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In Nevil Shute's 1957 classic Australian novel On The Beach, a bewildered but stoic group of people in Melbourne wait out the end of their world in the aftermath of a global nuclear war. Half a century later, delegates gathered in Melbourne to discuss another imminent threat to human civilization — but this time it's a non-fictional possibility. The three-day 'Four Degrees Or More?' conference held in July this year drew climate scientists from around the world to discuss the implications of average global temperatures increasing by four degrees above pre-industrial levels — a likely scenario by 2100, if not decades sooner, under current carbon emission trajectories.
The outlook for Australia would be brutal, the scientists reported: agricultural production severely slashed by mid-century, forcing a reliance on imports; sea levels rising more than one metre; record high temperatures (Table 1) and extreme fires; a collapse of the marine ecosystem; and a halving of rainfall across the south. The most surprising outcome of the conference, according to Will Steffen, director of the Australian National University (ANU) Climate Change Institute in Canberra, was “the wealth of ecological, biological and human information we actually have — even with the uncertainties — about what a four-degree-warmer world might look like in Australia.” Climate models project temperatures increasing well beyond four degrees in the twenty-second century, based on current emission rates.
Table 1 Average number of days per year above 35°C in the major cities of Australia for the present-day climate and predicted for 2070.
