Salinity intrusion
Water resources will suffer severely from sea level rise, as fresh water availability will be reduced by salinity intrusion. In Bangladesh, particularly in the south, there are severe concerns over fresh water availability. The major rivers of Bangladesh (Padma and Jamuna) are mainly located in central and northern Bangaldesh. In the South, over abstraction of ground water is leading to water deficit, as there is not enough fresh water recharging the aquifers. To add further to the problem, not only is salinity intrusion restricting the amount of fresh water, but also arsenic pollution.
Fisheries and aquaculture
There are currently 124 shrimp processing plants in the coastal zone – there would be much less of these if salinity intrusion hadn’t occurred. Although salinity intrusion has led to loss of biodiversity and loss of fresh water, it has had a major social impact of creating jobs for a substantial amount of people who would otherwise be unemployed. A flood in South-West Bangladesh in 2000 caused damage and losses of at least US$500 million to crops, fish farmers, property and infrastructure. The shrimp sector was the most affected sector, losing shrimp fields of equivalent US$230 million.
So, although sea level rise is having a social and environmental positive impact (creating jobs and shrimp fields), it is still a regressive act as the shrimp fields and infrastructure is being lost because of sea level rise. A shrimp farmer expressed “I have lost up to 400 million taka (US$7.4 million) invested in 40 shrimp projects, maybe I will never be well off again”. The economic impact of shrimp destruction is not only at local level – it will destroy the prospective foreign exchange earning sector of Bangladesh nationally
Impacts on agriculture
Salinity intrusion due to sea level rise will decrease agricultural production by unavailability of water and soil degradation. Ali (2005) investigated the loss of rice production in a village of Satkhira district and found that rice production in 2006 had declined by 69% of that in the year 1985. In addition to this, there is a further decrease in rice production because of the practicing of shrimp cultivation in saline water. At this present time, sea level rise is only affecting agricultural production in coastal areas. However, if sea levels continue to rise, crops inland will start to be affected by sea level rise. A study by BARC (1999) concluded that salinisation will cause a reduction of wheat production equivalent to US$ 586.75 million. Such loss of food could lead to Bangladesh failing to obtain food security.
Sea level rise > saline intrusion > Decreased agriculture > Decreased GDP > Decreased food production > Food shortage > Health hazards (or even famine) > High poverty > Aid from other countries
As you can see from the above, there is a vicious domino effect of social, economic and environmental impacts that will be hard to get out of just because of sea level rise.
Landmass and settlement
· Sea level rise of 0.1m will inundate 2,500km2
· Sea level rise of 0.3m will inundate 8,000km2
· Sea level rise of 1.0m will inundate 14,000km2
The potential land loss estimated by IPCC is even worse. It reports 29,864km2 area of land will be lost and 14.8 million people will be landless by a 1m sea level rise. Bangladesh has a population pressure, with an estimated population of 158 million (July 2011). Land stress is already a problem. If vast areas of land, such as that predicted by the IPCC, is actually lost, then there will be not enough land to house 14.8 million people. Bangladesh could face a crisis of whereby they will start to suffer from environmental refugees. Will India accept them when they have the same problems as Bangladesh, and have many tensions between them (such as the Farakka Barrage). The geology of Bangladesh’s coastal area does not help matters either. They are formed of silt and sandy soils which make them vulnerable to sea level rise, as they are easily eroded. A study by Hutton and Haque (2003) observed that some people were displaced ten times during the period of 1981-1993 because of erosion on coastal areas. Such erosion not only caused social upheaval because people lost their homes multiple times, but also financial loss for the displaced people to build their new homes.
Tourism
A significant part of Bangladesh coast is sandy beaches that attract tourists. Five of Bangladesh’s tourists spots are located in the coastal zone. All the tourist facilities in the coastal zone will be affected by sea level rise directly or indirectly. The tourism sector of Kuakata will suffer most because all the facilities are very close to the coastline. However, all the other four areas are highly vulnerable in terms of sea level rise. 19% of foreigners visiting Bangladesh are tourists. At national level, the tourism industry serves the nation with economic development. At local level, it helps to strengthen local economy, culture and heritage. As mentioned previously, tourism will not just be affected directly (e.g. loss of buildings). People’s perception and the perceived threat of sea level rise is enough to force tourists to choose other holiday destinations.
Health
Sea level rise may increase the risk of health hazards like diarrhoea and cholera, which can be fatal. Vibrio cholerae is the causing microbe of cholera that survives longer with high salinity levels. For this reason, the coastal area is a breeding and nursery ground of the cholera disease. Outbreaks of cholera in Bangladesh often occur after flooding, because the water supply becomes contaminated with sea water. Thus, sea level rise, by increasing flood risk, increases the risk of cholera outbreak too. Increased unavailability of fresh water will force people to drink contaminated water leading to cholera, diarrhoea and other water born diseases. Again, increased salinity in the coastal zone will decrease food production in the area, casing malnutrition for the coastal people.
Ecosystem
The Sundarbans is the largest single block of tidal halophytic mangrove forest in the world. According to the World Bank (2000), the Sundarbans will be completely lost with 1 metre sea level rise. Loss of this means great loss of heritage, loss of biodiversity, loss of fisheries resources, loss of life and livelihood and after all loss of a very highly productive ecosystem. Its biodiversity is its key quality – it is the hotspot for vast amounts of flora and fauna. It is the last habitat of Royal Bengal Tiger. It has many other species all listed in the IUCN red book, such as the fishing eagle and the critically endangered River Terrapin. Sea level rise will also decrease the availability of light for corals, affecting photosynthesis. Decreased rates of photosynthesis will decrease the growth of corals, causing destruction of St. Martin’s island, the only highly productive coral island of the country.
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