Does Climate Change Cause Migration? It’s Complicated

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CHAPTERS 

[00:01:58]: Climate and human mobility over time: from the Mayans to the Dust Bowl 

[00:04:23]: Understanding the limits of climate determinism 

[00:05:59]: Migration decisions along a spectrum: from voluntary to forced 

[00:09:16]: Trapped populations: who gets left behind and why 

[00:11:10]: Internal vs. international migration: what the data shows and where gaps remain 

[00:13:05]: How different types of climate events shape migration patterns 

[00:17:05]: Linking extreme weather events to climate change 

[00:20:00]: Insights from the World Bank's Groundswell report  

TRANSCRIPT

[00:00:03.21] 

Welcome to Changing Climate, Changing Migration, a podcast from the Migration Policy Institute about how the impacts of climate change are affecting migration. My name is Julian Hattem and I'm the editor of the Migration Information Source MPI's in house online journal. Over the next few episodes, we'll be discussing all aspects of climate migration. We'll ask how the impact of climate and environmental changes is affecting people's movement within their own country and around the world. As we will hear, migration is one response to fast moving disasters such as hurricanes and wildfires, as well as slower onset changes such as desertification and sea level rise. But it's not necessarily the default response, or even the best one for a lot of people. Instead, we'll be asking who it is that migrates in response to environmental change. Why, and what happens afterwards? This podcast is being produced in conjunction with a series of articles evaluating the current state of climate migration and what it might look like in the future. Those are online migrationpolicy.org/climate. Today I want to get a handle on one of the big issues of climate migration. I want to ask why people might decide to move in the face of environmental changes and how that decision might be a bit more complicated than it appears at first glance.

[00:01:25.21] 

My guest for this episode is Alex de Sherbinin. A lex is a geographer at Columbia University who focuses on the human aspects of environmental change. He has written, co-written or edited dozens of articles, book chapters and books on different issues related to climate change, including migration, vulnerability and resilience. Alex, thank you so much for coming on today.

[00:01:50.08] 

Yes, my pleasure, Julian.

[00:01:52.14] 

So one of the things that tends to be surprising to some people who encounter this field for the first time is that the notion of climate or environmental migration is not necessarily new. In fact, there is a very, very long history of this interplay between the climate and human movement. There are cases of this dating back to the Roman Empire and the Mayans in the United States. We might think of the Dust Bowl of the 1930s. So historically, what do we know about how the climate causes or affects migration?

[00:02:25.13] 

That's a good question. So climatologists and historians have been looking at how climate has induced populations to move in the past. Clearly, what we're experiencing today is not the first time the climate has shifted in different ways or that variability has increased. So, you know, looking back to the end of the Roman Empire, some scholars have indicated that there was a period of high migration coinciding with a great deal of climate variability around 500 AD with the fall of the Mayan empire. There's been good evidence to show that there was a prolonged drought that may have affected the hydrological infrastructure that the Mayans had so carefully set up. And in the Yucatan and other parts of Guatemala that led to the collapse of the Mayan Empire, we see on the converse, the case of the Mongolian expansion into Europe. Well, basically westward and as far west as Europe during the 13th century AD when wetter conditions prevailed. So in some cases, dry conditions can force people to move out of areas. And we've seen that as recently as the Great Sahelian drought, the 1970s and then into the early 80s, where a lot of people left rural areas and moved into cities in often precarious living environments around the outskirts of the Sahelian cities like Bamako and Nouakchott and Mauritania.

[00:04:08.07] 

But we've also seen the dust bowl, the 1930s. So the ebb and flow of population in relation to climate change, climate variability and change has been a long part of human history. I think what we need to be careful about is, that is not to become climate or environmental determinist, which basically is a school of thought that was prevalent, say, in geography in the first part of the 1920th century, where you ascribe a lot of causality to climate that may not be fully grounded. So you want to look at the situation and say humans have always had volition. Humans have always been able to choose where they live, and in some cases climate factors have exerted a push factor. But it's not necessarily the only thing that's going on and that many, many societies have successfully adopted or adapted, I should say, to changing environmental circumstances, especially if they occur gradually and over time.

[00:05:15.22] 

Yeah, I'd like you to talk a little bit more about that, actually, because in the popular discourse, we often talk about people who are being forced to move because of major climate change or kind of forced out of their homes. This word forced comes up a lot, but you note it's not as simple as that. So say a little bit about that distinction. And the difference between an individual's or a household's desire or volition to move versus being forced to move and some of the different factors that go into that decision making process.

[00:05:49.22] 

Yeah, well, my own conclusion is, you know, having studied this area for a while, is that even in some of the most dire circumstances, there are still elements of volition. Now, obviously, if someone's fleeing for one's life in a natural disaster context, people often, you know, run for their lives, as it were, and that can happen in conflict situations, of course, people flee to preserve themselves, but in a lot of other circumstances, people are still making choices. And so we talk about this spectrum from voluntary to forced, and I think an increasing number of scholars are saying it's a somewhat useful distinction to make between these two. But it's really in reality a spectrum, and that people fall on different levels or different places on that scale. The reality is that people are making choices and that often that locus of choice can also differ heavily from the household making a decision collectively to individuals who make decisions that are for their own good, but not necessarily taking into account the larger household. So there's a lot of factors at play. And then there's also situations that arise where people choose to move or they'd like to move, but they don't have the capability.

[00:07:25.03] 

So there's this notion of aspirations and capabilities that people may aspire a better life. They may aspire to escape circumstances, but either because of financial constraints or legal or policy barriers, they're unable to move. So there's a lot of factors at play determining whether someone is able to move or not.

[00:07:45.23] 

And so you're talking there about what we sometimes call trapped populations, right? So people who maybe can't afford or don't have the skills, or there are legal barriers or other things that prevent them from leaving an area that might be facing some severe climate environmental changes. Is that right? I mean, who are these people and I guess what are the barriers that they face?

[00:08:07.17] 

Yeah, good question. I mean, there's actually a bit of scholarly debate. I mean, this is an area of the social sciences where probably common to most of the social sciences, there's often more disagreement than there is common agreement. But the idea of trapped populations came up in the context of the foresight report on global change and environmental migration. And they basically had this notion that there were people who, for whatever reason, could not move, but they may be in need of assistance to move. So planned relocation might come into play or social protections. Then, of course, subsequently, a lot of social scientists have gone out to the field and said, well, where are these trap populations? Show me people who meet this criteria, this category. I think it's, as invariably, a little bit more complicated. And it depends on, you know, a lot of different contextual factors in different parts of the world. But, you know, commonly you'll find that there are women in certain regions of the world who are unable to move, maybe because of gender biases about migration. You know, they're not they or their children or their caregivers, and they're not able.

[00:09:29.10] 

So they're caregiving for the children or for their older adults in the family. And they're not able to move because they have that, that culturally defined role. You've got other circumstances where people simply may lack the means or there may be policy restrictions that keep them from going to where they want to go. Internal migration tends to be easier, but there's even countries in the world like China that have registration systems that are intended in part to impede people from moving by restricting access to benefits based on your assigned residency. So there are a lot of things that come into play in terms of whether people are able to move or not. My sense is that trap populations are in fact real and that they do exist, particularly in dryland environments and in some high mountain environments or high mountain environments where, you know, poverty levels are high and the ability to move is relatively restricted. But there's still some debate about that.

[00:10:39.16] 

And you mentioned their internal migrants, which are people who move within the confines of their own country. They don't go internationally. And I mean, these are the majority of migrants generally in the world, and also the majority of migrants who are moving in response to factors including climatic and environmental change. Right. I mean, most of these people we're talking about are going to be within their same country and different regions, as opposed to international. Right?

[00:11:06.11] 

Correct. I forget the exact ratio, but I think it's three or four times as many people migrate internally as migrate internationally or cross borders. Reality is we do not have a good fix that. In fact, the international data system, demographic data systems that we have in place, simply inadequate to really be able to give us a good read on the total numbers of people moving internally within countries. That's something that the demographic community is taking steps to try to address by increasing demographic surveillance and setting up monitoring systems. But the reality is that when people move, you could have serial moves where you move first to a local town and then you go to a slightly larger city and then you move to the capital and you have the temporal dimension, you have stocks and you have flows. All of this makes monitoring migration a lot more complex than say, monitoring births and deaths in a country.

[00:12:10.23] 

I also want to go back to something you just said. You referred to kind of drought situations in the ways that that can be a prompt for some people to move. I mean, I guess that gets to the question of what kind of events we're talking about here, both in terms of massive tsunamis, wildfires, what we call a quick onset, fast onset, major disasters versus slow moving, drought A gradual sea level rise, things like that. I mean, how, how do you think about those? How do you make a distinction between which kinds of environmental events drive which kinds of movement? And I mean, how do the people who are affected by those different events kind of weigh the different things happening to them and how that impacts their desire or their ability to move or not?

[00:12:59.02] 

Yeah, well, the sort of commonly held view is that rapid onset events such as floods or cyclones will drive an initial pulse of people outside of an area to seek protection, but that the most common response is to return to the areas that were initially affected. And, and that can often be for very illegitimate livelihood and other reasons. You know, I've heard of countless cases from Mozambique to the case of Tacloban, in which was hit by a massive cyclone. This is a Philippine city. This, this particular city was almost wiped off the map, but government officials actually sought to construct housing away from the area that was immediately affected by the cyclone and farther from the sh. And some of the people who were relocated to those housing units actually ended up renting those units to return to the shore because they were fisher folk or whatever and they had these very tight ties to livelihood systems that they depended on and they were reluctant to move that far away. So you have these cases where people have either been relocated or are pushed out temporarily, but then return, often living in risk prone environments.

[00:14:28.12] 

And this is a known factor. And one thing that may occur is you may see successive events that then essentially lower the threshold or the barrier to migrate and the people decide at a certain point. Look at, after the first cyclone, I could survive, I could manage. The second one came along and I was knocked on my knees. But the third one came along and I really needed, you know, I just realized that it was no longer sustainable to live in this area. And so they give up. And, you know, one wonders, we're talking largely in the developing country context, but one wonders whether people in parts of Northern California these days are beginning to say, look at, after the first forest fire alert, I was okay, but you know, now that we've had three or four come through and my house has been reduced to ash, you know, some of those people may begin really questioning the logic of living in that particular environment. So the other element you asked about is whether, you know, slower or more gradual changes are likely to affect longer term movements. That's certainly been the premise of some of my work and some modeling work, which we can touch on later with the World Bank.

[00:15:41.01] 

But the reality is that, you know, with the gradual erosion of livelihoods or the gradual reduction in crop yields or land degradation that may be hand in hand and an unfavorable policy or market environment that basically means that smallholder agriculturalists are not able to make a decent living. You know, these things start factoring into the logic, especially of young people and youth who are making decisions about, well, is this where I want to live my future or is this where I want to raise my kids? And so those kinds of more longer term, slower onset events, changes in temperature and precipitation over longer periods of time, maybe, you know, have a, may have also a causal link and may cause people to start questioning whether they can really adapt to those new and changing situations.

[00:16:36.01] 

And those are precisely the kinds of situations that are being exacerbated or that are being brought about by global climate change and global warming. Right. I mean, so I guess what's the relationship here? We talked about how climate events and environmental events historically have affected movement, but tell me how things are changing and aggravating those kinds of situations.

[00:16:59.09] 

Well, you bring up an important point and the issue of attribution. In other words, does anyone. Extreme event, whether it's the fires in California or a massive cyclone in Florida or some other part of the world actually linked to climate change. So there's an important part of the science that's going into attribution, and the climate science community is actually rising to that challenge and running models to show that in certain circumstances the probability of a certain event occurring has been increased substantially as a result of global warming or climate change. In other cases, they may say, well, this particular event might have happened anyway. So even though it seems quite extreme and the level of devastation was high, it is not outside the sort of historical range of probabilities that exist for these events. So one reason why some people have been reluctant, for instance, to expand the definition of refugees to include climate refugees is precisely this inability in some cases to tie specific events to climate change and therefore say these people move because the climate has shifted and the climate has shifted because, well, emissions have continued to remain high in the global north, and therefore we owe it to our brothers and sisters in the global south to help them out.

[00:18:30.10] 

So this essentially causal change from climate change to individual events or longer term changes, to someone deciding that they're going to move and then labeling them one way or another as a climate migrant or climate refugee, it can be considered pretty tenuous to make those connections. There's equally, well, though people on the other side who say, well, there's no doubt in our minds or in their minds that climate is really making the living situations of many people, aggravating situations for many people, especially in the Global south, and that therefore making these linkages is not such a leap.

[00:19:19.24] 

But it's a lot more complicated, it sounds like, than we'd like to imagine. It's not just a simple case of the rain comes, the storm comes, people leave their house. That's it. It's a. There's a lot going on, I guess. So we talked about some of these challenges, I guess what are the solutions or what are people, what are governments, what are academics, research organizations, etc.  doing to forestall or respond to or just get a sense of what kinds of movements are happening or are not happening in response to or in the midst of changing climate conditions.

[00:19:56.24] 

So one strand of work that I've been involved in is modeling future climate change migration. I would call it climate change migration. As I said, I'm going to caveat that immediately in saying that I'm actually increasingly discomfited by that notion because I think people move for a lot of reasons and climate is often maybe the last trigger or one of many factors that could in fact lead someone to migrate. So I'm going to call it climate migration. But understand that I have some reservations about that term. And so we for the World Bank produced a report called Groundswell, which is a report that essentially looks at out to 2050 internal migration and provides numbers which I wasn't super enthusiastic about, but that was something the bank really wanted, was to just be able to get a grasp on what kind of numbers we might be talking about in different parts of the world. And also it actually provides maps that show where people are likely to be leaving from and where people will likely be migrating towards. And we have those for all the countries that we've modeled. Shortly we'll have an updated report, Groundswell version 2.

[00:21:12.12] 

And in that report we'll cover pretty much all the developing world that is, you know, members of the World Bank or aid recipients of the World Bank. So that work is one way in which donor organizations are trying to get a grip on what might happen in the future in the case of the World Bank, to help their client governments actually understand what kinds of things, what the level of the challenge may be for them, and then what kinds of adaptation responses they may want to put into place place. So there's different types of responses that donors are putting into place. There's sort of two types, I would say, generally speaking. One is kind of addressing the root causes and among Them are these climate push factors. And so this notion of what's called in situ adaptation or local adaptation, where you essentially improve agricultural practices, maybe improve water management, you do a number of things to climate proof housing or otherwise make it, you know, people better able to sustain, let's say, extreme events and be able to stay there in place. So, you know, donors are providing assistance to try to make local conditions better.

[00:22:34.24] 

On the other hand, they're also working on things like migrant focused initiatives where you're either trying to facilitate insertion of migrants in destination areas or, or help people who are stranded at some level if they're migrating internationally. And generally speaking, these are targeted towards obviously people who have moved or are in the process of moving and trying to protect their rights and make sure that they actually have what they need to have in terms of protections. So there's a lot going on in this space. In the meantime, humanitarians are also jumping into the game and looking at climate resilience practices and trying to prevent displacement. So displacement is obviously at the forced end of the spectrum. And what can we do to help people sustain and kind of be resilient to the kinds of impacts that we might expect more of in the future?

[00:23:37.16] 

And you mentioned that you're a little skeptical about using numbers, but there are some pretty big numbers attached to, to these kinds of movements. And there has been, I guess, a fair amount of back and forth about those numbers. I mean, I believe for your previous World Bank report, you estimated, or you and your team estimated 100 something million people might be affected by this in a couple of different regions by 2050. I've seen several hundred, I've seen estimates of several hundred million people, I think a billion plus. Right. How many, very briefly people are we talking about here? And for the layperson, how difficult is it to make those kinds of measurements?

[00:24:19.06] 

Well, it's difficult and there's different methodologies for doing it. And I won't get into, I won't bore the audience with the nitty gritty of the different types of methods that are being used and the ways that people are trying to model this. But the World Bank produced some estimates that range from roughly on the low end around. This is the report I was mentioning earlier, the Groundswell, of roughly 30 million people on the low end to about 143 million people on the high end in three major regions, all of Latin America, Sub-Saharan Africa and South Asia.

[00:25:02.24] 

That's by 2050, right?

[00:25:04.18] 

That's by 2050. And as I said, we'll have new numbers that essentially incorporate more of the world in the future. There's other measures that have been other ways of estimating this. A group looked at the population that would be exposed to a 1 meter sea level rise and found that it was about 230 million people today. So let's assume that there's both population growth and that people may continue to favor the coast. So by the end of the century, when sea levels may rise up to a meter, and if you add in storm surge and other things that could be on top of that, you could well see 300 to 400 million people who are essentially, you know, in harm's way in those areas. Whether they move or not is an open question. There's ways of adapting to some of these things, but that, you know, it gives you a sense of the orders of magnitude that we may be looking at.

[00:26:11.22] 

A lot of people, I guess it's fair to say.

[00:26:13.20] 

Sure. Yeah.

[00:26:16.09] 

On that note, I guess I think we're out of time, so we should probably wrap it up there. But thank you so much for coming on. Alex de Sherbinin is the Associate Director for Science Applications and a senior research scientist at Columbia University's center for International Earth Science Information Network. As he mentioned, he's working on major updated report for the World Bank about climate migration and has published extensively on various aspects of the subject. Alex, thank you so much again. I really appreciated it. It's been fun to talk to you.

[00:26:48.16] 

It's been a pleasure, Julian, thank you.

[00:26:56.04] 

Alex and I touched on a lot of issues, but two things really stuck with me. One is that there is a long history of people moving in response to or amid climate and environmental change. It happened before, it will happen in the future, and it's also happening right now related to that. The other thing that stuck with me is this question of causation. When people move in the face of environmental change, is it those changes which are causing their movement or is it other things like changes to their ability to earn a living as a farmer, which may be distinct from, but related to the environment? In some cases it might be that the accumulation of lots of changes or repeated events over time are impacting their ability to move? As we've seen, this issue can be pretty messy, but that's what makes it really interesting and it's why I'm excited to continue exploring it. In coming episodes, I'll dive into some of the different aspects of this migration and movement. In some cases it can lead to violence. In others, it can be a way to build resilience against some of the negative impacts of climate change.

[00:27:58.03] 

So please stay with us. Find episodes online at migrationpolicy.org/podcasts or subscribe to your own favorite podcast app. And please leave us a review. You can also find articles about this topic from Alex and a range of other analysts at migrationpolicy.org/climate. This episode was produced by Lisa Dixon and Kenia Guerrero, with special assistance from Michelle Mittelstadt and Sara Staedicke. Music called Touch is from Patrick Patrikios. My name is Julian Hattem. Thank you for tuning in and I'll see you next time.