Well I'm a great admirer of George, a valiant environmental crusader. But he does occasionally argue from a cockeyed angle. Most upland in Britain up to 3000 feet was at one time under oak/birch/pine forest. Nearly all that has long gone, a process that started long before Jesus was a lad. If all upland farming was abandoned, the forest would not return to its former condition. We'd end up with poor-quality scrub with scattered trees, largely the non-native sycamore and rhododendron, with low biodiversity. Upland grazing regimes are by far the best option for maintaining a variety of habitats and the maximum diversity of species, and stocking the hillsides at appropriate densities would avoid the soil erosion that can lead to flooding and would maintain the pasture indefinitely. Problems are caused by bad practice, not by the fact that there are grazing animals present. Ok, those grazing animals produce a lot of carbon dioxide and methane, but so did the wild animals that preceded them, the cattle, boar and deer, etc., and so would those that would naturally replace them. Ecosystems depend on all manner of beasts, large and small, and they all fart at will. And I don't know where he gets the idea that hill farmers chuck fertiliser around the mountainsides. They may use some on the low-ground paddocks they use for finishing their animals but that would be as nothing compared to the vast inputs required on arable land. Pigs do churn up land but if they are used in sensible rotations on non-sloping land they can be used to clean the land of deep-rooted weeds then moved on, and pigshit is a superb fertiliser. He forgot to mention that. The runoff into rivers he mentions is avoidable, and what he should be arguing for is responsible, good practice, as he should in all the cases he refers to. Instead, he seems to be on an anti-meat crusade.

Those people who would like to see an end of animal husbandry should consider the vastly increased amount of nitrogen fertiliser that would be needed to replace the animal manure. In fact, in Africa very little artificial nitrogenous fertiliser is used in any case, so let's hear what they'd say to those farmers who can't afford to buy it and who currently depend on manure. While they're at it, they could contemplate the vast amounts of fossil fuel energy needed to feed the highly-polluting Haber process, without which we wouldn't have the ammonia needed to manufacture those fertilisers in the first place. The production of nitrogenous fertiliser is one of the leading generators of greenhouse gases. The trouble with George, sometimes, is that he isn't very good at balancing equations.