A lot of the population debate — such as it is — will be centred on the concept of control: how effectively Australia controls its borders, not just in relation to asylum seekers — in fact, not even primarily about that — but how well we manage the quality of our migrants.

The basic theme is: skilled = good; family = bad. Skilled migrants add to our productive capacity and help employers avoid paying higher wages to local staff. But families just add to demand.

With a migration program approximately running two-thirds skilled, one-third family, supplemented by a temporary visa program based entirely on skills, you’d think we’d got that balance right, although the Coalition, which is sending confused signals on immigration and upsetting its business constituency yet again, appears to be saying we need less skilled migration as part of a lower intake.

A bit like climate change, however, this idea of control is illusory. We may decide to rigorously safeguard our borders, but there’s an international context that makes that commitment problematic.

The displacement of populations by climate change is going to increasingly challenge our notion of border control. One commonly-quoted estimate is that in the next 40 years, 150 million people will be displaced by the impacts of climate change, and 75 million of those will be in the Asia-Pacific region.

That figure, based on a single study, may as well be meaningless — no one has a good grasp on how the impacts of climate change will affect different countries, so the numbers are guesswork.  How many of those would be externally-displaced — i.e. have to move to another country — and of those how many would seek to come to Australia, are guesses upon guesses.

However, the problem for Australia is that many of the countries most likely to be seriously affected by climate change are in the Pacific, a region for which, with New Zealand, we share great responsibility.  The Pacific is our backyard and always will be, and its eight million or so people are a special responsibility for us.

While we don’t know much about how climate change will affect migration flows, academic work and work undertaken by development banks (like, for example, this study undertaken by Australian and New Zealand universities for the Asian Development Bank), has given some ideas to guide us. First of all, climate change will be one of several factors driving internal and external migration, along with local conflict, economic opportunities and local developments like rural-urban migration. It is likely to reinforce existing patterns of migration, rather than impose new ones.

And where climate change does induce external migration, it is best envisaged as a spectrum. Migration will be over an extended period, and will not be induced by any one-off events.  Some external migration may be temporary — caused by natural disasters like cyclones, where communities can return to their countries of origin once rebuilding has completed.  Some migration may not be directly induced by the effects of climate change, but prompted by concerns about climate change in the future.

But we know the problem is going to get worse, because Pacific states have very high fertility rates, meaning large cohorts of young people will be reaching adulthood by the time the more serious impacts of climate change are being felt.

And external displacement will be patchy, depending on the circumstances of each Pacific community.

Some will be resilient enough to adapt, others will not be viable states in the long-term. Kiribati — population about 100,000 — and Tuvalu — about 12,000 — are already planning for the long-term need to abandon their countries, which are at strong risk from sea level rise.

States like Kiribati are already suffering the consequences of climate change not from too much water but not enough — drought is reducing the availability of already low and fragile sources of fresh water for outlying communities, exposing people to gastroenteritis — Kiribati has shockingly high levels of infant mortality from gastro.

Australia’s policy response to the long-term issue of what happens to the populations of Kiribati and Tuvalu, as well as other Pacific communities displaced by climate change, is the equivalent of sticking our fingers in our ears and talking loudly in the hope the problem will go away.

In a remarkable document released last year by Penny Wong’s Department of Climate Change called Engaging our Pacific Neighbours on Climate Change: Australia’s Approach, pictures of happy Pacific Islander children were juxtaposed with extensive discussion of the importance of adaptation to climate change, Australia’s commitment to a global emissions target and the resilience of Pacific peoples.

Only one box was given over to the issue of displacement.  “Australians are aware of and concerned about this issue,” the document avers, and goes on to observe:

Australia believes that the most effective way to reduce the likelihood of climate change‑induced displacement is to reach a strong and effective global agreement to reduce greenhouse gas emissions. For this reason, Australia is committed to playing its full and fair role in strong and decisive action to avert dangerous climate change.

As we saw in Copenhagen, that commitment’s not worth tuppence to Pacific communities. And this is while the governments of Kiribati and Tuvalu are actively planning the complete evacuation of their countries.

This refusal to accept reality means that as climate change-induced displacement begins to accelerate, we’ll have undertaken no research or preparation for handling the issue.  At this point we have no idea what displacement will mean for a country that only takes around 15,000 refugees a year.  And what will community attitudes be? Australians, aware of our long tradition of friendship with Pacific peoples, are less likely to regard them as simply yet more queue-jumpers.

In any event, there’ll be no chance of a Pacific Solution when it’s the Pacific that’s the problem in the first place.