Climate Induced future changes of temperature Climate Induced future changes of temperature and precipitation over Bangladeshand precipitation over Bangladesh

A.K.M. Saiful IslamInstitute of Water and Flood Management (IWFM)Bangladesh University of Engineer and Technology (BUET)

“4th International Symposium of BJSPSAA 2012 on “Global Climate Change: Impacts, vulnerability and adaptation”

Outline

• Global Warming, Green house effect and Climate Change.

• Global Climate Change Modeling and Scenarios.

• Regional Climate Change Modeling.

• Change of future Temperature and Rainfall.

• Potential Impact of Climate Change on Flood Inundation, Cyclone, Storm Surge, Drought, Agriculture and Food Production, Fisheries, Ecosystem, Human Health.

Green House Effect

• Co2 and some minor radioactively active gases are (known as greenhouse gases) acted 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

Global temperature and Greenhouse gases

Temperature variation past 1,000 years

CO2 from the measuring station at Mauna Loa (Hawaii) is located at an altitude of 3400 meters

Increasing trends of CO2

Trends of increase of Temperature

Cracks in Ice bars

Observed Ice melting

• Images gathered from the Defense Meteorological Satellite Program of NASA show the minimum Arctic sea ice concentration 1979 (left) and 2003 (right).

1979 2003

Source: http://www.worldwithoutwinter.com/melting%20ice%20caps.jpg

Prediction of Global WarmingFigure shows the distribution of warming during the late 21st century predicted by the HadCM3 climate model. The average warming predicted by this model is 3.0 °C.

Predicted Arctic sea Ice

Arctic Sea Ice in 2040

Arctic Sea Ice in 2000

Results from community climate system models

Prediction of Sea level rise

Climate Change Predictions

General Circulation Model (GCM)• General Circulation Models (GCMs) are a class of computer-driven

models for weather forecasting, understanding climate and projecting climate change, where they are commonly called Global Climate Models.

• Three dimensional GCM's discretise the equations for fluid motion and energy transfer and integrate these forward in time. They also contain parameterizations for processes - such as convection - that occur on scales too small to be resolved directly.

• Atmospheric GCMs (AGCMs) model the atmosphere and impose sea surface temperatures. Coupled atmosphere-ocean GCMs (AOGCMs, e.g. HadCM3, EdGCM, GFDL CM2.X, ARPEGE-Climate) combine the two models.

Schematization of 3D GCM

Regional Climate modeling• An RCM is a tool to add small-scale detailed information of future

climate change to the large-scale projections of a GCM. RCMs are full climate models and as such are physically based and represent most or all of the processes, interactions and feedbacks between the climate system components that are represented in GCMs.

• They take coarse resolution information from a GCM and then develop temporally and spatially fine-scale information consistent with this using their higher resolution representation of the climate system.

• The typical resolution of an RCM is about 50 km in the horizontal and GCMs are typically 500~300 km

PRECIS: Regional Climate change modeling in Bangladesh

• PRECIS regional climate modeling is now running in Climate change study cell at IWFM,BUET.

• PRECIS is a fully 3D dimensional atmospheric ocean coupled model.

• Uses LBC data from Hadley Center GCM (HadCM3).

• LBC data available for baseline, A2, B2, A1B scenarios up to 2100.

• Daily and hourly predictions is available.

Topography of Experiment Domain

Zoom over BangladeshSimulation Domain = 88 x 88 Resolution = 0.44 degree

Change of future temperature

Change of Annual Cyclone of Maximum and Minimum Temperature

68

10121416182022242628303234

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov DecTe

mpe

ratu

re in

ºC

1961 to 1990 2011 to 2040 2041 to 2070 2071 to 2100

20

22

24

26

28

30

32

34

36

38

40

42

44

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Tem

pera

ture

in ºC

1961 to 1990 2011 to 2040 2041 to 2070 2071 to 2100

Change of Seasonal Maximum and Minimum Temperature

Maximum Temp. Minimum Temp.

0

1

2

3

4

5

6

DJF MAM JJAS ON

Tem

pera

ture

in 0 C

2011 to 2040 2041 to 2070 2071 to 2100

0

1

2

3

4

5

6

DJF MAM JJAS ON

Tem

pera

ture

in C

2011 to 2040 2041 to 2070 2071 to 2100

Change of Number of Summer days when temperature is > 250C

2020s 2080s2050s

Change of Number of Cold nights when temperature is < 200C

2020s 2080s2050s

Change of future rainfall

Change of seasonal Rainfall

0

200

400

600

800

1000

1200

DJF MAM JJAS ON

1980s

2020s2050s

2080s

Max. 23%

Change of future Monsoon Rainfall

Difference Rainfall in 2020s from 1970s Difference Rainfall in 2080s from 1970s

Consecutive Wet Days

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

18 23 28 33 38

Prob

abili

ty

CWD (Consecutive Wet Days)

1970s

2020s

2050s

2080s

Daily Intensity of Rainfall

00.05

0.10.15

0.20.25

0.30.35

0.40.45

0.5

7.5 9.5 11.5 13.5 15.5

Prob

abili

ty

Daily Intensity (mm/rainy days)

1970s

2020s

2050s

2080s

No of days when rainfall > 20mm

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

6 11 16 21 26

Prob

abili

ty

Days of rainfall, rt > 20mm (days)

1970s

2020s

2050s

2080s

Impact of Climate Change

Possible Climate Change Impact for Bangladesh

• Increase of intensity and duration of natural disasterssuch as floods, Cyclones and Storm Surges.

• Increase of moisture stress (droughts) due to erratic precipitation

• Salinity intrusion due to Sea Level Rise• Inundation due to sea level rise leading towards

“Climate Refugees”• Effect on health and livelihood of coastal people. • Effect on Bio-diversity, Ecology & Sundarbans. • Hampered Food Security & Social Security.

Temperature Data Analysis of last 60 years (1947-2007)

Mean daily temperature of Bangladesh has increased with a rate of 1.03 0C per century

y = 0.0103x + 25.428R2 = 0.2996

23

24

25

26

27

1948

1953

1958

1963

1968

1973

1978

1983

1988

1993

1998

2003

2008

(c)

Increase of Costal Inundation due to Sea Level Rise and Intense Storm

Source: Murshed, M., Ahmed,Z., Khan, Z.H., and Hasan, M.M. (2010) Vulnerability of Coatal Region due to Storm Surge Inundation in Changing Climate, Proceedings of the International MIKE by DHI Conference 2010, Denmark

SMRC, 2005 IWM, 2010

Change of Flood Inundation area

Source: IWM study for WARPO (2001)

Impact of Crop Yield

-30

-20

-10

0

10

20

30

Rajbari Chapai Nawabganj

Satkhira Sunamganj

2020s

2050s

2080s

-2

-1

0

1

2

3

4

Rajbari Chapai Nawabganj

Satkhira Sunamganj

2020s

2050s

2080s

Boro Rice T. Aman Rice

Source: Mondal et al. (2012) Changes in the Spatial and Temporal Distribution of Temperature, Rainfall, Sunshine and Humidity in Bangladesh, Final Report, CDMP.

Responsibility ?

Global Emission

Per capita CO2 emission

Per capita emission

Bangladesh1990 – 0.1 ton2009 – 0.36 ton

Facing Climate Change • National Awareness building

– Capacity Building through Training – Innovative Research for knowledge generations

• Mitigation – Reduce Co2 emission, Use Green technology– Use of Alternative Energy sources – Solar, Wind etc.

• Adaptation –– Build Shelters, Rise Embankments & Polders, Roads, Houses– Salinity tolerant crops, Afforestation, Alternative livelihood, improve

warning system, migrations • Global and National Awareness & Justice

– Kyoto Protocol, COP, – BCCSAP…. Raise our voice !

Thank you