How can you talk about immigration without specifying WHICH immigrants you are talking about? Should we accept inmates from the prisons of Haiti, for instance? It is certainly true that Australia’s large numbers of bright and hard-working Han Chinese (now about 10% of the population) have been very benefical to Australia and Australians but it is equally true that the intake of Lebanese and African Muslims has done little more than push up the crime rate

It was the Herald’s IQ2 debate last night at City Recital Hall that got economists, scientists, public opinion leaders – and the audience – speaking on the topic that ”our current immigration rate is too high”.

Professor Tim Flannery, the scientist and 2007 Australian of the Year, kicked off proceedings by arguing that while population growth is in the interests of business and government, it is not in the long-term interests of individuals or humanity because of the strain on the environment.

”Every other species has natural factors which constrain its growth. We have removed them all except for our own volition,” he said.

The Herald columnist Tanveer Ahmed said migrants have ”driven the economy further, enriched the culture and fabric of our nation, and their children are, by and large, even more successful.”

John Sutton, vice-president of the Australian Council of Trade Unions, cited a number of labour-related reasons why migrants numbers should be reduced, including the small Australian labour market being unable to absorb supply.

An economist, Professor Helen Hughes, countered that well-managed migration raises the benefits to all involved.

But for all the talk of the economy, the author Tom Keneally concluded that migration was most importantly a moral and humanitarian concern, bringing discussion back towards the environment with a mention of climate refugees, and the social benefits migrants have brought to Australian culture.