My 2p, Cattle and Sheep are raised on lands generally unsuitable for horticulural use, the Scottish Highlands, Welsh valleys and the like.
One thing you must also look at is buying vegatables out of season. Consider the air miles of flying friut and veg up from South Africa etc.
There's a lot we can do without sacrificing out diets and life styles. Use soap not shower gel (reducing plastic) Change your light bulbs (most cost effective energy saver) Use your laptop/broadband router USB port to charge small devices rather than a separate charger. Use a water butt to water the garden or wash the car (not Evian). Don't use a lift for one, two or three flights of stairs, depending how fit you feel. Don't use an air conditioner, use shade and ventillate! Put your daily driver dashboard data onto 'consumtption' and you'll start to drive more efficiently trying to better your last score, without losing time on the road.
There's loads more small things you can do and like the recent 5p charge for a plastic bag , that can have a massive impact.