Climate change is not only altering weather patterns but also accelerating sea-level rise, leading to increased inundation and saline contamination of soils. Given projected sea-level rise, it is imperative to examine the extent to which farmers in coastal Bangladesh can adapt by diversifying economic activities before resorting to migration within and across borders. Here, to identify patterns in how households adapt to increased sea/freshwater flooding and soil salinity, we analyse nationally representative socioeconomic and migration data against a suite of environmental variables constructed at the sub-district level. Our results show that inundation alone has negligible effects on migration and agricultural production. However, gradual increases in soil salinity correspond to increasing diversification into aquaculture and internal migration of household members. Salinity is also found to have direct effects on internal and international migration even after controlling for income losses, with mobility restricted to certain locations within Bangladesh. Our study suggests that migration is driven, in part, by the adverse consequences of salinity on crop production.
Subscribe to Journal
Get full journal access for 1 year
only $4.92 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
The datasets generated during the current study and Stata dofiles utilized in the analysis are available upon request from the corresponding authors.
Clark, P. et al. Consequences of twenty-first-century policy for multi-milliennial climate and sea-level change. Nat. Clim. Change 6, 360–369 (2016).
Yu, W. H. et al. Climate Change Risks and Food Security in Bangladesh (Earthscan, Washington DC, 2010).
Gray, C. & Mueller, V. Natural disasters and population mobility in Bangladesh. Proc. Natl Acad. Sci. USA 109(16), 6000–6005 (2012).
Lu, X. et al. Unveiling hidden migration and mobility patterns in climate stress regions: a longitudinal study of six million anonymous mobile phone users in Bangladesh. Glob. Environ. Change 38, 1–7 (2016).
Call, M., Gray, C., Yunus, M. & Emch, M. Disruption, not displacement: environmental variability and temporary migration in Bangladesh. Glob. Environ. Change 46, 157–165 (2017).
Chen, J. J., Mueller, V., Jia, Y. & Tseng, S. K.-H. Validating migration responses to flooding using satellite and vital registration data. Am. Econ. Rev. 107, 441–445 (2017).
Banerjee, L. Effects of flood on agricultural productivity in Bangladesh. Oxf. Dev. Stud. 38, 339–356 (2010).
Alauddin, M. & Sharma, B. R. Inter-district rice water productivity differences in Bangladesh: an empirical exploration and implications. Ecol. Econ. 93, 210–218 (2013).
Alauddin, M., Amarasinghe, U. & Sharma, B. Four decades of rice water productivity in Bangladesh: a spatio-temporal analysis of district level panel data. Econ. Anal. Policy 44, 51–64 (2014).
Alpuerto, V.-L. E. B., Norton, G. W., Alwang, J. & Ismail, A. M. Economic impact analysis of marker-assisted breeding for tolerance to salinity and phosphorous deficiency in rice. Appl. Econ. Perspect. Policy 31, 779–792 (2009).
Hauer, M. E. Migration induced by sea-level rise could reshape the US population landscape. Nat. Clim. Change 7, 321–325 (2017).
Fussell, E. Oxford Handbook of the Politics of International Migration (eds Rosenblum, M. R. & Tichenor, D. J.) Ch. 1 (Oxford Univ. Press, New York, 2012).
Feng, S., Krueger, A. B. & Oppenheimer, M. Linkages among climate change, crop yields and Mexico–US cross-border migration. Proc. Natl Acad. Sci. USA 107, 14257–14262 (2010).
Cai, R., Feng, S., Oppenheimer, M. & Pytlikova, M. Climate variability and international migration: the importance of the agricultural linkage. J. Environ. Econ. Manage. 79, 135–151 (2016).
Cattaneo, C. & Peri, G. The migration response to increasing temperatures. J. Dev. Econ. 122, 127–146 (2016).
Xu, H. Modification of normalized difference water index (NDWI) to enhance open water features in remotely sensed imagery. Int. J. Remote Sens. 27, 3025–3033 (2006).
Ji, L., Zhang, L. & Wylie, B. Analysis of dynamic thresholds for the normalized difference water index. Photogramm. Eng. Remote Sensing 75, 1307–1317 (2009).
Ogilvie, A. et al. Decadal monitoring of the Niger inner delta flood dynamics using MODIS optical data. J. Hydrol. (Amst.) 523, 368–383 (2015).
Saline Soils of Bangladesh (Soil Resource Development Institute, 2012).
Welch, J. et al. Rice yields in tropical/subtropical Asia exhibit large but opposing sensitivities to minimum and maximum temperatures. Proc. Natl Acad. Sci. USA 107, 14562–14567 (2010).
Dodd, I. & Perez-Alfocea, F. Microbial amelioration of crop salinity stress. J. Exp. Bot. 63, 3415–3428 (2012).
Yan, N., Marschner, P., Cao, W., Zuo, C. & Qin, W. Influence of salinity and water content on soil microorganisms. Int. Soil Water Conserv. Res. 3, 316–323 (2015).
Azad, A. K., Jensen, K. R. & Lin, C. K. Coastal aquaculture development in Bangladesh: unsustainable and sustainable experiences. Environ. Manage. 44, 800–809 (2009).
Higgins, S. A. et al. InSAR measurements of compaction and subsidence in the Ganges-Brahmaputra Delta, Bangladesh. J. Geophys. Res. Earth Surf. 119, 1768–1781 (2014).
Black, R., Bennett, S. R., Thomas, S. M. & Beddington, J. Migration as adaptation. Nature 478, 447–449 (2011).
Islam, A. S., Bala, S. K. & Haque, M. A. Flood inundation map of Bangladesh using MODIS time-series images. J. Flood Risk Manag. 3, 210–222 (2010).
National Research Council NOAA’s Role in Space-Based Global Precipitation Estimation and Application (National Academies, Washington DC, 2007).
Tarek, M., Hassan, A., Bhattacharjee, J., Choudhury, S. & Badruzzaman, A. Assessment of TRMM data for precipitation measurement in Bangladesh. Meteorol. Appl. 24, 349–359 (2017).
Rosenzweig, M. R. & Binswanger, H. P. Wealth, weather risk and the composition and profitability of agricultural investments. Econ. J. (Lond.) 103, 56–78 (1993).
Ahmed, R. & Karmakar, S. Arrival and withdrawal dates of the summer monsoon in Bangladesh. Int. J. Climatol. 13, 727–740 (1993).
We thank K. Dotzel, Y. Jia, M. Kedir and S. Vallury for research assistance and S. K.-H. Tseng for sharing his code; C. Kinnan and participants of the National Socio-Environmental Synthesis Center (SESYNC) Pursuit Working Group on ‘A Forecast of the Timing, Locations, Sequence and Likeliest Destinations of Populations Displaced by Sea Level Rise and Coastal Extremes’ for providing constructive feedback on earlier versions of the manuscript. Financial support from the National Science Foundation via the Belmont Forum/IGFA Program (ICER-1342644) and the SESYNC Pursuit programme is acknowledged.
The authors declare no competing interests.
Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Chen, J., Mueller, V. Coastal climate change, soil salinity and human migration in Bangladesh. Nature Clim Change 8, 981–985 (2018). https://doi.org/10.1038/s41558-018-0313-8
Bridging Rare and Abundant Bacteria with Ecosystem Multifunctionality in Salinized Agricultural Soils: from Community Diversity to Environmental Adaptation
Current Opinion in Environmental Sustainability (2021)
Sowing Date and Genotype Influence on Yield and Quality of Dual-Purpose Barley in a Salt-Affected Arid Region
Journal of Soil Science and Plant Nutrition (2021)
Remote Sensing in Earth Systems Sciences (2021)