High-resolution Climate Scenarios for the 21st High-resolution Climate Scenarios for the 21st Century and Applications in Impacts Century and Applications in Impacts

Assessments on Water Resources in ChinaAssessments on Water Resources in China

Yinlong XU Yinlong XU （（许 吟隆许 吟隆））Institute of Environment and Sustainable Development in Agriculture,

Chinese Academy of Agricultural Sciences (CAAS)Beijing, China

Tel: +86 10 8210 9766; Fax: +86 10 8210 6012 E-mail: xuyl@ami.ac.cn

24 Feb. 2008

ContentContentBackground of climate change researchConstruction of high-resolution climate

change scenarios with PRECISClimate change responses under SRES A2

& B2 GHGs emissions scenariosMethodology to employ PRECIS outputs for

impacts assessmentsSome results of impacts assessments on

Chinese natural ecosystems and water resources

Questions to discuss

The warming is the most obvious in the mid- & high-latitudes

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

The warming ratio in 1901 － 2000 年）

℃/decade

The warming ratio in winter in 1976 － 2000

-1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

℃/decade

Warming BackgroundWarming Background

近近 5050 年温度变化年温度变化

There have been totally 22 warming winter already in China

Warming over China

Annual mean temperature

increase in past 50 years

The warming projection The warming projection in IPCC AR4in IPCC AR4

Data resources: Ding YH

An introduction to downscalingAn introduction to downscaling

GCMs

Horizontal resolution:

~110-600 km

ImpactsModels

Downscaling

Localdetails

Methods for downscalingMethods for downscaling

Simple interpolation

Statistical method

Regional climate model (RCM)

RCM + statistical

A demo for RCM downscalingA demo for RCM downscalingHadAM3P

PRECIS

A demo for RCM downscaling

Downscaling with RCMDownscaling with RCM

GCM Lateral Boundary

Initial Conditions

RCM

Other Forcings

What is PRECIS?What is PRECIS?

PRECIS—Providing Regional Climates for Impacts Studies

Purpose 1: to develop the regional-level SRES climate scenarios over the world

Purpose 2: to provide the datasets for the impacts assessments of climate change at the regional-level

The climate The climate change scenarios change scenarios

in China are in China are developed based developed based on SRES socio-on SRES socio-

economic economic assumptionsassumptions

SRES: IPCC 2000, Special Report on Emission Scenarios

PRECIS InterfacePRECIS Interface

Job status of PRECISJob status of PRECIS NCEP re-analysis data: 1979-20031979-2003

ECMWF re-analysis data: 1957-20011957-2001

ECMWF re-analysis data: 1979-19931979-1993

HadCM3HadCM3 （（ UK Met Office Hadley CentreUK Met Office Hadley Centre ）） Baseline (1961-1990): No1No1 No2 No3No2 No3

A2 (2071-2100): No1 No2 No3No1 No2 No3

B2 (2071-2100) : No1 onlyNo1 only

A1B (1961-2100): No1 onlyNo1 only

ECHAM4ECHAM4 （（ Germany MPIGermany MPI ）） A2 (1961-2100): No1 onlyNo1 only

B2 (1961-2100) : No1 onlyNo1 only

Domain of PRECISDomain of PRECIS

TerrainTerrain

Cliamte Change Responses over whole China Cliamte Change Responses over whole China under B2 scenariounder B2 scenario——Maximum/minimum Maximum/minimum

temperaturetemperature

Cliamte Change Responses over whole China Cliamte Change Responses over whole China under B2 scenario----precipitationunder B2 scenario----precipitation

Cliamte Change Cliamte Change Responses over Responses over

whole China whole China under A2 under A2

scenario in scenario in 2080s relative to 2080s relative to baseline (1961-baseline (1961-

1990)1990)

Temperature precipitationTemperature precipitation

Annual AnnualAnnual Annual

Winter WinterWinter Winter

Summer SummerSummer Summer

Temperature (Temperature (C) and precipitation changes (%) C) and precipitation changes (%) in Southwest China and whole Chinain Southwest China and whole China（（ 20712071 ～～ 2100 vs 19612100 vs 1961 ～～ 19901990 ））

SeasonSouthwest China Whole China

A2 B2 A2 B2

T P T P T P T P

Spr 3.8 16 2.6 9 3.8 21 2.9 13

Sum 4.2 13 3.1 8 4.9 13 3.8 6

Aut 4.0 16 2.7 7 4.5 23 3.3 3

Win 4.2 12 3.1 6 4.4 11 3.5 9

Anl 4.1 15 2.9 8 4.5 17 3.3 10

Extreme Climate Events Criteria-1Extreme Climate Events Criteria-1

Criteria Definition

SU daily maximum temperature is over 25 ℃

CFD the largest number of consecutive days with daily minimum temperature below 0 ℃

GSL

number of days between the first occurrence of at least 6 consecutive days with daily mean temperature above 5 and the first ℃occurrence after 1st July of at least 6 consecutive days with daily mean temperature below 5 ℃

R20mm

extreme precipitation events with daily precipitation amounts greater than or equal to 20 mm

Extreme Climate Events Criteria-2Extreme Climate Events Criteria-2

Criteria DefinitionRX5day maximum precipitation amount for the 5-day

interval

SDII

ratio of the daily precipitation amount for wet days (daily precipitation amounts greater than or equal to 1 mm) to the number of wet day

CDD

Consecutive dry days is calculated base on the largest number consecutive days with daily precipitation below 1mm

TX95

put daily maximum temperature of one year in a increase order, then TX95 is defined as the 95 percentage of the maximum temperature of this year

a. SU

b. CFD

c. GSL

d. R20mm

e. RX5day

f. SDII

(Unit: %)

Changes of Extreme Climate EventsChanges of Extreme Climate Events2071-2100 vs 1961-1990, SRES A22071-2100 vs 1961-1990, SRES A2

a. SU

b. CFD

c. GSL

d. R20mm

e. RX5day

f. SDII

(Unit: %)

Changes of Extreme Climate EventsChanges of Extreme Climate Events2071-2100 vs 1961-1990, SRES B22071-2100 vs 1961-1990, SRES B2

ImpactImpactss Assessment Assessmentss of Climate Change of Climate Change on on Chinese Chinese AgricultureAgriculture

HadCM2ECHAM4

MonthlyT, P

WeatherGenerator

DailyTmax/min, Pre, Srad

CropVarities

SoilData

ManagementData

CropModels

YieldChanges;

etc

ImpactImpactss Assessment Assessmentss of Climate Change of Climate Change on on Chinese Chinese AgricultureAgriculture

WeatherGenerator==>RCM

DailyTmax/min, Pre, Srad

CropVarities

SoilData

ManagementData

Cropmodels

YieldChanges,

etc

How to use future climate change scenariosHow to use future climate change scenariosfor impacts assessmentfor impacts assessment

Observation

Baseline Future scenarios

2050sunder B2 scenario

Impacts of CC Impacts of CC on natural on natural systemssystems

2080sunder B2 scenario

Changes of runoff in China

The drought would be enhanced along the Yellow River

While the potential flooding risk along the Yangtze River would increase under SRES A2 scenario

A2 与基准年

B2 与基准年

Similar to A2 scenario, but amplitude is not so large as A2 scenario

人均径流量变化图

不考虑气候变化

A2情景

B2情景

A2 （ 2080S ）与基准年

全国径流深变化图

气候变化对水资气候变化对水资源的影响源的影响

Questions to discussQuestions to discuss

To generate higher-resolution climate scenarios

More research fields to expandMore analyses on CC I&V assessmentsCase study on adaptation optionsAddressing the uncertaintiesDeveloping Provincial Strategies to Cope

with CC

ChinaChina’’s INC on CCs INC on CC & & thethe 11stst Version Version of National of National Assessment Report on CC ImpactsAssessment Report on CC Impacts

Computer network to run PRECISComputer network to run PRECIS

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