1. Climate change, agro-biodiversity and food
security in West Africa
Presentation at the workshop on applied Mathematics and Omics
Technologies for Discovering Biodiversity and Genetic resources for
Climate Change Mitigation and Adaptation to Sustain Agriculture in
Drylands. Rabat-Morocco, 24-27 June 2014
Dr Aichatou Assoumane,
Lecturer and Researcher at University Abdou
Moumouni of Niamey, Niger.
Associate researcher at the Natural Resources
Management Program of CORAF/WECARD

2. Presentation Outline
Environmental challenges: Review of current
regional trends
Impacts of climate change on biodiversity in West
Africa
Climate change in West Africa: Scenarios for the
future
Agricultural Research in the Region

3. Environmental challenges: Review of current
regional trends
Sub-Saharan Africa is faced with
such bio-physical constraints as
droughts, soil acidity, nutrient
depleted and degraded
agricultural and pastoral lands,
etc., which impinge on
agricultural development .
Class N (kg/ha/yr) P2O5
(kg/ha/yr)
K2O
(kg/ha/yr)
Low <10 <4 <10
Moderate 10-20 4-7 10-20
High 21-40 8-15 21-40
Classes of nutrient loss
(Source: Stoorvogel and Smaling, 1990)

4. Environmental challenges: Review of
current regional trends ( con’td)
In West Africa today, rainfall
generally decreases northward
from the coast. In the Sahelian belt,
extending from Senegal through
Mali, Burkina Faso, Niger, and
northern Nigeria, rainfall ranges
from 700 to 1,100 millimeters,
while Mauritania and most parts of
Mali and Niger are largely desert
Annual average precipitation in West Africa
(millimeters per year)
Source: WorldClim version 1.4 (Hijmans et al. 2005)

5. As rainfall decreases, from south to
north, temperature increases
northward from the southern coast.
Maximum temperatures range from
30°–33°C along the coast to 36°–
39°C in the Sahel and 42°–45°C on
the fringe of the desert.
Environmental challenges: Review of current
regional trends ( con’td)
Annual maximum temperature in West Africa (°C)
Source: WorldClim version 1.4 (Hijmans et al. 2005)

6. • The threats of climate change
could prove to be most
challenging to an already over-
stretched sub-regional
production system.
• 10 – 15% of species likely to be
lost in an Africa that is 2 ⁰C
warmer
• Yields from rainfed agriculture
fall by as much as 20% by 2020
• Many pests and diseases of
crops , animals and humans
could change
Impacts of climate change on biodiversity in
West Africa

7. • The threats of climate change
could prove to be most
challenging to an already
over-stretched sub-regional
production system.
• Productivity in fisheries is
likely to be reduced due to
habitat displacement
towards higher latitudes
• Niger river stream flow fell
by 30%
• Senegal and The Gambia by
60%
Impacts of climate change on biodiversity in
West Africa ( con’td)

8. Climate change in West Africa:
Scenarios for the future

9. •GCMs (General Circulation Models) model the physics and chemistry of the
atmosphere and its interactions with oceans and the land surface. Results
from 2 GCMs that are publicly available: CSIRO Mark 3 and MIROC 3.2.
• CSIRO Mark 3 (a climate model developed at the Australia
Commonwealth Scientific and Industrial Research Organization).
• MIROC 3.2. (Model for Interdisciplinary Research on Climate,
developed at the University of Tokyo Center for Climate System
Research).
• The A1B scenarios from the Fourth Assessment Report (AR4) of the
Intergovernmental Panel on Climate Change, is used to simulate greenhouse
gas emissions pathway. A1B is a greenhouse gas emissions scenario that
assumes fast economic growth, a population that peaks midcentury, and the
development of new and efficient technologies, along with a balanced use of
energy sources.
Climate change in West Africa:
Scenarios for the future

10. Changes in average annual precipitation 2000 –2050 (calculations based on
Jones, Thornton and Heinke, 2009): The rainfall scenarios are generally dissimilar
CSIRO, A1B (mm) MIROC, A1B (mm)
There is similarity in the predictions for reduction in rainfall in the southern parts of
Ghana, Togo, Benin, and Nigeria, but the CSIRO A1B scenario has a greater reduction in
precipitation than the MIROC A1B scenario. The CSIRO A1B scenario predicts no change
to as much as 100 millimeters per year decline in the Sahelian region and an increase in
precipitation along the coast of Sierra Leone and most parts of Liberia, while the MIROC
A1B scenario predicts an increase in precipitation in the Sahelian region (50–100 to 100–
200 millimeters per year) and severe drought in Liberia (a decline of 200–400
millimeters per year).
Climate change in West Africa:
Scenarios for the future (con’td)

11. Climate change in West Africa:
Scenarios for the future (con’td)
Changes in yields 2010-2050. DSSAT crop model: Rice
Rainfed rice yields are predicted to decrease by 5–25 percent in most parts
of Côte d’Ivoire, Ghana, and Togo based on both the CSIRO and the MIROC
models and in Nigeria as well based on the CSIRO model. Both models also
have an increase in rice yield in the Sahelian belt, while baseline area will
be lost in Mali and Niger.
CSIRO A1B MIROC A1B

12. Climate change in West Africa:
Scenarios for the future (con’td)
Changes in yields 2010-2050. DSSAT crop model: maize
A general decrease in maize yields of 5–25 percent of baseline in most
parts of the countries along the southern coast of West Africa and a yield
gain of 5–25 percent in the Sahel.
Both models also have a loss in baseline area in the northern most parts of
Mali, Burkina Faso, and Nigeria.
CSIRO A1B MIROC A1B

13. Climate change in West Afica:
Scenarios for the future (con’td)
Changes in yields 2010-2050. from DSSAT crop model: sorghum (rainfed)
Based on both the CSIRO and the MIROC climate outcomes in the A1B
scenario, sorghum yields will decline by 5–25 percent across West Africa,
with greater reductions in parts of Togo, Benin, and adjacent areas of
Ghana and Nigeria
Both climate scenarios also have a loss in baseline area in the Sudan
savanna from Senegal to Nigeria. However, the MIROC scenario has a
greater reduction than the CSIRO scenario.
CSIRO A1B MIROC A1B

14. In general, both climate models (CSIRO and MIROC)
indicate declining rains along the coasts of Nigeria,
Togo, Benin, Ghana, and Côte d’Ivoire, while there is
either increased rainfall (MIROC) or slight dryness or
wetness in the Sahel (CSIRO). This outcome seems to
be related to the relatively higher prevalence of yield
gain for both rice and maize in the Sahel compared to
the more pronounced yield loss in the coastal areas.
Climate change in West Africa:
Scenarios for the future (con’td)

15. The increase in wetness in the Sahel may suggest an
unfavorable condition for drought-tolerant and -adapted
sorghum, with yield loss under increasingly wet conditions.
This scenario suggests that farmers could face various
predicaments and they need to adapt to conditions they
are not used to.
Climate change in West Africa:
Scenarios for the future (con’td)

16. AGRICULTURAL RESEARCH

17. Promote sub-regional
cooperation
Create synergies & reduce
duplications
Solve common agricultural
development problems
through research
Mobilize resources
CORAF/WECARD - Brief overview
Vision: ..... Sustainable reduction of poverty and food
insecurity in West and Central Africa
380 million
inhabitants
Created in
1987
NARS of 22
countries

18. •
• Livestock, Fisheries and Aquaculture
• Staple Crops
• Non-Staple Crops
• Natural Resources Management
• Biotechnology and Biosafety
• Policy, Markets and Trade
• Capacity Strengthening
• Knowledge Management
Research Programs have been identified on the basis of sub-sectors
that can contribute significantly to increase the GDP of countries
Each program has a portfolio of projects implemented by NARS at
national level
Management is centralized at the Executive Secretariat (Dakar,Senegal)
CORAF/WECARD - Brief overview

19. NRM Research themes
 Sustainable management of land and water and
adaptation to climate change
 Sustainable intensification and diversification of
agriculture
 Biodiversity (Animal, plants, fisheries) conservation
and improvement
 Socioeconomics and policy research on natural
resource management
With Climate Change as a key and cross cutting issue in
natural resources management.

20. Sub themes for R&D related to biodiversity management
• Knowledge and conservation of genetic resources
• Use and improvement of genetic resources
• Rehabilitation of the productivity of agricultural and forestry
ecosystems
• Impact and adaptation of biodiversity to climate change and
assessment of environmental services
Biodiversity conservation and improvement (Animal, plants, fisheries)

21. Sub themes for R&D related to soil and water management
• Adoption of natural resource management technologies at
different scales
• Impacts of natural resource management technologies at
different scales
• Financial and economic analysis of proposed natural resources
management technologies
• Economic and social impacts of policies and programmes on
resource management at different levels
• Gender and natural resources management
Socioeconomics and policy research on natural resource management

22. Some thoughts for the way forward
• Combination of large and small scale- with a focus on environmental
sustainability
• Appropriate research within the framework of IAR4D (already
ongoing)
• Improve markets
• Enabling policy environment

23. THANK YOU