Where the Salt Is

Executive Summary. Approximately 5.26 million Bangladeshis live below five metres of elevation on land that already absorbs the leading edge of sea-level rise, salinity intrusion, and cyclone landfall. Bangladesh's contribution to global greenhouse emissions is 0.2 percent; its adaptation problem is among the largest in the world. Current adaptation spending is USD 1 billion per year against USD 2 billion in annual flood-and-cyclone damage tracked by CEGIS and a triage requirement on the order of USD 3 to 4 billion per year. The Tarique Rahman government's 180-day plan does not name climate adaptation as a priority; the FY27 budget later this year decides whether this stays a residual category or becomes a national-security file.

Late January 2026 in a union of Shyamnagar upazila in Satkhira, on the seaward edge of the Sundarbans, the boro sowing window is closing. A rice farmer named Sahabul Karim is standing in a half-prepared field watching his nephew test the soil's salinity with a small handheld meter borrowed from the local NGO office. The reading is 6.2 deciSiemens per metre. At that level, most conventional boro paddy varieties suffer fifty to seventy percent yield depression in the seedling and tillering stages. The Bangladesh Rice Research Institute has released a series of salt-tolerant varieties precisely for these soils: BRRI dhan47, BRRI dhan67, BRRI dhan73, BRRI dhan78. The institute's research stations at Satkhira and Kalapara have shown that BRRI dhan78 maintains 3.5 to 4.0 tonnes per hectare at salinity levels that drop the conventional varieties below 1.5.

Sahabul has not received any BRRI dhan78 seed this season. The upazila agriculture office issued a circular in November announcing it would be available. The seed arrived at the union parishad office three weeks after the optimum transplanting date. The farmers who collected it are using it for next year because using it now would mean missing the entire boro cycle.

This is the third year Sahabul has tried to obtain BRRI dhan78 on time and failed. His paddy yield in this field has fallen from approximately 4.6 tonnes per hectare in the 2018 boro season to roughly 2.8 tonnes per hectare in 2024. He has two more seasons before the field is uneconomical for rice. His eldest son moved to a Mirpur garments factory in 2023. His youngest son is in Class 8 and has been told by his father that the family expectation is that he will leave the union after SSC.

The salt is here. The seed exists. The state has not connected them.

The number that matters and the number that does not

Bangladesh's contribution to global greenhouse gas emissions is approximately 0.2 percent of the global total. Per-capita carbon dioxide emissions are around 0.52 tonnes, among the lowest in any sizeable country. Whatever we do or do not do on the mitigation side, our marginal impact on the global temperature trajectory rounds to zero. This is not a moral statement; it is an arithmetic statement. The country's climate problem is not what we put into the atmosphere. It is what the atmosphere is doing to a delta with 1,265 people per square kilometre.

The vulnerability numbers are large. Approximately 5.3 million Bangladeshis live in the low-elevation coastal zone below five metres of elevation, by GIS measurement aggregated from coastal-elevation data. The five-metre LECZ covers approximately 50,317 square kilometres of land, about a third of the country's total land area. The under-one-metre band covers 41,958 square kilometres. The ten-metre band covers 65,310 square kilometres.

The sea is rising in the Bay of Bengal at approximately 3.5 millimetres per year, slightly above the global average because of the regional tide-gauge and subsidence pattern. Land surface temperature in the country has risen by approximately one degree Celsius since 1900, observed at Bangladesh Meteorological Department stations. Monsoon rainfall has increased by roughly ten percent over the modern record; dry-season rainfall has decreased by roughly fifteen percent. Approximately twenty percent of the land area is annually flood-affected on average. Major cyclones make landfall on a three-year average frequency.

Salinity projections published in peer-reviewed work indicate a median 26 percent increase in coastal salinity by 2050, with the most exposed areas above 55 percent; salinity intrusion is on a path to reach Dhaka's water supply by the same horizon.

The displacement numbers are real. The International Organization for Migration's 2023 country estimate put internal climate-related displacement in Bangladesh at approximately seven million people on a cumulative basis. Most of the moves are short-distance, into peri-urban Khulna, Chittagong, Mongla, Patuakhali, and from there progressively into the slum-bordered margins of Dhaka. The visible end of the displacement is the Sahabul households whose teenage children have moved to Mirpur garments factories or to Cox's Bazar tourism work. The invisible end is the field that goes uneconomical, the village that loses its primary school because enrollment collapses, the union parishad that loses its tax base.

Two facts have to be held together. First, our mitigation effort is marginal because our emissions are marginal. Second, our adaptation problem is one of the largest in the world because the geography is unforgiving and the density is high. The policy implication of holding both facts together is that the climate file is not primarily an international advocacy file. It is an internal triage file.

What internal triage looks like

There are three lines on the triage map and the country has not built any of them at scale.

The first is in-place adaptation: the technical and infrastructural work that keeps Sahabul's field productive for the next twenty years rather than the next five. This is salt-tolerant rice variety distribution that actually arrives at the union parishad before the sowing window closes. It is rationalised polder management with the Water Development Board's khals and sluice gates maintained on a schedule rather than rebuilt after each cyclone breach. It is brackish-water aquaculture conversion subsidies that let farmers shift from monsoon-rice plus dry-season-rice to a shrimp-cum-bagda cycle when the salinity gradient passes the conventional crop threshold. It is rainwater-harvesting infrastructure that gives coastal households a dry-season drinking-water source that is not the deepening tube-well chasing receding fresh-water lenses. None of these is technically novel. All of them require institutional execution that has not happened.

The second is managed retreat: the deliberate, planned, compensated relocation of households and infrastructure from the polders and shoreline strips that the adaptive infrastructure cannot save on a 30-year horizon. The current pattern is distress-driven outmigration in which the family abandons the field and the village without compensation, the male wage-earner finds informal-sector work in Khulna or Dhaka, and the household ends up in peri-urban tenancy with no land title and no economic anchor. The alternative is structured: land-for-land or land-for-cash conversions in receiving areas (Khulna metropolitan area, Mongla economic zone, peri-Chittagong, the Faridpur belt), with portable land titles, transfer of agricultural extension and stipend programmes to the receiving area, and explicit decommissioning of the polder embankment maintenance budget once the area is depopulated. This is politically difficult because it admits that some land will be returned to the sea. It is economically inevitable because the alternative is the same outcome reached through repeated reconstruction cycles that the budget cannot sustain.

The third is upstream investment that pre-positions the receiving infrastructure: the housing stock, school capacity, health facility capacity, drainage and water supply that the climate-displaced households will need in the receiving areas. The current Khulna metropolitan plan assumes a population growth trajectory that significantly under-projects the climate-displacement inflow. The current peri-Chittagong land-use plan has the same gap. The Greater Faridpur belt has been identified in successive long-term plans as a strategic receiving area for inland migration; the infrastructure to make it absorptive at the projected scale has not been built. The political economy of receiving-area investment is hard because the visible voters are the existing residents, not the future climate migrants, and infrastructure pre-positioned for future demand is easy to defer through one budget cycle after another.

The institutional gap

The state machinery to deliver internal triage exists in pieces and is not assembled. The Ministry of Disaster Management and Relief responds after the cyclone hits and the embankment breaches. The Bangladesh Water Development Board maintains the polders and the embankments. The Department of Agricultural Extension distributes (or fails to distribute) the salt-tolerant rice seed. The Ministry of Environment, Forest and Climate Change holds the international climate-finance file and produces the NDC documents and the national adaptation plans. The Bangladesh Climate Change Resilience Fund and the Bangladesh Climate Change Trust Fund hold pools of domestic and pooled donor money. The Local Government Engineering Department and the city corporations of Khulna, Chittagong, Mongla, and Cox's Bazar handle receiving-area infrastructure.

None of these institutions is responsible for the triage map. There is no single agency whose mandate is to look at Sahabul's field in Shyamnagar, decide whether it can be saved with adaptation or has to be retreated from, and execute the relevant programme. The result is that all five institutions operate within their narrow mandate and the strategic question goes unanswered. The adaptation spending tracked by MoEFCC is approximately USD 1 billion per year, of which a substantial share is donor-funded. Estimated loss and damage costs run higher; the CEGIS framework places annual cyclone-and-flood economic damage at roughly USD 2 billion per year on a long-run average. The gap between adaptation spending and damage realisation is the part that nobody is making smaller.

The institutional reform required is the creation of an integrated Climate Adaptation and Resettlement Authority, with statutory mandate to operate across MoEFCC, WDB, DAE, MoDMR, the LGED, and the relevant city corporations on triage planning at union and upazila granularity. The institutional precedent exists in the form of the post-2008 Bangladesh Climate Change Strategy and Action Plan governance structure that was supposed to do something like this and did not. The post-2024 reform window, which the Tarique Rahman BNP government (sworn in on February 17) has inherited from the Yunus interim period, is the opportunity to build the institution with the authority and the budget envelope to actually operate.

The Tarique Rahman government's published 180-day priority plan does not include climate adaptation among its four named priorities (law and order, essential-goods prices, electricity and gas, and railway connectivity). The omission is itself the relevant political fact. The scientific case has been made for two decades; the institutional case has been made for one; the budget case is being made now in the first BNP-era fiscal cycle. The CEGIS-tracked annual flood-and-cyclone damage of roughly USD 2 billion is roughly the same magnitude as the Tarique government's projected FY26 savings from the IPP renegotiation discussed in the fourth piece in this series. The fiscal envelope released by power-sector reform is approximately the right size to fund the missing adaptation budget. Whether that connection is made in the FY27 budget tabled later this year is the test of whether the climate file is treated as a long-arc national-security question or as a residual category of the development budget. The Sundarbans, on which approximately 10 million coastal residents depend directly, sits in the middle of both the sea-level-rise and salinity trajectories.

What it costs and what it buys

The annual incremental cost of internal triage, if executed seriously over a fifteen-year horizon, is on the order of USD 3 to 4 billion per year in 2026 prices, against the current adaptation-spending baseline of USD 1 billion. That is roughly 0.7 to 0.9 percent of GDP, similar to the bank-recapitalisation magnitude described in the second piece in this series. The composition is approximately one-third in-place adaptation, one-third managed-retreat-and-compensation, and one-third receiving-area infrastructure.

The international climate finance contribution to this number, at current realisable pledges and disbursement velocities, is on the order of USD 1 to 1.5 billion per year. The Loss and Damage Fund agreed at COP28 and the new collective quantified goal negotiations may eventually raise this number, but the operational realisation on the disbursement side has historically been a fraction of the headline pledge. The gap that has to be filled from domestic resources is something like USD 1.5 to 2 billion per year, or roughly 0.4 to 0.5 percent of GDP. This sits inside the fiscal space that opens up if the property-tax and VAT reforms described in the first piece in this series are executed.

What the spending buys is two things. First, the prevention of the unmanaged collapse scenario in which the receiving areas are overwhelmed by distress migration on a timetable they cannot absorb, the urban informal sector swells to a point where it cannot be absorbed by formal-sector job growth, and the political-economy stress of large unintegrated populations in peri-urban Dhaka, Chittagong, and Khulna creates governance instability beyond the climate file itself. Second, the preservation of agricultural productive capacity in the parts of the coastal belt that can be kept productive with adaptation, which preserves the rural-economy base and the food-security buffer that the country has depended on for the entire post-independence period.

The alternative to internal triage is not preservation of the status quo. The alternative is the same outcome reached chaotically rather than deliberately, twenty years from now rather than continuously over the next twenty, with the costs concentrated on the receiving urban areas rather than distributed across the planning horizon.

The series, and Sahabul's field

Six reforms have been described in this series. Tax mobilisation, the foundation that pays for everything else. Banking recapitalisation, the financial-system precondition for productive credit. LDC-graduation cushioning, the diplomatic file that protects the export base. Energy transition, the industrial-policy file that determines whether the manufacturing base can move up the value chain. Education quality, the human-capital file that determines whether the demographic dividend translates into productivity. Climate adaptation, the geographic file that determines whether the parts of the country we cannot relocate are kept liveable.

Each of these reforms has a binding constraint that is not analytical: the reforms have been studied; the data is available; the policy texts have been drafted. Each of them has a binding constraint that is political: the reforms require asking concentrated interest groups to pay for diffuse public goods, and the political economy of asking has not been resolved by any government in the last twenty years.

The BNP government has roughly twelve months from its February inauguration to commit publicly to the package and roughly five years to execute the first half of it visibly enough that the second half becomes politically self-sustaining. The reforms are interdependent: without tax revenue, the banks cannot be recapitalised; without recapitalised banks, the energy transition cannot be financed; without the energy transition, the post-LDC industrial upgrading cannot happen; without the industrial upgrading, the education investments cannot translate into the labour market; without the demographic dividend playing out productively, the climate file cannot be financed at the scale required. Each reform's success is each other reform's precondition.

Sahabul's field in Shyamnagar is the smallest unit on the policy map. The seed that did not reach him is one administrative failure. The salt that has come is one geographic fact. The country that has the analytical capacity to know exactly what to do for him and has not done it is the country that the reform stack in this series is trying to repair. The work is not impossible. The work has not been started.

Sources

• bdpolicylab GIS, low-elevation coastal zone area and population at 5 m. Internal: data/bdpolicy.db series 1348-1353.
• Bangladesh Meteorological Department, temperature and rainfall trend series. bmd.gov.bd
• Intergovernmental Panel on Climate Change, AR6 Working Group I (regional sea-level rise estimates). ipcc.ch/report/ar6/wg1
• International Organization for Migration, Bangladesh internal displacement country estimate, 2023. iom.int/countries/bangladesh
• CEGIS, annual flood and cyclone economic damage assessments. cegisbd.com
• BRRI salt-tolerant rice varieties (BRRI dhan47/67/73/78) research station performance. brri.gov.bd
• Sea-level rise drivers (climate change, freshwater inflow): Salinity dynamics in the Sundarbans of Bangladesh. pmc.ncbi.nlm.nih.gov/articles/PMC12537767
• Coastal salinity drivers: What drives changes in surface water salinity in coastal Bangladesh? Frontiers in Water. doi.org/10.3389/frwa.2024.1220540
• COP28 Loss and Damage Fund, operational status. unfccc.int
• MoEFCC, Bangladesh Climate Change Resilience Fund and Climate Change Trust Fund disbursement reports. moef.gov.bd