The over-exploitation of fishing stocks, for example, is viewed as harming the environment for people; the hunting of animals to extinction means that humans in the future will derive no enjoyment from them; poaching results in financial loss to the owner, and so on. Notwithstanding the interest in animal welfare of the previous century, the situation for animals arguably deteriorated in the 20th century, particularly after the Second World War.
This was in part because of the increase in the numbers used in animal research—300 in the UK in 1875, 19,084 in 1903, and 2.8 million in 2005 (50–100 million worldwide), and a modern annual estimated range of 10 million to upwards of 100 million in the US—but mostly because of the industrialization of farming, which saw billions of animals raised and killed for food on a scale not possible before the war.
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