Climate change refers to any change in climate over time, whether due to natural variability or as a result of human activity. This usage differs from that in the United Nations Framework Convention on Climate Change (UNFCCC) which defines"climate change" as: 'change in climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural variability observed over comparable time periods".
Climate change presents many complex risks to different groups and sectors over different timeframes and localities. Adaptation is likely to be successful if people are informed about climate change, how it affects them, and options for doing something about it. Successful climate change interventions are dependent on high-quality accessible information to allow effective decision making.
As the impacts of climate change are difficult to predict accurately, adaptation activities need to be flexible and responsive to new information, and robust to withstand a wide range of plausible futures. The use of risk management and coping thresholds is an area of applied adaptation research of growing importance.
Climate change can directly affect health because high temperatures place an added stress on human physiology. Changes in temperatures place and precipitation including extreme weather events and storms can cause deaths directly, or by altering the environment, result in an increased incidence of infectious diseases. Air pollution can be exacerbated by higher temperature and humidity.
Finally, virtually all effects of global climate change, ranging from sea-level rise to impacts on agriculture and human infrastructures are linked at least indirectly to human health.
The incidence and severity of many health problems increase with increasing temperature. As temperatures increase, the body expands added energy to keep cool.
The most immediate Consequence, if the body's temperature rises above 41 C, is heat stroke. This disturbance to the temperature regulating mechanism lf the body results in fever, hot and dry skin, rapid pulse and sometimes progress to delirium and coma. Also, temperature stress can exacerbate many existing health conditions including cardiovascular and cerebrovascular disease, pneumonia, asthma, and influenza.
Mortality from such diseases, especially among children and the elderly, increases dramatically during periods of usually during periods of usually hot weather. Quantitative algorithms based on historical data that relate morbidity and mortality to weather conditions suggest that global warming will increase heart related morbidity and mortality.
Climate the average condition of the atmosphere near the earth's surface over a long period of time, taking into account temperature, precipitation, humidity, wind, cloud, barometric pressure, etc. Geographical location and physical settings govern the climate of any country. Bangladesh extends from 20°34'N to 26°38'N latitude and from 88°01'E to 92°41'E longitude.
Except the hilly southeast, most of the country is a low-lying plain land. It is surrounded by the Assam Hills in the east, the Meghalaya Plateau in the north, the lofty Himalayas lying farther to the north. To its south lies the Bay of Bengal, and to the west lie the plain land of West Bengal and the vast tract of the Gangetic Plain. Dhaka (Geology) the capital city of Bangladesh was founded about 400 years ago by the side of the river Buriganga.
The importance of Dhaka increased exponentially after 1971, when it became the capital of independent Bangladesh. As a result the city expanded phenomenally and according to the census of 1991 the area and population of Dhaka Megacity or Dhaka Statistical Metropolitan Area (DSMA) were 1,600 sq km and 6.83 million respectively.
According to the same census the area under the Dhaka City Corporation (DCC) was 360 sq km, with a population of 3.39 million. The present population of DSMA is about 9.0 million (2001). Urbanization in Dhaka is restricted mostly to the north bank of the river Buriganga.
Rapid urbanization without considering the geological aspects has brought significant changes in the geo-environment of the city area. Water logging, pollution, and change in the hydro geological system, localized land subsidence and building collapse are the hazards associated with these changes in the geo-environment. Groundwater withdrawal has increased more than 900% over the last 30 years resulting in groundwater mining and lowering of the water level by 20m.
The combination of higher temperatures and potential increases in summer precipitation could create the conditions for greater intensity or spread of many infectious diseases. However, risk in the human health sector is low relative to climate change induced risks in other sectors (such as water resources) mainly because of the higher uncertainty about many of the health outcomes. Increased risk to human health from increased flooding and cyclones seems most likely. Changes in infectious disease are less certain.
The causes of outbreaks of infectious disease are quite complex and often do not have a simple relationship with increasing temperature or change in precipitation. It is not clear if the magnitude of the change in health risks resulting from climate change will be significant compared to current risks. It is also not clear if increased health risk will be apparent in the next few decades. On the whole climate change is expected to present increased risks to human health in Bangladesh, especially in light of the poor state of the country's public health infrastructure.
Climate change is a recurrent phenomenon of Bangladesh. Human health will suffer from many aspects of climate change. Direct impacts include increasing incidences of thermal stress, leading to cardiovascular and respiratory morbidity and mortality. Indirect impacts will probably result from increases in certain vector borne diseases. During the research there would be a opportunity to share the experience with the farmers, and farm owners and mean while the knowledge of climate variation could be shared with the people.
The writer is an environmental analyst & associate member, Bangladesh Economic Association
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