changes in agricultural yields without co2 fertilization, cline 2007
TRANSCRIPT
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