A presentation by Mr. Debal Ray, Department of Environment (Government of West Bengal)

1. Projected Climate Change in Sundarbans and its Impacts Debal Ray Department of Environment Government of West Bengal

2. scenarios

3. Special Report on Emission Scenarios A1 Scenario Rapid economic growth. A global population that reaches 9 billion in 2050 and then gradually declines. The quick spread of new and efficient technologies. A convergent world. A2 Scenario A world of independently operating, self-reliant nations. Continuously increasing population. Regionally oriented economic development. Slower and more fragmented technological changes

4. Special Report on Emission Scenarios B1 Scenario Rapid economic growth as in A1, but with rapid changes towards a service and information economy. Population rising to 9 billion in 2050 and then declining as in A1. Reductions in material intensity and the introduction of clean and resource efficient technologies. An emphasis on global solutions to economic, social and environmental stability. B2 Scenario Continuously increasing population, but at a slower rate than in A2. Emphasis on local rather than global solutions to economic, social and environmental stability. Intermediate levels of economic development. Less rapid and more fragmented technological change than in A1 and B1

5. Scenarios of GHG and Projected Surface Temperature (Modified from IPCC, 2007)

6. Climatic and non-climatic fragility of sundarbans

7. Inherent Fragility An estuarine ecosystem is typically rich in biomass but poor in diversity. Typically gives U shaped curve when biodiversity is plotted against salinity Narrow base of biodiversity makes the ecosystem less resilient to stress. Low redundancy species doing same ecological function. Less resistance to invasive species. Future adaptation option largely depends on ecosystem services.

8. External Stressors High population Pressure Overexploitation of resources Reduced freshwater supply Tilting of Bengal Basin towards east Sea level Rise & Progressive salinization Pollution

9. Reasons for disproportionately Large Impact in Sundarbans The phenomenon of recurvature of tropical cyclones in the Bay of Bengal Shallow continental shelf, especially in eastern parts of Bangladesh High tidal range Triangular shape at the head of the Bay of Bengal Almost sea level geography of coastal land High density of population

10. Projected temperature & precipitation

11. Projected change in Rainfall in B1 scenario in 2080-2100 compared to 1980 -1999 (mm)

12. Projected change in Temperature in B1 scenario in 2080-2100 compared to 1980 -1999 (mm)

17. Sea level trend

18. Sea Levels: past and future

19. Net Sea Level Trends Sinking of delta Unnikrishnan & Shankar, 2007

20. Important Tide Gauge Locations

21. PSMSL record of Diamond Harbour

22. PSMSL record for Sagar

23. Projections of Global Sea level Rise

24. Possibility of submergence of low lying areas

25. Trend of tropical cyclone

26. Tropical Cyclone : some facts Although science is not conclusive, IWTC (2006) noted that: If projected rise in sea level due to global warming occurs, then the vulnerability to tropical cyclone storm surge flooding would increase Some increase in cyclone peak wind speed and rainfall will occur if climate continues to warm Model studies and theory project a 3-5% increase in wind speed per degree Celsius increase of sea surface temperature.

28. Composite Track of Cyclones in Bay of Bengal 1961-1990 2071-2100 (Unnikrishnan, 2009)

29. Frequency Distribution of Cyclones in Bay of Bengal 1961-1990 2070-2100

30. Trend of Storm Surge Red line –A2 scenario Blue line – B1 scenario

31. impacts

32. Projected per Capita Water Availability

33. Natural Disaster: Relative Risk* *Decile of global distribution of each variable. The higher the value, the higher the relative risk.

34. Impact of CC on Agriculture in Sundarbans

35. Projected Loss of Rice in Bangladesh http://cigrasp.pik-potsdam.de/maps/potential-rice-production-loss-t-bangladesh-1m-slr

36. Endangered plant species Botanical Survey of India, 2006

37. Endemic Plant Specis Sonneratiaapetala Heritierafomes Phoenix paludosa

38. Thank you