The main driver of wildlife extinction is not climate change but humanity's rapacious harvesting of species for food and trophies, along with our ever-expanding agricultural footprint, said researchers, pleading for a reset of conservation priorities.
In an analysis of nearly 9,000 “threatened” or “near-threatened” species, the scientists found that three-quarters are being over-exploited for commerce, recreation or subsistence.
Demand for meat and body parts, for example, have driven the Western gorilla and Chinese pangolin to near extinction, and pushed the Sumatran rhinoceros - prized in China for bogus medicines made from its horn - over the edge.
And more than half of the 8,688 species of animals and plants evaluated are suffering due to the conversion of their natural habitats into industrial farms and plantations, mainly to raise livestock and grow commodity crops for fuel or food.
By comparison, only 19 per cent of these species are currently affected by climate change, they reported in a study published in the peer-reviewed journal Nature .
Conservation agenda
Conservation budgets, the researchers argued, must reflect this reality.
“Addressing the old foes of overharvesting and agricultural activities is key to turning around the biodiversity extinction crisis,” said lead author Sean Maxwell, a professor at the University of Queensland in Australia.
These threats, rather than climate change, “must be at the forefront of the conservation agenda,” he said in a statement.
The provocative appeal - which elicited sharp reactions - comes a month before a crucial meeting of the International Union for Conservation of Nature (IUCN), a policy-oriented umbrella grouping of governments, industry and NGOs that meets every three or four years.
The IUCN also manages the gold-standard Red List of endangered species, tracking and cataloguing the health of Earth's flora and fauna.
The Nature analysis acknowledges global warming could become an increasingly dominant menace for biodiversity in the coming decades.
“But, overwhelmingly, the most immediate threat comes from agriculture and over-exploitation,” said co-author James Watson, a biodiversity expert at the Wildlife Conservation Society. “Unless we tackle these problems now, many species may disappear by the time the full impacts of climate change really kick in.”
Mass extinction
Earth, he pointed out, has now entered a “mass extinction even” in which species are disappearing 1,000 to 10,000 times more quickly than a century or two ago.
There have only been six such wipe-outs in the last half-billion years, some of them claiming up to 95 per cent of all life forms.
“It is hard to exaggerate just how dramatic the threat to Earth's species really is,” Watson said.
Other conservationists were critical of both the Nature analysis, and the accompanying appeal.
“There is no need to see tradeoffs among different conservation priorities - we need them all,” Peter MacIntyre, an expert on the ecology of fresh-water systems at the University of Wisconsin said.
MacIntyre illustrated that very point in a study, published this week that fingered climate change, as well as over-fishing and pollution, for the depletion since 1950 of fish stocks in central Africa's Lake Tanganyika, a vital source of protein for millions.
“What good is it protecting a habitat that becomes oxygen-deprived or too hot for its current species due to climate warming, or where lake levels drop due to changes in precipitation patterns?” he asked.
It does not, in other words, makes sense to look at different problems in isolation.
Christopher Wolf, an expert on large carnivores at Oregon State University, agrees with the Nature analysis, noting that hunting and habitat loss are - at least for big cats and wolves - much greater dangers in the near term.
But all the pressures closing in on Earth's biodiversity do have one thing in common, he added: “all threats faced by species are caused by man.”
