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)
13. 14. 15. 16. 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.
27. 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