I've posted a few times about the effect of climate change on migration, including on my own research about the effects of climate change on internal migration in New Zealand. I'm often asked about how climate change is going to affect international migration to New Zealand, and whether we will face a flood of 'climate refugees' in the near future. Especially, people tend to focus on the effect of sea level rise on island nations.
There are a number of important points to make in relation to climate refugee flows to New Zealand. First, New Zealand is a long way away from the most populous places that will be most affected by sea level rise, including Bangladesh, the Mekong Delta, and the Red River delta in South and South East Asia (there are many places more distant that may be even more affected). Travelling a long distance entails a high cost that is prohibitive to most people. Second, the places that are relatively close and affected by sea level rise, like the Pacific Islands, generally do not have large populations. The most populous islands tend to also be larger and have inland areas that will be less affected by sea level rise. Migrating inland is a much lower cost alternative than migrating internationally (albeit with its own challenges). Third, even if people choose to migrate internationally, New Zealand is just one of many alternative destinations they could choose, including Australia, the United States, or other Pacific islands. Finally, if New Zealand chose to admit a large number of climate refugees on humanitarian grounds and covered the cost of their travel and settlement, that still only covers the monetary cost. People have an attachment to place, and moving away entails a psychic cost (for example, see here). That explains why many people prefer to migrate short distances rather than long distances, even when they have the means to migrate further away.
It is on the basis of those points that I make the case that climate refugee flows to New Zealand are likely to be small. There is a theoretical model underlying most of those points, and that is related to the costs of migration.
A new article by Hugh Roland and Katherine Curtis (both University of Wisconsin-Madison), published in the journal Population and Environment (sorry, I don't see an ungated version online), demonstrates the importance of costs in the migration decision, in the context of environmental change. Roland and Curtis use five-year origin-destination migration data from the Kiribati Censuses of 2005 and 2015. They set out to compare two competing environment-migration theories:
According to the traditional, dominant framework known as the environmental scarcity thesis, poor environmental conditions may prompt out-migration in search of more hospitable natural environments and better livelihoods. In contrast, the environmental capital thesis asserts that resource scarcity and limited financial means associated with poor environmental conditions may actually restrict out-migration...
Notice that the environmental capital thesis exacerbates the points I made above, in relation to migration costs. Roland and Curtis test these theories by comparing how migration rates to the main island of Tarawa have changed over time between islands that are more isolated from Tarawa, and those that are less isolated. As they explain:
Isolation dampens the migration-promoting effect of declining natural resources asserted in the environmental scarcity thesis. However, isolation exacerbates the migration-prohibiting effect of declining natural resources outlined in the environmental capital thesis. With this theoretical distinction in mind, we anticipate that the migration-incentivizing role that environmental and economic challenges play in the environmental scarcity hypothesis only pertains to contexts in which migration costs are reasonable and, associated, distances to potential destinations are short. In remote settings, the environmental capital thesis is likely the more applicable framework.
Kiribati has been experiencing acute and increasing impacts of climate change over the period Roland and Curtis study. They expect to confirm that the environmental capital thesis dominates, and indeed, that is what they find based on cross-sectional comparisons:
Analysis of migration probabilities shows that out-migration to Tarawa is higher among the least geographically isolated islands as compared with the more isolated islands... Consistent with the environmental capital thesis, probabilities of Tarawa-bound migration from the more spatially proximate North and Central Gilbert Islands in 2000–2005 are generally larger than probabilities for the more distant South Gilbert Islands... While small numbers, the direction of the differences in out-migration is consistent with the environmental capital thesis and contrasts with the environmental scarcity thesis.
Then, looking at changes over time:
At first glance, the increase in out-migration among the North and Central Gilbert Islands appears consistent with the environmental scarcity thesis: as environmental, related economic, and other conditions decline, residents migrate to new places in search of better opportunities and livelihoods. For more geographically isolated islands, however, we generally find negative changes in migration probabilities. Such declines are consistent with the environmental capital thesis: isolation exacerbates the migration-prohibiting influence of environmental degradation. The positive change in outmigration probabilities for the North and Central Gilbert Islands contrasts with the negative changes in out-migration probabilities found for most of the more isolated islands...
The differences in the changes in out-migration probabilities between more and less geographically isolated islands support the environmental capital thesis. Migration is markedly lower from more isolated islands than from less isolated islands and generally decreases during a period in which environmental and economic conditions worsened.
Migration costs are an important constraint on migration. If climate change reduces access to the resources necessary to fund migration, people will not be able to migrate, even as the climate continues to worsen. The environmental capital thesis may be thought of as a type of climate-induced poverty trap. I think that this research is also instructive in terms of wider migration flows arising from climate change in the Pacific, because this dynamic is likely to apply (perhaps even more so) in the case of international migration.
It would be really interesting to conduct a similar study looking at how Pacific international migration flows are changing over time and how isolation, or a more proximate estimate of migration costs, affects those migration flows. I would expect to see something similar, justifying my contention that we are unlikely to face a flood of climate refugees from the Pacific in the near future.
Read more:
- Climate change won't much affect internal migration in NZ
- Climate change and migration in poor and middle-income countries
- Why Tuvaluans aren't migrating due to climate change, yet
No comments:
Post a Comment