Will there be a climatic exodus?

Droughts, floods and rising sea levels. The disasters announced with climate change often foreshadow massive migrations. Experts gathered at the last annual meeting of the American Association for the Advancement of Science (AAAS), in early March in Washington, believe that these forecasts are exaggerated.

Three years ago, Fabrizio Natale began combing through African meteorological and demographic databases.

“Our goal was to see if there would really be a massive exodus from Africa to Europe because of climate change, as predicted by alarmist analyses”, explains the researcher from the Joint Research Center (JRC) of the European Commission, in an interview on the sidelines of the AAAS session. “In some cases, we were talking about millions of people. »

To see clearly, they divided sub-Saharan Africa into cells of 25 km^⁠2 with data ranging from 1975 to 2015. If the thesis of climatic migrations is correct, we should already see the results with the climatic changes of the last decades, explains Mr. Natale.

Result: the climate seems to have had little or no influence on migration.

“We saw a small effect in the Sahel for the droughts, but that’s all,” says Mr. Natale. The communities most affected by climate change seem trapped in their homes. Other studies show that droughts impoverish populations. However, it takes money to emigrate. »

Mr. Natale is now fine-tuning his analysis with one kilometer cells and data up to 2021. Of note, the migrations recorded by Mr. Natale’s analysis were of people moving out of their original 25km square . And even on this small scale, climatic migrations seemed rare.

“Emigration is expensive”

Hélène Benveniste, a geostatistician from Harvard University, is one of the researchers who have studied the migratory behavior of the poorest populations on the planet.

In Nature Climate Change in 2022, it concluded that by 2100, climate change will reduce the probability of migration of the world’s poorest populations by 10% to 35%. “Emigration is expensive,” says M^me Benveniste, who was not at the AAAS convention.

Climate shocks have less impact on the middle classes of poor countries, which are also less affected by droughts.

Another AAAS speaker, Esha Zaveri of the World Bank, notes that the poorest populations of developing countries, who are generally rural, tend to migrate to the cities of their countries during ” climatic shocks”.

“Studies have shown that financial assistance can then facilitate migration,” explains Ms.^me Zaveri. Otherwise, these poorer households must save before migrating. But we can also help the poor who do not want to migrate with targeted programs that have yet to be determined. »

Demographic pressure

Elsewhere in the world, it is not the drought that is the problem, but the rising waters. Pacific island nations have regularly made headlines about it.

“In most cases, when we say that we have to abandon islands, it’s because of the lack of water,” explains Alex de Sherbinin, a geographer at Columbia University in New York, also a lecturer at the AAAS.

“Generally, it is because of excessive extraction of groundwater due to demographic pressure. But more recently, we have also seen cases of salt water infiltration due to sea level rise. That said, by 2100, there are going to be island nations that are going to disappear. »

The UN estimates that 50,000 people leave the Pacific Islands each year due to climate change and natural disasters. This confluence sometimes mixes the cards.

“In Central America, we heard about people migrating after hurricanes Eta And Iota and also because the summer drought is getting longer and longer,” says Mr. de Sherbinin.

In 2021, a report by the UN World Food Program estimated that 6% of Central American migrants cited climate change as the reason for their migration.

The New York geographer specifies that he prefers not to use the term “climate refugee”.

“Current refugee conventions do not provide for climate asylum claims. There could be a remedy for truly climate migrants under humanitarian law, but that remains to be demonstrated. »

Planned withdrawal

In 2021, the UN launched with Pacific island nation states the Rising Nations Initiative (RNI). One of the immediate goals is to preserve the maritime rights of island nations that are going to have to be abandoned with rising sea levels.

“But there is also talk of the possibility of rich countries taking in some nations as reparations for past greenhouse gas emissions,” says de Sherbinin. It would be easier in countries that already have territorial agreements with their own indigenous nations, such as Canada and the United States. »

Either way, researchers assume that there will be migrations with climate change.

Mr. de Sherbinin is hosting the third conference on “planned withdrawal” at the end of June at Columbia University (managed retreat), which includes presentations ranging from government buyout programs for frequently flooded properties by the U.S. government to the thorny debate over whether climate change is exacerbating conflict.