timescales for adaptations & transformations in african staple crops
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Timescales for adaptations & transformations in African staple crops
Sonja Vermeulen, Head of Research, CCAFS
ccafs.cgiar.org
Recent NCC paper
Purpose of the research
• Assess likely effect of two different climate change scenarios on cultivation areas for nine most important crops in sub-Saharan Africa (50% food production, 40% value & 60% protein).
• Work out timeframes for adaptation policy and practice in order to maintain food security & livelihoods (first time this has been done).
• KEY MESSAGE: Possible to be prepared & pro-active ahead of the adaptation challenge.
Levels of impact & adaptation
When do we cross viability thresholds in African cropping systems?
Vermeulen et al PNAS 2012
Buzzword “transformation”
• AR5 WG2 2014: transformation involves “changes the fundamental attributes of a system in response to climate and its effects”
• Park et al. 2012 fundamental changes to function, form or location of the agri-food system
• Here we look at a very specific but important transformation case: shift away from cultivating a major staple crop in a given farming region
Methods
2 CMIP5 scenarios
19 GCMs
EcoCrop
suitability thresholds
Caveats:
Uncertainties in both models & drivers e.g. socio-economic change
Chance of more positive mitigation scenarios than 6.0 and 8.5?
Adaptations, including breeding, are not modeled – source of optimism
Crop suitability simulations were carried out for the historical period
(1961-1990) and for 93 years in 21st century (2006-2098)
Preparatory phase: suitability > viability threshold for 10-15 years in 20
Transformation phase: suitability > viability threshold for <10 years in a 20
Assumes farmers are “smart” and switch at 50% crop failure rate
Results: headlines
• Governments will need to prepare for possible large losses in national production potentials, and production
areas, of up to 15% by 2050 and over 30% by 2100.
• In some areas transformations will need to take place
as soon as 2025 which means the preparatory phase
must start now.
Results: which crops, when, where?
Which? Maize, bananas and beans
millets, sorghum, yams, cassava & groundnut are (mainly) stable.
When and where? Bananas
Northern Ghana
Togo and Benin,
which are highly
dependent on
bananas &
plantains for
nutrition, will need
to undergo
transformation in
the next ten years.
When and where? Beans
Beans will lose 60%
cropping area (RCP
8.5): 1.85 million
hectares of current
bean cropping
systems in Uganda
and Tanzania,
which grow 41% of
total sub-Saharan
African bean
supply, will be
unable to do so by
2100.
When and where? Maize Projected maize
transformations
represent 5% of
Nigeria's current
production by the
2050s and 25%
by 2100 (RCP 8.5)
0.5% maize areas
have no viable crop
substitution option
These areas total
0.8 Mha in the dry
zones of South
Africa (currently
grow 2.7 Mt)
Pockets of change for other crops too
e.g. Yam: early impacts,
but less coincidence
with areas of major
dependence
How should we respond?
Incremental phase
• Delay the threshold if possible (G x E x M)
• Genetic gains (15 year cycle)
• Management gains e.g. irrigation
Preparatory phase (15
years ahead)
• Prepare for transformations / substitutions
• Support to farmer & pvt sector innovation
• Flexible enabling environment
Transformation phase
• Crop substitution
• Farming system substitution
• Livelihood substitution
• Dietary substitution
How should we respond 1: delaying the viability threshold
Incremental phase
• Delay the threshold if possible
• Genetic gains (15 year cycle)
• Management gains e.g. irrigation (G x E x M)
Preparatory phase (15
years ahead)
• Prepare for transformations / substitutions
• Support to farmer & pvt sector innovation
• Flexible enabling environment
Transformation phase
• Crop substitution
• Farming system substitution
• Livelihood substitution
• Dietary substitution
Timeframe to release a new variety
Year activity
0 installation of a collection
1 selection of parents and multiplication
of selected parents
2-3 crosses and seed germination
4-5 F1 selection, cloning and evaluation
6-7 multiplication and crosses
8-9 F2 selection, cloning and evaluation
10-13 multi-locational testing
14-16 on-farm testing
17 large scale distribution
Understanding physiology of climate change impacts (heat- and drought-)
(Taiz and Zeiger, 2002)
• Transpiration ~ evaporative cooling
• Reduced transpiration: detect by Infrared imaging
Cachaco (ABB) Nakitengwa (AAAh)
Drought
Slide courtesy Rony Swennen, University of Leuven
Impacts on heat-sensitive common bean
But anything is possible with a great genepool
(a) Historical (b) Future (no adaptation) (c) Future (+3 ºC adapted)
Ramirez-Villegas and Thornton (2015)
Testing new varieties with farmers
Beans are a women’s crop
Important to combine heat-tolerance
and drought-tolerance with other
valued traits
Not looking to promote a single variety
everywhere; local preferences and
plasticity matter
Bean variety testing with 215 female &
143 male farmers
Men value traits: yield & market value
Women also value traits: short cooking
times, tastiness, high nutritional value
& climate responses
Mukankusi et al 2015. CCAFS WP 143
Drought-tolerant maize
Masuka et al. submitted
Yiel
d u
nd
er d
rou
ght
stre
ss (
t h
a-1
)
Current yield gain
Expected yield gains based on incorporating new technologies (doubled haploid, breeder ready markers, increased selection intensity, remote sensing, decision support tools)
Drought Tolerant Maize for Africa initiative has already benefited 30-40 million
people in 13 African countries.
Is more benefit possible?
Heat-tolerant maize
New heat stress tolerant hybrid Most popular hybrid in southern Africa
HEAD START: heat tolerance breeding work started
5 years ahead of demand from private sector –
ready in 2016 not 2021
How should we respond 2: preparation & transformation
Incremental phase
• Delay the threshold if possible (G x E x M)
• Genetic gains (15 year cycle)
• Management gains e.g. irrigation
Preparatory phase (15
years ahead)
• Prepare for transformations / substitutions
• Support to farmer & pvt sector innovation
• Flexible enabling environment
Transformation phase
• Crop substitution
• Farming system substitution
• Livelihood substitution
• Dietary substitution
Crop substitutions
Policy pointer: Invest now in
genetic gains in key substitution
crops
Farming system & livelihood substitutions
Jones & Thornton Env Sci Pol 2009
Up to 3% Africa’s land area
Support up to 35 million
people
Support up to 23 million
Tropical Livestock Units of
cattle, sheep & goats
Typically 8 hours travel to
centre of 250k people
Higher levels of poverty &
chronic under-nutrition
Likely shift from mixed
cropping to livestock
systems by 2050
Policy pointer: Target support for transformation to poorest regions
Dietary substitutions
Policy pointer: Take note of climate
change crop impacts in efforts to
promote dietary diversity & nutrition
Khoury et al PNAS 2014
1920s
Flexible enabling environments
- cross-border
biodiversity &
seed protocols
- national R&D
investments
- improved
input markets
- climate
information
and financial
services
- market
information &
extension
- finance for
processing
and storage
facilities
- piloting of
markets for
by-products
- consumer
education
- food and
nutrition
standards
- government
procurement
Improve conditions for self-directed change among
farmers, consumers and value chain participants
Conclusions / Recap
KEY MESSAGE: It is possible to be prepared & pro-active ahead of the adaptation challenge
SUPPORT:
1. Efforts to delay the crossing of viability thresholds
2. Flexible enabling environments for preparatory phases and transformations
Thank you for your
support to this research
ccafs.cgiar.org