The link between climate change and migration has received academic and public interest in recent years. Many studies found that environmental hazards affect migration. But the links are nuanced and depend on the economic and socio-political conditions in the respective regions of origin.
So what makes people move and where are they going? And what is the connection between these decisions and changes in climatic conditions?
To answer these questions, we have a meta-analysis to systematically analyze previous findings in the literature on environmental migration. We have combined evidence from 30 studies at the country level that estimate the effect of slow and rapid environmental events on internal and international migration worldwide. This allowed us to investigate migration managers and identify hotspots where climatic and other environmental factors are likely to have a strong influence on migration.
Our findings highlight the complexity of what lies behind people’s decisions to migrate. We found that migratory responses differ depending on the local conditions of the affected population. Environmental migration, for example, was most prevalent in agriculture-dependent and middle-income contexts where populations have sufficient resources to migrate. In low-income contexts, on the other hand, people were more restricted in their mobility and stopped the danger of getting caught up in difficult environmental conditions.
In fact, abundant research, including our own study, shows that environmental migration is primarily internal or within a region and rarely over great distances. Instead of focusing only on numbers, it is important to understand the real situations of communities affected by climate change in order to effectively support and protect vulnerable populations.
Our analysis shows that changing climatic conditions and ecological hazards are a major migration driver in sub-Saharan Africa. Some threats are slow at first. This includes rising temperatures, desertification, loss of biodiversity, country and forest decline. On top of that, the increase frequency and intensity of extreme events such as floods and droughts, which have led to major displacements in recent years.
For households exposed to environmental stress, migration can be an important life and adjustment strategy, especially in rural areas. Often it is individual household members migrating in an effort to open up and diversify new sources of income.
Most migration caused by the environment is internal – or within a region – with a large proportion of migrants turning to urban centers, as seen in the map below. It poses its own risks and challenges, especially in sub-Saharan Africa, with the majority of the urban population living in informal settlements, 53.6% in 2018 according to UN HABITAT, the UN program for human settlements.
In recent decades, several cities in sub-Saharan Africa have seen it rapid population growth and is today one of the fastest growing in the world. Cities that already house several million people are expected, such as Dar es Salaam in Tanzania, Kampala in Uganda, Abuja in Nigeria, Ouagadougou in Burkina Faso and Bamako in Mali. double by 2035. The rapid urbanization has important implications. It holds new opportunities as well as risks.
The rapid and often unplanned nature of the urbanization process in many countries has led to several challenges. These include inadequate infrastructure, housing and the provision of public services such as health care, education and transport.
While migration to an urban area provides opportunities for migrants, it carries risks. Many migrants entering cities from rural areas have limited resources and are very vulnerable. In the hope of a better life, many end up in backward and marginalized neighborhoods with poor access to water, sanitation and public services.
After fleeing environmental threats in their regions of origin, climate migrants may expose themselves to new dangers in their urban destinations. Many informal settlements are located on marginal land in risk areas. Due to the low quality of construction materials in these areas, the insufficient infrastructure and high population densities, disasters can have fatal consequences.
Urban floods in particular are a major challenge. For example, in 2018, six of the ten biggest flood events which caused displacement in sub-Saharan Africa, and urban areas had the greatest consequences. This year, too, severe floods are affecting the entire region a few hundred thousand people and led to serious damage and displacement.
Climate migration is already a reality for many people and will remain so. The World Bank Groundswell reports projects that up to 86 million people may be forced to migrate within their own countries by 2050 to escape the effects of climate change in sub-Saharan Africa.
A large proportion of these migrants will move to cities. If planned and managed well, urban growth can have the social and economic benefits for both migrants and the destination areas. It requires infrastructure development and inclusive economic policies.
For adequate preparation, it is important to understand why and under what circumstances people migrate and where they are going. To do this, climate change forecasts need to be more strongly integrated into migration scenarios. Better data and comprehensive research on migration dynamics can improve policy making and raise awareness.