1 Introduction
According to the Third Assessment Report of IPCC, South Asia is the most vulnerable region of the world to climate change impacts (McCarthy et al., 2001). The international community also recognizes that Bangladesh ranks high in the list of most vulnerable countries on earth. Bangladesh’s high vulnerability to climate change is due to a number of hydro-geological and socio-economic factors that include: its geographical location in South Asia; its flat deltaic topography with very low elevation; its extreme climate variability that is governed by monsoon and which results in acute water distribution over space and time; its high population density and poverty incidence; and its majority of population being dependent on crop agriculture which is highly influenced by climate variability and change. Despite the recent strides towards achieving sustainable development, Bangladesh’s potential to sustain its development is faced with significant challenges posed by climate change (Ahmed and Haque, 2002). It is therefore of utmost importance to understand its vulnerability in terms of population and sectors at risk and its potential for adaptation to climate change. Increased climate variability means additional threats to drought-prone environments and is considered a major crop production risk factor.
The impact of climate variability and change on agricultural production is a global concern. However, the impact is particularly important in Bangladesh where agriculture is the largest sector of economy, accounting for some 35 percent of GDP and 63 percent of the labor force (Ahmed, 2004). Agriculture in Bangladesh is already under pressure from increasing demands for food and the parallel problems of depletion of agricultural land and water resources from overuse and contamination. Climate variability and projected global climate change makes the issue particularly urgent.
Adaptation to climate change is one of the approaches considered likely to reduce the impacts of long-term changes in climate variables. Adaptation is a process by which strategies to moderate and cope with the consequences of climate change, including climate variability, can be enhanced, developed and implemented. Obviously, many countries already are adapting to current climatic events at national, provincial, state, district and local levels in short-, medium- and long-term time frames.
However, in the past, many structural, physical and institutional adaptation mechanisms, implemented through conventional top-down approaches, lacked community participation and livelihood focus. Appropriate adaptation strategies also require balancing the need to reduce climate change impact with any constraints in national policy-making processes. The objectives of this seminar paper are to highlight the impact and adaptation to climate change in Bangladesh.
2 CLIMATE CHANGE SCENARIOS EXPERIENCE IN THE USE OF MODELS
Since climate change is a dynamic phenomenon, changes will occur over time, and implications will only be understood in future, it is not possible ‘to define a changing climate’ that might occur ‘within a defined period in future’. In order to appreciate changing climate over a geographic region and/or a country, efforts are made to ‘define one or more scenarios of a changing climate’ in relation to the area in question.
For Bangladesh, efforts have been made to develop climate change scenarios using various generic methods. In early stages of assessing climate change impacts, in absence of appropriate models and modeling facilities, researchers have used ‘expert judgments’ to come up with climate scenarios. With the proliferation of computer assisted Atmosphere-Ocean Global Circulation Models (AOGCM), scientifically more rigorous and acceptable scenarios have been developed in the second stage. Only in recent times, with further development of regional models as well as strengthening of computational capabilities, scenarios have been developed by using Regional Climate Models (RCM).
Ahmed and Alam (1998) reproduced the climate change scenarios, which were largely used for a number of subsequent national assessments. It was reported that the average increase in temperature would be 1.3oC and 2.6oC for the two projection years, 2030 and 2075, respectively. It was found that there would be a seasonal variation in changed temperature: 1.4oC change in the winter and 0.7 oC in the monsoon months in 2030. For 2070 the variation would be 2.1oC and 1.7 oC for winter and monsoon, respectively. It was reported that the winter rainfall would decrease at a negligible rate in 2030, while in 2075 there would not be any appreciable rainfall in winter. On the other hand, monsoon precipitation would increase at a rate of 12 per cent and 27 per cent for the two projection years, respectively. Table 1 summarizes the climate change scenarios developed by Ahmed and Alam (1998).
Table 1. Outputs of GCM exercise using GFDL transient model (Ahmed and Alam, 1998) Year | Average Temperature | Temperature increase | Average Precipitation | Precipitation increase | | Winter | monsoon | average | Winter | monsoon | average | Winter | monsoon | average | Winter | monsoon | average | | (°C) | (°C) | mm/month | mm/month | 1990 | 19.9 | 28.7 | 25.7 | 0.0 | 0.0 | 0.0 | 12 | 418 | 179 | 0 | 0 | 0 | 2030 | 21.4 | 29.4 | 27.0 | 1.3 | 0.7 | 1.3 | 18 | 465 | 189 | +6 | 47 | 10 | 2075 | 22.0 | 30.4 | 28.3 | 2.1 | 1.7 | 2.6 | 00 | 530 | 207 | -12 | 112 | 28 |

3 Climate Change Impacts in Bangladesh
The impact of climate change is a global concern. It also a great threat for Bangladesh. The fluctuation of climatic components has negative impacts on low lying landmasses like Bangladesh. Increased climate variability means additional threats to environments and is considered a major crop production risk factor also.
3.1 Hydro-geomorphic Contexts of Climate Related Impacts in Bangladesh
Bangladesh is located between 20o34/ to 26o38/ North latitude and 88o01/ to 92o42/ East longitude. It is bordered on the west, north and east by India, on the south-east by Myanmar and on the south by the Bay of Bengal. The country occupies an area of 147,570 sq. km (BBS, 2005). Geologically it is a part of the Bengal Basin which has been filled by sediments washed down from the highlands on three sides of it, especially from the Himalayas. A network of rivers originated in the Himalayas flow over the country that carry sediments (the building blocks of the landmass of the delta). The major river systems of the eastern Himalaya (the Ganges, the Brahmaputra, and the Meghna (GBM) their tributaries and distributaries crisscross the floodplains (Figure 1).

Figure 1. The River Systems of Bangladesh (Halcrow, 2004)
The country consists of low and flat land formed mainly by the sediments carried by the Ganges and the Brahmaputra River systems except for the hilly regions in the north-eastern and south-eastern parts. From physiographic point of view, about 80 per cent of the land is floodplains with very low mean elevation above the sea level with the rest made up of hills and elevated lands. Topography of the country is characterized by very low differences in the elevation between adjoining ridge tops and depression centres, which range from less than 1 meter on tidal floodplains, 1 to 3 meters on the main river and estuarine floodplains, and up to 5 to 6 meters in the Sylhet Basin in the north-east (Rashid, 1991). The physiography of the country is exhibited in Figure 2.

Figure 2. Physiography of Bangladesh (Halcrow, 2004)
3.2 Water Resources: Current Status and Availability as Against Climate Variability
In terms of per capita water availability the country fares well compared to many other countries. However, due to high seasonal variability in terms of water availability, ecosystem and human activities suffer considerably because of reduced availability of water in the dry season. It is anticipated that the current sufferings due to lower water availability in the dry season will be accentuated not only by climate change, but also by increase in demand exerted by increased population.
Generally, the country is highly prone to natural hazards. In most cases, however, disasters are manifested as hydrological events caused by climatic extremes (Khan, 2000). The country’s geographical location, high dependence on the overall GBM regional hydrology, spatial and temporal distribution of water resources all contribute to the high degree of susceptibility of Bangladesh to water-related extreme events (Ahmed and Alam, 1998). In order to appreciate the future vulnerabilities to climate change, it is necessary to understand the interrelationship between climatic regime and associated risks in the form of water-related disasters. A combination of upstream inflows and runoff generated from rainfall within the country feed all the rivers, canals, creeks, beels, natural and man-made seasonal and/or perennial reservoirs (i.e., haors, baors, dighees and ponds), and all other forms of water bodies which constitute the natural surface water resources in Bangladesh. The major water bodies provide a dense network of river systems. According to preliminary estimates, the cross-border annual flows into the country amount to around 1010 billion cubic meters (BCM), and an additional amount of 340 BCM is generated from local rainfall, considering an average of about 2300 mm per annum (Halcrow , 2004). Of this total quantum of available water (1350 BCM), about 190 BCM of water is lost in the atmosphere through evaporation and evapo-transpiration, while the balance of 1160 BCM is available for use or flows into the Bay of Bengal. Over eighty per cent of this huge flow of water is concentrated in the five-month monsoon period of June to October. The minimum dry season water availability is 3,710 million cubic meters in March, and the maximum availability in August is 111,250 million cubic meters (MPO, 1991).
Variability in climate system affects six sectors which are found to be the major users of water in Bangladesh. These include agriculture (for irrigation), domestic or municipal, fisheries, navigation, industry, and environment (in-stream flow including salinity control). Other than in the low-flow season, available water resources are found to be sufficient to meet the present demand. Over the next 25 years, however, with the increase in the absolute size of the population the per capita water availability in Bangladesh will progressively be reduced (Ahmad and Haque, 2002). However, such reduction in water availability will only affect the country’s huge population during the dry season, where the current availability is already very low. Moreover, per capita water demand might also be increasing gradually due to a number of factors. According to government statistics, about 3 million hectares of net cropped area are yet to be brought under irrigation, mostly in the dry season. Keeping in view the poor water availability in the dry season, the per capita available supply will be much less, while demand for irrigation and other purposes will continue to rise. A few water-related problems are highlighted below.
3.2.1 Floods
The most common water-related natural hazard in a deltaic floodplain such as Bangladesh is flood. Flooding in Bangladesh is the result of a complex series of factors. These include a huge inflow of water from upstream catchment areas coinciding with heavy monsoon rainfall in the country, a low floodplain gradient, and congested drainage channels, the major rivers converging inside Bangladesh, tides and storm surges in coastal areas. Different combinations of these various factors give rise to different types of flooding (Ahmed and Mirza, 2000). Four main types of natural floods occur in Bangladesh: flash floods, river floods, rainwater floods, and coastal floods induced by storm surges (Ahmad and Alam, 1998). Flooding usually begins in flashy rivers in the hilly areas during the pre-monsoon months of April and May. Flash floods cause extensive damages to crops and property, particularly in the haor areas. Early floods (in April-May) generally cause severe damages. Normal river floods generally occur during monsoon. River floods result from snow-melt in the high Himalayas and heavy monsoon rainfall over the Himalayas, the Assam Hills, the Tripura Hills and the upper Brahmaputra and Ganges floodplains outside Bangladesh. The large catchment of the GBM systems receives a huge amount of rainfall in each monsoon, about nine-tenths of which flows through the major rivers in Bangladesh. These rivers sometimes cannot drain all the waters coming from the combined GBM catchments. Floods of high intensity occur when huge rate of discharge of the Bangladeshi rivers is grossly fall behind the rate of accumulation of water. Discharge is often impeded because of low river gradients, unplanned infrastructure and strong backwater effect at the confluences of large rivers, the latter being induced by high oceanic stages. The confluences between the Brahmaputra and the Ganges and between the Meghna and the combined flow of the earlier two rivers (known as the Padma) become two huge water pools during the peak seasons and cause high intensity flooding, particularly in the central part of the country. The catastrophic floods of 1987, 1988 and 1998 are characterized by comparing the peak water levels of the major rivers at those representative points as against their respective flood danger levels and recorded maximum water levels (FFWC, 1998). The comparative analysis of peak water levels is presented in Table 2.
Table 2. Water level at four important points along the major rivers (FFWC, 1998) River (station) | Recorded maximum | Danger level | Peaks of the year | Days above danger level | | | | 1987 | 1988 | 1998 | 1987 | 1988 | 1998 | | m | m | M | m | M | m | m | M | Brahmaputra (Bahadurbad) | 20.62 | 19.50 | 19.68 | 20.62 | 20.37 | 13 | 27 | 66 | Ganges(Hardinge Bridge) | 15.04 | 14.25 | 14.80 | 14.87 | 15.19 | 55 | 23 | 27 | Padma(Bhagyakul) | 7.58 | 6.00 | 6.99 | 7.43 | 7.5 | 56 | 47 | 72 | Megna (Bhairab) | 7.66 | 6.25 | 6.91 | 7.66 | 7.30 | 30 | 68 | 68 |

Severe floods, which cause extensive damages to crops and some damage to property, especially roads, occur at intervals of about 7-10 years. Catastrophic floods, occurring at intervals of 20-50 years or more, almost totally destroy crops in adjoining floodplains, and also cause considerable damages to houses, roads and other infrastructure. The 1988 and 1998 floods are rated as 50-100 year events. Coverage of inundation and damage caused by major floods during the period 1954 to 1998 is presented in Table 3.

Table 3. Inundation area and damage caused by various floods during 1954-2004 (Choudhury et al., 2003) Year | Area inundated | Proportion of total area | Cost of damage (approximate) | Population affected | Deaths | | Square kilometers | % | Million Taka | Million persons | Number of persons | 1954 | 36920 | 25 | 1200 | N/A | 112 | 1955 | 50700 | 34 | 1290 | N/A | 129 | 1956 | 35620 | 24 | 900 | N/A | N/A | 1962 | 3740 | 25 | 560 | N/A | 117 | 1963 | 43180 | 29 | 580 | N/A | N/A | 1968 | 37300 | 25 | 1160 | N/A | 126 | 1970 | 42640 | 28 | 1100 | N/A | 87 | 1971 | 36475 | 24 | N/A | N/A | 120 | 1974 | 52720 | 35 | 28490 | 30 | 1987 | 1984 | 28314 | 19 | 4500 | 20 | 553 | 1987 | 57491 | 38 | 35000 | 30 | 1657 | 1988 | 89970 | 62 | >100000 | 47 | 2379 | 1998 | >100000 | 74 | >120000 | >55 | 1050 | 2004 | >58000 | ~40 | >200000 | >36 | ~750 |

3.2.2 Droughts
Drought is primarily an agricultural phenomenon that refers to conditions where plants are responsive to certain levels of moisture stress that affect both the vegetative growth and yield of crops. It occurs when supply of moisture stored in the soil is insufficient to meet the optimum need of a particular type of crop. Bangladesh has a distinct dry season (November to May) and monsoon season (June to October) and these seasonal influences need to be part of delineating dry regions. Bangladesh, a land of 5.46 million ha, has a long dry spell accompanied by moderate to severe droughts. Considering the agro-ecological zone (AEZ) database and land resources inventory map, BARC has identified and mapped drought-prone areas of Bangladesh for kharif and rabi seasons (Figure 3). The maps define classes of drought severity as slight (15 to 20 percent yield losses), moderate (20 to 35 percent), severe (35 to 45 percent) and very severe (45 to 70 percent) for different crops. A yield loss of more than 10 percent has a huge impact on rural livelihoods, as large proportions of farmers in this region are tenants who pay 50 percent of their production to land owners.

Figure 3. Drought severity maps for kharif and Robi seasons in Bangladesh (BARC)
3.2.3 Riverbank Erosion
Most of the rivers of Bangladesh flow through unconsolidated sediments of the Ganges-Brahmaputra-Meghna floodplain and delta. The riverbanks are susceptible to erosion by river current and wave action. River erosion includes channel shifting, the creation of new channels during floods, bank slumping due to undercutting, and local scour from turbulence caused by obstruction. The Brahmaputra-Jamuna has changed course completely after 1762. This is a highly braided river, has steadily migrated westward in recent years, eroding the old floodplain and creating new sections of floodplain on its east bank. The Ganges, with larger areas of resistant clay on its older floodplain, is more stable than the Brahmaputra. The Bangladesh Water Development Board (BWDB) estimated that about 1,200 kilometers of riverbank has been actively eroded and more than 500 kilometers has been facing severe problems related to erosion. Satellite-image studies of the Ganges-Brahmaputra-Middle-Meghna rivers show that an area of 106,300 hectares has been lost due to erosion between 1982 and 1992, while the accretion amounted to only 19,300 hectares. The net erosion rate was therefore estimated at 8,700 hectares per annum. Erosion of border riverbanks is serious because it can cause loss of land to neighboring countries (Halcrow, 2004).
3.2.4 Sedimentation
Bangladesh is the outlet of all the major upstream rivers and the average annual sediment load that passes through the country to the Bay of Bengal ranges between 0.5 billion to 1.8 billion tons. All rivers in Bangladesh are alluvial and highly unstable. Alluvial channels consist primarily of deposited sediment that originated upstream. Constant interactions occur within the suspended sediment load of the channel, leading to significant changes in channel geometry. A part of the sediment load is deposited on the floodplain, gradually changing its topography and often severely reducing the water conveyance capacity and navigability of the drainage channels.
3.2.5 Salinity Ingress
Ingress of salinity is a major problem in Bangladesh. The coastal zone directly affected by salinity is extensive (Karim, 1996) and is inhabited by a large population. The zone includes major urban centers of Chittagong and Khulna. All the rivers of Bangladesh, except for those in Chittagong in the extreme southeast, combine to form a single, broad, and complex estuary popularly known as the Meghna estuary. The greatly diminished flow in the dry season allows salinity to penetrate far inland through this estuarine river system. Salinity limits opportunities for supplemental irrigation of Aus crops in freshwater areas and damages the same crops by flooding during very high tides. The upland progression of saline water during the dry season eliminated surface water potentials for significant land areas in the southwest, south-central and southeast regions. Fresh groundwater for human and industrial consumption is also affected by salinity. The shallow coastal aquifers in fact have high salinity. Therefore, water supply wells must penetrate 250 meters or more to find water of acceptable quality. The recharge zones of these deep coastal aquifers are located away from coastal zones in Jessore, Kushtia, Faridpur and Comilla areas and perhaps further north. Environmental degradation caused by salinity intrusion is a major problem in southwestern Bangladesh. Bangladesh NAPA document has also highlighted the concerns regarding salinity ingress the isohaline lines on surface water systems, as a response to rising sea level of 32 and 88 cms, are shown in Figure 4.

Figure 4. Line of equal salinity (5ppm) for different sea level rise during the dry season (CEGIS, 2006)
3.3 Impacts of Climate Change on Bio-geophysical Systems and Implications
Global warming and the resultant climate change could have profound effects on the water resources of Bangladesh (both surface and ground water).Translating the GCM projections of climate parameters provided in section 2, it may be concluded that the country will be highly susceptible to: (a) increased flooding, both in terms of extent and frequency; (b) increased moisture stress during dry periods leading to increased drought susceptibility in terms of both intensity and frequency; and (c) increased salinity intrusion during the low flow conditions. These changes in the physical system of the country will directly affect a number of major productive systems that include (a) crop agriculture, (b) livestock production, (c) aquaculture and fish production, (d) coastal shrimp production, and (e) forest and vegetation. Due to changes in temperature and humidity, human health will also be affected. The high susceptibility to water-based natural hazards will affect settlement of the population and also physical immobile infrastructure. Based on secondary sources, the following sub-sections provide brief understanding on anticipated impacts of climate change on bio-physical aspects of the country.
3.3.1 Flood and Water-logging
The projected increase in rainfall during monsoon would be reflected in the flow regimes of the rivers of Bangladesh. Increased flooding and drainage congestion, therefore, are the expected consequences of increased rainfall from a warmer and wetter condition. The increased run-off would also aggravate the existing drainage problems and create new ones. Bangladeshi rivers, especially the major ones, have lost gradient during the past several decades. Consequently, their conveyance capacity is diminished significantly. An increase in monsoon rainfall, therefore, will complicate drainage problem further resulting in increasing duration of floods. The ‘best-estimate’ scenario for the year 2030 is that monsoon rainfall could increase by 10 to 15 per cent. For the scenario year 2075 the average rainfall in monsoon will increase by about 27% with respect to the base year. Breach of existing coastal embankments will also inundate land with saline waters. 3.3.2 Cyclone and Storm Surge The current level of understanding in relation to adverse impacts of cyclone and subsequent storm surge under climate change is rather tentative. In earlier writings speculations (qualitative statements) have been made that the coastal zones of the country will be increasingly vulnerable to climate change driven cyclonic storm surge (BCAS-RA-Approtech, 1994). In the published literature, no quantified estimation has been quoted to justify such claims. Ali (1999) however provided rationale that not only the frequency of occurrence of cyclones along the Bay of Bengal would increase as a response to rising Sea Surface Temperature (SST), cyclonic intensity would also increase, with a corresponding increase in surge height in newly inundated shoreline. It is, however, also argued that the surge height along the continental shelf would somewhat decrease as a consequence of sea level rise (Ali, 1999).
3.3.3 Crop Production
Rice is by far the most important crop in Bangladesh. Together with the possible reduction in Aman rice area (as a result of greater spread of flood waters, and longer duration of flooding) and a reduction in the Boro rice area, the total area suitable for rice production may in the future stagnate or possibly decrease (WB, 2000). Centre for Environmental Geographic Information Services (CEGIS, 2006) has shown that due to sea level rise along the southwestern region of Bangladesh Aman suitable areas would decrease significantly. Floods affect agriculture production considerably. It is reported that, Aus production would suffer by 27 per cent while wheat production would decline by 61 per cent under a moderate climate change scenario. Under a severe climate change scenario which is associated with 60 per cent moisture stress, yield of Boro might reduce by 55 to 62 per cent.
3.3.4 Coastal Shrimp Culture
Stronger surge and tidal bores would increase potential for saline water to overtop coastal embankments. Shrimp farms outside embankments create earthen mini-polders, locally known as ghers, to produce shrimp in captivity. It is now a days a big business in the coastal districts of Cox’s Bazaar, Satkhira, Khulna and Bagerhat. High tides would certainly threaten these ghers both inside and outside embankments (WB, 2000). On the other hand, salinity ingress in new areas to the north of current shrimp growing zones would facilitate shrimp business (CEGIS, 2006).
3.3.5 Livestock In addition to affecting human beings, natural disasters cause tremendous sufferings for the livestock population of Bangladesh. Livestock suffer large-scale death in cyclonic storm surge (Haider et al., 1991). Prolonged flood can also cause death of livestock through a number of direct and indirect mechanisms (Choudhury et al., 2003). During droughts, livestock in Bangladesh do not suffer death, but lack of water increases their vulnerability to diseases. Since climate change would increase susceptibility to natural disasters, as mentioned in earlier sections, the anticipated toll on livestock sector would be quite high (Ahmed, 2005b; GOB, 2005).
3.3.6 Forest and Vegetation The Sundarbans forest, the home of many endemic species including the Royal Bengal Tiger (Panthera tigris), will be severely affected under climate change. The mangrove forest depends largely on the freshwater supply along the Ganges system. Under climate change induced aggravated low-flow conditions, the Gorai system might not be able to supply adequate quantum of freshwater. The problem is likely to be compounded by withdrawal of surface flows in the upstream areas to offset increasing moisture stress. In such a scenario, salinity is likely to penetrate inland and the salinity regime, on which the succession process of the vegetation of the forest depends, will be disturbed, leading to a gradual decline in the forest vegetation. It is inferred that poor quality shrubs will dominate with increasing salinity and high-value timber species will gradually disappear (Ahmed, 2005b). The recent research findings suggest that vegetation health index for Sundri species (H. fomes) would deteriorate significantly. 4. ADAPTATION TO CLIMATE CHANGE The word adaptation has been evolved from the term ‘adapt’, which means “making things/conditions/situations more suitable by altering”. According to Smit et al. (2000), ‘adaptation’ refers to both the process of adapting and the condition of being adapted. Adaptation to climate is the process through which people reduce the adverse effects of climate on their health and well-being, and take advantage of the opportunities that their climatic environment provides (Burton, 1992; Burton, 1997); Adaptability refers to the degree to which adjustments are possible in practices, processes, or structures of systems to projected or actual changes of climate. Adaptation can be spontaneous or planned, and can be carried out in response to or in anticipation of change in conditions (Watson et al., 1996).
The implications of high intensity floods cannot be overemphasized in Bangladesh. Management of flood in future will remain a major challenge, especially in view of further densification in increasingly flood vulnerable lands (Ahmed and Alam, 1998, Faruque and Ali, 2005). Creation of flood defense along the major rivers has been recommended by several authors (Mahtab, 1989; Faruque and Ali, 2005). Community efforts to cope with floods can tremendously benefit from issuance of early warning. Improvement of current flood warning system and dissemination in people-friendly manner are thought to be highly potential adaptation option for future (Ahmed, 2005a). To enable this, one may contemplate further improvements in terms of modeling of monsoon rainfall throughout the GBM region and effective regional cooperation for on-time transfer of data from upstream areas along the GBM river systems as necessary pre-conditions for adaptation (Mirza and Ahmed, 2003).
For drought management, making water available to offset moisture deficit appears to be the major adaptation modality (Karim, 1996). However, creation and recreation of water storage systems (ponds, khals, reservoirs etc.) operated and maintained by vulnerable communities - needs to be given due emphasis (WB, 2000). Choice of low-water-consuming crops instead of paddy will reduce immense pressure on dwindling ground water aquifers (Ahmed, 2005b). Such an adaptation will not only help diversify crop agriculture, it will also counteract gradual lowering of piezoelectric surface of groundwater aquifer system (Ahmed, 2005a).
In addition to adaptation in water-resources sector, one must consider adaptation in agricultural sector. The gravity of the issue and its importance on people’s livelihoods deserve special treatment, which is why the potential adaptation options in agriculture are discussed separately in the following section. 4.1 Adaptation in Agriculture: Identifying Potential
Crop agriculture in Bangladesh is highly susceptible to variations in the climate system. It is anticipated that crop production would be extremely vulnerable under climate change scenarios, and as a result, food security of the country will be at risk. Despite being highly vulnerable, very little efforts have so far been made to understand potential of agricultural adaptation in Bangladesh. Ahmed (2004) made an early attempt to analyse the adaptation potential of the country's crop agriculture in a warmer world. Faisal and Parveen (2004) examined food security aspect and implications of climate change; however adaptation potentials were not discussed. A brief account of adaptation types, based on IPCC typology of adaptation (UNEP, 1996), and limitations of a few adaptation Options in agriculture are provided below.
4.1.1 Bear Crop Losses
When potential loss of a standing crop is totally accepted by the growers, bearing crop losses is an adaptation option. It is however criticized that the option is rather theoretical, with limited applicability in Bangladesh (Ahmed, 2004). In practice, it is argued that, it is possible only when the cost of adaptation appears to be higher compared to the net crop loss. Such responses are often strategic and situation-specific.
4.1.2 Share Losses
The anticipated crop losses may be shared among the stakeholders. Compensating the farmers for trying out agricultural activities under high threats of crop loss can be a potential mechanism for sharing loss. Provision of insurance against crop loss has worked well in advanced economies. Provision of government subsidies and remission of taxes for the farmers operating in susceptible croplands could be other possible options where some of the losses might be shared among the different stakeholders. Loss sharing strategies necessitate strong political will, adequate financial resources and careful planning. Loss sharing mechanisms can be a very local affair, and sometimes can even be extended to the worldwide family of humanity.
4.1.3 Modify the Threats to Crop Production
This appears to be the mostly practiced option in Bangladesh. Vulnerability analysis may provide important lessons concerning the nature and extent of the threats to crop production under a given climate regime. In such cases, adequate precautionary measures might possibly modify the threats. Although most of the precautionary measures are anticipatory in nature, there might be some spontaneous measures as well. Modifications may be approached either on an individual or a collective basis. Many such measures are technology-oriented and may require early investment for research and extension.
Development of drought and/or salinity tolerant varieties, switching to alternative cropping patterns with respect to altered agro-ecological zones etc. could modify the threat to a significant extent. Good extension programmes would help achieve awareness up to a desired level so that the farmers may respond to the threatening environmental factors. Adequate policy framework and market instruments (technology availability at subsidized rates, credit, etc.) coupled with social engineering processes could facilitate implementation of such measures.
4.1.4 Prevent Adverse Effects
Some measures might consider preventing the losses in agricultural production. Preventive measures are anticipatory and might require large-scale investments. Building of large embankments to protect prime agricultural lands from excessive flooding may be cited as an example of preventive measure. Preventive measures often involve financial and institutional support of the government for planning and implementation.
4.1.5 Change Land Use In case it becomes extremely risky to continue agricultural activities under an altered climate scenario, an alternative land use might be considered as the next available option. If the suitability of Aus paddy in pre-Kharif months (March-June) appears to be too low, the farmers should alter the land use and instead grow other suitable crops. In beel areas, growing kachu & kachu-mukhee (a local vegetable) appears to be better land use option than growing paddy with a risk of higher levels of inundation. In water logged areas, attempts have been made under the RVCC project to create floating gardens (i.e., hydroponics) by the use of water hyacinth and grow vegetables. The application of a indigenous practice through capacity building and extension allowed farmers of Jessore District to profitably change their land use and maintain livelihoods (Ahmed and Schaerer, 2004).The project titled Reducing Vulnerability to Climate Change (RVCC), implemented in six southwestern Districts of Bangladesh during 2002 till 2005, applied a few interesting adaptation measures in a bid to reduce vulnerability of communities to climate change by increasing people’s coping capacity (RVCC, 2003; Ahmed and Schaerer 2004). The agricultural adaptations worth special mention, due primarily to their simplicity and their overall social acceptance. Table 4 highlights the agricultural adaptation measures considered under the project. Strategy | Measure | Brief Description of Measure | Household level strategies in agriculture (crop, fishery, agro-forestry, & livestock) | Increase food through agriculture | Drought tolerant crops/vegetables | Introduction of drought tolerant crops such as groundnuts, watermelon, etc | | Floating gardens | Cultivation of vegetables on floating beds of water hyacinth (hydroponics) | | Low-cost irrigation | Demonstration of treadle pump and other simple technologies for irrigation | | Homestead gardening | Cultivation of vegetables and fruits on homestead plots for consumption and market | | Saline tolerant non-rice crops | Introduction of saline tolerant varieties of chili, mustard, maize and potato | Increase incomethrough alternativelivelihoods | Integrated farming systems | Using small area of land, small water body, and surrounding embankments to produce rice, fish and vegetables | | Cage aquaculture | Small-scale fish farming in cages, implemented in household ponds or common water bodies | | Prawn fish poly-culture | Prawn and fish culture in fresh-water ghers (ponds) | | Shrimp fish poly-culture | Shrimp and fish culture in salt-water ghers (ponds) | | Cattle rearing | Raising cattle for consumption and market | | Poultry rearing | Raising chickens to produce meat and eggs for consumption and market | | Duck rearing | Raising ducks to produce meat and eggs for consumption and market | | Apiculture & honey processing | Beekeeping and processing of honey for market | | Nursery & homestead afforestation | Establishment of community nurseries and distribution (with handling instructions) of indigenous varieties of tree saplings (mango, coconut, sofeda, korai, guava, mehaguni, neem, kewra, etc.) to beneficiaries for homestead planting | | Saline tolerant tree plantation | Planting of saline tolerant fruit and timber trees for longer term income generation | Table 4. Strategic Approaches Considered for Agricultural Adaptation for RVCC Project (Ahmed and Schaerer, 2004.) 4.2 Adaptation Measures as Prioritized in National Adaptation Programme of Action (NAPA) By collating available information from literature and through four regional consultations, the NAPA document highlighted a few adaptation measures and prioritized them. The following are the adaptation measures which have received endorsement of the Government of Bangladesh through NAPA exercise.
Intervention Type Measures • Promoting adaptation to coastal crop agriculture to combat salinization through maize production under Wet Bed No-tillage Method and Sorjan systems of cropping in tidally flooded agro-ecosystem. • Adaptation to agriculture systems in areas prone to enhanced flash flooding - North East and Central Region through no-tillage potato cultivation under water hyacinth mulch in wet sown condition, and Vegetable Cultivation on Floating Bed. • Adaptation to fisheries in areas prone to enhanced flooding in North East and Central Region through adaptive and diversified fish culture practices. • Construction of flood shelter, and information and assistance centre to cope with enhanced recurrent floods in major floodplains. • Reduction of Climate Change Hazards through Coastal afforestation with community focus. Facilitating Type Measures • Capacity building for integrating Climate Change in planning, designing of infrastructure, conflict management and landwater zoning for water management institutions. • Exploring options for insurance and other emergency preparedness measures to cope with enhanced climatic disasters (e. g. flood, cyclones and drought). • Mainstreaming adaptation to climate change into policies and programmes in different sectors (focusing on disaster management, water, agriculture, health and industry). • Inclusion of climate change issues in curriculum at secondary and tertiary educational institution. 5 Conclusions
Adaptation can significantly reduce adverse impacts of climate change. Adaptation is an important part of societal response to global climate change. Planned, anticipatory adaptation has the potential to reduce vulnerability and realize opportunities associated with climate change effects and hazards. Substantial reductions in climate change damages can be achieved, especially in the most vulnerable regions, through timely deployment of adaptation measures. In the absence of planned adaptation, communities will adapt autonomously to changing climatic conditions, but not without costs and residual damages. However, losses from climate-related extreme events are substantial and, in some sectors, increasing- indicating patterns of development that remain vulnerable to temporal variations in climatic conditions and to climate change. The key features of climate change for vulnerability and adaptation are those that relate to variability and extremes, not simply changed average conditions. In addition, the speed of changes in event frequency is important. Most communities, sectors, and regions are reasonably adaptable to changes in average conditions, unless those changes are particularly sudden or not smooth. However, these communities are more vulnerable and less adaptable to changes in the frequency and magnitude of conditions other than average, especially extremes. Adaptations to current climate and climate-related risks (recurring droughts, storms, floods, salinity, sea level rise and other extremes) generally are consistent with adaptation to changing and changed climatic conditions. Adaptations to changing climatic conditions are more likely to be implemented if they are consistent with or integrated with decisions or programs that address non-climatic stresses. Adaptive capacity varies considerably among regions, countries, and socioeconomic groups. The ability to adapt and cope with climate change impacts is a function of wealth, technology, information, skills, infrastructure, institutions, and equity. Groups and regions with limited adaptive capacity are more vulnerable to climate change damages. Development decisions, activities, and programs play important roles in modifying the adaptive capacity of communities and regions, yet they tend not to take into account risks associated with climate variability and change. This omission in the design and implementation of many recent and current development initiatives results in unnecessary additional losses to life, well-being, and investments in the short and longer terms.

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