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Climate Change, Displacement, and Managed Retreat in Coastal India

Climate Change, Displacement, and Managed Retreat in Coastal India

Source Panda ClimateChange Bishnu Sarangi Pixabay

The Sundarbans region is one of the most hazard-prone areas on the Indian subcontinent. (Photo: Bishnu Sarangi)

India’s coastal regions, home to about 170 million of the country’s 1.4 billion people, are on the front lines of a shifting climate, experiencing sea-level rise, erosion, and natural disasters such as tropical storms and cyclones. The latest evidence of this vulnerability occurred in May 2020, as the strongest storm recorded in decades in the Bay of Bengal—Cyclone Amphan—hit, forcing several million people to evacuate.

India lost 235 square kilometers of land to coastal erosion between 1990 and 2016, placing people’s livelihoods and homes in jeopardy, with flight to safer places occurring voluntarily or, as a last resort, through government intervention. According to the Internal Displacement Monitoring Centre, about 3.6 million Indians were displaced annually between 2008 and 2018, most as a result of flooding from monsoon rains that are the heaviest in South Asia in absolute terms. While most of the existing policies in India address displacement from rapid-onset disasters such as monsoons and cyclones under disaster reduction and rehabilitation policies, displacement due to slow-onset disasters such as coastal erosion has yet to find a place at the policy level. Given the challenges of climate change, the relocation of many human settlements as a pre-emptive disaster management strategy will be unavoidable as the intensity and frequency of disaster increase in the future, requiring a future-looking national-level policy on managed retreat in India.

Special Issue: Climate Change and Migration

This article is part of a special series about climate change and migration.

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Although it is difficult to identify and quantify the monocausality of climate change on human mobility, emerging scientific evidence suggests that human-caused climate change is influencing the pattern of migration and displacement more visibly along the Indian coast. While displacement and migration due to sudden-onset disasters are easy to recognize, it is often harder to examine migration patterns from slow-onset disasters such as sea-level rise. Population displacement due to rising seas is taking place in India, with many families migrating or already relocated to other areas. It is highly likely that climate change may intensify the current pattern of displacement along the coastal areas of India, such as the Sundarbans.

With the global coastal population projected to increase during this century, migration and displacement along coasts will be a costly and permanent consequence of climate change. In fact, 1 billion people around the world now occupy land less than 10 meters above current high-tide lines, and of this number an estimated 230 million live on land less than 1 meter below current high-tide lines, according to a 2019 study on global vulnerability to sea-level rise and coastal flooding. While local-level policies in India have responded to displacement in coastal communities, the response has not addressed many current and future impacts resulting from sea-level rise and coastal flooding. Indeed, Indian and state governments must put forth additional effort to reduce risk, manage retreat for coastal populations pre-emptively, and prepare proactive plans for people at high risk of displacement. India’s current response of segregated planned relocation and strengthening or expanding coastal protective structures through coastal zone management at best can provide only a temporary respite.

This article discusses principles that could inform the design and implementation of policies to manage migration that results from coastal flooding and inundation from coastal areas in India. It does so by analyzing three examples from India’s eastern coast, including displacement from the coastal villages of Odisha, increasing migration from the Sundarbans delta in the state of West Bengal, and decreasing landmass of Majuli island in the state of Assam.

Figure 1. Case Study Areas in Assam, Odisha, and West Bengal, India

Note: The territory in pale purple represents areas long contested by India, Pakistan, and China.

Uneven Climate Change Impacts Along India’s Coastline

India’s more than 7,500 square kilometers of coastline are at high risk for impacts of climate change related to sea-level rise. Sea levels along the Indian coast have risen by 8.5 centimeters during the past 50 years, and scientific prediction suggests that 36 million Indians are likely to be living in areas experiencing chronic flooding by 2100. Yet certain coastal regions are more vulnerable than others, evidenced by multiple, repeated displacements in the same places. Communities along the country’s east coast are exposed to tropical storms from the Bay of Bengal; in the north and northeastern parts of India, the Brahmaputra, Ganges, and Yamuna river basins are also vulnerable to flooding due to erosion. A 2017 study on Indian shoreline change occurring between 1989-2001 revealed the highest percentage of erosion occurred in West Bengal, with change along 70 percent of its coast, followed by Kerala (65 percent), Gujarat (60 percent), and Odisha (50 percent).

Beyond displacement and migration along the eastern coast, sea-level rise and flooding might also lead to increased relocation in major coastal cities. The floods of 2018, which displaced about 1.4 million people in the state of Kerala, offer a reminder of the kind of likely consequences for future displacement if the impacts of climate change increase. Similarly, mega cities such as Mumbai, Chennai, and Kolkata are at high risk of flooding and sea-level rise, with millions living in these urban coastal areas likely to be relocated to safer places in the future. In such circumstances, forced migration and displacement would be inevitable in the absence of well-managed, pre-emptive relocation of populations from high-risk areas.

Managed Retreat Saves Lives and Villages in Odisha

In May 2019, the major cyclone Fani hit Odisha, a state along India’s eastern coast that is home to around 46 million people. State authorities utilized an effective early-warning system to evacuate 1.2 million people in 24 hours—one of the biggest evacuations in history, and subsequently praised by the United Nations. Odisha, which experienced about 10,000 fatalities when a super cyclone hit in 1999, continues to face frequent cyclones and visible impacts of sea-level rise and coastal inundation along its coast on the Bay of Bengal. India’s Ministry of Earth Sciences estimates 28 percent of Odisha’s 550 kilometers of coastline experienced erosion between 1990 and 2016, with half of the coastal line accreting (e.g. its coastal sediment becoming visible).

Odisha witnessed one of India’s first cases of managed retreat after decades of slow shoreline changes and coastal erosion sparked involuntary displacement and migration around several villages in the Kendrapada district. These areas mostly lie around the village of Satabhaya (locally understood as seven villages). As the Satabhaya villages disappeared one by one over the 1980s and 1990s due to cyclones and sea-level rise, the final one going underwater in 2011, the state government started the process of planned relocation around 2011. The situation became so severe that in 2016 the state government established a resettlement colony 12 kilometers away. This was the result of a 2011 resettlement and rehabilitation policy announced by the state government’s Revenue and Disaster Management Department to relocate 571 families using a relief package, citing the “threat perception on account of their close proximity to the sea.” Apart from these 571 families, the plan contemplated rehabilitating 247 houses at the Bagapatia resettlement colony. The families, described by some as India’s first “climate refugees,” were compensated with agricultural plots, housing, and other facilities.

However, planned relocation often involves more complex social, political, and psychological questions that occur during and after relocation, in addition to funding decisions. In pre-emptive planned relocation, questions such as fairness of compensation, land rights, and loss of original livelihoods are hard ones to settle. The case of Odisha, which represents the first case of displacement of Indians from the threats of climate change, is not without its failures. Odisha’s government used its legal authorities to relocate residents from hazard-prone areas. Although the relocation has been praised as an effective strategy, there has been criticism about the resettlement policy, lack of fair compensation and post-settlement livelihoods, and the number of houses being resettled from the original location. While there has been very little academic analysis on the outcome of such displacement, it is clear that if the impacts of climate change worsen, many more people will have to be relocated from the coast at a larger scale and with higher cost.

Despite Planned Relocation, Long-Term Vulnerability on the Rise in the Sundarbans

Compared to Odisha, the Sundarbans in the neighboring state of West Bengal present a more complicated case of migration, climate change, and displacement. The Sundarbans region represents one of the richest ecosystems globally and contains the world’s largest continuous mangrove forest, at nearly 10,000 square kilometers. About 40 percent of the Sundarbans forest lies within West Bengal; the rest is in Bangladesh. The ecosystem directly or indirectly supports the livelihood of more than 1.3 million people, with a population of more than 4.4 million residents. More importantly, it also moderates the physical impacts of cyclones on the region, as with Cyclone Amphan, where the impacts would have been much more severe in Bangladesh had the forest not been there. India’s Sundarbans are characterized by high levels of poverty and exposure to natural hazards. Sea-level rise, soil and water salinization, cyclones, and flooding make this one of the most hazardous areas on the Indian subcontinent. Climate change is likely to further worsen the situation.

However, India’s Sundarbans region—where 54 of the 104 islands are inhabited—has faced the constant threat of sea-level rise and coastal erosion for many decades. Scientific evidence shows that the average yearly sea-level rise along the Sundarbans delta is much higher at 8 millimeters as compared to the global average of 3 millimeters annually; further the Indian part of the Sundarbans and its delta are sinking at a rate of about 2 to 4 millimeters a year. Climate change and sea-level rise, combined with other morphological reasons, led to a staggering land erosion of 170 square kilometers between 1973-2010 along the Sundarbans coastline. Considering the risk from rising seas and coastal inundation, by 2050, an estimated 1 million people will need to relocate from more vulnerable locations of the Indian Sundarbans, and managed relocation will most likely have to be done on a larger scale in the future.

The history of coastal erosion and recognition of the problem goes back to 1977, when the government of West Bengal declared it would withdraw funding support from two of the Sundarbans islands—Ghoramara and Lohachara—because of high rates of erosion there. Lohachara eventually disappeared in 1991, while Ghoramara, about 30 kilometers north of the Bay of Bengal, has seen unprecedented erosion in last few decades. From 26 square kilometers, it has shrunk to around 6.7 square kilometers. Erosion has been rapid during the past four decades, with the population, once around 40,000, now numbering just 5,193, according to India’s 2011 census.

The first case of planned relocation of residents from Lohachara and Ghoramara to a nearby island named Sagar started in the late 1970s, forming the first kind of environmental migrants in the Sundarbans. Resettled residents were provided land and housing under the relocation plan; however, entitlements were reduced over time as available public land in Sagar shrank due to land erosion. Evidence suggests that Sagar itself is now facing disappearance—as sea rise is happening at a rate of 12 millimeters a year—after few decades of serving as a new home for earlier displaced populations. While an important example of managed relocation, this flags the important lesson that if not properly planned, climate-induced change may make current places of relocation vulnerable in the future.

Although, managed relocation enabled people to stay in the Sundarbans, the long-term viability of such an arrangement has come into question. The current development strategy, which encourages migration into the resource-rich area and hampers long-term vulnerability reduction and economic development, will lead to increased human vulnerability to sea-level rise.

Shrinking Fast, Residents of the Majuli Islands Often Become Internally Displaced

Further northeast from the states of Odisha and West Bengal lies Majuli, the world’s largest river island, in the Indian state of Assam along the Brahmaputra valley. Assam state is well known for regular flooding that displaces many millions temporarily: at the peak, 2 million to 3 million people are displaced annually, affecting more than 12 percent of the state’s geographical area. Majuli likewise is severely affected by floods and erosion. In 1951 the island spanned approximately 1,250 square kilometers, with a population of 81,000. During the next 60 years, the population more than doubled to 167,000, but the island had been reduced by two-thirds. Between 1950 and 2016, 107 of the 210 villages on Majuli were partially or completely lost to the river. Others, like Majuli, face the threat of extinction, including surrounding districts on the banks of the Brahmaputra River that are losing lands to floods that also displace people. Experts warn that increased frequency of flooding of the Brahmaputra, along with melting glaciers from the Himalayas, could lead to the disappearance of Majuli by 2040. Local officials estimate 10,000 people have already been displaced in the last 12 years.

The central government, with the help of state governments, has invested resources and funding projects to control erosion by raising embankments and installing a system of river-training supports to capture sediment and slow the river’s flow. But these measures have not proven as effective as expected.

The rising risk of regular floods has contributed to increased migration from Majuli to cities and other areas. Although there is no official number of internal displacement in the region, there is a clear trend of increasing outmigration when adaptation limits are reached. Government officials have largely resorted to a series of technical solutions—riverbank stabilization, creation of embankments at strategic locations, and the establishment of a flood warning system, among them—but there has yet to be consideration of policies such as providing support for the displaced or relocating people from the area.

Toward a Comprehensive Framework on Internal Displacement

Internal migration has been an integral part of the development process in India, and people have long moved within the country for better economic and social opportunities, among other reasons. According to the 2017 Economic Survey of India, the magnitude of interstate migration was close to 9 million people annually between 2011 and 2016, while the 2011 census records the total number of internal migrants at a staggering 139 million—or about 10 percent of the population. Climate change presents an additional stressor to internal migration trends.

At the policy level, there have been very few national-level efforts to plan for residents being displaced from their homes due to climate-related hazards, let alone a comprehensive national-level policy for planned relocation for those affected by climate change. The current legal and institutional frameworks in India do not explicitly recognize people displaced due to climate change or environmental reasons. The current Inter-State Migrant Workmen Act of 1979 (which governs interstate migration) does not have a separate category for people displaced due to climate change hazards nor there have been any amendments to deal with climate migrants.

While most of the sudden-onset displacement caused by cyclones and typhoons is addressed within the legal and institutional provisions of disaster management policies at the state level, India lacks policies for managing displacement and migration arising from slow-onset events such as sea-level rise. More recently, India’s State Action Plans on Climate Change serves as the primary policy document at the subnational level to address vulnerabilities related to climate change and advance necessary infrastructure projects and policies; yet very little focus has been given to displacement due to climate-related hazards. Although separate policies on coastal zone management exist at national and state levels, they barely examine the human impacts of displacement and instead largely focus on the development of climate-resilient infrastructure and other measures such as protective sea walls and dykes.

Future-Minded Policies Are Needed to Mitigate Impacts

With increasing impacts of climate change, countless more people may migrate or be displaced from high-risk areas along the Indian coast. Without concrete climate and development action, many families could be forced to move within their own state or further afield to escape the impacts of sea rise and coastal inundation. The cases highlighted in this article point toward increased internal climate migration over the next decades. While there is still a lack of evidence of direct attribution of climate change to sea-level rise and coastal inundation, there is enough evidence at global and regional levels demonstrating that climate change could potentially displace massive numbers of people if proactive actions are not taken.

Relocating communities from hazard-prone areas is a potentially important adaptation option—if properly managed—to providing alternatives to physical protection. However, relocation programs face many challenges given the large scale of projected displacement and the problems inherent with resettling entire communities. In the three cases presented here, relocation has been undertaken in view of the threat from coastal inundation, flooding, and sea-level rise. Overall, current local and regional policies are not adequate to deal with the challenges of migration and displacement arising from sea rise. The displacement has been addressed mostly as a post-disaster response, while there is a need for more forward-looking national and local polices on pre-emptive managed retreat for at-risk coastal populations.


Agence France Presse (AFP). 2020. “Everything Is Lost”: Life on the Edge of the Brahmaputra. AFP, January 13, 2020. Available online.

Board, Jack. 2020. Climate Change Supercharging Extreme Events, Scientists Say, as “Super Cyclone” Amphan Hits Bangladesh and India. Channel News Asia, May 21, 2020. Available online.

Danda, Anamitra Anurag, Nilanjan Ghosh, Jayanta Bandyopadhyay, and Sugata Hazra. 2019. Managed Retreat: Adaptation to Climate Change in the Sundarbans Ecoregion in the Bengal Delta. Journal of the Indian Ocean Region 15 (3): 317-35.

Dhara, Chirag. 2019. West Bengal’s Climate Chance Conundrum Part III: Extraordinarily Rapid Sea-Level Rise in Sundarbans Turns Families into Refugees. Acclimatise News, March 21, 2019. Available online.

Dutta, M.K., Swapnali Barman, and S.P. Aggarwal. 2010. A Study of Erosion-Deposition Processes Around Majuli Island, Assam. Earth Science India 3 (4): 206-16. Available online.

Ginoya, Namrata, Uttara Narayan, and Jesse Worker. 2019. As India Revises State Climate Plans, Who Should Have a Voice? World Resources Institute blog, July 25, 2019. Available online.

Government of India, Ministry of Finance, Department of Economic Affairs. N.d. Economic Survey of India 2016-2017. Accessed May 20, 2020. Available online.

Harza, S., A. Mukhopadhyay, A.R. Ghosh, D. Mitra, and V.K. Dadhwal, eds. 2017. Environment and Earth Observation: Case Studies in India. Berlin: Springer.

Internal Displacement Monitoring Centre. 2020 India: Country Information. Accessed May 20, 2020. Available online.

Kankara, R.S., M.V. Ramana Murthy, and M. Rajeevan. 2018. National Assessment of Shoreline Changes along Indian Coast, Status Report for 26 Years, 1990-2016. Pallikkaranai, Chennai: Ministry of Earth Sciences, National Centre for Coastal Research. Available online.

Kulp, Scott A. and Benjamin H. Strauss. 2019. New Elevation Data Triple Estimates of Global Vulnerability to Sea-Level Rise and Coastal Flooding. Nature Communications 10 (4844): 1-12. Available online.

Kumari Rigaud, Kanta, et al. 2018. Groundswell: Preparing for Internal Climate Migration. Washington, DC: The World Bank. Available online.

Mohanty, P.C., R.S. Mahendra, R.K. Nayak, and T. Srinivasa Kumar. 2017. Impact of Sea-Level Rise and Coastal Slope on Shoreline Change Along the Indian Coast. Natural Hazards 89: 1227-38.

Mortreux, Colette, Ricardo Safra de Camposa, W. Neil Adger, Tuhin Ghosh, Shouvik Das, Helen Adams, and Sugata Hazra. 2018. Political Economy of Planned Relocation: A Model of Action and Inaction in Government Responses. Global Environmental Change 50: 123-32. Available online.

Office of the Registrar General and Census Commissioner, India. N.d. 2011 Census of India. Updated January 9, 2020. Available online.

Panda, Architesh. 2010. Climate Refugees: Implications for India. Economic and Political Weekly XIV (20): 76-79. Available online.

Rahman, Abdullah F., Danilo Dragoni, and Bassil El-Masri. 2011. Response of the Sundarbans Coastline to Sea Level Rise and Decreased Sediment Flow: A Remote Sensing Assessment. Remote Sensing of Environment 115 (12): 3121-128.

Rahman, Sadiqur. 2020. Sundarbans Shields Southwestern Bangladesh, Again. The Business Standard, May 21, 2020. Available online.

Roychoudhury, Murchana. N.d. Exploring the Environment and Migration Nexus in the Brahmaputra Valley. Kolkata: Mahanirban Calcutta Research Group. Available online.

Sahay, Avijit and Nikhil Roy. N.d. Shrinking Space and Expanding Population: Socioeconomic Impacts of Majuli’s Changing Geography. Focus on Geography. Accessed May 20, 2020. Available online.

Schwartzstein, Peter. 2019. This Vanishing Forest Protects the Coasts—and Lives—of Two Countries. National Geographic, July 2019. Available online.

Singh, Shiv Sahay. 2019. Hungry Tides of the Sundarbans: How the Rising Seas Create Environmental Migrants. The Hindu, November 23, 2019. Available online.

TNN. 2019. Your City May Go Under Water by 2050. TNN, October 31, 2019. Available online.

World Bank. 2014. Building Resilience for Sustainable Development of the Sundarbans, Strategy Report 88061. Washington, DC: World Bank. Available online.