A new British study supports New Zealand's argument that it can produce and ship meat to the other side of the world with a lower carbon footprint than locally-produced meat.
The study, by the agriculture research organisation CGIAR, found 29% of man-made greenhouse gases in the UK come from food production, twice as much as previously estimated.
It says growing food for sheep, cows and pigs takes up far more land and emits more greenhouse gases than producing crops for human consumption.
And it makes the provocative suggestion that from an environmental perspective, Britain would be better off importing lamb from New Zealand, which has been produced more efficiently than on its own farms.