It didn't get much notice, but it's a sign of something serious.

Three months ago, one of Australia's newest treaties came into force, called the Australia-Tuvalu "Falepili Union" treaty.

Tuvalu is a tiny Pacific nation, with a population of roughly 11,200, that sits north of Fiji and south-east of Nauru.

Under the terms of the agreement, Australia is now obligated to help Tuvalu when it calls for help to respond to "the devastating impacts of climate change."

Both countries are working on creating a special mobility pathway that will see Australia offering up to 280 Tuvaluans each year (2.5 per cent of its population) the choice to live, work or study in Australia, temporarily or permanently.

It will help Tuvaluans escape the impacts of rising sea levels by migrating here.

A king tide in Tuvalu in February this year, followed by another one in March, raised questions for Tuvaluans about how long they can keep living in their country.

They should have raised questions for Australians, too.

Australia's future lies in the Indo-Pacific. Many of our neighbours in the region will bear the brunt of climate change.

How will our immigration system adjust to this reality in coming decades?

Australia's new geopolitical realities

Former public service chief Martin Parkinson asked similar questions in his recent review of Australia's migration system.

The final report of his review was handed to the Albanese government in March last year, and it has informed the government's thinking about our migration challenges.

It said the Indo-Pacific was critical to Australia's future prosperity and security.

It warned the region was undergoing a "profound transition," with economic and strategic weight shifting between countries, and global norms coming under increasing pressure.

It said in the face of these rapidly changing geopolitical realities, Australia had to engage more deeply with its island neighbours.

It said our migration system could be used to ensure that Australia remained relevant to important economic and political actors in the region as their attention shifted to our north.

And it said we had to understand that geopolitics and climate change were linked.

"Australia must prepare for the effects of climate change displacement in the Pacific region, including by fostering economic and social resilience in Pacific Island countries," it said.

"In the past decade, the level of forced displacement has dramatically outpaced the solutions available for displaced people. Climate change will increasingly affect where people can live and the resources they can access.

"By 2050, a reduction in the availability of arable and inhabitable land, combined with increasing scarcity of water and other resources, will likely be a further source of displacement, triggering significant cross-border and internal migration.

"Countries in our region will be particularly vulnerable and Australia will need to be ready to respond," it said.

There are record levels of forced displacement globally

The Parkinson Review didn't pull those ideas out of thin air.

It pointed to a huge body of work that had already been done on the problem.

For example, it referenced a 2020 paper written by experts Jane McAdam and Jonathan Pryke and published through the University of New South Wales' Kaldor Centre for International Refugee Law.

Their paper was titled Climate Change, Disasters and Mobility: A Roadmap for Australian Action.

In their paper, they warned the adverse impacts of disasters and climate change were prompting millions of people around the world to move.

They said disasters were now displacing many more people within countries each year than conflict, and the Asia-Pacific region was the hardest hit.

"Between 2008 and 2018, this region alone saw more than 80 per cent of all new disaster displacement," they said.

"Australia cannot afford to ignore the fact that in its own region, internal and cross-border displacement within and from the Pacific Islands is likely to increase as disasters intensify and become more frequent, exacerbated by the impacts of climate change.

"Most Pacific Islanders want to remain in their homes, and this should be enabled to the extent possible through disaster risk reduction, climate change adaptation and development policies.

"At the same time, there is widespread recognition that planning for mobility is necessary so that people can move before disaster strikes," they said.

They said global efforts to confront this problem began years ago.

In 2012, the first inter-governmental body dedicated to the study of climate change, disasters and displacement was created, called the Nansen Initiative on Disaster-Induced Cross-Border Displacement.

In 2015, Australia was one of 109 governments that endorsed the Nansen Initiative's agenda for the protection of people who are displaced across borders by disasters and climate change.

Since 2016, the Platform on Disaster Displacement (PDD) has been working to implement the recommendations of Nansen's agenda for protecting displaced persons.

Australia is on the steering group of the PDD.

These international efforts, supported by the work of legions of experts working in migration law, development economics, and foreign policy, have been substantial.

It explains some of the things we're seeing in Australia this year.

For example, the Albanese government's new Pacific Engagement Visa (PEV) program will see up to 3,000 citizens of Pacific Island countries and Timor-Leste migrating to Australia as permanent residents each year.

It's specifically designed to grow Pacific and Timor-Leste communities in Australia with ongoing connections to their home countries.

The new visa differs from the Pacific Australia Labour Mobility (PALM) scheme, which is a temporary worker program that is supposed to meet workforce shortages in rural and regional Australia, while supporting the economic development of Pacific countries.

That program was announced by the Morrison Government in late 2021, and took effect in early 2022. It merged the previously existing Seasonal Worker Programme (SWP) and Pacific Labour Scheme (PLS).

Iterations of that scheme have been plagued by disaster.

How do we treat migrant workers from our Pacific Island neighbours?

According to the Department of Foreign Affairs, 68 Pacific Island temporary workers have died in Australia since July 2020. 

Joe Koumera, a father of four from Vanuatu, a participant in the PALM scheme, was found dead in South Australia in October.

In September this year, the NSW anti-slavery commissioner published a damning report on the treatment of some temporary workers participating in the scheme.

"There is an increasingly urgent need to address the situation of a minority of temporary migrant workers in NSW who are at risk of modern slavery," the report said. 

"Temporary migrant workers, particularly low-wage workers in agriculture, horticulture and meat processing in rural NSW, face risks of debt bondage, deceptive recruiting, forced labour and, in extreme cases, servitude, sexual servitude or even human trafficking.

"The information presented to me over the last two years paints a consistent picture of growing vulnerability to modern slavery for some of these workers, notably in the agriculture, horticulture and meat processing sectors," it said.

It raised severe questions about our behaviour as a country.

"As these industries rely increasingly on the labour provided by temporary – but in some cases reasonably long-term – guest-worker populations, we have important questions to ask ourselves about the hospitality we are providing these workers, many of whom are our regional neighbours and part of the so-called 'Pacific Family'," it said.

It should be obvious to anyone that our treatment of temporary workers under this scheme is at odds with our need to build closer bonds with our island neighbours.

Our migration system was built over many years

But let's wrap things up.

Where does this leave our national debate on immigration?

The federal opposition has made it clear that it plans to make migration an issue in next year's federal election.

But what will its complaints be?

Yes, we've seen record levels of net overseas migration in the past couple of years, but those record levels come with a qualifier.

They reflect an unusual element of "catch-up" to past migration patterns following a couple of years in the pandemic when migration disappeared and our national population growth turned negative for a while.

And during the past four years, Australia has still experienced less population growth than it experienced in the four years before the pandemic.

Or, there's the question of how so many temporary migrants are coming to Australia right now.

That's simple. They're coming because they can. Temporary visas are not capped like permanent visas. Lots of businesses are bringing them here. Our universities are inviting them in.

This is all happening within the rules of the migration system previous Coalition and Labor governments built, and which the Albanese government inherited in May 2022.

We have hundreds of thousands of temporary migrants coming to Australia each year with no formal plan that links growth in net overseas migration with a definite supply of extra housing and other infrastructure. Previous governments left that problem on the shelf.

And we still don't have a national population plan.

Last week, when the Assistant Minister for Immigration, Matt Thistlethwaite, and a Liberal senator for Tasmania, Jonathon Duniam, appeared on the ABC's Afternoon Briefing, they were asked about the high levels of migration to Australia currently.

Mr Duniam, a federal opposition MP, said we had large numbers of people arriving in Australia but not the requisite infrastructure to match.

"Housing, health, roads, you name it," he said.

"It is the government's fault who are allowing numbers to come in, in the order that they are, but doing nothing to cater for those extra people who are coming to our country.

"It is the government's responsibility to actually provide these services … this does cause tension and the government needs to fix this mess.

"They're the ones in charge and they've got the levers to pull to be able to do so," he said.

Curiously, Mr Duniam didn't explain why our contemporary migration system works this way.