benefits can be gained.
The research was carried out as part of the Carbon Calculations over the Life Cycle of Industrial Activities (CCaLC) project at The University of Manchester.
Professor Azapagic said, "Measuring carbon footprints of industrial and other human activities is a first step towards a better understanding of our impacts on climate change. Because, what can be measured, can be managed.
"But the devil is in the detail - measuring carbon footprints is not a trivial task. Industrial and human activities are notoriously complex, so capturing that complexity is a challenge.
"It is particularly so if we expect businesses - and consumers - to make everyday decisions based on the estimations of carbon footprints of their activities.
"And yet this should be the ultimate aim, as only then can we hope to make a real contribution towards mitigating the effects of climate change.
"We have considered all life cycle stages in estimating the carbon emissions - including long-distance transportation for imported food and short distances related to food shopping.
"Food production and processing are responsible for up to three quarters of the total carbon footprint for most food products - so this sector is an important part of our work."