On 15 November the world will mark the arrival of 8 billion people on the Earth. Sustainable Population Australia (SPA) says it is a cause for concern, not celebration.
SPA argues that humans have overpopulated the Earth by exceeding the boundaries that ensure the renewal of life.
SPA national president, Ms Jenny Goldie, says rising scarcity of natural resources, accelerated climate change, worsening pollution, environmental degradation, extinction of species, increasing hunger and pandemic disease, mass population movements, and unaffordable housing and food, are all indicators that we have exceeded the carrying capacity of the planet.
"We doubled the global population in less than 50 years," says Ms Goldie. "It is not levelling off. The last billion was added in only 11 years. In that time, 90 million were added to the global population every year. The details are explained in our latest Briefing Note on 8 Billion: Facts and Myths.
"WWF's latest Living Planet Report estimates that we have lost 68% of all vertebrate wildlife populations since 1970. That's more than two thirds of all birds, mammals, reptiles, amphibians and fish gone. In addition, flying insect populations have crashed by three-quarters since 1989.
"It's not just human numbers responsible for this dire state of affairs, of course. Rising living standards, particularly across Asia, also have a big environmental impact, even though they are welcome in terms of lessening inequalities between people.
"Yet if populations continue to grow, whether in richer or poorer countries, inequalities will increase by putting downward pressure on wages and placing more demands on natural resources.
"As human numbers increase, cities, infrastructure and cropland grow and in turn fragment habitats, often leaving animal populations too small to survive. Australia's koalas are at the forefront of this assault.
"As Britain's then Chief Scientist, Sir David King, said in 2006: It is self-evident that the massive growth in the human population through the 20th century has had more impact on biodiversity than any other single factor."
Ms Goldie says agriculture already takes up half of all habitable land on Earth, and four fifths of threats to mammal and bird species are due to agricultural expansion.
"The more people, the more agriculture and the less forest. This is the main reason climate models find it unfeasible to contain global warming below 2oC in a world of more than 10 billion."
Ms Goldie says that global population is now four times what it should be to allow for an advanced standard of living for all people.
"We know what we have to do to stabilise then reduce human population numbers," she says. "In high-fertility countries, it comes down to the political will to provide family planning services, to promote the benefits of small families and to shift cultural norms that impose early marriage, motherhood and large families on women.
"Rich countries, however, also have a responsibility to contain their own population growth and to greet population decline as an opportunity, not a threat."
