climate change, water security and agriculture

Climate Change, Water Security

and Agriculture

Jinxia Wang Jikun Huang

Center for Chinese Agricultural Policy (CCAP)

Chinese Academy of Sciences

Presentation

• Impacts of climate change on net crop

revenue

• Farmers’ response to climate change

• Impacts of climate change on water security

and agriculture

Impacts of Climate Change on

Agriculture

• Agronomic studies (In China and other developing countries):

Climate change reduces crop yield (-)

Assume the same crops in the same place

Without considering farmers’ adaptations

• Economic studies based on Ricardian model (Africa,

South America, Brazil, India, …):

Climate change reduces farmer revenue

Except in cool locations and some places with irrigation (Egypt)

Considering farmers’ adaptations

• So, considering the adaptations, what will happen to

China when climate changes?

Research Questions

• What are the impacts of climate

change on agriculture (net crop

revenue)?

• How do farmers adapt to climate

change (irrigation or crop choice)?

Economic Approach: Ricardian

Model

• Regress net revenues (or land values)

on climate, soil, characteristics of

village and household

• Include climate by season in

quadratic (second order

approximation) form

• Examine all farms, rainfed and

irrigated farms.

Data…

• Climate data:- Source:

National Meteorological Information Center

- Monthly temperature and precipitation from

meteorological 733 stations

- 1951~2001

- Divide into four seasons:

Spring: 3~5; Summer: 6~8

Fall: 9~11; Winter: 12~2

- Calculate the average annual temp. and prec.

for each season using data from 1951~2001

Data…

• Socio-economic Data

-- Source:

China’s National Bureau of Statistics

Nation-wide Household Income and Expenditure

Survey

-- Sample:

Counties having both meteorological stations and HH

8405 HH in 915 villages, 124 counties and 28 provinces

Data…• Socio-economic Data

-- Net crop revenue by HH:

Gross crop revenue (or total sales for each crop) less

than

All expenditures for production (seed, fertilize, irrigation,

pesticide, machinery, plastic sheeting, hired labor and

custom services, not including land rent and family labor)

Return to land and family labor

-- Household and village characteristics

Education level of household members

Family’s land area

Topographical environment of each village (plain or mountain)

Irrigation status (share of irrigated areas)

Easy to access to market (road, distance to township government)

Data

• Soil Data

-- FAO

-- Clay, sand and loam soils

-- Share of cultivated areas with

each

type of soil at county level

Average Annual Marginal Impacts of

Climate Change on Net Crop Revenue in

China

All farmIrrigated

farm

Rainfed

farm

Temperature -10 68 -95

Precipitation 15 27 23

Changes of net revenue due to minor change of climate (USD/ha)

Minor increase of temperature will reduce the net revenue of all

farms, especially for rainfed farms; however, minor increase of

precipitation will increase the net revenue of all farms

Marginal Temperature Effect, Irrigated Farms

Warmer temperature are more beneficial in the Southeast and southwest region.

Farms in the Central region enjoys mild benefits from warming, however,

the far north will be damaged by warming

Marginal Precipitation Effect, Irrigated Farms

Almost all Irrigated farms enjoy small benefits from increased rainfall

Marginal Temperature Effect, Rainfed Farms

Warming is likely helpful to rainfed farmers in very cold places but it will

likely harm rainfed farmers in most of China and especially the far south

Marginal Precipitation Effect, Rainfed Farms

More rain is likely to be harmful to rainfed farmers in the wet

southeast but will benefit farmers in the remaining regions

Summary: Impacts of Climate Change

on Net Crop Revenue in China

• The average impact of higher temperature is negative and the average impact of more precipitation is positive;

• However, effects will vary by region;

• Rainfed farmers are more vulnerable

than irrigated farmers;

• Irrigated farmers are less sensitive to

temperature and gain from increased

rainfall.

Advantage of Economic

Approach and Its Limitation

• Advantage of the Economic Approach (Ricardian model)-- It provides an estimate of the benefits derived from adaptation

-- After considering adaptations, farmers’ losses from warming will be

greatly reduced and even slightly gain especially for irrigated farms

-- The results of crop model can be treated as without adaptation

• Limitation on the data-- Do not know how much water farmers used in irrigation, cannot

quantify the effect of water in the economic model

-- If climate change does reduce water supplies, there will be harmful

impacts on agriculture

When Climate Changes, How

Farmers Make Response?

• How will changes of temperature

and precipitation influence

irrigation choice?

• How will changes of temperature

and precipitation influence crop

choice?

Annual Marginal Effect of Climate

Change on Irrigation Choice in China

Sign of Marginal Effect

Temperature _

Precipitation _

Increasing temperature and precipitation will promote

farmers to switch from irrigated agri. to rainfed agri.,

Chinese farmers are more likely to irrigate when facing

lower temperatures and less precipitation

Annual Marginal Effect of Climate

Change on Crop Choice in China

Temperature Precipitation

Wheat + -

Maize + -

Rice - +

Cotton + +

Oil + +

Potato - -

Soybean - +

Sugar - +

Vegetable - +

Summary: Adaptation

Results

• As temperatures warm, move away

from cool loving crops towards heat

tolerant crops

• As precipitation falls, move away

from wet loving crops towards

drought tolerant crops

• Impacts of climate change on

water security and agriculture

Climate Changes Other drivers

(Temp./ Prec.) (social/economic/policy/institution…)

CWSM: to project changes in water

supply/availability/water demand

CAPSiM/GTAP: to project agricultural

production/trade/price/income/policies

Adaptation measures to mitigate

climate change risksRisk of climate

change

Simulation: options for institutional and

policy instrument to facilitate adaptation

Conceptual Framework: From Separate to Comprehensive

Models Used in the Analysis

• China’s Water Simulation Model

(CWSM)

• China’s Agricultural Policy

Simulation Model (CAPSiM)

• Global Trade Analysis Program

(GTAP)

Surface water supply

Climate Change(Temp. /Prec.)

Social/Economic, Policy and

Institutional Changes

Groundwater supply

Irrigation water

demand

Industry water

demand

Domestic water

demand

Water

supply

Irrigatedarea

Irrigation efficiency

Industry

GDP

Water productivity

Domestic water quota

Water

demand

Water Surplus or Deficit

Ecological water

demand

Crop ET/Effective rainfall

Population/Urbanization

China’s Water Simulation Model (CWSM)

Output price

Input price

investment：－R&D

－Water

Climate

Others

Area

Yield

Production Stock

Import

Export

Price

Demand

Food

Feed

Seed and others

China’s Agricultural Policy Simulation Model (CAPSiM)

Income

Price

Population

Urbanization

Market

Others

Supply

Livestock product model

Global Trade Analysis Program (GTAP)

• Multi-country, multi-sector computable

general equilibrium model;

• Used for international trade analysis;

• Based on the assumptions that producers

minimize their production costs and

consumers maximize their utilities subject to a

set of certain common constraints;

• Supplies and demands of all commodities

clear by adjusting prices in perfectly

competitive markets

CAPSiM

Crop sown areas

Rainfedsown area

Net irrigationrequirement

per areaIrrigatedsown area

Net irrigation requirement

Water demand for irrigation

China’s Water Simulation model Basin efficiency

Direct impacts of climate change on crop yield (irrigated and rainfed yield) from crop simulation model

Change of crop irrigated areas and its indirect impacts on crop yields

Change of average crop yield/irrigated areas/sown areas

Impacts of climate change on agricultural production/ trade/ price/ farmer income

GTAPImpacts of climate change

on agri. Prod. in the rest

of the world

Market priceLinkage among

models

Study Areas

3H Region

Hai RB

Yellow RB

(down)

Huai RB

GEF project provinces:

Hebei, Henan, Anhui,

Jiangsu and Shandong

Scenarios

Baseline:No climate change, only influenced by

socio- economic development

Alternative scenarios, considering:1) A2 and B2

2) With and without CO2 fertilization effect

3) Climate change on in China or in all

countries;

4) Water use only in the agricultural sector or

in all sectors will be influenced by water

balance (or water reallocation)

Alternative Scenarios Analyzed in the Study

A2 B2Worst

scenario

W/O

CO2

With

CO2

W/O

CO2

With

CO2

A2-

W/O

CO2

B2-

W/O

CO2

Reducing water supply in all sectors

Only climate change in

ChinaS1 S3 S5 S6

Climate change in all

countriesS2 S4

Reducing water use only in agricultural sector

Only climate change in

ChinaS8

Climate change in all

countriesS7

A2 and B2 ScenarioBasin Scenario

Change of Precipitation(%)

Change of Temperature

(℃)

HaiheRiverBasin

A2 scenario

2015s 3.76 0.86

2030s 6.67 1.51

B2 scenario

2015s 6.5 1.02

2030s 4.78 1.6

Yellow River Basin

A2 scenario

2015s 3.87 0.84

2030s 8.31 1.41

B2 scenario

2015s 3.43 1

2030s 3.3 1.42

Huaihe River Basin

A2 scenario

2015s 4.83 0.78

2030s 7.6 1.39

B2 scenario

2015s 1.63 1.02

2030s 3.21 1.41

Data sources: MWR; 2015(2001-2030); 2030 (2016-2045)

Baseline Assumption (I)Variables Year Haihe RB Huaihe RB YellowRB_dn

Temp.(oc) 2006 11.3 14.6 9.4

Prec.(mm) 2006 476 888 864

Temp./prec 2015/2030 Same to 2006

Crop ET 2006 Averaged from 2005-2007

2015/2030 Same to 2006

South-north water

transfer

projects(km3)

2006 0 0 0

2015 5.8 8.4 0.4

2030 8.7 9.9 0.5

Irrigated area

(0.1 million Ha)

2006 7.0 9.7 1.1

2015/2030 Same to 2006

Basin efficiency for

irrigation

2006 73 65 52

2015 86 76 61

2030 96 85 67

2006 is averaged from 2005-2007

Baseline Assumption (II)Variables Year Haihe RB Huaihe RB YellowRB_dn

Crop sown area

(CAPSiM model)

(thousand ha)

2006 9.72 16.23 1.89

2015 9.87 15.69 1.88

2030 10.03 15.23 1.89

Industry GDP

(billion yuan)

(CGE model)

2006 7791 12621 781

2015 14457 23419 1449

2030 33079 53588 3316

Population (million)

(IIASA)

2006 1.47 2.28 0.27

2015 1.54 2.36 0.28

2030 1.59 2.41 0.31

Urbanization rate

(%)(IIASA)

2006 44 40 25

2015 51 45 29

2030 63 54 36


Baseline Assumption (III)Variables Year Haihe RB Huaihe RB YellowRB_dn

Industry water

use/GDP

(m3/10000 yuan)

2006 71 83 95

2015 53 62 71

2030 28 36 43

Water use per

capita (rural)

(L.day.person)

2006 55 55 45

2015 57 56 46

2030 58 57 47

Water use per

capita (urban)

(L.day.person)

2006 168 149 153

2015 170 150 154

2030 171 151 156


Simulation Results

Results to obj.1: Impacts of climate change

on water availability, irrigation water demand

and water security;


on agricultural production, demand, trade,

prices, food security and farmer income;

Results to obj.3: policy implications

Percentage change of water supply compared

with baseline under A2 and B2 scenario for each

river basin (%)

Haihe Huaihe Yellow

2015_A2 1.95 -0.38 3.05

2030_A2 0.24 -2.34 -1.14

2015_B2 -4.28 -0.98 -0.01

2030_B2 -3.26 -2.34 -0.04

Source: Simulation results from CWSM model

2015 Rice Wheat MaizeCoarse

grains

Pulse Tuber Sugar

crops

Oil

crops

Cotton Vegetable Others

Haihe RB 5.30 5.38 5.35 5.63 5.62 5.39 5.41 5.28 5.38 5.36 5.35

Huaihe RB 4.97 5.04 5.06 5.26 4.98 4.96 5.04 4.76 4.99 5.02 5.02

Yellow RB

down3.01 3.13 3.12 3.09 3.10 3.08 3.36 2.92 2.99 3.05 2.89

2030

Haihe RB 9.36 9.51 9.50 9.96 9.98 9.55 9.57 9.33 9.52 9.49 9.47

Huaihe RB 8.93 9.07 9.12 9.47 8.97 8.93 9.06 8.55 8.97 9.04 9.04

Yellow RB

down5.07 5.28 5.27 5.21 5.23 5.20 5.68 4.92 5.04 5.14 4.88

Change of crop ET under A2 Scenario

(compared with baseline) (%)

2015 Rice Wheat MaizeCoarse

grains

Pulse Tuber Sugar

crops

Oil

crops

Cotton Vegetable Others

Haihe RB 6.29 6.39 6.37 6.69 6.68 6.40 6.43 6.27 6.39 6.37 6.35

Huaihe RB 6.52 6.62 6.65 6.91 6.54 6.52 6.61 6.24 6.55 6.59 6.59

Yellow RB

down3.58 3.73 3.73 3.68 3.70 3.67 4.01 3.48 3.56 3.63 3.45

2030

Haihe RB 9.93 10.09 10.08 10.57 10.59 10.13 10.16 9.89 10.10 10.07 10.05

Huaihe RB 9.06 9.20 9.25 9.61 9.10 9.07 9.19 8.67 9.10 9.17 9.17

Yellow RB

down5.11 5.32 5.31 5.25 5.27 5.23 5.72 4.95 5.07 5.18 4.91

Change of crop ET under B2 Scenario

(compared with baseline) (%)

Water shortage as percentage of water

demand under A2 and B2 scenarios for each river

basin in 2015 and 2030 (%)

Haihe RB Huaihe RBYellow RB

down

2015_A2 -1.05 -1.98 1.88

2030_A2 -4.43 -5.41 -2.17

2015_B2 -6.53 -6.35 -1.80

2030_B2 -9.07 -7.97 -2.74

Source: Simulation results from CWSM model

• Under the assumption of climate

change, if water demand cannot be

satisfied by supply, how about its

impact on water use, irrigated areas

and crop yields?

Percentage change of irrigation water demand

under alternative scenarios (compared with

baseline, Haihe River Basin )

-9

-6

-3

0

3

6

9

12

2015_A2 2030_A2 2015_B2 2030_B2

Before water balance Reducing water in all sectors

Reducing water in agri.



baseline, Huaihe River Basin )

-6

-3

0

3

6

9

12

15

2015_A2 2030_A2 2015_B2 2030_B2

Before water balance Reducing water in all sectors

Reducing water in agri.



baseline, Yellow River Basin )

-3

0

3

6

9

12

2015_A2 2030_A2 2015_B2 2030_B2

Before water balance Reducing water in all sectors Reducing water in agri.

Percentage change of crop irrigated areas under A2 and B2

Scenarios in each river basin (compared with baseline)

Haihe RB Huaihe RB Yellow RB (down)

After rebalancing water supply and demand

Reducing water use in all sectors

A2

2015 -1.05 -1.98 1.88

2030 -4.43 -5.41 -2.17

B2

2015 -6.53 -6.35 -1.8

2030 -9.07 -7.97 -2.74

Reducing water use only in agricultural sector

A2

2015 -1.63 -3.33 2.84

2030 -7.46 -10.38 -3.76

B2

2015 -10.16 -10.38 -2.71

2030 -15.13 -14.93 -4.71

Percentage change of irrigated and sown areas by crop in 3H

(Reducing water in all sectors)

A2 B2

Irrigated areas

Crop sown areas

Irrigated areas

Crop sown areas

2030 Rice -2.80 -2.80 -7.83 -7.83

Wheat -1.98 0.18 -6.34 0.37

Maize -1.97 0.23 -6.91 0.60

Coarse grains -1.69 1.20 -5.69 3.94

Soybean -1.92 1.57 -5.89 4.68

Tuber -1.68 0.72 -5.19 2.23

Sugar crops -2.07 0.52 -7.32 1.69

Oil crops -2.14 0.91 -6.60 2.75

Cotton -2.27 0.93 -7.90 2.91

Vegetable -2.19 -1.88 -6.94 -5.93

Others -1.76 1.35 -5.28 4.28

Percentage change of irrigated and sown areas by crop in China

(%) (Reducing water in all sectors)

A2 B2

Irrigated areasCrop sown

areas

Irrigated

areas

Crop

sown

areas

2030 Rice -2.80 -2.80 -4.15 -4.15

Wheat -1.98 0.18 -3.27 0.20

Maize -1.97 0.23 -3.60 0.29

Coarse

grains-1.69 1.20 -2.86 2.06

Soybean -1.92 1.57 -2.96 2.45

Tuber -1.68 0.72 -2.60 1.18

Sugar crops -2.07 0.52 -3.66 0.93

Oil crops -2.14 0.91 -3.34 1.46

Cotton -2.27 0.93 -3.98 1.55

Vegetable -2.19 -1.88 -3.56 -3.04

Others -1.76 1.35 -2.65 2.23

Impacts of climate change on crop yield under A2 scenario in

3H region and China (Percentage change compared with

baseline)

Crop yields (%)

Due to

change

of

irrigate

d areas

Due to direct effect of

climate change

Due to change of irrigated

areas and direct effect of

climate change

W/O CO2 With CO2 W/O CO2 With CO2

2030

3H region

Rice 0.00 -8.90 3.20 -8.90 3.20

Wheat -1.06 -9.56 13.94 -10.62 12.88

Maize -0.85 -7.40 3.76 -8.25 2.90

China

Rice 0.00 -8.90 3.20 -8.90 3.20

Wheat -0.55 -9.56 13.94 -10.11 13.40

Maize -0.44 -7.40 3.76 -7.84 3.32

Source: Simulated results from CWSM model

Impacts of climate change on crop yield under B2 scenario in

3H region and China (Percentage change compared with

baseline)

Crop yields (%)

Due to

change

of

irrigate

d areas

Due to direct effect of

climate change

Due to change of irrigated

areas and direct effect of

climate change

W/O CO2 With CO2 W/O CO2 With CO2

2030

3H region

Rice 0.00 -1.10 -0.40 -1.10 -0.40

Wheat -1.77 -3.48 9.01 -5.24 7.24

Maize -1.50 -4.62 0.40 -6.12 -1.10

China

Rice 0.00 -1.10 -0.40 -1.10 -0.40

Wheat -0.91 -3.48 9.01 -4.39 8.09

Maize -0.78 -4.62 0.40 -5.40 -0.38

Simulation Results to

Objectives


on water availability, irrigation water demand

and water security;


on agricultural production, demand, trade,

prices, food security and farmer income;

Results to obj.3: policy implications

• If do not consider the climate change,

how about the change of crop price,

sown areas and cropping pattern?

Change of Crop Price (2030/2006)

(w/o climate change)

-60

-40

-20

0

20

40

60

Ric

e

Whea

t

Mai

ze

Swee

t pota

to

Pot

ato

Oth

er c

oarse

gra

in

Soy

bean

Cot

ton

Oil

crops

Sug

ar c

rops

Veg

etab

le

2030/2006

% Increase rate of crop price (2030/2006)

Crop Sown Area

0

5000

10000

15000

20000

25000

30000

35000

1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

rice wheat maize sweetpotato potato othercoarse

soybean cotton oils sugar vegetable othercrops

Unit: 1000 ha (1980-2030)

maze

rice

oils

wheat

soybean

vegetable

other coarse

potato

cotton

other crops

sugar

sweetpotato

Cropping Pattern

0

5

10

15

20

25

1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030

rice wheat maize sweetpotato potato othercoarse

soybean cotton oils sugar vegetable othercrops

Share of crop sown areas (%)

maze

rice

wheat

vegetable

oils

soybean

other crops

cotton

other coarsepotato

sweet potato

sugar

• After considering the climate change,

what are possible change for crop price,

crop output, sown areas, food security

and trade issues at the national level?

The impacts of climate change on productions of three major crops

in China under different scenarios (relative to baseline)

S1 S2 S3 S4

Impacts in percentage (%)

In 2015

Rice -2.5 -2.2 0.1 0.1

Wheat -2.7 -2.0 3.6 3.9

Maize -1.7 -1.4 0.8 0.9

In 2030

Rice -6.3 -4.7 0 -0.4

Wheat -6.3 -4.3 7.2 8.5

Maize -5.6 -4.1 2.2 2.7

Source: simulation results from GTAP and CAPSiM models.

The impacts (%) of climate change on grain prices in China

under different scenarios (relative to baseline)

S1 S2 S3 S4

In 2015

Rice 6.0 6.6 -1.2 -1.3

Wheat 4.5 5.9 -5.4 -5.2

Maize 3.7 4.4 -2.0 -2.0

In 2030

Rice 11.4 15.2 -1.1 -1.7

Wheat 9.3 13.6 -9.1 -8.1

Maize 5.9 8.4 -3.0 -3.0


The impacts (%) of climate change on sown area of three major

grain crops in China under different scenarios (relative to

baseline)

S1 S2 S3 S4

In 2015

Rice 1.1 1.3 -1.2 -1.2

Wheat 1.8 2.2 -2.2 -2.0

Maize 1.6 1.7 -0.6 -0.4

In 2030

Rice 1.2 2.3 -2.8 -3.0

Wheat 3.8 5.1 -4.2 -3.3

Maize 2.8 3.4 -0.8 -0.4


The impacts (thousand tons) of climate change on exports and imports of

three major grains in China under different scenarios (relative to baseline)

S1 S2 S3 S4

Export in 2015:

Rice -460 -79 117 34

Wheat -423 -84 472 680

Maize -320 -170 180 245

Export in 2030:

Rice -2837 -210 393 -225

Wheat -2134 -323 2219 3655

Maize -577 -271 329 490

Import in 2015:

Rice 133 52 -22 -11

Wheat 877 178 -773 -971

Maize 1392 854 -644 -820

Import in 2030:

Rice 110 39 -7 1

Wheat 1081 128 -622 -796

Maize 7671 3773 -2637 -3685

The impacts of climate change on self-sufficiency (%)

of three major grains in China under different

scenarios in 2030 (relative to baseline in 2030)

S1 S2 S3 S4

Rice -2.7 0.0 0.4 -0.3

Wheat -3.6 -0.4 2.9 4.7

Maize -3.1 -1.6 1.1 1.6

The impacts of climate change on grain production, price, trade

in China under scenarios 5 and 6 in 2030 (relative to baseline).

S5 S6

Production (%)

Rice -3.2 -2.8

Wheat -3.1 3.3

Maize -4.1 -1.2

Price (%)

Rice 4.5 1.3

Wheat 4.7 -3.9

Maize 4.3 1.0

Export (in thousand tons)

Rice -1928 -1806

Wheat -1013 1175

Maize -516 -200

Import (in thousand tons)

Rice 40 14

Wheat 441 -251

Maize 5277 1248

The impacts of climate change on self-sufficiency in China under

scenarios 5 and 6 in 2030 (relative to baseline in 2030)

S5 S6

Self-sufficiency change (%)

Rice -1.9 -1.9

Wheat -1.6 2.0

Maize -2.2 -0.4

The impacts of climate change on grain production, price, trade and self-

sufficiency in China (relative to baseline in 2030)

Without CO2 fertilization effect and reducing water only in theagricultural sector

A2 and climate change both in

China and the rest of the world

B2 and climate change only

in China

S7 S8

Production ( %)

Rice -5.8 -4.3

Wheat -4.4 -3.1

Maize -4.6 -4.2

Price ( %)

Rice 20.7 10.7

Wheat 16.9 7.5

Maize 12.3 7.6

Net import (in thousand tons)

Rice 1009 2109

Wheat 711 1759

Maize 4762 6002

Self-sufficiency change ( %)

Rice -0.65 -1.90

Wheat -0.68 -1.94

Maize -1.84 -2.26

Summary and Policy Implications (I)

• This study further advances the impact

assessments in the following 2 areas:

- Indirect impact of climate change on

crop yield through its impact on crop

irrigation area.

- The impacts of climate change on

crop production through market response

mechanism.

Summary and Policy Implications (II)

• While the impact of change of climate

on water supply (or availability) is

important, its impact on crop demand

for water is also equally important;

• Under B2 scenario, water supply in all

three river basins in 3H region will be

reduced and irrigation water demand

will tend to increase;

Summary and Policy Implications (III)

• Due to change of water supply and water demand, in 3H region, water scarcity will become more serious under climate change;

• Our further simulation show that under the climate change, if we do not take any adaptation measures, the irrigated areas of all crop will have to be declined;

• In addition, we found that in order to rebalance water supply and water demand, if the reduction of water use only occurs in the agricultural sector, the decrease of irrigated areas and agricultural production will be more serious.

Summary and Policy Implications (IV)

• This study also shows that the indirect impacts of climate change on crop yield cannot be ignored, particularly under B2 scenario;

• Under the climate change, water use efficiency (both agricultural and industry sectors) have to be substantially improved, otherwise irrigated areas have to be reduced, which will result in the decline of crop yields and negative impacts on crop production;

• More important, this study finds that, with appropriate market response, the impacts of climate change will be moderate.

Summary and Policy Implications (V)

• The climate change will have significant impacts on the comparative advantage of different agricultural commodities in China;

• Some commodities will gains their comparative advantage in the international markets, while others will lose;

• However, the results highly depend on assumptions on CO2 fertilization effects;

Summary and Policy Implications (VI)

• Without considering CO2 effects, the

comparative advantage of three major grains

will be worse off. But with consideration of

CO2 fertilization effects, China’s comparative

advantage of grain sector, particular wheat

will be better off;

• Therefore, technologies that could improve

CO2 fertilization effects are critics in

mitigation of the impact of climate change on

agriculture.

Summary and Policy Implications (VII)

• While the climate change will have impacts

on China’s food security (or self-sufficiency),

the impacts differ among alternative

scenarios. Impacts will range from about -4

percent to about +4 percent in grain self-

sufficiency.

• If China wants to reduce the shocks on self-

sufficiency of rice, maize and vegetables, it is

necessary to increase the investment on

agricultural productivity enhanced

investment (e.g., R&D, irrigation

infrastructure, etc).

Summary and Policy Implications (VIII)

• The impacts of climate changes on farmer’s income differ largely in 3H region and among alternative assumptions, which implied that there is equity implication of climate change;

• China needs to help those farmers who are likely negatively affected by climate changes;

• It is interesting to note that while climate change may have a negative effect on crop production, income of farmers who plant the crop may increase (rather than fall or not decrease much) because price impacts;

• But rising food price will obviously affect consumers, particular low income consumers in urban China.

Summary and Policy Implications (VIIII)

• Regional development: impacts in 3H

differ largely from the rest of China.

This is not only because of CC differs

among region, but also crop structure

also differ largely between 3H and the

rest of world.

– Policy implications: China needs regional

specific development policy to adapt to CC

climate change, water security and agriculture

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