Wild Australia
Reserving 50 per cent of Earth for nature could be more achievable than it seems and keep us from catastrophe.
EARTH’S human population is expected to soar past 8 billion by 2023. So it’s no wonder the leading threat facing the vast majority of imperilled plants and animals on the IUCN Red List of threatened species is habitat loss. The number of people has doubled since 1970 while populations of other vertebrates – fish, amphibians, lizards and our mammalian cousins – have collapsed, shrinking by as much as 60 per cent. They have been the losers as our urban, agricultural and industrial areas have ballooned to cover an ever-expanding area of the planet’s surface.
This is one factor supporting the theory that we are now in the early stages of the sixth mass extinction in the history of life on Earth, with species being lost at many times the typical ‘background’ extinction rate. As pioneering projects seek to build wildlife corridors to join up protected areas and give species the space they need to survive, a far more ambitious proposal imagines we could stem biodiversity loss by setting aside half of the Earth’s surface for nature.
The idea has been raised in various forms in recent years and given a thorough treatment in the book Half-Earth: Our Planet’s Fight for Life, by famed American naturalist Edward O. Wilson. “Half of the species described today will be gone by the end of the century, unless we take drastic action,” Wilson beseeches readers. “We’re extinguishing Earth’s biodiversity as though the species of the natural world are no better than weeds and kitchen vermin. Have we no shame?”
Our current conservation approach is too piecemeal and reactionary to succeed, claims Wilson, who believes turning half of Earth into protected areas might allow us to save up to 80 per cent of species alive today. If it sounds ambitious, that’s because it is.
Currently only about 15.4 per cent of the planet’s land area, and 7 per cent of oceans, is managed for conservation. In Australia, only 19.74 per cent, or 1,517,875sq.km, is currently protected in some way.
The half-Earth idea would build on existing wildlife corridors, such as the Gondwana Link project in south-western Western Australia (see Restoring nature’s former glory, page 92), to create broad areas of connected habitats – and it might not be as difficult to achieve as it first seems. A study by National Geographic Society (NGS) researchers, published in the journal Scientific Reports last October found that about 56 per cent of the world’s land surface remains in a relatively natural state and has been little impacted by people, offering some sense of where increases to protected areas might come from.
There also appears to be broad support for the idea. The NGS was behind a survey on the proposal, which sought the opinions of 12,000 people in 12 countries including the USA, Australia, China and Brazil. Published last September, it revealed that most respondents supported the concept of dramatically increasing the amount of land currently managed for conservation.
There is already reason to hope. As Wilson writes, existing conservation efforts have reduced extinction rates by as much as 20 per cent compared with what would have been lost had we done nothing. We just need to redouble our efforts – governments, NGOs, landholders and others must think on a grander scale and embrace far more radical efforts to dedicate land for conservation purposes. As Wilson says, it’s going to require a major shift in our thinking.