Climate Change Impact in Bangladesh

The impacts of global warming and climate change are worldwide. For Bangladesh they are most critical as large part of the population is chronically exposed and vulnerable to a range of natural hazards (DoE, 2007). The Intergovernmental Panel on Climate Change (IPCC) predicts that global temperatures will rise between 1.8 C and 4.0 C by the last decade of the 21st century (IPCC, 2007). The impacts of global warming on the climate, however, will vary in different regions of the world (GoB, 2008). In South Asia, the 4 IPCC Report predicts that monsoon rainfall will increase, resulting in higher flows during the monsoon season in the rivers, which flow into Bangladesh from India, Nepal, Bhutan and China. These flows are likely to further increase in the medium term due to the melting of the Himalayan glaciers. The IPCC also forecasts that global warming will result in sea level rises o between 0.18 and 0.79 meters, which could increase coastal flooding and saline intrusion into aquifers and rivers across a wide belt in the south of the country (GobB, 208 and GoB, 2009).

Bangladesh is one of the most climate vulnerable countries in the world and will become even more so as a result of climate change. Floods, tropical cyclones, storm surges and droughts are likely to become more frequent and severe in the coming years (GoB, 2008 and GoB, 2009). Already, the human suffering and cost to development is massive to this country and its people who are victims of human induced global warming. Between 1991 and 2000, 93 major disasters were recorded in Bangladesh, resulting in nearly 200,000 deaths and causing US $ 5.9 billion in damages with high losses in agriculture and infrastructure (DoE, 2007). DoE (2007) mentioned according to IPCC in their recently published Fourth Assessment, the following changes have been observed in climate trends, variability and extreme events are

• In Bangladesh, average temperature has registered an increasing trend of about 1°C in May and 0.5°C in November during the 14 year period from 1985 to 1998.
• The annual mean rainfall exhibits increasing trends in Bangladesh. Decadal rain anomalies are above long term averages since 1960s.
• Serious and recurring floods have taken place during 2002, 2003, and 2004. Cyclones originating from the Bay of Bengal have been noted to decrease since 1970 but the intensity has increased.
• Frequency of monsoon depressions and cyclones formation in Bay of Bengal has increased.
• Water shortages has been attributed to rapid urbanization and industrialization, population growth and inefficient water use, which are aggravated by changing climate and its adverse impacts on demand, supply and water quality.
• Salt water from the Bay of Bengal is reported to have penetrated 100 km or more inland along tributary channels during the dry season.
• The precipitation decline and droughts has resulted in the drying up of wetlands and severe degradation of ecosystems.

GoB 2008 and GoB 2009 mentioned that Climate change will exacerbate many of the current problems and natural hazards the country faces. It is expected to result in:

•  Increasingly frequent and severe tropical cyclones, with higher wind speeds and storm surges leading to more damage in the coastal region;
• Heavier and more erratic rainfall in the Ganges- Brahmaputra-Meghna system, including Bangladesh, during the monsoon resulting in:

               Higher river flows, causing over-topping and breaching of embankments and widespread flooding in rural and urban areas,

                  River bank erosion resulting in loss of homes and agricultural land to the rivers;

                  Increased sedimentation in riverbeds leading to drainage congestion and water logging;

• Melting of the Himalayan glaciers, leading to higher river flows in the warmer months of the year, followed by lower river flows and increased saline intrusion after the glaciers have shrunk or disappeared;
• Lower and more erratic rainfall,  resulting in increasing droughts, especially in drier northern and western regions of the country;
• Sea level rises,  leading to submergence of lowlying coastal areas and saline water intrusion up coastal rivers and into groundwater aquifers, reducing freshwater availability; damage to the Sundarbans mangrove forest, a World Heritage site with rich biodiversity; and drainage congestion inside coastal polders, which will adversely affect agriculture;
• Warmer and more humid weather, leading to increased prevalence of disease and disease vectors.

Each of these changes is likely to seriously affect agriculture (crops, livestock and fisheries). The higher temperatures and changing rainfall patterns, coupled with increased flooding, rising salinity in the coastal belt and droughts are likely to reduce crop yields and crop production. IPCC estimates that, by 2050, rice production in Bangladesh could decline by 8% and wheat by 32% (against a base year of 1990) (GoB, 2088). It also mentioned shortage of safe drinking water is likely to become more pronounced, especially in the coastal belt and in drought-prone areas in the north-west of the country. This will impose hardship on women and children, who are responsible for collecting drinking water for their families. Increasingly saline drinking water may also result in health hazards, especially for pregnant women. Climate change is likely to adversely affect women more than men (GoB, 2008 and GoB 2009).

Increased river bank erosion and saline water intrusion in coastal areas are likely to displace hundreds of thousands of people who will be forced to migrate, often to slums in Dhaka and other big cities. All of these changes threaten the food security, livelihoods and health of the poor (GoB, 2008 and GoB, 2009).

Climate change is likely to increase the incidence of water-borne and air-borne diseases. Bacteria, parasites and disease vectors breed faster in warmer and wetter conditions and where there is poor drainage and sanitation. In view of this, it will be important to implement public health measures (immunization; improved drainage, sanitation and hygiene) to reduce the spread of these diseases and to improve access to health services for those communities likely to be worst affected by climate change. Unless these steps are taken, the health of many of the poorest and most vulnerable people will deteriorate. Acute illness is known to be one of the main triggers driving people into extreme poverty and destitution in Bangladesh (GoB 2008 and GoB, 2009).

Several studies indicate that the coastal zone vulnerability would be acute due to the combined effects of climate change, sea level rise, subsidence, and changes of upstream river discharge, cyclone and coastal embankments (GoB, 2005, BCAS/RA/Approtech, 1994 and WB, 2000). Four key types of primary physical effects i.e. saline water intrusion; drainage congestion; extreme events; and changes in coastal morphology have been identified as key vulnerabilities in the coastal area of Bangladesh (GoB, 2005 and WB, 2000). According to GOB (2005) effects of climate change in the coastal zone are given below:

·         The effect of saline water intrusion in the estuaries and into the groundwater would be enhanced by low river flow, sea level rise and subsidence. Pressure of the growing population and rising demand due to economic development will further reduce relative availability of fresh water supply in future. The adverse effects of saline water intrusion will be significant on coastal agriculture and the availability of fresh water for public and industrial water supply will fall (GoB, 2005).

• The combined effect of higher sea water levels, subsidence, siltation of estuary branches, higher riverbed levels and reduced sedimentation in flood-protected areas will impede drainage and gradually increase water logging problems. This effect will be particularly strong in the coastal zone. The problem will be aggravated by the continuous development of infrastructure (e.g. roads) reducing further the limited natural drainage capacity in the delta. Increased periods of inundation may hamper agricultural productivity, and will also threaten human health by increasing the potential for water borne disease.

• Disturbance of coastal morphological processes would become a significant problem under warmer climate change regime. Bangladesh’ coastal morphological processes are extremely dynamic, partly because of the tidal and seasonal variations in river flows and run off. Climate change is expected to increase these variations, Climate change is expected to increase these variations, with two main (related) processes involved:

                    i.Increased bank erosion and bed level changes of coastal rivers and estuaries. There will be a substantial increase of morphological activity with increased river flow, implying that riverbank erosion might substantially increase in the future.

                          ii. Disturbance of the balance between river sediment transport and deposition in rivers, flood plains and coastal areas. Disturbance of the sedimentation balance will result in higher bed levels of rivers and coastal areas, which in turn will lead to higher water levels.

• Increased intensity of extreme events. The coastal area of Bangladesh and the Bay of Bengal are located at the tip of northern Indian Ocean, which has the shape of an inverted funnel. The area is frequently hit by severe cyclonic storms, generating long wave tidal surges which are aggravated because the Bay itself is quite shallow. Cyclones and storm urges are expected to become more intense with climate change. Though the country is relatively well equipped particularly in managing the aftermath of cyclones, the increased intensity of such disasters implies major constraints to the country’s social and economic development. Unless proper adaptive measures are undertaken, private sector investment in the coastal zone is likely to be discouraged by the increased risks of cyclones and flooding.

In 2005, we developed the National Adaptation Programme of Action (NAPA) after extensive consultations with communities across the country, professional groups; and other members of civil society. The National Adaptation Programme of Action (NAPA) for Bangladesh has been prepared by the Ministry of Environment and Forest (MOEF), Government of the People’s Republic of Bangladesh as a response to the decision of the Seventh Session of the Conference of the Parties (COP7) of the United Nations Framework Convention on Climate Change (UNFCCC).The strategic goals and objectives of future coping mechanisms are to reduce adverse effects of climate change including variability and extreme events and promote sustainable development. Future 15 coping strategies and mechanisms are suggested based on existing process and practices keeping main essence of adaptation science which is a process to adjust with adverse situation of climate change.

Government has since taken this process forward, including through the adoption of the Bangladesh Climate Change Strategy and Action Plan (BCCSAP), which will be the main basis of government efforts to combat climate change over the next ten years. This document has also been prepared after extensive consultations with all important sections of our citizens, including disadvantaged groups, such as those identified as major groups in Agenda 21. This will be achieved by implementing an Action Plan , which will have six pillars: (1) Food security, social protection and health; (2) Comprehensive disaster management; (3) Infrastructure development; (4) Research and knowledge management; (5) Mitigation and low-carbon development; and (6) Capacity building and institutional development. The Action Plan will be an integral part of national development policies, plans and programmes.

Reference

Banglapedia (2012a) Assasuni Upazila, National Encyclopedia of Bangladesh.

Banglapedia (2012b) Shyamnagar Upazila, National Encyclopedia of Bangladesh.

BCAS/RA/Approtech (1994) Vulnerability of Bangladesh to Climate Change and Sea Level Rise: Concepts and Tools for Calculating Risk in Integrated Coastal Zone Management, Dhaka, Bangladesh: Bangladesh Centre for Advanced Studies (BCAS).

DoE (2007) Climate Change and Bangladesh, Dhaka: Climate Change Cell, Department of Environment, Government of the Peoples Republic of Bangladesh.

GoB (2005) The National Adaptation Programme of Action (NAPA), Dhaka: Ministry of Environment and Forests, Government of the Peoples Republic of Bangladesh.

GoB (2008) Bangladesh Climate Change Strategy and Action Plan 2008, Dhaka: Ministry of Environment and Forests, Government of the Peoples Republic of Bangladesh.

GoB (2009) Bangladesh Climate Change Strategy and Action Plan 2008, Dhaka: Ministry of Environment and Forests, Government of the Peoples Republic of Bangladesh.

IPCC (2007), Climate Change 2007: The Physical Science Basis, Summary for Policy Makers, Intergovernmental Panel on Climate Change, Working Group 1, p. 13.

World Bank (2000) Bangladesh: Climate Changeand Sustainable Development, Report no. 21104- BD, Dhaka:  Rural Development Unit, South Asia Region, The World Bank (Wb).