Climate Change Impacts on Water, Agriculture and Food
Security
Dr. EJ Mwendera
Institute for Soil, Water and Climate of the Agricultural Research Council (ARC-ISCW), Pretoria, South Africa
CN+ Expert Workshop on Climate Change, Food Security & Water Resources
AU Commission, Addis Ababa, Ethiopia 25–26 June 2013
Presentation outline
• Relationships between water, agriculture and food security
• Climate change affecting water, agriculture and food security
• Predicted effect of climate change on agriculture and food security
• Some water and climate change research
• Main issues for bio-regional research and technology development
Relationships between water, agriculture and food security
Food security
Food Availability Production; Distribution; Exchange
Food utilization Nutritional value; Social
value; Food safety
Food Access Affordability; Allocation;
Preference
Food availability Food access
Food utilization
(Modified from: FAO, 2002)
Water and agriculture • Agriculture is by far the biggest user of water, accounting for
almost 70% of all withdrawals, and up to 95% in developing countries.
• The water needed for crops amounts to 1 000-3 000 cubic meter per tonne of cereal harvested. Put another way, it takes 1 - 3 tonnes of water to grown 1kg of cereal.
• The daily drinking-water requirements per person are 2-4 litres.
• However, it takes 2 000 - 5 000 litres of water to produce a person’s daily food.
(Source: FAO)
Access to water and food security
A composite indicator that incorporates measures of water resources (from rainfall, river flows and aquifer recharge), access, environmental issues (water quality) and pressure on resources
(Source: FAO, CEH Wallingford)
Causes of food emergencies in developing countries
(Source: FAO)
Climate change affecting water, agriculture and food security
Climate change links
Increased water demand Reduced water availability
Reduced food security Reduced agricultural production
(Photo: Howard Burditt/Courtesy Reuters) (Photo : World Food Programme)
(Photo : Scienceworldreport.com)
Growth in yields
Source: US data, USDA’s National Agricultural Statistics Service; all other regions, FAOSTAT.
Rainfall variability vs GDP in Ethiopia
Source: World Bank, 2006. A Country Water Resources Assistance Strategy for Ethiopia
Key findings in Ethiopia
• Extreme hydrological variability is echoed in its economic performance; • Vast majority (80%) of Ethiopia’s population subsists on rainfed agriculture; • People’s welfare and economic productivity are linked to the volatile rains; and • There is a strong correlation between rainfall and overall GDP.
Rainfall variability vs GDP in Zimbabwe
SOURCES: Craig J. Richardson, 2005; Meteorological Services Department, Zimbabwe, and World Bank (2002) World Development Indicators
Role of agriculture in climate change problem
Contribution of agriculture to climate change is often overlooked;
IPPC estimated that 31% of total emission of GHGs in 2004 came from agriculture and forestry;
Hence, mitigation efforts must also address contribution of agriculture to the climate change problem
Predicted effect of climate change on agriculture and food security
-1.9
-5 -4.3
3.7
-3.9
-1
-8.6
15.9
-10
-5
0
5
10
15
20
Developing world Sub-Saharan Africa Asia Latin America
Per
chen
t ch
ange
in a
gric
ult
ura
l GD
P a
nd
cer
eal p
rod
uct
ion
Percent change in agricultural GDP
Percent change in cereal production
Projected CC impact on agricultural GDP and cereal production in 2080
Source: International Institute for Applied System Analysis
Predicted change in net revenue as a result of decreased rainfall and increased temperatures
Turpie and Visser (2012) using three Atmospheric Oceanic General Circulation Models (AOGCM) of Canadian Climate Center (CCC), Centre for Climate System Research (CCSR), and Parallel Climate Model (PCM) models.
Some water and climate change research
Water and climate change research at ARC-ISCW
Institute for Soil, Climate and Water (ISCW)
Agricultural Research Council (ARC)
(Source: ARC-ISCW, Arcadia, Pretoria, RSA)
ARC-ISCW Agroclimatology Programme
Main research activities:
Climate monitoring;
Climate and crop modelling;
Weather dissemination (radio, TV);
GHG emission monitoring;
Adaptation and mitigation
Weather station network • 60 Mechanical • 500 Automatic
(Source: Agroclimatology Programme ARC-ISCW, Arcadia, Pretoria, RSA)
ARC-ISCW Geoinformatics Programme
(Source: GeoInformatics Programme, ARC-ISCW, Arcadia, Pretoria, RSA)
Soil information for land evaluation, ranging from commercial farmers to small-scale farmers
ARC-ISCW Soil Science Programme
(Source: Pedometrics Programme ARC-ISCW, Arcadia, Pretoria, RSA)
Water quality management in agro-ecological systems;
Efficient utilisation of water in rain-fed and irrigated agricultural systems, forestry and livestock production systems;
Sustainable management of water resources in wetlands to enhance ecosystem health and functioning.
Assessment of climate change impacts on water and agro-ecological systems
ARC-ISCW Water Science Programme
(Source: Water Science Programme ARC-ISCW, Arcadia, Pretoria, RSA)
ARC-ISCW Analytical Services Laboratory
- Soil analysis;
- Water analysis
- Spatial inorganic/biological analysis
(Source: Christa Lombard, Projects Office, ARC-ISCW, Arcadia, Pretoria, RSA)
LOCATION OF CASE STUDY AREAS
Cons agriculture, Qunu, E Cape
Cons agriculture, Pretoria, Gauteng
Rain water harvesting, Thaba Nchu, Free State
(Source: Beukes, DJ Botha, JJ, Steinke, MF & Wood, PC, 2011)
200
220
240
260
280
300
320
340
360
380
400
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150Day of year
So
il w
ate
r co
nte
nt
(mm
)
ConIRWHDULLLRain-200
IRWH>Con: 43%
IRWH>Con: 38%
320
340
360
380
400
420
440
460
480
0 10 20 30 40 50 60 70 80 90 100 110 120 130
Days after planting
So
il w
ate
r co
nte
nt
(mm
)
ConIRWHDULLLRain-320
Soil water under rainwater harvesting
(Source: Beukes, DJ Botha, JJ, Steinke, MF & Wood, PC, ARC-ISCW, 2011)
Enhances rainwater productivity
Assessment of maize and sunflower over:
48 Growing seasons
Six different locations
Mean seasonal rainfall: 320 mm
RWP (kg grain ha-1 mm-1 water):
Conventional tillage: 2.7
IRWH practice: 4.1 (+52%)
(Source: Beukes, DJ Botha, JJ, Steinke, MF & Wood, PC, 2011)
Crop yields under rainwater harvesting
Crop Yield under
conventional
tillage (kg/ha)
Yield under infield
IRWH system
(kg/ha)
Yield increase in
IRWH system
(%)
Maize 1,070 3,753 250
Dry beans 262 407 55
Sunflower 1,037 1,698 64
(Source: Botha et al., 2012, ARC-ISCW, Glen, Bloemfontein, RSA)
Linking roof water harvesting to irrigation
• Can improve household food security in rural areas
(Source: Botha et al., 2012, ARC-ISCW, Glen, Bloemfontein, RSA)
Climate change coping and adaptation strategies
Providing water for livestock
Restoring degraded areas
Scarce water for livestock
Degraded areas (Source: Mwendera et al., 2010, IUCN, Nairobi, Kenya)
Climate change coping and adaptation strategies (cont’d)
Installing efficient water infrastructure
Exploiting groundwater resources
Degraded water infrastructure
Limited surface resources
(Source: Mwendera et al., 2010, IUCN, Nairobi, Kenya)
What is needed:
1) Better information on availability
1) Access to technologies
2) Promote sustainable use
Groundwater – offers opportunities for the rural communities.
Harnessing groundwater
(Source: Karen G. Villholth, IWMI-SA, 2012
Information Days
(Source: Corrie Swanepoel & Danie Beukes, 2012)
Establishing water use associations and catchment forums
Climate change coping and adaptation strategies (cont’d)
(Source: Mwendera EJ, 2010, IUCN, Nairobi, Kenya)
Main issues for bio-regional research and technology
development
Understanding the problem
There is currently much uncertainty in the climate change projections.
Predicting how these uncertain changes will affect agricultural and food systems is still difficult.
Most of the vulnerability and sensitivity mapping studies have been at regional scales, masking enormous variation at the local level.
Challenge of downscaling of vulnerability assessment and mapping exercises.
The policy challenge
1. Producing the evidence to guide policy;
2. Engaging with the policy world to ensure
that policy responds to the evidence;
3. Understanding the real impacts of such
policies and policy change; and
4. For policy makers to provide a fast enough
response to meet the urgency of the
situation.
Engagement and communication
The process by which knowledge informs action.
Agriculture is intensely local, and requires that information be relevant and useful at that level.
Close gaps between knowledge and action, in the wake of a plethora of new tools for information exchange.
Strategic partnerships and learning platforms,;
Providing knowledge and support to the institutional changes needed for uptake and scaling out of technologies.
Key questions in AWM interventions
Access to technology, seeds, fertilizers?
Is there enough money or credit to buy them?
Are markets available to sell?
Financially viable?
Water and land resources available (including rights)?
Is it sustainable – socially, financially, ecologically?
Are there supportive institutions?
Do we have supportive policies?
Example of an approach to revitalize small-scale irrigation schemes
Irrigation system analysis Water availability analysis Socio-economic analysis
Market linkages study Monitoring & evaluation Entrepreneurial training
(Source: Mwendera, E.J. and P. Chilonda (2013). Conceptual framework for revitalisation of small-scale irrigation schemes in southern Africa. Journal of Irrigation and Drainage 62(2): 2008–220)
ARC Climate Change Focus Areas & NR Requirements
Map production areas (present & future)
Adaptation/
Mitigation
Pests/
diseases/
vectors
Climate/water
data;
probabilities
Soil/terrain/
suitability data
NR integrated/
land cover/
monitoring
ARC CC Program Focus Priorities &
examples of initial R&D
Mapping production areas
• Crop suitability
• Commodities: maize, wheat, soya beans, potatoes as 1st phase
Pests, vectors, parasites & diseases (plant and animal health)
• Rift Valley Fever, African Horse Sickness
• Plant diseases e.g. common rust, gray leaf spot and emerging diseases
Mitigation and adaptation
• Conservation agriculture (soil-water-nutrient-biodiversity conservation)
• Climate-smart interventions
ARC CC Program Objectives
1. Identify, characterize & map existing & potential production areas
for food, feed & fibre crops & livestock under current climatic
patterns and to-be-agreed scenarios of climate change
2. Investigate possible effect of CC on vector, parasite, pest and weed
distribution/dynamics and on epidemiology of plant/animal diseases
3. Develop & implement strategies for mitigation of and adapting to
CC through breeding & production practices
4. Promote inter-institutional cooperation in addressing larger CC
challenges across disciplinary boundaries through effective
research
5. Create an effective network with international, regional and national
organizations working on CC
Effective ARC CC Network priorities Institution Relevant R&D/ value CC Research focus
DAFF, PDAs, DRDLR Land suitability/planning; risk
assessments; drought monitoring;
climate change/climate smart-related
R&D; funding
Mitigation & adaptation
Mapping production areas
Pests, vectors, diseases
SA Weather Service Climate research partner;
supplementing climate data; climate
predictions/probabilities; modeling
Mapping production areas
Mitigation/adaptation
Pests/diseases
DEA, DWA & WRC, DST Water, wetlands, climate change &
CA-related R&D; funding
Mitigation/adaptation
Mapping production areas
Pests/diseases/vectors
Universities Partnership & training per university’s
field of specialized expertise e.g.
climate modeling
Mitigation/adaptation
Pests/diseases
Mapping production areas
CSIR & SANBI NR management R&D partners e.g.
water management, wetlands &
climate change; SANBI as
coordinator of selected DEA project
funds
Mitigation & adaptation
Mapping production areas
FAO Soil, water, conservation agriculture
partner/funder; access to UN funds
e.g. GEF
Mapping production areas
Mitigation/adaptation
Thank You !
“Anyone who can solve the problems of water will be worthy of two Nobel Prizes – one for peace and one for science”
John F Kennedy
(Source: David Molden, IWMI, 2010)