International organizations are struggling to agree on how to deal with the massive population displacements linked to climate change and environmental crises. In a recently published book on African Economies in 2024 demographer Serge Rabier devotes a chapter to how this problem affects Africa in particular.

Are climate and environmental migrations a problem unique to our times, or are they a constant in human history?

Serge Rabier: We know our direct ancestor Homo sapiens lived in the Middle East 70,000 years ago, following…migrations that were linked to "global" climate change. While "Out of Africa 2" [one of several waves of mass migration out of prehistoric Africa] can be explained by the drought that struck the east of the continent, it was a drop in sea levels during the last ice age that enabled the crossing of the Bering Strait between Asia and the Americas 35,000 years ago.

However, on the scale of small hunter-gatherer communities, nomadism can be explained by more localized variations in climate and their impact on the movements of game herds, the food items gathered, and the possibilities of finding a safe habitat.

Later, between Late Antiquity and the Middle Ages, the so-called great invasions (from the Huns to the Mongols) are associated with the flight of populations from Asia to western and southern Europe. These can be explained in part by major climate changes like droughts, pasture shortages, and big temperature gaps.

[There is a clear] link between climate and environmental degradation on the one hand and migratory movements on the other. This is an issue we will have to increasingly pay attention to.

Why is it so hard to agree on an internationally accepted term for climate or environmental "migrants", "refugees", or "displaced persons"?

The proliferation of terms reflects the difficulty in distinguishing between movements that are permanent vs. temporary, or forced vs. voluntary.

Between the term "migrant" as defined by the International Organization for Migration, that of "refugee" set by the 1951 Geneva Convention, or that of "displaced person", the latter two terms seem most closely linked to climate and/or environmental mobility. Climate refugees or displaced persons represent a more distinct category, whose causes of mobility are more specifically attributed to the consequences of development in the Anthropocene.

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Climate change is a "threat multiplier". It exacerbates tensions linked to agricultural, forestry, and mining resources. Not to mention those of food; water; land use; and economic, political, and ethnic or religious conflicts.

Who are the climate and/or environmental migrants already forced to travel the planet in search of safer shelter, and how many are there?

Identifying and categorizing people who migrate for climate and/or environmental reasons remains a difficult task, given the complexity and multi-faceted nature of mobility. In any given region, all sectors of the population are affected by climate change. However, there are significant differences according to where people live and to the resilience and adaptation capacities in countries suffering high levels of poverty combined with very unequal access to water, food, and basic social services such as hygiene, health care, and education.

Geographically, a Notre Dame Global Adaptation Initiative study noted that 17 of the 20 countries most vulnerable to climate change in the world are located in Africa, and 9 of them are additionally undergoing violent conflicts and/or strong security crises. These are Chad, Central African Republic, Democratic Republic of Congo, Sudan, South Sudan, Niger, Somalia, Mali and Burundi.

In 2022, climate disasters caused the internal displacement of an estimated 7.4 million people in sub-Saharan Africa, the highest figure ever reported for the region.

Asia is also heavily impacted, with another more than 12 million internally displaced persons or migrants due to climate reasons recorded in 2022 in South Asia and more than 10 million in East Asia and the Pacific Region.

What can development actors do to deal with this seemingly ongoing trend, and what type of action can be taken?

Migration due to climate change must be linked to its causes, particularly greenhouse gas emissions. For the emitting countries, effective action means several actions:

• They must reduce their emissions through mitigation
• They must compensate the countries that suffer loss and damage impact. Those countries need investments to deal with the effects of climate change, from extreme droughts and floods and rising coastal waters to temperature variations and forest fires.
• It's also crucial to finance adaptation programs and support programs to build people's resilience

Development policies then have to tackle these issues, a task that still seems elusive given the heated debates.

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And yet, in the case of climate migration in particular, agreements could make it possible to organize this mobility under acceptable and effective conditions of reception, support, integration, and return.

Capacity to produce statistics is crucial for anticipating these movements. It would also help us end displacement and work toward conflict resolution, peacebuilding, disaster-risk reduction, climate resilience, food security, and poverty reduction.

We need appropriate systems that recognize the situation of displaced persons by:

• Providing legal assistance
• Working to prevent systems of violence and discrimination, especially against women and girls
• Setting up psychosocial support resources
• Supplying basic goods and services such as food, hygiene, health care and education

To this end, taking human rights into consideration should enable us to treat-with humanity and dignity-the people who cannot or don't wish to return to the country or region they left behind.

L'Économie africaine 2024was published in French in January by Éditions La Découverte. The first chapter is available here in English.