Changes in Agricultural Yields

without CO2 fertilization, Cline 2007

Changes in Agricultural Yields

with CO2 fertilization, Cline 2007

improved water use efficiency under higher CO2

water intensity per kg of yield

changing diets

FAOSTAT

Liu et al 2008

changing diets

per-capita water demand in China

250 -> 860 m3

between 1960 and 2000

China‘spopulationdoubledduring thatperiod

Lannerstad 2009

changing diets

1 500

2 000

2 500

3 000

3 500

4 000

USA EU 15 Mexico Brazil Nigeria Kenya India Bangla Indone China

Aver

age

per c

aptia

food

supp

ly(k

ilo ca

lorie

s per

per

son

per d

ay)

For every country the columns represent : 1961, 1971, 1981, 1991 and 2001

Animal calories

Vegetal calories

land use change

FAOSTAT

1990-2007

land use change & land productivity change

Haberl et al 2007

NPP – Net Primary Productivity

Conway & Waage 2010

increasing bioenergy demand

ethanol and biodiesel production

Sagar et al, 2007

bioenergy & land demand

Sagar et al, 2007

m3 water required per GJ from:sugar cane: 2516maize: 2570wheat: 4946sorghum: 9812rapeseed: 14201jatropha: 19924

global average Gerben-Leenes, Hoekstra et al 2009

bioenergy & water demand

1liter of biofuel requires about the same amount of water as feeding one person for one day

ethanol

biodiesel

Jatropha cultivation - Fairless, 2007

„every land use decisions is a water use decisions“ (Comprehensive Assessment 2007)

bioenergy & water demand

Green and blue water in Agriculture

Siebert et al 2009

%fraction of blue water in total agricultural water use

• increased water productivity - adaptation to drier climate (and reduced pressure on other ecosystems)

• enhanced carbon sequestration in soils – mitigation of climate change

• reduced CO2 emissions (zero tillage saves 80kg/ha/yr compared to conventional tillage from reduced tractor fuel needs) • increased (agro-bio) diversity – more resilient systems• reduced erosion, nutrient and pesticide loads

FAO 2007

soil carbon sequestration potential

Multi-functional systems – integrating climate mitigation and adaptation

e.g. conservation agriculture

in multi-functional systemsMulti-functional systems e.g. agroforestry - rotational woodlands, Tanzania

intercroping of food crops with leguminous trees (Acacia)

Verchot 2007

felling trees after 10 years

Critical hotspots: rainfed “drylands”

Rockström et al 2009

Critical hotspots: rainfed “drylands”low yield / water productivity

all crops Wisser et al 2009

dry spells and droughts

projected to increase with climate change

Critical hotspots - hunger

fertilizer gap in Africa

FAO

annual average N-P-K application 1997-1999

-80

-60

-40

-20

0

20

40

60

80

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

year

per

cen

tag

e

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

rainfall variation around the mean

GDP growth

-80

-60

-40

-20

0

20

40

60

80

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

year

per

cen

tag

e

-30

-25

-20

-15

-10

-5

0

5

10

15

20

25

rainfall variation around the mean

GDP growth

-250

-200

-150

-100

-50

0

50

100

150

200

250

1960 1970 1980 1990 2000

Years

Nat

ion

al r

ain

fall

in

dex

: V

aria

tio

n f

rom

tre

nd

(m

m)

-800

-600

-400

-200

0

200

400

600

800

To

tal

cere

al p

rod

uct

ion

- V

aria

tio

n f

rom

tre

nd

('0

00 t

on

s)

National rainfall index

Cereal production

Burkina Faso

Zimbabwe Ethiopia Grey, 2004/2005

climate variability, agriculture, GDP link

Foreign Direct Investment („land grabbing“)

GTZ 2009

e.g. by Chinese companies:• IKO: 10,000 ha rice in Cameroon• SUCOCOMA: 10,000 ha sugarcane in Madagaskar• Viscount Energy: sugarcane in Nigeria• Int. Water & Electric Corp: 100,000 ha corn in Tanzania• Heibei Company: 40,000 ha poultry etc in Uganda• Int. Water & Electric Corp 100,000 ha corn in Zimbabwe

also „water grabbing“

Other pressures

financial incentives – payments for environmental services

Enabling conditions / incentives

-> water implications of CDM

-> integration of adaptation & mitigation

Syria 4Morocco 22 Lebanon 28Algeria 79Tunisia 97Jordan 196Libya 557

net VW imports as % of renewable water resources

Yang et al 2007

however, there are concerns about national food security and local livelihoodswhen relying on virtual water imports

and there is an employment problem if local agriculture is phased out

imports of virtual water in the MENA region

Regreening Sahel - a success story

Geo 4 2007

Regreening Sahel - a success storyBurkina and Niger

Reij et al 2009

Zai pits

Regreening Sahel - a success storyBurkina and Niger

Reij et al 2009

Contour stone bunds

Regreening Sahel - a success storyBurkina and Niger

Reij et al 2009

Farmers-managed natural regeneration (FMNR) of trees