c_h clearly doesn't understand that seeking asylum is a legal right. Calling refugees illegal migrants is just plain wrong.
Australia has no irregular migration situation comparable to Europe or the United States. Instead we have this weird thing where the right wing media and dog-whistling politicians call refugees "illegal immigrants". So, Kaiser, when c_h refers to "illegal" migrants he is actually referring to asylum seekers and refugees.
It doesn't. Australia is probably far beyond it's reasonable carrying capacity at this point.
Australia actually has the lowest population per square km of arable land in the world, and an economy
consuming maybe 1% of the water that falls on the continent (2009-10 saw 13,476 GL consumption from 64,076 GL extraction. Rainfall in a relatively dry year like 2004-5 was on the order of 2,000,000 GL with runoff around 200,000 GL).
Water scarcity is entirely an agricultural and hydro-electric industry issue and it's an economic scarcity, not a physical one. The linking of population with agricultural water usage doesn't actually make much sense. Tailless has the right of it - Australian industrial-scale agriculture faces issues similar to other parts of the world, but it's not especially doomed. What we actually have is a poorly managed agricultural basin (the Murray-Darling) with probably an overallocation of water rights, which is in serious need of crop use changes and a more rational approach to water allocations.
Specifically, when you look at Australian farming, the
value add by irrigation is only about 30% of total agricultural production - mostly fruit, grapes and dairy. The rest of our farming is all meat production, cereal, sugar, and the like, which are all far less affected by irrigation water availability. The impact of serious drought or long term drying from climate change is our export cropping gets severely limited, we take an economic hit and industries and communities disappear, not that we run out of food. That's what I mean by economic scarcity rather than physical.
More to the point, when you consider that:
-over half Australian water consumption is for agriculture
-a lot of that water is self-extracted (ie, rain water)
-and that a lot of that water-intensive farming activity is for export
...then physical water scarcity really has very little to do with population growth. Demand for water doesn't grow very much with each new person added. Household water consumption is about 14% of total water consumption, so you can double the population and households are still using less water than agriculture. The way you deal with potable water supply issues is with storm-water collection, water recycling, greywater usage and general demand-side water efficiency, with desalination as a stand-by water security option for activation in times of prolonged drought.
Finally, Australians are currently some of the most resource-wasteful people on the planet. In terms of environmental sustainability we will get far more bang for our buck changing our lifestyle patterns (reduced resource usage, reduced house size, increased city density, etc) than by restricting immigration and damaging the whole economy and tax base.
We're not saying that rapid population growth is an absolute imperative. Population growth levels will be whatever they are depending on net migration flows from year to year (one reason Australian population is growing rapidly is large chunks of our huge diaspora returning home to escape Northern Hemisphere financial woes), but restricting migration in the interests of the environment is not even really a thing. Water is really not a real constraint on
population growth here - merely a major management challenge and a sometime brake on parts of the economy.
Overcultivation is easily solved once you stop giving farmers subsidies for overproducing.
