Dhaka, Oct 23 – Increased soil salinity, due to climate change-induced rises in sea-levels, is likely to force nearly 200,000 coastal residents to migrate to inland areas within Bangladesh to find alternative livelihoods, according to a landmark study by researchers at the International Food Policy Research Institute (IFPRI) and The Ohio State University. The study examines, for the first time, the complex relationship between flooding, soil salinity, rural livelihoods, and migration; as well as the probable adaptation strategies.
“Many parts of Bangladesh are under severe threat of future sea-level submergence, but studies show the migratory response to flooding is likely to be minimal, as most farmers have already adapted their
cultivation practices to cope with changes in the frequency and intensity of flooding in this deltaic region. However, our study shows increased soil salinity from rising seas will push nearly 140,000
coastal residents to migrate to another location within their district, and nearly 60,000 would move to alternate districts,” says Valerie Mueller, senior research fellow, IFPRI.
The study shows only a few are likely to migrate to northern areas, while most migrants are likely to enter the capital city of Dhaka, and onward to neighbouring districts in the coastal region.
The study titled “Coastal Climate Change, Soil Salinity, and Human Migration in Bangladesh”, co-authored by IFPRI’s Valerie Mueller (also Assistant Professor, Arizona State University); and Ohio State
University’s Joyce Chen will be published in an upcoming edition of the journal, Nature Climate Change.
The study draws on socio-economic data from the country’s Bureau of Statistics’ Sample Vital Registration System and agricultural production data from Household Income and Expenditure Surveys,
covering nearly half a million coastal households in a year.
The recent United Nation’s Intergovernmental Panel on Climate Change’s (IPCC) report lays bare that a country like Bangladesh is particularly vulnerable to climate change and likely to lose most economically.
Given this, its citizens will need to adopt coping strategies to deal with climate change-induced accelerating sea-level rise, leading to increased inundation and saline contamination of soils. Increased
salinity adversely impacts crop production and income, driving those who rely on it for their livelihood to migrate from coastal to inland areas.
To offset the loss from crop production income, households move to aquaculture, and the findings from the study reveal households who are already engaged in both crop production and aquaculture heavily rely on the latter to buffer adverse environmental conditions.
“As soil salinity increases from low to high salinity levels, we see a nearly 57 percent increase in the share of revenue from aquaculture,” says Mueller. For most households, however, the prohibitive costs
associated with converting cropland to fish ponds deter additional diversification.
Increased aquaculture production in the coast, the study points out, brings more job opportunities, reducing international migration.
“So, people that would normally migrate abroad might be staying to take jobs that were made available by aquaculture production. Also, poorer households affected by the changes may have less money
available for more expensive international migration,” says Chen.
The study finds increasing soil salinity from the lowest to the highest levels observed in the data would likely increase internal migration by nearly 25 percent, while decreasing international migration by 66 percent. The number of migrants who move to a different location within the district is more than double of those who move out of the district.
“Financial constraints limit poor households from moving over longer distances, signalling a trapped population dynamic, raising concerns that the most vulnerable households may be the least resilient in the face of climate change,” adds Chen. Only those with greater financial, human or social capital may take the giant step to move internationally.
Due to a rise in soil salinity, Chittagong and Khulna districts are likely to witness highest within-district additional migration, estimated between 15,000 and 30,000 migrants per year. These two districts also contain the second and third largest cities in the country. Districts without large cities, like Bagerhat, Bhola and Feni generally will expect smaller within-district flows, between 5000 and 15,000, but larger out-of-district flows, particularly to districts with large cities.
“To minimize moving costs, and remain close to family, individuals may move inland where the demand for agricultural labour is relatively unaffected by salinity. However, higher wages and denser labour markets may draw workers instead to urban areas,” says Mueller. With three of the country’s five largest cities in the saline belt, migration may not reduce vulnerability to sea-level rise in the long-run.
According to the study, soil salinity reduces total annual crop revenue: households facing moderate saline contamination earn almost Taka 5,000 (Bangladeshi taka; approximately US $60) or 21 percent less in crop revenue each year, compared to households facing only mild soil salinity. Researchers didn’t find any significant effect of flooding on crop revenue.
Studies show that in another 120 years, coastal areas, currently home to 1.3 billion people, are projected to be inundated by sea level rise. “A two-pronged approach will be necessary to address this
growing concern,” Mueller points out.
“First, government efforts to incentivize individuals that live in these key vulnerable areas to relocate may be necessary, especially to detract movement away from population-dense areas, like Chittagong and Khulna. A study in the Brazilian Amazon suggests that compensation-based resettlement programs can be welfare-enhancing in the short term. Second, policymakers may adopt more forward-looking
development strategies to take advantage of the surplus labour provided by the coastal areas to promote modern economic activities, like manufacturing, in less populated areas,” adds Mueller.
Expanding the demand for labour in modern industries located in secondary towns can sustain job growth as more and more migrants reach these targeted locations. Researchers point out that infrastructure
projects such as embankments and polders may have more limited success; saline contamination increases pressure to increase aquaculture which, in turn, increases the demand for brackish water,
making households reluctant to maintain such infrastructure.
The International Food Policy Research Institute (IFPRI) seeks sustainable solutions for ending hunger and poverty. IFPRI was established in 1975 to identify and analyze alternative national and international strategies and policies for meeting the food needs of the developing world, with particular emphasis on low-income countries and on the poorer groups in those countries. – Staff Reporter
