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Presentation by Jinxia Wang, IGSNRR at the People's Republic of China's (PRC) 1st National Workshop on the Economics of Climate Change and Low Carbon Growth Strategies in Northeast Asia
Citation preview
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
2006 is averaged from 2005-2007
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
2006 is averaged from 2005-2007
Simulation Results
Results to obj.1: Impacts of climate change
on water availability, irrigation water demand
and water security;
Results to obj.2: Impacts of climate change
on agricultural production, demand, trade,
prices, food security and farmer income;
Results to obj.3: policy implications
Simulation Results
Results to obj.1: Impacts of climate change
on water availability, irrigation water demand
and water security;
Results to obj.2: Impacts of climate change
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.
Percentage change of irrigation water demand
under alternative scenarios (compared with
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.
Percentage change of irrigation water demand
under alternative scenarios (compared with
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
Results to obj.1: Impacts of climate change
on water availability, irrigation water demand
and water security;
Results to obj.2: Impacts of climate change
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
Source: simulation results from GTAP and CAPSiM models.
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
Source: simulation results from GTAP and CAPSiM models.
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