How climate change affects migration

Will climate change, as often claimed, indeed result in large-scale human migration, notably from poor to rich countries? Vally Koubi and Thomas Bernauer answer.

This content was published on February 28, 2018 - 11:00
Vally Koubi and Thomas Bernauer, ETH Zurich, Swiss Federal Technology Institute ETH Zurich

Global warming is bound to have increasingly adverse consequences for humanity and ecosystems. While there is strong agreement in the scientific community about most of these consequencesExternal link, there is significant controversy about how climatic changes could affect human migration. 

Some political leaders, international organizations, and scientists claim that climate change will lead to massive population shifts in the international system, notably mass migration from poor to rich countries

Vally Koubi is an adjunct professor and senior scientist at the Center for Comparative and International Studies (CIS) at the Swiss Federal Technology Institute ETH Zurich. ETH Zurich

Mass migration to Europe?

A recent publication in the journal ScienceExternal link, for instance – which we strongly disagree withExternal link predicts that climate change could drive up the number of people seeking asylum in the European Union by nearly 200 percent by the end of this century. Similarly, other studies claim that climate change will force millions of people to migrate in the coming decades. The title of an article in the GuardianExternal link reflects such claims: “Climate change ‘will create world's biggest refugee crisis’”.

Wrong focus

Our own research suggests that such sweeping predictions, much like earlier predictionsExternal link about climate change causing wars, are highly speculative and not sufficiently supported by robust scientific evidenceExternal link. The main reason to be very skeptical of such predictions is that they usually focus on people exposed to increased climatic risks, rather than on people actually expected to migrate. Moreover, they typically do not account for adaptation potential and different levels of vulnerability to climatic changes, both of which are essential factors in people’s migration choices.

We shed light on the climate-migration nexus in two recent articles in World DevelopmentExternal link and Population and EnvironmentExternal link. This research is based on systematic interviews (surveys) with around 4,000 men and women in Cambodia, Nicaragua, Peru, Uganda, and Vietnam.

Thomas Bernauer is a professor of political science, and Director of the Institute of Science, Technology and Policy (ISTP) at the Swiss Federal Technology Institute ETH Zurich. ETH Zurich

We collected information on peoples’ perceptions of climatic changes and the impact these changes had on their living conditions, including their decision to migrate or stay where they were. Our work is one of the few research endeavors that systematically collects information on both people who left their homes and people who chose to stay after experiencing specific types of climatic changes. This distinction is crucial since one can only identify the potential reasons for climate change-induced migration by comparing migrants and non-migrants.

Assessing the migration motivations

We distinguished between two types of climate change-related events in our research: 1) those that occur suddenly and typically are of short duration, such as storms and floods; and 2) those that evolve slowly and are prolonged, such as droughts, or increasing water and soil salinity. We argue that when it comes to the former type of climate change manifestation, individuals often have little choice but to move, usually within the respective country, rather than to countries far away. In contrast, slowly and more gradually evolving climatic changes are more likely to allow for adaptation to such changing conditions.

“Given the possibility to adapt to climatic changes, most individuals are likely to stay and adapt, rather than migrate.”

- Thomas Bernauer and Vally Koubi

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Migration, and especially migration to another country, is a very costly choice for most individuals, since it requires economic resources and social networks necessary to undertake the move. Furthermore, most individuals are strongly attached to their home location because of economic, social and cultural ties. Consequently, given the possibility to adapt to climatic changes, most individuals are likely to stay and adapt, rather than migrate.

And indeed, our analysis shows that climatic changes very often do not induce migration. While extreme climatic changes often leave individuals no other option than to migrate, gradual climate change events usually do not lead to migration. That said, it is still possible that some individuals stay not because they choose to, but rather because they are unable to move due to failed adaptation efforts and depletion of economic resources necessary to undertake the move.

Need for adaptation support

Poorly substantiated studies claiming that climate change will cause millions of people to migrate are not only questionable from a scientific viewpoint. They are also questionable from a policy viewpoint. In particular, they divert attention from the fact that people severely affected by climatic changes will overwhelmingly prefer to stay rather than migrate.

This means that massively increased international climate change adaptation support will be essential. It is essential not primarily to prevent mass migration from developing to industrialized countries, as some studies on the climate change-migration link suggest. It is needed to mitigate human suffering of those trapped in parts of the world exposed most severely to changing climatic conditions.

The original textExternal link of this article was published on the Swiss Federal Technology Institute ETH Zurich's ZukunftsblogExternal link on February 16, 2018. The views expressed in this article are solely those of the authors, and do not necessarily reflect the views of 

Opinion series publishes op-ed articles by contributors writing on a wide range of topics – Swiss issues or those that impact Switzerland. The selection of articles presents a diversity of opinions designed to enrich the debate on the issues discussed.

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