Population: the lost priority

Australian National University Professor Tony McMichael says while human numbers increasing towards nine billion are eroding Earth’s capacity to sustain life, the UN’s Millennium Development Goals for poorer nations are at high risk of failure.

Dr John Coulter from Sustainable Population Australia, highlights that increasing per-capita consumption impacts are being ignored here. “In Australia, state governments are talking about reducing per-capita water consumption by 20–25 per cent, but it will all come to nothing if we continue with our current rapid rate of population increase of a million people every four years,” Dr Coulter says.

Professor Graeme Hugo from the University of Adelaide believes we need truly multidisciplinary discussions in aiming for benign population impacts. ”Environmental and social scientists tend to talk past each other. Economists say we have to have growth, while environmentalists say we have to stop population growth. The answer lies between these extremes,” he says.

Professor McMichael echoes the view that population growth has been largely discounted in the climate change debate. He says: ”The broader constituency of scientific disciplines engaged in the debate – especially within the IPCC – has been dominated by climate scientists, other natural scientists, technologists and economists.”

Another ‘sleeper’ sustainability issue discussed in Ecos 142 is that of ocean acidification due to increased carbon dioxide levels, which already appears to be threatening the Great Barrier Reef.

At the moment, the 27 billion tonnes of carbon dioxide released each year by human activity are absorbed by the oceans, turning seas more acidic and changing the chemical environment required for organisms with chalky skeletons – such as coral-forming polyps and certain oceanic phytoplankton¬ at the base of the marine food web – to survive.

University of Queensland Professor Ove Hoegh-Guldberg predicts that if carbon dioxide levels reach 500 ppm by mid-century as predicted in some scenarios, the world’s coral reefs will “simply die off”.

Other researchers warn that ocean acidification will be essentially irreversible during our lifetimes unless we can rapidly reduce CO₂ emissions to the atmosphere.

Ecos 142 also contains reports on:

• Smarter irrigation in a drier century: With global climate models indicating a 20 per cent drop in rainfall in south-eastern Australia by 2030, farmers and agricultural research agencies are looking to new technology to make irrigated agriculture viable.
• Clean development opportunities: Global warming mitigation activities in Australia along with carbon credits from partnerships with developing nations under a UN scheme could make Australia carbon-neutral by 2050.
• The rise of the green city in the land of the red flag: China’s rapid urbanisation agenda includes energy-efficient initiatives taken by cities such as Rizhao, Wuhan and Beijing.

Issue 142 of ECOS is available at major newsagents or at: www.publish.csiro.au/ecos

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