Water Modeling in GCAM

Mohamad Hejazi, Jae Edmonds, Leon Clarke, Vaibhav Chaturvedi, Page Kyle, Evan Davies*, Pralit Patel, Marshall Wise, Sonny Kim

Joint Global Change Research Institute

November 30, 2011

College Park, MD

Overview

Motivation

Overall framework

Water supply modeling

Water demand modeling

Water markets

Conclusions

2

Water is not fully integrated into any of the present

generation of IAMs. Though all of the major IAM programs

are working on the problem.

Yet,

Climate change hydrology (the amount, timing, and

reliability of fresh water)

Changes in land use and land cover hydrology

Changes in the number of humans, their income levels,

and their energy and food demands human water

demands

What are the implications of explicitly considering water in

IAMs?

Do we have sufficient water to realize a climate policy

world?

Motivation

3

Regional

Labor Force

Regional GDP

Regional

Labor

Productivity

Energy

Demand

Technologies

Energy

Demand

Regional

Resource

Bases

Regional

Energy

Conversion

Technologies

Energy

Supply

Energy

Markets

Energy

Production.

Transformation

& Use

GHG

Emissions

Demand•Crops•LivestockForests products

SupplyRegional Land

Categories and Characteristics

Ag-Land Markets

Production•Crops•Livestock•Forests products

•Biomass energy

Commercial

Biomass

Land Use Change

Emissions

Technology

Land Use

•Crops•Livestock•Managed Forests•Unmanaged

•Crops•Livestock•Biocrops

•Foresty Products

•Land rent•Crop prices•Livestock prices

•Forest product prices•Biomass prices

The GCAM Systems

4

Ocean Carbon

Cycle

Atmospheric

Composition,

Radiative

Forcing, &

Climate

Terrestrial

Carbon Cycle

Energy System

Land Use System

Climate System

Economy System

Water

Allocation and

Use

Water

Demand

Water

Supply

Water

Markets

Agricultural

Sector Demands

Energy Sector

Demands

Industrial Sector

Demands

Household

Sector Demands

Commercial

Sector Demands

Surface Water &

GW Recharge

Fossil GW &

natural lakes

Desalinization

Ecosystem,

Navigation,

Inter-basin

Transfers

(prescribed)

Water System Land use

system

Reservoirs

GCMs

WATER

SUPPLY

WATER

DEMAND

WATER

SUPPLY

Model & Results

Source: http://www.wildfire-burning-thirsts.com/water-cycle.html

Pre

cip

ita

tio

n

11

0,0

00

km

3

Eva

po

tra

ns

pir

ati

on

65

,20

0 k

m3

Runoff + GW Recharge

44,800 km3

5

Water Supply

Model

Maximum Soil Moisture Capacity

Precipitation

Temperature

Potential Evapotranspiration (PET)

Actual Evapotranspiration (AET)

Storage

Runoff

Monthly Water

Balance Model

6

MODEL INPUTS

MODEL OUTPUTS

Model Validation

7

This

Study

Fekete et al.

(2000)

WBM

8

Continue…

Model Validation

This Study

FA

O

Climatic Future Projections

9

Climatic Future Projections (2100)

10

Climatic Future Projections (Q2100 – Q2000)

Model Long name IPCC number

CGCM2 Canadian Centre for Climate (Modelling and Analysis) (Canada) 7

CSIRO mk 2 Commonwealth Scientific and Industrial Research Organisation (Australia) 10

DOE PCM Parallel Climate Model (NCAR - USA) 30

HadCM3 Hadley Centre Coupled Model 23 11

WATER DEMAND Model & Results

Water

Supply

Water

Withdrawal Extraction

Return Flow

Water Consumption

• Evapo[transpi]ration

• Incorporated into products or crops

• Contaminated

• Unavailable to other users

Water use in three parts:

1. Domestic

2. Industrial

3. Agricultural

Differentiate between withdrawal and consumption

12

Domestic

Water Demand TechPriceGDPC93.2WUc 3.0$)2005(

4.0)/$2005()//( 3 USCapitaUSyrcapitam

13

Global Domestic Water Withdrawals

14

Domestic Water Withdrawals

15

(2100 vs. 2005)

Industrial Water

Demand

16

Industrial Water Use

Energy

Primary Electricity

Manufacturing, mining

Coal

Oil

Natural Gas

Uranium

Cooling water

(thermoelectric)

Reservoir losses

(hydropower)

Thermoelectric plants may be

cooled in four ways:

1. Once-through flow: oldest and

cheapest

2. Evaporative cooling towers:

newer, more capital

3. Cooling ponds: newer, hard to

classify...

4. Dry cooling: newer, expensive

STEPS:

• Water withdrawal and consumption

coefficients (m3/MWh) for each elec.

tech. and GCAM region

• Cooling system deployments (%) for

each elec. tech. and GCAM region

• Projected changes in each (now-2100)

Global Energy Water Demand

(Withdrawal vs. Consumption)

17

Withdrawal Consumption

Total

biophysical

water

consumption

Green Water

Water from

precipitation, directly

used by crops or stored

as soil moisture

Blue Water

Water withdrawn for

irrigation from rivers,

lakes, aquifers or dams

Blue water

demands on

irrigated lands

Green water

demands on

rain-fed lands

Green water

demands on

irrigated lands

0

2000

4000

6000

8000

10000

12000

14000

16000

2005 2020 2035 2050 2065 2080 2095

Mt/

yr

Agricultural Production FiberCrop

PalmFruit

OtherGrain

OilCrop

Rice

Wheat

Corn

Root_Tuber

FodderHerb

FodderGrass

MiscCrop

SugarCrop

Calculating Water Consumption

Irrigate

d

Rain

fed

Agric Water Demand

18

Energy crops’ water

consumption also

increases, especially in

the later half of the

century

Biophysical Water Consumption

19

Total biophysical water

consumption to almost

double by 2050, after

which the increase will be

marginal

0

2000

4000

6000

8000

10000

12000

14000

16000

2005 2020 2035 2050 2065 2080 2095

km

3/y

r

Biophysical water consumption- CROPS

Biomass

FodderGrass

FodderHerb

PalmFruit

FiberCrop

SugarCrop

Root_Tuber

OtherGrain

Wheat

Rice

OilCrop

MiscCrop

Corn

Agricultural Water Demand

Consumption 20

Effect of Climate Policy:

Total Global Water Demands

21

Solve all markets simultaneously for land, energy, and water among the competing demand

sectors to establish prices & shares by source 22

Downscaled

GCMs climatic

variables

Climate Mitigation

Policy from GCAM

Pattern scaling

of climatic

variables

Renewable surface

water

Renewable

groundwater

Fossil groundwater

Brackish & saline

water bodies

Natural water

bodies (lakes)

Pre

defin

ed

Cost 1

Cost 2

Cost 3

Cost 4

Cost 5

Agricultural water demand

Energy & Industrial water

demand

Domestic water demand

Evaporation losses from

reservoirs

Ecosystems, recreations,

and navigations

Gravity Model Global land use

model (GLM)

Run GCAM for one

time period (5 years)

t=2005 t=t+5

SOLVING WATER MARKETS IN GCAM

Energy markets (~120) Land use markets (~60)

Water Demands

Global Water Supply Model

Water markets (~125)

GCM simulations

over 21st century

AEZ scale

(151 regions)

GCAM regional

scale (14 regions)

Basin scale

(125 regions)

0.5ox0.5o map of

land use types

Monthly 0.5ox0.5o maps of

climatic variables (P, T)

Sp

atia

l D

ow

nsc

alin

g

Wa

ter

de

ma

nd

s

at

ba

sin

sc

ale

Water

Demand

Water

Supply

Land

Demand

land

Supply

Energy

Demand

Energy

Supply

Some Preliminary Observations from GCAM

Water Systems Research

Agriculture is the largest user of water (70% withdrawals; 85%

consumption) - Bio-energy crops can potentially become

important source of water demand in the future

Developing countries demands for water can be expected to

grow over time, particularly in the first half of the century.

Energy systems need water—large source of withdrawals, much

smaller consumer.

Cooling water demands for power generation (the largest energy

user of water) can be expected to grow in the future, particularly

in the developing world.

New cooling technologies could dramatically reduce fresh water

withdrawals, but increase fresh water consumption.

NEXT: Allocate water among the competing water users +

downscaling 23

Impact Assessment: Water Scarcity

24

Domestic

Agriculture

(irrigation & livestock)

Electricity

Generation

Primary Energy &

Mining

Manufa-cturing

Global Water

Demand

For a given climate mitigation policy scenario & particular year:

Global gridded-map of total

water demands

Requirement: Downscale

demands to grid scale

Water Supply

Severe Stress:

0.4 ≤ WSI

Moderate Stress:

0.2 ≤ WSI < 0.4

Low Stress:

0.1 ≤ WSI < 0.2

No Stress:

WSI < 0.1

Impact Assessment:

Water Scarcity

(downscaling)

25

Irrigation

Downscale demands to grid scale

Population

Global Energy Water Demand

(No Policy vs. Climate Policy)

26

Withdrawal Withdrawal

Biophysical Water Consumption

27

Most of the water

demand is in the

developing nations of the

world

0

2000

4000

6000

8000

10000

12000

14000

16000

2005 2020 2035 2050 2065 2080 2095

km

3/y

r

Biophysical water consumption- REGIONS

Korea

Japan

Eastern Europe

Canada

Australia_NZ

Middle East

Western Europe

Former Soviet Union

USA

China

Latin America

India

Southeast Asia

Africa

More than 70% of water

for agriculture is

consumed by developing

regions, which increases

to above 75% in 2095

70% 75%