Climate change and urban migration in Africa

 By Robin Wylie

Africa is one of the most rapidly urbanizing places on Earth…

Africa is one of the most rapidly urbanizing places on Earth. Though the majority of its population still lives in rural area, in the last 20 years urban centers in Africa have been growing at an average rate of around 3.5 percent per year — the highest level of urban growth in the developing world— with the continent predicted to maintain this rate of urbanization until at least 2050.
Numerous factors have been suggested to explain Africa’s rapid urban migration, including overcrowding of rural areas, conflict, famine and natural disasters. But a recent study suggests that climate change could also be playing a significant role.
In the study, researchers from the London School of Economics, Tufts University and the World Bank analyzed patterns of urban migration in Sub-Saharan Africa (SSA) between 1950 and 2009, and compared these with rainfall and temperature records for the same time period: In recent decades, many parts of SSA have experienced reduced and more unpredictable rainfall patterns, and the researchers wanted to see if this climate change might be correlated to changes in urban populations.
The results showed that, indeed, the degree of urban migration was correlated with changes in rainfall in various parts of SSA. Specifically, the team’s analysis found that, for the most highly industrialized parts of SSA, drier conditions corresponded to a statistically significant increase in the urban population during the study period, suggesting that Africa’s changing climate change might have contributed to its growing urban demographic.
The team only observed the correlation between rainfall and urbanization in districts where industry was present; not in areas which were entirely dependent on agriculture. This suggests, they say, that lower or less predictable amounts of rainfall could be driving farmers away from agricultural areas to seek industrial work in urban areas. In other words, urbanization could offer an “escape” from the negative impact of climate change on agricultural production.

Repeated failed rains have left Kenya facing it's worst drought crisis in over 30 years (Russell Watkins, DFID)

“Our analysis suggests that agroclimatic conditions do indeed influence urbanization rates, with better conditions retarding urbanization and unfavorable conditions leading to greater urban population growth,” the authors say in the study.
Previous research had pointed to a similar connection between climate change and urban migration in Africa. A 2006 study found evidence that, in Sub-Saharan Africa, reductions in rainfall were correlated to an increase in urbanization at a rate of 2:1; while a 2012 study predicted that weather anomalies (another likely consequence of climate change in Africa) will lead to lower rural wages, and thereby cause workers to move from the country-side into the cities in search of work.
However, the link between climate change and urban migration is still an issue of contention. Some researchers have argued that natural population growth in cities is a more important dynamic in the pattern of human settlement in Africa, and may be overlooked by an emphasis on the potential impact of environmentally induced migration.
If the connection does exist, however, it could have critical implications for Africa’s response to future climate change. According to the authors of the new study, their findings suggest that adaptation to climate change in Africa will only be successful where cities can absorb the excess labor resulting from agricultural decline.
The consequences of increased urban migration could be a mixed bag. Urban growth generally leads to significant economic growth (on average roughly 80 percent of economic growth occurs in urban centers); however, urban centers also place substantially more pressure on natural resources than rural communities, given their population density and the attendant demands on water, agricultural, energy and other resources. Studies have also warned that increased urbanization combined with climate change could amplify disease burdens.
There are some opportunities that policymakers and others could pursue to help dampen the impact of potential climate disruptions on urban cities, such as improving humanitarian assistance and disaster relief training, and improving climate change awareness at the local level. But with the scale of the burden from climate change still highly uncertain, it remains to be seen how Africa will have to adapt in the future.

READ MORE: Climate change and migrations in South Africa by Nicholas Newman

about the author
Robin Wylie
Freelance earth/space science journalist. Currently finishing off a PhD in volcanology at University College London.