Impact of Climate Change on India’s Monsoonal Climate and Development of High Resolution Climate Change Scenarios for India Presentation made to Shri Jairam Ramesh, Hon. Min. MoEF 14 October, 2009, New Delhi
K. Krishna Kumar (
[email protected])
Indian Institute of Tropical Meteorology, Pune
Things to follow… Observed changes in India’s Monsoonal Climate Climate Change Projections based on IPCCAR4 Development of high-resolution regional climate change scenarios and projections
IPCC-AR5 Climate Modeling Strategies
Changes in the Frequency Distribution of Extremes during 1951-1970 and 1980-2000
Goswami et al., Dec., 2006
Indian Trends: 0.51C/100yr (1901-2007); 0.20C/10yr (1971-2007) Global Trends: 0.82C/100yr (1901-2007); 0.24C/10yr (1971-2007)
Possible Role Aerosols in Indian Temperature Trends Tmax Nov-May
1951-1990
1991-2007
Tmax Nov-May
North of 20N
South of 20N
Tmin Nov-May
240
Trend = -0.89
235
2
Flux (W/m )
230
Aerosols
Radiation Received At the surface
225 220 215 210 205 200 1980
1984
1988
1992
1996
Year
2000
2004
2008
Important points emerging from the Met. Observations of 20th Century
No long-term trend in all-India mean Monsoon Rainfall since 1871 Epochs of above/below normal monsoon activity with a periodicity of approximately 3 decades – the current below normal epoch is still continuing Some changes are taking place in the monsoon rainfall character increase in the frequency and intensity of heavy rainfall events at the expense of low rainfall events Substantial decline in monsoon depressions and increase in low-pressure systems All-India mean annual temperatures during 1901-2007 show an increasing trend of 0.51C/100yrs with an accelerated warming of 0.21C/10yrs after 1970s. Flattening of trends during the current decade with a warming of 0.1C/10yrs Temperature trends in India are slightly lower compared to Global trends – probably due to large aerosols presence in the Indo-Gangetic region
Expected Future Changes Under Increased GHG Conditions IPCC-AR4
IPCC AR4 Simulations
Historical run: 20th Century simulation Future climate simulations (initial conditions from end of the 20th Century simulation):
“Committed Climate Change”: hold concentrations at year 2000 SRES A2 to 2100 SRES A1B to 2100 then fix concentrations (~720 ppm) for an additional century (with one realization extended to 2300) As above but with SRES B1 (~550 ppm)
Global Mean
Indian Region
The model simulation data of the above runs are available through IPCC-DDC/ PCMDI, USA and has already exceeded 40TB
Expected Future Changes in Rainfall and Temperature over India under IPCC SRES A1B GHG Scenarios
Krishna Kumar et al, 2009
Expected Future Change in Monsoon Rainfall and Annual Surface Temp for 2020’s, 2050’s and 2080’s
Rainfall
Temp
Krishna Kumar et al, 2009
Other Expected Changes in Monsoon Features Length of Season
Annual Cycle
Monsoon Variability
Monsoon & ENSO
Krishna Kumar et al, 2009
Future (A1b-20C) Global Rainfall/SST Column integrated Moisture
Precipitation
SSTa
Monsoon Circulation Strength
Krishna Kumar et al, 2009
Cascade of uncertainty in climate change prediction
Emissions Scenarios
Concentration Calculations Biogeochemical/Chemistry Models Global Climate Change Simulation AOGCMs, Radiative Forcing Regional Climate Change Simulation. Regionalization Techniques Impacts Impact Models
Natural Forcings
Interactions and Feedbacks Land Use Change
Policy Responses: Adaptation and Mitigation
Socio-Economic Assumptions
Major Outcomes of IPCC-AR4 Model Projections for India
No significant change in monsoon rainfall until about 2050s and an increase in the order of 8-10% towards the end of 21st Century – biases and larger spread across models in the projected changes leading to lesser confidence Projected future increase in the monsoon rainfall appears to be caused by an increase in the total moisture content in the atmosphere rather than an increase in the strength of monsoon circulation A hint of ~10% increase in the variability of monsoon rainfall from the current levels in the future; possibility for the stretching of monsoon season with a substantial increase in the rainfall during May and October An El Nino like response of sea surface temperatures in the Pacific associated with increased monsoon could have implications for the seasonal prediction of monsoon in the future Expected future changes in temperatures over India range from 1C to 4C for a range of IPCC GHG emission scenarios – lesser spread across models indicate higher confidence in the projected changes
High-Resolution Regional Climate Change Scenarios Dynamical Downscaling using Regional Climate Models
GCMs to Regional Adaptive Responses : Modelling Path Cs = f(Cl, Øs ) Cs - small scale climate Cl - large scale climate Øs - physiographic details at small scale
PRECIS Runs at IITM (Resolution: 50km)
Evaluation experiment using LBCs derived from ERA-15 (1979-93)
LBCs from Hadley Centre Models • Baseline (1961-90) – 3 members • A2 scenario (2071-2100) -3 members • B2 scenario (2071-2100) • 3 Members of QUMP (1961-2100) – A1b
LLBCs from ECHAM Baseline 1961-1990; A2 scenario :1991-2100; B2 scenario : 1991-2100
Climate change research in India INDO-UK GEF/UNFCCC MoEF Govt. of India
ERM Int. India
Climate Change Scenario Development I.I.T.M, Pune Agriculture IARI, Delhi
Ecology & Forests
Water
IISc, Bangalore
IIT, Delhi
Energy TERI, Delhi
Sea Level NIO, Goa
Industry & Transportation IIM, Ahmedabad
PRECIS captures important regional information on summer monsoon rainfall missing in its parent GCM simulations. HadCM3
PRECIS
Possible Climate Change impacts are examined in the:
Extremes in rainfall and temperature Onset and advance of Monsoon Active/break cycles Intensity and frequency of Monsoon Depressions
Impacts of Climate Change on Monsoon Depression Tracks and Intensity
Projections of Regional Tmax and Daily Rainfall Changes
Highest daily Tmax (C) in The Baseline Period
Expected change in Tmax in Future under A2
Expected change in No. of Rainy Days In future under A2
Expected change in Rainfall Intensity in a rainy day in future
Krishna Kumar et al, 2009
Impact of Growing Season Rainfall and Night time Temps on Rice Yields in India Tmin (°C) Baseline SRES A2
Tmax (°C)
Impact of Daily Tmax on the Mortality rate at Delhi (Source: Hazat et al 2005) Krishna Kumar et al, 2009
Flattening Food Production Trends
Ground Water Status
Milesi et al, 2009
Further insights emerging from highresolution RCM based regional scenarios
Providing regional climate inputs for impact assessments in different sectors Decrease in number of rainy days and increase in the intensity of rainfall on a given rainy day in the future Extremes in rainfall and temperature are showing an increase No significant change in the date of onset of monsoon but the variability of onset date appears to be higher in the future No significant change in the frequency of cyclonic storms/monsoon depressions but the intensity of storms seem to be higher by 10% in the future More simulations are needed to gain confidence in the projected future changes in the finer characteristics of monsoon
IPCC-AR5 Modeling Strategy
IPCC RCP Scenarios
IMS Extremes Workshop, New Delhi, 19 April, 2007
A Coordinated Regional Climate Downscaling Experiment under WCRP CORDEX
Current thinking on Coordinated Regional Projection Experiment framework The regional climate change information in Chapter 10 of the TAR and AR4 was essentially based on AOGCM simulations
The resolution of CMIP5 simulations that will form the main input for IPCC-AR5 are not going to be very different in the resolution compared to CMIP-3 (IPCC-AR4)
Resulting in the relevance & usefulness of high-resolution regional Scenarios using RCMs for the IPCC-AR5 (Source: Fillippo Georgi, ICTP)
IMS Extremes Workshop, New Delhi, 19 April, 2007
Regional Inter-comparison Projects ARCMIP PRUDENCE ENSEMBLES NEWBALTIC PIRCS NARCCAP SGMIP AMMA AFRMIP AIACC
PLATIN ARC
RMIP
Issues on which a Scientific Consensus has not yet been arrived On the future projected strength of monsoon circulation and the quantum of rainfall Projected changes of sub-seasonal monsoon behavior (eg. Onset, ISOs, Monsoon Depressions, Extremes etc.) – Partly Limited by Resolution of CMIP3 The response of ENSO to Global Warming The future strength of ENSO-Monsoon link
Current Gaps in Modeling/Observations
Problems with the current generation of coupled models in simulating some features of mean monsoon and its interannual/decadal variability Large biases in the simulated ENSO characteristics and its tele-connection with Monsoon
Role of Regional Aerosols on the Monsoon and their non-explicit inclusion in coupled simulations
Large gaps in observations (both on land and ocean) leading to problems with modeling tropical convection, particularly over the monsoon region
Thank you!
Some Aspects of Asian Summer Monsoon Rainfall and Its ENSO Teleconnections as simulated by AR4 Models in 20th Century Mean Monsoon Rainfall
Monsoon and ENSO
Krishna Kumar et al, 2009
Tropical Waves; MJOs
Lin et al. 2006, J. Climate
New Observational Programs
AMY (Asian Monsoon Years, 2007-2012, a multi-national program under WCRP) YOTC (Year of Tropical Convection :2008-2012, WCRPWWRP/THORPEX joint Initiative) MAHASRI (Monsoon Asian Hydro-Atmosphere Scientific Research and Prediction Initiative; 2006-2015,WCRP) CTCZ (Continental Tropical Convergence Zone : 2009, a multi-year program under Indian Climate Research Program) CAIPEEX (Cloud Aerosol Interaction and Precipitation Enhancement Experiment: 2009-2012, a multi-institutional program under IITM/MoES, Govt. of India)
