Sea-Level is Rising

Bangladesh : Predictable Disasters

Feisal Rahman

Nearly two thirds of Bangladesh's land area is less than five metres above sea level. The country's terrain is flat and low-lying, situated in the Delta of three major rivers: the Ganges, Brahmaputra and Meghna. According to the Intergovernmental Panel on Climate Change (IPCC, 2014), 21 million people in Bangladesh will be at risk due to the rising sea level by 2050.

Bangladesh's Ministry of Environment and Forests reckons that the sea-level rise (SLR) will amount to 14 centimetres by 2030, to 32 centimetres by 2050 and to 88 centimetres by 2100. The common perception is that land will be inundated, so people will be displaced. This danger is real, but it is probably overestimated as inundation of mass land area is unlikely (Nishat, 2017; Brammer, 2014). Migration to the cities from the coastal areas, especially Dhaka, the capital, is more likely to be driven by livelihood stress arising from salinisation (the situation is similar on the Indian side of the border).

The country's fresh water supply will be affected as saline water is pushed upstream. The water logging potential will grow. Salinisation will thus affect arable land. It will also affect underground aquifers. Agriculture in coastal areas will suffer.

Salinity is not only increasing because of SLR and tidal surges, however. Other issues matter too. For instance, the Farrakka barrage on the Ganges in India has reduced the inflow of fresh water. Land erosion, land-use change and the construction of embankments and dykes along coasts are adding to the problem.

Climate models, however, show that salinity levels will increase further as the sea level rises. Coastal communities will find it ever harder to get safe water.

The World Health Organisation (WHO) recommends a daily dietary intake of 2.0 grammes of salt. As freshwater sources become scarce, people in the south-west coastal region are forced to drink saline water. A study (Khan ct al, 2011) found that people's daily salt consumption in the Khulna District already amounted to five to 16 grammes of salt from drinking water in the dry season. Such levels of salt consumption are linked to multiple health risks, including hypertension, kidney failure and diarrhoea. Pregnant women are at risk of pre-eclampsia, which may lead to severe headaches, organ damage and even death (Khan et al, 2014). A study commissioned by the World Bank (2015) showed that saltwater consumption during pregnancy is also linked to infant mortality.

Rising salinity, moreover, degrades agricultural land. Accordingly, fields that were historically used to cultivate rice and other crops have been converted into ponds for shrimp farming. This trend is particularly evident in Satkhira, one of the districts most affected by salinisation. In 1975. 80% of the area was used for fields. In 2005, the share was only 15 percent. In the same time span, the area used for shrimp cultivation increased from two percent to 72 percent.

Such developments have serious social implications. Shrimp farming mostly benefits rich farmers, whereas poor farmers and marginalised communities suffer. One reason is that shrimp farming is not as labour intensive as rice farming, so landless labourers and sharecroppers lose out. Eventually, the men are forced to look for work in urban areas, while women are left behind with children and the elderly. In lack of male partners, women become more vulnerable, but their economic activity becomes more important. For obvious reasons, however, there are fewer opportunities to work in agriculture.

Data from 14 districts for the years 1994 to 2010 indicate that crop failures have a strong impact on migration (Gray and Mueller, 2012). Some coastal areas, where three rice harvests were feasible in the past, now only have one crop, mostly because of rising salinity.

Generally speaking, moreover the poor depend more on ecosystem services which are degraded by climate change. For example, the livelihoods of poor communities who rely on the Sundarbans mangrove forest will suffer because of salinisation. Scholars, assessed different aquatic salinity scenarios on behalf of the World Bank (2016). They predict that rising salinity will negatively affect 14 mangrove species, and in particular the valuable Sundari trees. The authors argue that "the greatest negative impacts" will be felt in the poorest sub-districts. The reasons are loss of timber value, reduced honeyproduction and more incidents involving wildlife, including predators such as crocodiles and tigers.

For people's food security, more-over, freshwater fish is very important. Unfortunately, relevant species are affected by salinisation,...


Vol. 50, No.2, Jul 16 - 22, 2017