Home > The Great Unraveling? > What’s Driving the Migration of Humans and Other Species?

Over 70 million people have been forcibly displaced worldwide, with large increases in recent years having been driven by a complex mix of factors, including environmental shocks, conflict, and economic crisis.

As ever, the vast majority of these people stay within countries or regions and suffer. At the same time, regressive political movements often exploit misperceptions about migration to the further detriment of migrant populations.

In this episode of the “Great Unraveling?” series, Sonia Shah joins Laurie Laybourn-Langton to explore the factors driving migration–how fragilities in social, economic, and political systems, as well as environmental destabilization, could impact migration into the future, and how we should think differently about migration as a problem.

Sonia Shah is a science journalist and prize-winning author. Her books include Pandemic: Tracking Contagions from Cholera to Coronaviruses and Beyond, and The Next Great Migration: The Beauty and Terror of Life on the Move.


Laurie Laybourn-Langton
Over 70 million people have been forcibly displaced worldwide, with large increases in recent years having been driven by a complex mix of factors, including environmental shocks, conflict, and economic crisis.

As ever, the vast majority of these people stay within countries or regions, and suffer. Meanwhile, perceptions of migration, which are often incorrect, are exploited by regressive political movements. This episode explores the factors driving migration, how fragilities in social, economic, and political systems, as well as environmental destabilization, could impact migration into the future, and what this could mean.

To do so I’m joined by Sonia Shah, who is a science journalist and prize-winning author. Her books include Pandemic: Tracking Contagions, From Cholera to Coronaviruses and Beyond, and, this year, The Next Great Migration, the Beauty and Terror of Life on the Move, which explores centuries long assumptions about migration, and its potentially life saving power in the face of climate change.

Sonia, welcome.

Sonia Shah
It’s nice to be here.

Laurie Laybourn-Langton
Let’s kick off with a question about migration, the migration situation across the world at the moment. What factors are driving that? And how has that changed in recent years?

Sonia Shah
The first thing to say is that migration is not very well tracked. What we really know about are the most conspicuous migratory flows, usually the most disruptive ones. The very picture of how much mobility there is in the world, especially human mobility, is not very well understood. So that’s sort of the base level thing to say.

But on top of that, we do know that we have more people living outside of the countries of their birth than ever before. We have more people who are displaced from their homes than ever, at any time since the Second World War.

We know, in the natural world, that 80% of wild species are moving their habitats also—they are shifting their ranges towards the poles and up into the heights. We know that what is driving these migrations is they’re trying, they’re moving in sync with the changing climate.

Now for humans, of course, our movements are constrained by the invisible lines that we draw on the landscape and our whole process of controlling human movements through documents and the like. So it’s kind of hard to put the whole picture together. But we know that this exodus is happening.

As we, you know, re-scramble the habitation—like where people can live on the planet—people are going to have to move out into new places, and it’s already starting to happen.

Laurie Laybourn-Langton
So let’s let’s take that last point a bit further. We often hear from agencies like the UN or the World Bank that there is this potential for many more people than are currently been displaced, to be displaced by factors relating to climate change. And sometimes we hear these larger estimates—up to a billion, sometimes you hear in the news—of people being displaced by climate change.

How realistic are those projections? And how useful are the narratives that often stem from them?

Sonia Shah
Right. I think what we tend to do, which I trace in my book, what we’ve been doing for hundreds of years now, is we equate migration with crisis and catastrophe. So migration itself is seen as disruptive and something that we can control. And, you know, that we should sort of try to repel it and turn the faucet off, and that kind of thing. There’s this sense of migration as exceptional, as rare, as anomalous, as disruptive, and that we can actually control it.

But I think what the reality is—and what we’re piecing together through new scientific techniques of understanding the past, our own human past of migration, and the the amount of mobility that’s happening in nature, generally—is that we’ve been moving all along. And our movements are, on the whole, life-saving and contribute to our resilience, which is why we’ve been doing it ever since we walked out of Africa, right?

We didn’t just walk out of Africa and dispersed into the continents, and then stayed still, for millennia as the, you know, sort of conventional wisdom has it. We’ve kept moving all along, including into places that were very difficult to get to. And we did it multiple times.

We walked into the Tibetan Plateau. We sailed out on canoes into the featureless expanse of the Pacific Ocean to settle Polynesia—not just once, several times, over hundreds of years in ancient times using ancient navigation technology. So migration is really baked into how we have survived on a changing planet.

The whole issue right now is that we are entering a new era of migration because of the climate crisis. We can either look at that as a catastrophe in and of itself, or we can think of migration… of course it it stems from a crisis, a slow motion crisis of our own making, but the migration part of it, itself, can be part of the solution.

What it will depend upon is how we respond to it. Do we respond to new migrants moving as a crisis that we need to repel and then we put up walls, we close borders? That’s sort of the situation we’re in right now.

But what you can also see is that when we do that migration doesn’t stop. We just have a lot more migrants dying. And we make migration more conspicuous, which also heightens xenophobic sentiment. These are things that we can manage if we had the political will.

Laurie Laybourn-Langton
Let’s take the alternative narrative to the one you mapped out at the end there—the xenophobic one, the defensive one, one that’s often described as appealing to lifeboat ethics, I’ve read from some people. What’s an alternative narrative to that? What is that narrative that would be enable a political situation where migration becomes a life-saving part of our response to the climate crisis?

Sonia Shah
I think we have to recover the lost history of our own migrations. We have this idea of our past as being basically still, basically sedentary. We have this idea that people belong in certain places. That they’ve evolved, that they’ve adapted to those places, that those are very specialized adaptations that are very unique. And if you take a certain kind of people from one place into another place, that is very disruptive, and you’ve disrupted nature’s order. I think we need to reevaluate those ideas.

You know, what I did in my book is try to trace those back to their original sources. And a lot of that science was shoddy and flawed from the beginning, and has been completely undermined by new knowledge, new scientific knowledge. So what we see is, as I said, that we’ve been moving all along. And we haven’t been moving because of crises, you know.

We didn’t walk out of Africa because we ran out of food or space. We walked out of Africa nonetheless. And we didn’t just do it once. We walked out of Africa into North America, and then back into Europe, back into Asia. Our past was as complicated in terms of our migratory flows as our present is.

And so that tells us something right? That is a meaningful fact, because it means that over the long course of our history, that migratory instinct… And we know it’s costly, right? We know, it’s hugely costly. We know when we move around, we introduce diseases into new places, we have conflicts with each other, we are highly aware of all of the the disruptiveness of migration.

But if you look at the bigger picture, we’ve kept doing it nonetheless. So overall, the benefits have to outweigh the risks. And we can see that in sort of the broad scale.

If we look at migration, even on a more local level, we can see that. You know, the way we evaluate migration is usually in this very reductive way of like, well, what are the economic costs, right? But even then, if we have a long enough time span, we get we see the benefits, right?

We have short term costs of migration, for sure. But we have long term benefits, and we’ve actually been able to detect those. So we need to resurrect the overall story of migration in our past to really have a good-faith conversation about what should our policies be to manage migration. If we manage it as an investment as part of our resilience, as opposed to concerning it a crisis that we need to repel or somehow contain.

Laurie Laybourn-Langton
In a world that’s heating up, one in which we already have some of this nativism being a dominant political narrative, at least in some countries, how do you think that these kind of more positive and constructive narratives can win favor among populations who would be looking around the world and seeing, you know, higher instances of migration and seeing a higher incidence of climate catastrophe?

Sonia Shah
We have to expose migration in its full glory. You know, we have not done that. There is so much migration and mobility that is happening beneath our notice. It is like the blood pumping through our veins. It’s happening all around us, but we are unaware of it.

The only times we become aware of migration is when it’s made conspicuous by policy choices. When policymakers say, “Well, we’re going to put up a border here, we’re going to make these people apply for extra documents, or we’re going to, you know, detain them in the centers or whatever,” we make migration suddenly conspicuous and that’s when we have the xenophobic response.

And of course, for right-wing populists who are currently in power, that’s really good for them because it justifies, you know, what their argument was for gaining power.

But I think if we can start to see how much mobility there is, among us, how connected we really are—whether it’s long distance, international movements, or you know, short distances or to and fro movements—all of that is happening all around us all the time, and we just ignore it essentially.

You know, this pandemic has been really interesting in that aspect. Because one thing I think it’s exposed is how much movement there is. The virus came up in Wuhan and policymakers around the world were like, “That’s Wuhan. Let’s just close our borders, and we won’t get any here.” Well, 7 million people had already left Wuhan by the time that city was locked down.

Thousands of people had already moved into Europe with the virus and had brought it into New York, Seattle, etc. So, you know, we need to understand migration, not just on the margins, which is what we do now—we look at only the disruptive effects and only the most conspicuous migratory flows. If we want to understand what migration is, and plan for the future of migration, we need to see it in a holistic view.

Laurie Laybourn-LangtonSonia, I think that’s a great note to finish on. Thank you so much for joining us today.

Sonia Shah
Okay, thank you.