'Australia is very, very short of good soils. We're an weathered continent."
Wilson da Silva, Canberra New Scientist 12-Oct-96
Dust to Dust. Low rainfall means vegetation grows too slowly.
AUSTRALIA is heading for extinction. The world's driest habitable continent, already groaning under the weight of its existing population, is exhausting its soils and may well go the way of Easter Island-where civilisation descended into anarchy and eventually collapsed. That is the prognosis of several prominent scientists speaking at the ANZAAS meeting in Canberra last week. According to Barney Foran, of the Division of Wildlife and Ecology of the CSIRO, Australia's national research organisation, the current population of 18-3 million is already close to consuming all the continent's lifesustaining resources. The "ecological footprint" of modern Australians-the amount of good arable land needed to provide food, water, forest products and energy-is 4-1 hectares per person. But Australia is losing its soils at an alarming rate as a result of intensive agriculture. "Australia is very, very short of good soils. We're an old weathered continent," said Foran. Once the ecological footprint gets up to about 3 to 4 hectares per person and the population hits about 20 million, "we start to about equal our stock of reasonable soils", he said. "If our science and technology can't deal with the ageing soil at the rate of 1 per cent a year, just to maintain it, then that is a problem. It is our core life support," Foran said. Although Australia has enough land devoted to food production to sustain the population into the middle of the next century, other resources such as energy, water and forests will dry up more quickly. "By the time we get to 40 million people in 2050, the standard of living will not win you many elections," he said. The noted American biologist Jared Diamond, who has visited Australia every year since 1964, was more forthright. He told the meeting that modern Australians are consuming the meagre resources of their parched continent so fast that they are heading for extinction. As inhabitants of a dry land mass at the mercy of climatic El Nino, the often unpredictable phenomenon that periodically brings drought to the country, Australians cannot afford to be as cavalier with their environment as people living in wetter climes. And yet Australians treat the country like a slice of Europe, with scant regard for the fact that they live in "by far the smallest, the flattest, the driest, the least fertile and climatically the most unpredictable continent". Diamond compared Australia to Easter Island, off the coast of Chile and also subject to the visitations of El Nifio. Although drier than most of Polynesia, Easter Island is not as dry as most of Australia, and has more fertile volcanic soils. Archaeological finds and ancient pollen show that when the Polynesians arrived on Easter island, it was covered with "a lush subtropical forest of palm trees and giant sunflowers, inhabited by land birds and breeding sea birds", said Diamond. A sophisticated civilisation arose which not only carved and trans ported the famous stone statues, and developed a written language, but sustained a population of 58 people per square kilometre. But the burgeoning population stripped the forests bare and killed the native animals. By 1500, all that was left was grassland. "People turned to the largest protein source around-cannibalism," said Diamond. "Easter Island society collapsed in an epidemic of warfare." When the first Europeans reached the island in 1722, two thirds of its population had died. This was not an isolated case. in the past few thousand years, 12 other dry land masses in the Pacific subject to the whim of El Nino have seen human societies collapse, in some cases leading to the complete disappearance of a people. Meanwhile, Polynesian societies on wetter islands with more predictable climates, such as Tonga and Samoa, survived the changes wrought by humans. "The main difference seems to be wly that societies in low-rainfall environments were the ones especially prone to collapse by destroying vegetation. Low rainfall means that vegetation regrows slowly, so it can easily happen that regrowth doesn't keep pace with cutting," said Diamond. He warned that Australia might meet a similar fate, even if it could harness technology to delay the collapse for a while. "Australia is the continent whose human population faces the most problematic future," he said. Foran was less pessimistic. But without technological fixes over the next 20 years, he said, living standards would fall. "That's not being gloomy ... that's what the data say. You can't ignore it. But hopefully, science and technology will have the answers." Foran's colleague, Doug Cocks, disagreed that collapse was imminent. He believes that while Australia will become much more crowded and polluted in the next 50 years, there was no foreseeable combination of events that would make the continent uninhabitable for up to 36 million people by 2045.