“The principal cause of extinction is habitat loss. With a decrease of habitat, the sustainable number of species in it drops by (roughly) the fourth root of the habitable area,” Wilson wrote via email, referencing the species-area curve equation that describes how many species are capable of surviving long-term in a particular area.
No, not really, the clue is here:
Wilson is known as the father of sociobiology, a specialist in island biogeography,
That is true of island biogeography, at least so far as is generally accepted. But there’s not a linear relationship as we get to larger and larger areas. the equation for Australia is not the same as the one for an island in the Torres Strait.
The basic idea though, half the world for us and half for everything else doesn’t bother me in the slightest.
And that presents us with a question: is setting aside half of our land for nature even possible? Maybe – but maybe not. In 2005, scientists with the University of Wisconsin-Madison estimated that humans used around 40% of the world’s land area already for farming (an additional 3% of land area is taken up by urban development). There is no question that the percentage of land devoted to agriculture has gone up in the last decade, even as the global population has risen by nearly a billion people since then. However, notably, 75% of our agricultural land area is currently devoted to growing crops for livestock consumption. The amount of land required for agriculture today could be drastically curtailed – but only if people eat significantly less meat and livestock products, a trend that is currently going in the opposite direction globally.
More urbanisation, more industrial (not organic) farming and we’d be pretty much there already. So, why not?