ABSTRACTS - CLIMATE CHANGE AND AFRICA

Africa-Wide Studies

Jones, Peter G., and Philip K. Thornton. 2003. "The potential impacts of climate change on maize production in Africa and Latin America in 2055," Global Environmental Change, Vol. 13, No. 1, pp. 51 - 59.
ABSTRACT: The impacts of climate change on agriculture may add significantly to the development challenges of ensuring food security and reducing poverty. We show the possible impacts on maize production in Africa and Latin America to 2055, using high-resolution methods to generate characteristic daily weather data for driving a detailed simulation model of the maize crop. Although the results indicate an overall reduction of only 10% in maize production to 2055, equivalent to losses of $2 billion per year, the aggregate results hide enormous variability: areas can be identified where maize yields may change substantially. Climate change urgently needs to be assessed at the level of the household, so that poor and vulnerable people dependent on agriculture can be appropriately targeted in research and development activities whose object is poverty alleviation.

Hulme, M., R.M. Doherty, T. Ngara, M.G. New, and D. Lister. 2001. "African climate change: 1900-2100," Climate Research, Vol. 17, No. 2, pp. 145-168.
AUTHOR'S DRAFT: http://www.cru.uea.ac.uk/~mikeh/pubs/cr_africa.pdf
ABSTRACT: This paper reviews observed (1900-2000) and possible future (2000-2100) continent-wide changes in temperature and rainfall for Africa. For the historic period we draw upon a new observed global climate data set which allows us to explore aspects of regional climate change related to diurnal temperature range and rainfall variability. The latter includes an investigation of regions where seasonal rainfall is sensitive to El Niño climate variability. This review of past climate change provides the context for our scenarios of future greenhouse gas-induced climate change in Africa. These scenarios draw upon the draft emissions scenarios prepared for the Intergovernmental Panel on Climate Change's Third Assessment Report, a suite of recent global climate model experiments, and a simple climate model to link these 2 sets of analyses. We present a range of 4 climate futures for Africa, focusing on changes in both continental and regional seasonal-mean temperature and rainfall. Estimates of associated changes in global CO2 concentration and global-mean sea-level change are also supplied. These scenarios draw upon some of the most recent climate modelling work. We also identify some fundamental limitations to knowledge with regard to future African climate. These include the often poor representation of El Niño climate variability in global climate models, and the absence in these models of any representation of regional changes in land cover and dust and biomass aerosol loadings. These omitted processes may well have important consequences for future African climates, especially at regional scales. We conclude by discussing the value of the sort of climate change scenarios presented here and how best they should be used in national and regional vulnerability and adaptation assessments.

Magadza, C.H.D. 2000. "Climate Change Impacts and Human Settlements in Africa: Prospects for Adaptation," Environmental Monitoring and Assessment, Vol. 61, No. 1, March, 193-205.
ABSTRACT: Climate change impacts on African human settlements arise from a number of climate change-related causes, notably sea level changes, impacts on water resources, extreme weather events, food security, increased health risks from vector home diseases, and temperature-related morbidity in urban environments.
Some coastlines and river deltas of Africa have densely populated low-lying areas, which would be affected by a rise in sea level. Other coastal settlements will be subjected to increased coastal erosion. Recent flooding in East Africa highlighted the vulnerability of flood plain settlements and the need to develop adaptive strategies for extreme weather events management and mitigation. In the semi arid and arid zones many settlements are associated with inland drainage water sources. Increases in drought will enhance water supply related vulnerabilities. Inter-basin and international water transfers raise the need for adequate legal frameworks that ensure equity among participating nations.
Similarly, water supply and irrigation reservoirs in seasonal river catchments might fail, leading to poor sanitation in urban areas as well as food shortage. Hydroelectric power generation could be restricted in drought periods, and where it is a major contributor to the energy budget, reduced power generation could lead to a multiplicity of other impacts. States are advised to develop other sources of renewable energy.
Temperature changes will lead to altered distribution of disease vectors such as mosquitoes, making settlements currently free of vector borne diseases vulnerable. Rapid breeding of the housefly could create a menace associated with enteric disorders, especially in conditions of poor sanitation.
The dry savannahs of Africa are projected as possible future food deficit areas. Recurrent crop failures would lead to transmigration into urban areas. Pastoralists are likely to undertake more trans-boundary migrations and probably come into conflict with settled communities.
Adaptive measures will involve methods of coastal defences (where applicable), a critical review of the energy sector, both regionally and nationally, a rigorous adherence to city hygiene procedures, an informed agricultural industry that is capable of adapting to changing climate in terms of cropping strategies, and innovations in environment design to maximise human comfort at minimum energy expenditure. In the savannah and arid areas water resource management systems will be needed to optimise water resource use and interstate co-operation where such resources are shared.
Climate change issues discussed here raise the need for state support for more research and education in impacts of climate change on human settlements in Africa.

Feddema, Johannes J. 1999. "Future African Water Resources: Interactions between Soil Degradation and Global Warming," Climatic Change, Vol. 42, No. 3, July, pp. 561-596.
ABSTRACT: This study uses a well-established water balance methodology to evaluate the relative impact of global warming and soil degradation due to desertification on future African water resources. Using a baseline climatology, a GCM global warming scenario, a newly derived soil water-holding capacity data set, and a worldwide survey of soil degradation between 1950 and 1980, four climate and soil degradation scenarios are created to simulate the potential impact of global warming and soil degradation on African water resources for the 2010-2039 time period. Results indicate that, on a continental scale, the impact of global warming will be significantly greater than the impact of soil degradation. However, when only considering the locations where desertification is an issue (wet and dry climate regions), the potential effects of these two different human impacts on local water resources can be expected to be on the same order of magnitude. Drying associated with global warming is primarily the result of increased water demand (potential evapotranspiration) across the entire continent. While there are small increases in precipitation under global warming conditions, they are inadequate to meet the increased water demand. Soil degradation is most severe in highly populated, wet and dry climate regions and results in decreased water-holding capacities in these locations. This results in increased water surplus conditions during wet seasons when the soil's ability to absorb precipitation is reduced. At the same time, water deficits in these locations increase because of reduced soil water availability in the dry seasons. The net result of the combined scenarios is an intensification and extension of drought conditions during dry seasons.

Downing, Thomas E. 1991. "Vulnerability to hunger in Africa: a climate change perspective,"
Global Environmental Change, Vol. 1, No. 5, December, pp.365-380.
ABSTRACT: Limitations of present assessments of climate change impacts on food supplies are addressed, and a new approach is proposed. This uses the concept of vulnerability to hunger as a point of departure. A typology of vulnerability indices is developed and several measures of vulnerability are explored using information from case studies reported in the literature and research coordinated by the author's research group. An initial synthesis of data about climate change and vulnerability to hunger is illustrated for Africa.

Sub-Regional Studies

Amissah-Arthur, Abigail. 2003. "Targeting Climate Forecasts for Agricultural Applications in Sub-Saharan Africa: Situating Farmers in User-Space," Climatic Change, Vol. 58, No. 1-2, May, pp. 73-92.
ABSTRACT: Several meteorological services in Africa now issue seasonal climate forecasts on an operational basis. However, the failure to develop a comprehensive profile of users has resulted in a considerable gap between the information that is likely to be useful to farmers and that provided and disseminated by these services. The present study develops a methodology to characterize smallholder production systems in order to identify farmer groups who may adopt and benefit from the climate forecast information in sub-Saharan Africa. Through an extensive literature review, data and information was derived from a national household survey of 1540 smallholders in 1995-1997 by the Kenya Agricultural Research Institute and spatial georeferenced data from leading world data centers. The data were analysed and synthesized using the GIS. Considerable opportunities exist for farming communities to improve their profitability using climate forecasts. Although the needs and demand for climate forecasts vary according to the production systems and market forces that determine credit, demand and input availability and, thus, the usability of forecasts depend on the characteristics of the farmers and their place in space. Based on production strategies and options available to farmers, three zones were identified grouping farmers with highly probable, probable and less probable potential of adopting climate forecasts to alter their production practices. Although a climate forecast may be useful to all farmers in the region considered, due to different options available to individual groups of farmers, however, the benefits derived from its use may not be equitable. Some of the options available to farmers in Kenya were considered in this study with a view to highlighting why some may benefit more than others. The methodology demonstrated here could be adopted for other parts of the world for: (1) selecting survey sites to determine the benefits of climate forecasts using farmers participatory rapid rural appraisals and simulation approach, and (2) target climate information where it would be most useful.

Sene, K. J., E. L. Tate and F. A. K. Farquharson. 2001. "Sensitivity Studies of the Impacts of Climate Change on White Nile Flows," Climatic Change, Vol. 50, No. 1-2, July, pp. 177-208.
ABSTRACT: Several exploratory studies are presented on the sensitivity of the water balance of the White Nile to climate change, using both observed and stochastic time series to drive the models. Example results are presented using various assumed climate change scenarios and results from a General Circulation Model (GCM). The relative merits and shortcomings of each modelling approach are also discussed. A simple analytical model for Lake Victoria is also used to illustrate some of the overall features of the lake's likely response. Particular difficulties with the White Nile system are that, due to the huge area of open water in the basin, transient responses to short-lived events can occur over timescales comparable with those for which long term climate change impacts are being studied, and predicted changes in flows are extremely sensitive to estimates for the rainfall and evaporation at lake and swamp surfaces. Of the modelling approaches considered, the network simulation approach with stochastic inputs is recommended as a way of smoothing out these transient effects, and assessing the uncertainty in the results due to inaccuracies in the data, the model parameters and the climate change predictions. The paper concludes with a brief discussion of some other areas of uncertainty in the hydrological modelling of White Nile flows and possible alternative external forcing mechanisms for flows in the next few decades.

Wilkie, David, Gilda Morelli, Fiona Rotberg, and Ellen Shaw. 1999. "Wetter isn't better: global warming and food security in the Congo Basin," Global Environmental Change, Vol. 9, No. 4, December, pp. 323-328.
ABSTRACT: Over 20 million forest farmers practice slash and burn agriculture in the forests of the Congo Basin (Bahuchet and de Maret, 1995. State of Indigenous Populations Living in Rainforest Areas, European Commission DG XI Environment, Brussels). They rely on the long dry season (December-February north of the equator) to ensure that their new fields, cleared from regrowth forest, burn sufficiently well to deposit nutrients into the soil and to minimize the labor required to prepare the field for planting. Data from the Ituri forest in northeastern Democratic Republic of Congo show that the strength of the annual dry season (a) has a direct positive impact on the size of fields cleared each year by slash and burn farmers, and consequently on food production and the severity of the subsequent year's pre-harvest hunger period; and (b) is inversely related to total annual rainfall. These results suggest that the 1 mm/d increase in rainfall predicted for much of the Congo Basin by the 2050s may cause a basin wide increase in the frequency of heavy rains during the dry season, causing a reduction in the size of slash and burn farmers' fields, and potentially a substantial increase in the food insecurity of poor rural families across the region.

Jallow, Bubu P., Sekou Toure Malang, M. K. Barrow, and Assa Achy Mathieu. 1999. "Coastal zone of The Gambia and the Abidjan region in Côte d'Ivoire: sea level rise vulnerability, response strategies, and adaptation options," Climate Research, Vol. 12, pp. 129-136.
ABSTRACT: The aerial videotape-assisted vulnerability analysis (AVVA) technique was combined with various data sets to assess the vulnerability of the coastal zone of The Gambia to sea level rise. Land loss due to inundation, flooding, and erosion was estimated. Costs of damage and population at risk were also evaluated. Only historical data and maps were used to assess the vulnerability of the coastal zone of the Abidjan region of Côte d'Ivoire to sea level rise. Results show that with a 1 m sea level rise the whole of the capital city of Banjul will be under mean sea level in the next 50 to 60 yr as a greater part of the city is below 1 m. The mangrove systems on St. Mary's Island, Kombo St. Mary, and the strand plains in the north bank will be inundated. About 1950 billion Dalasis (US $217 million) worth of land will be lost. The most appropriate response would be to protect the whole of the coastline of Banjul, the shoreline area from the Banjul cemeteries to Laguna Beach Hotel, the infrastructure at Sarro, and the hotel complex at Cape Point. Innovative sand management, repair of the damaged groins, and construction of dikes, breakwater structures, revetments, and low-cost seawall are some of the shoreline stabilization and hardening techniques suggested for the protection of this area. For the Abidjan region, the same response strategies should be used. Adaptation responses identified for both regions include public awareness, increase in height of coastal infrastructure, urban growth planning, wetland preservation and mitigation, and development of a coastal zone management plan.

Joubert, A. M., S. J. Mason, J. S. Galpin. 1996. "Droughts Over Southern Africa in a Doubled-CO2 Climate," International Journal of Climatology, Vol. 16, No. 10, pp. 1149-1156.
ABSTRACT: The southern African region is susceptible to climatic extremes and particularly to extended dry periods. Possible changes in the probability of dry years under doubled-CO2 conditions are examined using output from the CSIRO nine-level general circulation model. Changes in annual mean rainfall are not expected to be significant. However, the model simulates an increase in the probability of dry years in the tropics, to the south-west of the subcontinent, as well as over the western and eastern parts of South Africa and southern Mozambique, where large percentage increases in the most intense dry spells are indicated. A decrease in the frequency of dry years is simulated over much of the interior of the subcontinent south of 10°S. In regions where the frequency of dry years decreases, the most severe events occur less often. The CSIRO nine-level model indicates a shift in the frequency distribution of daily rainfall events under doubled-CO2 conditions. A small change in the frequency distribution of daily rainfall events may have further implications for the frequency of mid-summer droughts during the peak summer rainfall period of December-February. Increases in the frequency of mid-summer droughts are simulated over the eastern part of the subcontinent south of 20°S.

Schulze, Roland E., Gregory A. Kiker and Richard P. Kunz. 1993. "Global climate change and agricultural productivity in southern Africa," Global Environmental Change,
Vol. 3, No. 4, December, pp. 330-349.
ABSTRACT: An analysis tool was developed to simulate primary productivity and crop yields for both present and possible future climate conditions. Southern Africa was delineated into 712 relatively homogeneous climate zones, each with specific climate, soil and vegetation response information. The primary productivity and crop yield models were linked with the climate zones via a cellbased agrohydrologlcal model, with the final output coordinated using a Geographic Information System. The results of this preliminary study show a large dependence of production and crop yield on the intra-seasonal and inter-annual variation of rainfall. The most important conclusion from the study is the readiness of the developed tool and associated infrastructure for future analysis into social, technological and political responses to food security in southern Africa.

Glantz, Michael H. 1992. "Global warming and environmental change in sub-Saharan Africa," Global Environmental Change, Vol. 2, No. 3, September, pp. 183-204.
ABSTRACT:Now that governments are beginning to consider actions to respond to the potential threat of global warming (even if they do not yet believe that it will definitely occur), their representatives search the scientific literature for `clues' about the positive or negative impacts of a few degrees Celsius increase in global temperature. There is a growing number of `guesstimates' (often called scenarios) about climate change impacts in sub-Saharan Africa. A review of the existing scenarios highlights conflicting, if not opposing, views about those impacts. Such scenarios must be used with caution and labelled as speculation. No single scenario should be used for determining irreversible policy responses to the potential regional consequences of global warming.

Country-Level Studies

Egypt

Strzepek, Kenneth M., and David N. Yates. 2000. "Responses and Thresholds of the Egyptian Economy to Climate Change Impacts on the Water Resources of the Nile River," Climatic Change, Vol. 46, No. 3, August, pp. 339-356.
ABSTRACT: Are there "thresholds" in greenhouse gas (GHG) concentrations above which associated climate change impacts become economically, socially or environmentally unacceptable? If thresholds exist, then emissions might be limited in such a way that GHG concentrations are not exceeded. Environmental, social, and economic systems should be examined in order to determine these threshold levels.
This paper addressed the potential impacts of climate change on the water resources of the Nile River and associated impacts on the Egyptian economy through the use of a recursively dynamic general equilibrium model. The model was used to examine both economy-wide and sectoral impacts, and impacts on social and national policy indicators under various economic growth and climate change scenarios. Macro-economic indicators such as Gross Domestic Product (GDP) showed that strict economic thresholds, characterized by discontinuities in the response function, did not occur. This was because autonomous economic adjustments generated a smooth socioeconomic transition over the 70-year simulation period. The economy underwent a gradual structural transformation, as capital and resources were moved from cropped agricultural to both the livestock and the non-agricultural sectors. Under "wet" climate scenarios, surplus water beyond 75 billion cubic meters (BCM) remained unused, as the marginal value of water dropped to zero and other resource constraints limited agricultural growth. For drier scenarios (below 75 BCM), water was a constraint to agricultural production into the 21st century, as resources were diverted to less water demanding crops and the livestock and non-agricultural sectors. The reduced water scenarios showed agriculture declining in its total share of GDP, burdening the agricultural wage earner. Egypt increased its dependence on imports to meet food demand, dramatically decreasing grain self-sufficiency, while increasing protein self-sufficiency. If national policy requires a certain level of food self-sufficiency, then these metrics could be used in defining policy-based thresholds.

Raey, M. El, Kh. Dewidar, and M. El Hattab. 1999. "Adaptation to the impacts of sea level rise in Egypt," Climate Research, Vol. 12, pp. 117-128.
ABSTRACT: Assessment of the vulnerability of and expected socioeconomic losses over the Nile Delta coast due to the impact of sea level rise (SLR) was carried out in detail. Impacts of SLR on the Governorates of Alexandria and Port Said, in particular, were evaluated quantitatively. Options and costs of adaptation were analyzed and presented. Multi-criteria and decision matrix approaches based on questionnaire surveys were carried out to identify priorities in the 2 case studies. Results indicate that there are very limited possibilities of changing jobs for vulnerable stakeholders; cost is the main barrier of implementation; the majority of stakeholders recommend protection actions; and beach nourishment with limited hard structures (groins and breakwaters) is the best immediate option for adaptation, while the ICZM approach is the best available strategic option.

Yates, David N., and Kenneth M. Strzepek. 1998. "An Assessment of Integrated Climate Change Impacts on the Agricultural Economy of Egypt," Climatic Change, Vol. 38, No. 3, March, pp. 261-287. ABSTRACT: This study used a quadratic programming sector model to assess the integrated impacts of climate change on the agricultural economy of Egypt. Results from a dynamic global food trade model were used to update the Egyptian sector model and included socio-economic trends and world market prices of agricultural goods. In addition, the impacts of climate change from three bio-physical sectors - water resources, crop yields, and land resources - were used as inputs to the economic model. The climate change scenarios generally had minor impacts on aggregated economic welfare (sum of Consumer and Producer Surplus or CPS), with the largest reduction of approximately 6 percent. In some climate change scenarios, CPS slightly improved or remained unchanged. These scenarios generally benefited consumers more than producers, as world market conditions reduced the revenue generating capacity of Egyptian agricultural exporters but decreased the costs of imports. Despite increased water availability and only moderate yield declines, several climate change scenarios showed producers being negatively affected by climate change. The analysis supported the hypothesis that smaller food importing countries are at a greater risk to climate change, and impacts could have as much to do with changes in world markets as with changes in local and regional biophysical systems and shifts in the national agricultural economy.

El-Shaer, H.M., C. Rosenzweig, A. Iglesias, M.H. Eid, and D. Hillel. 1997. "Impact of climate change on possible scenarios for Egyptian agriculture in the future," Mitigation and Adaptation Strategies for Global Change, Vol. 1, pp. 233-250.
ABSTRACT: If no timely measures are taken to adapt Egyptian agriculture to possible climate warming, the effects may be negative and serious. Egypt appears to be particularly vulnerable to climate change because of its dependence on the Nile River as the primary water source, its large traditional agricultural base, and its long coastline, already undergoing both intensifying development and erosion. A simulation study characterized potential yield and water use efficiency decreases on two reference crops in the main agricultural regions with possible future climatic variation, even when the beneficial effects of increase CO2 were taken into account. On-farm adaptation techniques which imply no additional cost to the agricultural system did not compensate for the yield losses with the warmer climate or improve the crop water-use efficiency. Economic adjustments such as the imporvement of the overall water-use efficiency of the agricultural system, soil drainage and conservation, land management, and crop alternatives are essential. If appropriate measures are taken, negative effects of climate change in agricultural production and other major resource sectors (water and land) may be lessened.

Onyeji, S Chib, and Günther Fischer. 1994. "An economic analysis of potential impacts of climate change in Egypt," Global Environmental Change, Vol. 4, No. 4, December, pp. 281-299.
ABSTRACT: Projections of climate impacts on crop yields simulated for different General Circulation Model (GCM) scenarios are used, in a recursively dynamic general equilibrium framework, to account for potential economy-wide impacts of climate change in Egypt. Comparing these impact projections to those obtained under a reference, business-as-usual, scenario assuming some moderate changes in the political, economic or technological spheres, indicates that global warming has potentially negative effects. The analysis is based on a global assessment of potential climate change-induced variations in world commodity production and trade. The Egyptian agricultural sector, and the non-agricultural sector to a lesser extent, are projected to be increasingly less self-sufficient. Specific potential adverse impacts are identified. The simulation results show that high-cost adaptation measures involving major changes in the agricultural system and practices may mitigate these adverse impacts. Stimulating economic development of the rural areas and creating appropriate conditions for effective diffusion and development of technologies -- particularly for the agricultural sector -- would seem a desirable strategy. Perhaps, more importantly, the simulation results show that the assumption of exogenously determined technological progress may be inappropriate, in which case the potential adverse impacts of a future warming of the global climate are likely to be fewer than is indicated in this study -- if prevailing constraints on productivity growth in the major food and feed grains are `released' by endogenous advances in technology.

Ethiopia

Hailemariam, Kinfe. 1999. "Impact of climate change on the water resources of Awash River Basin, Ethiopia," Climate Research, Vol. 12, pp. 91-96.
ABSTRACT: An attempt was made to investigate the sensitivity of water resources to climate change in the Awash River Basin in Ethiopia. The climate of the basin varies from humid subtropical to arid. The basin was divided into 3 subcatchments for better resolution in calibration and simulation. Station-based meteorological data were processed to obtain areal averages necessary for the simulation. Different sets of temperature and rainfall scenarios were developed using GCM (both transient and CO2 doubling) and incremental scenarios. The IIASA integrated water balance model (WatBal) was used to estimate runoff under a changed climate. The model represents the water balance among surface outflow, subsurface outflow, and evapotranspiration. The model was calibrated using a 10 yr period (1971 to 1980), validated with the next 6 yr period (1981 to 1986), and then applied for different climate scenarios. Results of the impact assessment over the basin showed a projected decrease in runoff, which ranged from -10 to -34%, with doubling of CO2 and transient scenarios of CO2 increase (GFD3, CCCM, GF01). Sensitivity analysis based on incremental scenarios showed that a drier and warmer climate change scenario results in reduced runoff.

Malawi

Mkanda, Francis X. 1999. "Drought as an analogue climate change scenario for prediction of potential impacts on Malawi's wildlife habitats," Climate Research, Vol. 12, No 2-3, pp. 215-222.
ABSTRACT: This study compares precipitation and temperature from recent drought episodes with general circulation model outputs to examine the likely effects of climate change on herbaceous layer productivity, ground cover, and forage utilization in Malawi's Lengwe National Park. There are no differences in precipitation distribution and temperature during the drought episodes and climate change scenarios. The implication is that deteriorating habitat conditions such as those observed during the drought incidents might occur under climate change. Herbacious layer productivity was 2 to 6 times lower than in a normal year; ground cover was reduced to 22-32%; and the number of intensely browsed plants increased significantly (chi-square = 10.5, p = 0.01) as the drought progressed. Consequently, it is unlikely that the degraded habitat would support large mammal populations in Lengwe specifically, or in Malawi in general.

Morocco

Parish, R., and D. C. Funnell. 1999. "Climate change in mountain regions: some possible consequences in the Moroccan High Atlas," Global Environmental Change, Vol. 9, No. 1, April 1999, pp. 45-58.
ABSTRACT: Mountain areas are particularly sensitive to climate change. Seasonal and annual variations in climate already strongly influence agro-ecosystems, and although there is much speculation about the precise effects in such areas, any response of the communities will emerge from existing coping practices. Using examples from the High Atlas in Morocco, the paper explores the implications for livestock management, arboriculture and tourism. Although the local agro-ecosystem may prove resilient initially, the need to change tenure conditions and other rules of management may lead to conflict which exceeds the capacity of local institutions to resolve. At the same time national considerations may also draw the state more fully into conflict with mountain communities over resource use. However, the paper argues that these issues are just as likely to emerge from the evolution of the national economy as from climate change.

Niger

Mohamed, A. Ben, N. van Duivenbooden, and S. Abdoussallam. 2002. "Impact of Climate Change on Agricultural Production in the Sahel - Part 1. Methodological Approach and Case Study for Millet in Niger," Climatic Change, Vol. 54, No. 3, August, pp. 327-348.
ABSTRACT: In the last 30 years the climate of the West African Sahel has shown various changes, especially in terms of rainfall, of which inter-annual variability is very high. This has significant consequences for the poor-resource farmers, whose incomes depend mainly on rainfed agriculture. The West African Sahel is already known as an area characterized by important interaction between climate variability and key socio-economic sectors such as agriculture and water resources. More than 80% of the 55 million population of West African Sahel is rural, involved in agriculture and stock-farming, the two sectors contributing almost 35% of the countries' GDPs. It is therefore obvious that climate change seriously affects the economies of these countries. Adding to this situation the high rate of population increase (~3%), leading to progressive pressure upon ecosystems, and poor sanitary facilities, one comes to the conclusion that Sahelian countries, Niger amongst them, will be highly vulnerable to climate change. This paper investigates the impact of current climate variability and future climate change on millet production for three major millet-producing regions in Niger. Statistical models have been used to predict the effects of climate change on future production on the basis of thirteen available predictors. Based on the analysis of the past 30-years of rainfall and production data, the most significant predictors of the model are (i) sea surface temperature anomalies, (ii) the amount of rainfall in July, August and September, (iii) the number of rainy days and (iv) the wind erosion factor. In 2025, production of millet is estimated to be about 13% lower as a consequence of climate change, translated into a reduction of the total amount of rainfall for July, August and September, combined with an increase in temperature while maintaining other significant predictors at a constant level. Subsequently, various potential strategies to compensate this loss are evaluated, including those to increase water use efficiency and to cultivate varieties that are adapted to such circumstances.

N. van Duivenbooden, S. Abdoussalam, and A. Ben Mohamed. 2002. "Impact of Climate Change on Agricultural Production in the Sahel - Part 2. Case Study for Groundnut and Cowpea in Niger," Climatic Change, Vol. 54, No. 3, August, pp. 349-368.
ABSTRACT: During the last 30 years, the climate of the West African Sahel has undergone various changes, especially in terms of rainfall. This has large consequences for the poor-resource farmers depending mainly on rainfed agriculture. This paper investigates the impacts of current climate variability and future climate change on groundnut and cowpea production in Niger for three major agricultural regions, including the groundnut basin. Niger was one of the largest West African groundnut producing and exporting countries. Groundnut production - as a cash crop - dropped from about 312,000 tons in the mid 1960s (about 68% exported) to as low as 13,000 tons in 1988 and increased again to 110,000 tons in 2000. Cowpea, a food crop, shows a different tendency, going from 4,000 tons in the mid fifties to a maximum of 775,000 tons in 1997, and its cultivated area is still increasing. It is also a cash crop in local economies (especially for women). To highlight the impact of climate change on groundnut and cowpea production (significantly determined by rainfall in July, August and September), the following components of the rainfall regime were calculated for the period 1951-1998: mean annual and monthly rainfall, beginning, end and length of the rainy season, number of rainy days per month, amount of rainfall per rainy day and the maximum length of dry spell per month. Three sub-periods whose duration varied per region were defined: for Dosso 1951-1968, 1969-1984 and 1985-1998; for Maradi 1951-1970, 1971-1987 and 1988-1998; and for Zinder 1951-1966, 1967-1984 and 1985-1998. A change in rainfall regime components was observed between the three sub-periods, which were characterized in chronological order by wet, dry and intermediate conditions. To assess the impact of climate variability and change on groundnut and cowpea production, a statistical modeling approach has been followed, based on thirteen predictors as described and discussed in the preceding paper. Climate change is mimicked in terms of reduced total amount of rainfall for the three main rainfall months and an increased temperature, while maintaining other significant predictors at a constant level. In 2025, production of groundnut is estimated to be between 11 and 25% lower, while cowpea yield will fall maximally 30%. Various strategies to compensate this potential loss are presented for the two crops.