Australia's most senior policeman, federal police commissioner Mick Keelty, thinks climate change will be the major security issue of the 21st century. For Australia, he says, the impact of climate change on China poses a particular problem.
According to Mr Keelty, 'for China to feed its predicted 2030 population, it needs to increase its food production by about 50 per cent above today's levels. How does it achieve this if its available land is dramatically shrinking and millions of people are on the move because of land and water [problems]?'
The result might well be a mass displacement of Chinese to countries like Australia. Such forced migration would exacerbate existing cultural tensions, Mr Keelty warns.
The spectre of millions of displaced Chinese looking to Australia for a better life is not a scenario that Prime Minister John Howard or Defence Minister Brendan Nelson wants to contemplate as they gear up for this year's general election. Both believe terrorism and Islamic fundamentalism are the greatest threats facing the globe.
Mr Keelty's remarks have fed into that long-held xenophobic fear among some Australians that China wants to invade Australia.
One of Mr Howard's closest confidants, Senator Bill Heffernan, this week issued a warning about Asian climate-change refugees resettling in Australia. But others have dismissed Mr Keelty's comments.
Should Australians be examining more closely what climate change will do to China over the next few decades? And should Australia prepare for the possibility that it ought to accept climate change refugees from the mainland?