By Tom Heap Costing the Earth, Radio 4

Cows consume 8kg of grain for 1kg of meat

Feel-good food just got tricky.

It was easy when “good” meant anything which could have stepped off a John Constable canvas: free range chicken, foraging pigs and grazing cattle.

But then climate change came along. No one noticed at first, still concentrating their fire on the obvious targets like 4×4s, long flights and coal power stations; but our meaty diet is laden with greenhouse gases, and trying to reduce them throws up some unpalatable choices.