EIA and Mitigation Dr. A.K.M. Saiful Islam, IWFM, BUET Introduction to Climate Change Dr. A.K.M. Saiful Islam Bangladesh University of Engineering and Technology Training Course of Small Scale Water Resources Project (SSWRP-II)

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Climate Systems The complicated system consisting of various components, including the dynamics and composition of the atmosphere, the ocean, the ice and snow cover, the land surface and its features, the many mutual interactions between them, and the large variety of physical, chemical and biological processes taking place in and among these components. Climate refers to the state of the climate system as a whole, including a statistical description of its variations.  Atmosphere –78% nitrogen, 21% oxygen, and 1% other gases. –Carbon dioxide accounts for just %. –Water vapor 0 to 2%

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Components of Climate System

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Green house gases  CO 2 and some other minor gases 1.Absorb some of the thermal radiation leaving the surface of the earth. 2.Emit radiation from much higher and colder levels out to space.  These radiatively active gases are known as greenhouse gases. –They act as a partial blanket for the thermal radiation from the surface which enables it to be substantially warmer than it would otherwise be, analogous to the effect of a greenhouse.

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Green house effect

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Green house effect

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Human induced climate variation  Perturbations of the atmospheric composition – the enhanced greenhouse effect  Effect of aerosols: –direct effect (scattering of incoming solar radiation) –indirect effect (affecting the radiative properties of clouds)  Land-use change (agriculture, deforestation, reforestation, afforestation, urbanisation, traffic, …)

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Increasing trends of CO2

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Human induced changes of green house gases

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Global temperature and Greenhouse gases

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Temperature variation past 1,000 years

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Increase of Temperature past 140 year

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Trends of increase of Temperature

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Predicted changes of Temperature

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Trends of Precipitations

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Trends of Seal Surface temperature

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Sea Level Rise

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Impacts of climate change  Human Health impacts  Ecosystem Impacts  Agriculture Impacts  Water Resources Impacts  Market Impacts

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Human Health impacts  Expansion of the areas of potential transmission of malaria and dengue fever (medium-to-high confidence); roughly 300 million more people at risk of malaria  Increased heat-related deaths and illness, affecting particularly the elderly, sick, and those without access to air conditioning  Increased risks to human life, risk of infectious disease epidemics and many other health risks where floods, droughts or storms increase in frequency and/or intensity  Decreased winter deaths in some temperate regions

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Ecosystem Impacts  Coral death from exposure to 3-4 ºC higher seasonal maximum sea- surface temperatures for 6 months or more  Substantial reduction in glacier and ice-cap volume; tropical glaciers particularly vulnerable to elimination  Loss of unique vegetation systems and their endemic species (e.g. vegetation of Cape region of South Africa and some cloud forests)  Extensive reduction in Arctic summer sea-ice extent with benefits for shipping but adverse effects on sea-ice dependent animals (e.g. polar bears, seals, walrus)  Coastal wetland loss from sea level rise (up to 10% globally for 20 cm rise, higher percentages in some areas)  Increased disturbances of ecosystems by fire and insect pests  Increase net primary productivity of many mid- and high-latitude forests  Extinction of some critically-endangered and endangered species

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Agriculture Impacts  General decrease in cereal crop yields in mid-latitudes  Decreased crop yields in areas of increased drought  Food prices increase relative to projections that exclude climate change  Decreased cereal crop yields in most tropical and subtropical regions  Increased heat stress in livestock and crop damage from heat waves  Decreased frost damage for some crops

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Water Resources Impacts  Decreased water quantity and quality in some areas of increased drought  Increased flood damage due to more intense precipitation events  Decreased water supply in many water stressed countries (half-billion people in central Asia, southern Africa, and countries surrounding the Mediterranean affected)  Increased water supply in some other water stressed countries (e.g. parts of Asia)

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Market Impacts  Net market sector losses most regions and for global aggregate  Increased insurance prices and reduced insurance availability in response to increased frequency and intensity of some extreme climate events  Decreased energy demand for heating buildings in winter and increased energy demand for cooling buildings in summer  Net market sector losses in many developing countries

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Climate change and Bangladesh  The country is located in the Bengal Basin, a low-lying very flat delta. About 80 per cent of Bangladesh is floodplains with very low mean elevation above the sea level.  Differences in the elevation between adjoining ridge tops and depression centers 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. –Only in the extreme north-west land elevations exceed 30 meters above the mean sea level.

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Climate change and Bangladesh  The flat topography makes a significant part of Bangladesh vulnerable to sea level change. The active delta and dynamic morphology complicates the reliable estimation of vulnerability of tidal floodplains to sea level rise.  The net sea level rise would result in –Inundation of coastal land –Reduced drainage and hence prolonged flooding due to high backwater. –Higher precipitation within GBM basin would result in greater flood magnitude and frequency.

Copy Dr. A.K.M. Saiful Islam, IWFM, BUET Emission of CO 2 ->who is responsible?  Per capita emissions of CO2 is less than 0.2 ton annually in Bangladesh, compared to 1.6 tons in the developing countries