A glimpse into the future

Climate change, migration, and Bangladesh

October 15, 2021

In mid-July, Germany has been hit by one of the worst flood disasters in its history. Houses were swept away, roads and train lines were broken, entire villages were covered by mud and debris. Almost 200 people died. How can it be that flooding has such enormous effects in a country that should have sufficient funds and capacities to prepare for and prevent such disasters? According to Saleemul Huq, director of the International Centre for Climate Change and Development (ICCCAD) in Bangladesh, an important factor is that people in Germany are no longer used to such disasters and hence underestimate the risks. In Bangladesh, by contrast, flooding occurs every year during the monsoon season. In consequence, people anticipate the floods and have adapted to them, so that flood-related damages have been reduced drastically.

In fact, floods are not the only environmental event to which Bangladeshis have learnt to adapt. The country regularly gets hit by cyclones which have – in extreme years – caused up to 100.000 deaths. Through the construction of cyclone shelters, a cell-based early-warning system, and investments in education, recent cyclones caused no more than a handful of deaths.

Both floods and cyclones, as well as other phenomena affecting Bangladesh such as coastal erosion, saliniziation, or droughts, are projected to get more severe with progressing climate change. With its position in one of the largest river deltas of the world and just a few meters above sea level, Bangladesh is at the forefront of climate change, offering a glimpse into the near- to mid-term future of other regions on the planet.

As such, it does not come as a surprise that many universities, NGOs, and International Organizations work in Bangladesh to study the impacts of and adaptation to climate change. Likewise, its exposure to climate change was an important factor why we have chosen Bangladesh as the case study for our research project »Climate change, land loss, and migration: Evidence from a quasi-experiment in Bangladesh« (see this post for an intro into the research topic and questions).

Out of the multitude of environmental events occurring in Bangladesh, we focus our research on riverbank erosion and flooding. Flooding happens every year during the monsoon season. In regular years, around 30% of the country’s area are covered by water for some time in July, August, or September. If the monsoon brings a lot of rain, it can flood up to 70% of the country. In Germany, 70% of the country would correspond to the entire area of what used to be West Germany being flooded. Hard to imagine.

In Bangladesh, flooding is seen not only negatively. The flood water brings valuable nutrients and humidity to the agricultural fields, making the delta fertile and productive. If flooding occurs only weakly or not at all, it can result in a reduction of crop yields in the upcoming season. If, by contrast, the flood water stays too long on the fields, it destroys the crops. Moreover, such extreme flood years usually come with more water, increasing the damages to housing and infrastructures such as streets. While regular floods have occurred in Bangladesh throughout its history, severe floods used to be a rare thing, occurring only every ten or twenty years. In recent years, climate change has affected the rainfall patterns during the monsoon, making severe floods happen more often.


When the river eats your house

Closely related with flooding is the phenomenon of riverbank erosion. When the rivers carry more water and gain more force during the monsoon season, they start taking chunks of the riverbank with them. While this happens in many rivers in Bangladesh, it is particularly pronounced along one of the country’s largest streams, the Jamuna River (sometimes also called Brahmaputra). The Jamuna flows through a region with very sandy and hence unstable soil. In some stretches, the river eats several hundred meters of land within one monsoon season. This can make entire villages disappear within a few days.

Riverbank erosion affects between 100.000 and 150.000 people each year in Bangladesh. Most of them lose either their agricultural land, their house, or both. Besides the obvious economic loss (many farmers are subsistence farmers), land also has a high emotional value in Bangladesh. It is passed on from generation to generation. Seeing it eaten up by the river, sometimes also eroding their ancestors’ graves, causes great emotional and mental distress to people.

Although closely linked (erosion occurs mostly at the onset of the monsoon flooding), erosion and flooding have different characteristics which make them an interesting case study for our research. Floods occur every year and throughout the entire river system. Erosion happens much more irregularily, both with respect to geography and time. Most parts of the river see some erosion (up to a few meters a year), but severe events arise only in a handful of hotspots. Usually, erosion occurs several years in a row in one place, before it slows down and a new hotspot emerges elsewhere.

More importantly, erosion affects people differently than flooding. Regular floods have a positive effect on agriculture by fertilizing fields. Material damages occur mostly during severe floods, when there is either a lot of water or when it stays too long. Nevertheless, even a regular flood season is the most challenging time of the year for many people, since the water makes economic activities in the villages mostly impossible. Many households react by moving as a whole or by sending one member to a nearby place to earn some money there until the water has receded.

Erosion, by contrast, permanently destroys land, housing, and infrastructures such as schools, mosques, or roads. In theory, it should thus have a stronger effect on migration moves than floods, given that people irreversibly lose their most important economic resources and/or their homestead. Whether this is actually the case is one of the research questions of our project.


Millions on the move!

By now, it should have become clear that Bangladesh is a prime case to study the effects of environmental and climatic changes. At the same time, it is also a good place to do research about migration. The World Bank Groundswell Report estimates that by 2050, 3.6 to 13.3 million people could migrate within Bangladesh (the huge difference between the two numbers is due to different climate change scenarios).

Migration is, however, not an issue of the future. Already today, around one third of rural households sends individual members to work seasonally in locations with better economic opportunities. The most impressive place to get a feeling for the magnitude of migration in Bangladesh is its capital city Dhaka. Every year, an estimated 400.000 to 800.000 people move to Dhaka, making it one of the fastest growing mega cities of the world. Being the residence of around 20 million people today, Dhaka’s population could rise to 36 to 44 million people by 2050.

Dhaka’s infrastructure is at the limit already today. Hourlong traffic jams are normal, providing drinking water and housing is a challenge, the air quality is regularly ranked among the worst on the planet. So what will happen to the city if its population doubles within the next 30 years? To prepare for the years to come, a more thorough understanding of migration rates, patterns, and motives is quintessential. Only then can appropriate measures be taken to prepare Dhaka, other cities, as well as the regions of origin for the immense challenge posed by these vast projected numbers of migrants.

The evidence collected by our research project will hopefully be relevant not only to Bangladesh, but likewise to other world regions. An interesting aspect of the discussions in the aftermath of the flood catastrophe hitting Germany this summer was the question of planned retreat: Should we rebuild the destroyed villages in the same – risky – locations, or should we declare certain areas as too flood-prone and rebuild the villages in a safer location? Such questions have been discussed for years in Bangladesh and other countries of the Global South. With the rapid escalation of the climate crisis, they are increasingly posed in the Global North. Therefore, it is worthwhile to consider what we might be able to learn from experiences and practices in the Global South:

»We actually don’t expect so many deaths from floods in Bangladesh! We get a lot of floods which cause a lot of damage but we no longer have so many deaths! We would be happy to share our knowledge with Germany!«

Saleemul Huq