Quantifying the Likelihood of Climate Change over the Zambezi River Basin: A Hybrid Approach

Transcription

1 Quantifying the Likelihood of Climate Change over the Zambezi River Basin: A Hybrid Approach Quantify the climate-change risk of the greater Zambezi River Basin, by covering the range of uncertainty in the global and regional climate response as well as emissions under climate policies. C. Adam Schlosser (MIT), Ken Strzepek (MIT), Channing Arndt (WIDER), Xiang Gao (MIT), Andrei Sokolov (MIT), James Thurlow (WIDER), Sergey Paltsev (MIT), Arthur Gueneau (MIT), Charles Fant (WIDER), and Sherman Robinson (IFPRI) UNU-WIDER World Institute for Development Economic Research

2 UNCERTAINTY IN REGIONAL CHANGE Simulated Precipitation Change in 21 st Century: A1B Scenario Opposing Climate Model Results at the Regional Scale HOW TO PREPARE WHEN REGIONAL CHANGES DIFFER IN SIGN?

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6 HOW DEPENDABLE ARE CLIMATE-CHANGE FORECASTS?

7 HOW DEPENDABLE ARE CLIMATE-CHANGE FORECASTS?

8 HOW DEPENDABLE ARE CLIMATE-CHANGE FORECASTS?

9 HOW DEPENDABLE ARE CLIMATE-CHANGE FORECASTS?

10 HOW DEPENDABLE ARE CLIMATE-CHANGE FORECASTS?

11 The MIT Integrated Global System Model (IGSM) An Integrated Assessment Model (IAM) (IGSM2: SOKOLOV ET AL., 2005, JP TECH. REPORT #124 EPPA: PALTSEV ET AL. 2005, JP TECH. REPORT #125 LAND: SCHLOSSER ET AL., 2007 JP TECH REPORT #147 OCEAN: DUTKIEWICZ ET AL., 2005, JP TECH. REPORT #122)!

12 Emissions Policy and Prediction Analysis (EPPA) APPROXIMATELY 100 (UNCERTAIN) PARAMETERS THAT INCLUDE:" PRODUCTIVITY GROWTH" ENERGY EFFICIENCY" EASE OF SUBSTITUTION" COSTS OF NEW TECHNOLOGY" MAIN OUTPUTS: EMISSIONS, PRICES, GDP, AND WELFARE"

13 Key Uncertain Elements in Climate Change EMISSIONS UNCERTAINTY CLIMATE SENSITIVITY (CHANGE IN TEMPERATURE DUE TO CHANGE IN RADIATIVE FORCING). HEAT UPTAKE BY DEEP OCEAN (& CARBON UPTAKE) RADIATIVE FORCING OF AEROSOLS CO 2 FERTILIZATION EFFECT ON ECOSYSTEM (WIDE RANGE) TRENDS IN PRECIPITATION FREQUENCY Forest et al., 2008

14 IGSM Scenarios (Sokolov et al., 2009, and Webster et al., 2009)

15 HOW CAN WE EXPRESS THE VALUE OF A CLIMATE POLICY UNDER UNCERTAINTY THAT TRANSLATE INTO ODDS OF CLIMATE CHANGE? Compared with NO POLICY 96% chance > 3ºC What would we achieve with STABILIZATION of CO 2 at 550 ppm? 14% chance > 3ºC A NEW WHEEL with lower odds of EXTREMES

16 IGSM Precipitation Changes: Unconstrained Emissions Changes in decadal-averaged precipitation at time of CO 2 doubling mm/day Whisker plots convey plausible range in projections ZAMBEZI LATITUDE

17 CHARACTERIZING REGIONAL CLIMATE- CHANGE UNCERTAINTY IN THE IGSM: A HYBRID APPROACH Schlosser et al., Journal of Climate, 2012 (in press) V IGSM =(C + dc x,y * ΔT IGSM IGSM )*V x,y x,y!! dt Global y Global dc x,y Regional climate change kernel shi$ in pa)erns in tandem with global : temperature, based on the CMIP3/IPCC archive (~17 GCMs). dt Global

18 Surface-air temperature: Seasonal Averages C December-February Summer June-August Winter CRU OBSERVATIONS

19 Precipitation: Seasonal Averages mm/day December-February SH Summer June-August SH Winter GPCP OBSERVATIONS

20 Regional Climate-Change Kernels: DJF Surface-Air Temperature CMIP3/IPCC Models CMIP3/IPCC Model Mean Schlosser et al., 2012 Climate- change pa_ern kernels from the IPCC AR4 climate models used to construct hybrid climate- change distribuaons from the IGSM. Shown are the relaave changes in DJF surface- air temperature in response to a unit global temperature increase as a result of anthropogenic greenhouse emissions.

21 Regional Climate-Change Kernels: DJF Precipitation CMIP3/IPCC Models CMIP3/IPCC Model Mean Schlosser et al., 2012 Climate- change pa_ern kernels from the IPCC AR4 climate models used to construct hybrid climate- change distribuaons from the IGSM. Shown are the relaave changes in DJF precipitaaon in response to a unit global temperature increase as a result of anthropogenic greenhouse emissions.

22 Western Zambezi Frequency Distributions 2050 Decadal Average Surface-Air Temperature Change: Spring!"'$#!"'!#!"&$#./0)/12345/67#895115)/1# %#()#%"&$# %"&$#()#%"$# %"$#()#%"*$# %"*$#()#&#,-# &#()#&"&$# &"&$#()#&"$# &"$#()#&"*$# &"*$#()#'# '#()#'"&$# '"&$#()#'"$# '"$#()#'"*$# '"*$#()#+# Schlosser et al., 2012

23 Eastern Zambezi Frequency Distributions 2050 Decadal Average Surface-Air Temperature Change: Summer Schlosser et al., 2012

24 Western Zambezi Frequency Distributions 2050 Decadal Average Precipitation Change: Spring!")!#!"(!# <0:30,-=/>0+9#?7>,,>30,# *+,,#-./0#1)# 1)#23#1(# 1(#23#1'# 1'#23#1&# 1&#23#1%# 1%#23#1$# 1$#23#!#!#23#$# :/9;# $#23#%# %#23#&# &#23#'# '#23#(# (#23#)# )#23#4# 4#23#5# Schlosser et al., 2012

25 Eastern Zambezi Frequency Distributions 2050 Decadal Average Precipitation Change: Summer!"($#!"(!# )*A*B#$#C,.D?B?E.F3/#!"!'#!"!&#!"!%#!"!$#!"!!# )*++#,-./#0&# 01"1#23#01# 0%"1#23#0%# 04"1#23#04# 0$"1#23#0$# 0("1#23#0(# 0!"1#23#!#!"1#23#(# ("1#23#$# $"1#23#4# 7889:*;.:<# 4"1#23#%# %"1#23#1# 1"1#23#&# &"1#23#5# 5"1#23#'# '"1#23#6# 6"1#23#(!# Schlosser et al., 2012

26 Closing Remarks Approach to span plausible outcomes across economic and global-to-regional climate uncertainties. Effect of economics and policy is multi-faceted in the climate distributional responses. Seasonality Mode Skewness Results from higher- resoluaon regional model (right column) compared to its global climate model counterpart. GFDL2.1 RCM3 Beyond linearity? More details please? THANK YOU!