Climate disruption, conflict, resource scarcity and political instability are driving rising migration, with much larger movements of people likely in coming decades.

The human tsunami is building irresistibly, with one person in every 20 worldwide now seeking to relocate from their home country to another.

In 2026 there are over 420 million people on the move, seeking new homes in places not torn by war, famine, climate disruption, resource scarcity or political, religious and economic savagery.

Migrants now comprise the world’s third largest population, behind that of India and China, but significantly outnumbering the USA, Indonesia, Pakistan and Nigeria.

At its root the building migrant tsunami is fed by overpopulation, but also by the forces accompanying it – scarcity of key resources like water, land or food, conditions progressively more hostile and more toxic to family life, and a plague of bad governments bent on war, repression and autocracy.

Humans and our ancestral species have been natural migrants for going on two million years, as revealed by a trail of prehuman remains stretching from Ethiopia to China and Indonesia – so there is nothing surprising about our endless quest for new opportunities and horizons. It’s what we do naturally when local resources no longer appear sufficient.

But there is something exceptional about this building tsunami of migration, especially if it results from the abandonment of large areas of the Earth or its megacities as they become uninhabitable. It will be the greatest upheaval in all human history.

The movement has two main components – refugees and voluntary migrants. At last count there were a record 124 million refugees and stateless people adrift, up by over 300 per cent since 2000 (38 million). Just above half of these were displaced within their home countries but looking to move. Presently, one person of every 67 on Earth has been forced to flee.

There were also 304 million voluntary migrants worldwide in 2024 – a doubling in numbers since 1990 and a tripling since 1975. A Canadian study shows the primary reasons to leave home include education, career, concern about overpopulation and the environment, providing for family, politics, religion, culture, healthcare and poverty. Those, however, are what the migrants state on their applications. There is growing evidence a great many people are relocating ahead of disasters – climatic, environmental or political – which they foresee in their homeland.

Resisting the trend towards migration is a global wave of anti-migrant sentiment, notably in countries that have traditionally welcomed new settlers and refugees. Whipped up by right-wing politicians in North America, Europe, Oceania and parts of Asia, “far-right political actors strategically manufacture anti-immigrant sentiment to garner electoral support through systematic fearmongering and racialisation of migrants,” says Olivia Weninger of the Human Rights Research Center. In other words, the protests are less about immigration than about the flexing of raw political power by neofascist minorities.

However, fear and resentment of immigrants will do nothing to stem the tidal surge of migration that is coming. In 2019 the Climate Foresight Report estimated there could be as many as one billion migrants moving worldwide by 2050. Five years later Swiss insurance giant Zurich put the estimate of the displaced as high as 1.2 billion – one human in every eight.

Largely dismissed by politicians and media at the time as alarmist, these predictions have acquired far more substance in view of the fact that the Earth’s migrant population has more than doubled since 2000 – and, on a linear projection alone, is likely to more than double again by 2050. If one adds progressive breakdown of global food and water systems, overheating of the climate, state failures, the global rise in authoritarian governments and spontaneous wars (possibly nuclear), the projection of 1.2 billion migrants in 2050 is starting to look very conservative. If the forecast by British actuaries is borne out, of 2–4 billion dead, then the mass migration preceding it will involve more than half the world’s population.

The region worst affected by the burgeoning crisis – and the likely source of most of the outmigration – is the tropics which, by 2050, will contain over 4.5 billion people including two thirds of the world’s children. Tropical Africa, especially, is at risk, but equally so are South Asia and Central America. The tropics will shed their human populations first – and the wave will break over the temperate regions.

‘Lifeboat’ nations such as Australia and New Zealand will find themselves facing not ten but hundreds of millions of immigrants in an unquenchable flood.

The human tsunami undeniably represents the principal security threat to all countries and people going forward – not the petty nationalistic rivalries and military chest-thumping that have disgraced human history hitherto. It arises directly from the heart of the Planetary Emergency.

The human tsunami can only be contained by finding ways to keep people happily settled in their own homelands. This will involve:

1. An accelerated program to deliver family planning to every woman on Earth and so slow population growth.

2. Urgent worldwide adoption of both renewable food and renewable energy, to overcome hunger, replace fossil fuels and cool the climate as fast as possible.

3. A global program to put back the forests, grasslands and wetlands ruined by human ‘development’ over the past century and repair the Earth’s life support system everywhere.

4. Adoption of a circular global economy, especially for key resources such as water and nutrients, but also for building materials, metals, timber, fibre etc.

5. Redoubling world aid efforts, to assist those regions most likely to collapse to become self-sufficient in food, water and energy.

6. Agreement to ban all nuclear weapons and scale back world military spending, redirecting resources to food, health, education and environmental repair.

All of these measures are readily affordable – by the simple expedient of cutting the world arms budget of $2.7 trillion by 25–30 per cent or so and re-directing the funds to repair of the planet and its ability to sustain human life. Such a cut was accomplished back in the 1990–2000s, so don’t believe anyone who tells you it can’t be done. One trillion dollars would go a long way towards rescuing a habitable planet and forestalling the human tsunami. That should be the budget.

There are many other scientifically based methods needed to head off global mass migration and most of them can be found in How to Fix a Broken Planet. However those listed above are among the largest and most pressing.

Inaction, apathy and disinterest will allow the human wave to engulf us all.

The views expressed in this article may or may not reflect those of Pearls and Irritations.