State of Climate Change and Water Modeling in Bangladesh A.K.M. Saiful Islam Associate Professor, IWFM Coordinator, Climate Change Study Cell Bangladesh University of Engineer and Technology (BUET) Training Program on Water Security and Climate Change

Presentation Outline Overview of the Trend of temperature of Bangladesh and Climate System Modeling of Climate Change General Circulation Model (GCM) IPCC SRES Scenarios Climate Change Scenarios Regional Climate Model (RCM) Climatic Modeling at BUET Storm Surge and Salinity modeling due to SLR

Location of BMD Stations Temperature Stations (30) Rainfall Stations (30)

Trends of Temperature of Bangladesh ( ) Max. Temp. = C/100 year Min. Temp. = C/100 year

Trends of Discharge

Maximum Temperature Maximum increase: at Shitakunda Minimum increase: at Rangpur Minimum Temperature Maximum increase: at Bogra Minimum increase: at Tangail Spatial Distribution of Trends of Temperature ( )

Climate Models Climate models are computer-based simulations that use mathematical formulas to re-create the chemical and physical processes that drive Earth’s climate. To “run” a model, scientists divide the planet into a 3-dimensional grid, apply the basic equations, and evaluate the results. Atmospheric models calculate winds, heat transfer, radiation, relative humidity, and surface hydrology within each grid and evaluate interactions with neighboring points. Climate models use quantitative methods to simulate the interactions of the atmosphere, oceans, land surface, and ice.

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.

GCM typical horizontal resolution of between 250 and 600 km, 10 to 20 vertical layers in the atmosphere and sometimes as many as 30 layers in the oceans.

Heart of Climate Model Conservation of momentum Conservation of mass Conservation of energy

Complexity of GCM

Hardware Behind the Climate Model Geophysical Fluid Dynamics Laboratory

Special Report on Emissions Scenarios (SRES) The Special Report on Emissions Scenarios (SRES) was a report prepared by the Intergovernmental Panel on Climate Change (IPCC) for the Third Assessment Report (TAR) in 2001, on future emission scenarios to be used for driving global circulation models to develop climate change scenarios. It was used to replace the IS92 scenarios used for the IPCC Second Assessment Report of The SRES Scenarios were also used for the Fourth Assessment Report (AR4) in 2007.

SERS Emission Scenarios A1 - a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter, and the rapid introduction of new and more efficient technologies. Three sub groups: fossil intensive (A1FI), non-fossil energy sources (A1T), or a balance across all sources (A1B). A2 - A very heterogeneous world. The underlying theme is that of strengthening regional cultural identities, with an emphasis on family values and local traditions, high population growth, and less concern for rapid economic development. B1 - a convergent world with the same global population, that peaks in mid-century and declines thereafter, as in the A1 storyline. B2 - a world in which the emphasis is on local solutions to economic, social and environmental sustainability.

GCM output described in the 2007 IPCC Fourth Assessment Report (SRES scenarios), multilayer mean ModelsVariables BCC:CM1 BCCR:BCM2 CCCMA:CGCM3_1-T47 CCCMA:CGCM3_1-T63 CNRM:CM3 CONS:ECHO-G CSIRO:MK3 GFDL:CM2 GFDL:CM2_1 INM:CM3 IPSL:CM4 LASG:FGOALS-G1_0 MPIM:ECHAM5 MRI:CGCM2_3_2 NASA:GISS-AOM NASA:GISS-EH NASA:GISS-ER NCAR:CCSM3 NCAR:PCM NIES:MIROC3_2-HI NIES:MIROC3_2-MED UKMO:HADCM3 UKMO:HADGEM1  specific humidity  precipitation flux  air pressure at sea level  net upward shortwave flux in air  air temperature  air temperature daily max  air temperature daily min  eastward wind  northward wind

Prediction of Global Warming Figure 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.

Prediction of Temperature increase

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)

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

Regional details of Climate Change

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

Regional Climate change modeling in Bangladesh PRECIS regional climate modeling is now running in Climate change study cell at IWFM,BUET. Uses LBC data from GCM (e.g. HadCM3). LBC data available for baseline, A2, B2, A1B scenarios up to Predictions for every hour. Needs more than 100 GB free space.

Domain used in PRECIS experiment

Topography of Experiment Domain Zoom over Bangladesh Simulation Domain = 88 x 88 Resolution = 0.44 degree

Yearly Average Temperature

Yearly Average Temperature Map Station PRECIS

Yearly Average Precipitation of Bangladesh

Yearly Average Precipitation Map Station PRECIS

Predicted Change of Mean Temperature ( 0 C) using A1B Baseline = 2000

Change of Mean Rainfall (mm/d) using A1B Scenarios Baseline = 2000

Predicting Maximum Temperature using A2 Scenarios [Output of PRECIS model using SRES A2 scenario]

Change of Mean Rainfall (mm/d) using A1B Scenarios Baseline = 2000

Change of mean climatic variables of Bangladesh using A1B Scenarios Temperate ( 0 C)Rainfall (mm/d)

High-resolution Regional Climate Change Information for Bangladesh to inform Impacts assessments, Vulnerability indicators and Adaptation policies Experiment IDDescription of the SimulationTime FrameLength( years) adqcmERA40:Reanalysis erainERA-Interim: Reanalysis ncepbNCEP_R2:Reanalysis addfaHadAM3P:Baseline# addfbHadAM3P:Baseline# addfcHadAM3P:Baseline# addjaHadAM3P:SRES_A2# addjeHadAM3P:SRES_A2# addjfHadAM3P:SRES_A2# addjdHadAM3P:SRES_B aenwhHadCM3Q0:SRES_A1B echfaECHAM4:Baseline echjaECHAM4:SRES_A echjdECHAM4:SRES_B echvcECHAM5:SRES_A1B

Storm Surge Model during SIDR Source: Advanced Circulation (ADCIRC) model to predict storm surge Hassan Mashriqui, an assistant extension professor of coastal engineering of Louisiana State University (LSU) Has simulated storm surge model during SIDR

2D Hydrodynamic Modeling for Salt water Intrusion Five ppt line for different sea level rise in dry season IWM studied “Impact of Sea level Rise on Coastal Rivers of Bangladesh”

What will happen to Artic Polar Bears ?

Antarctic Penguins are watching…

The Sundarbans..Mangrove forest?

Thank you