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Flood recession farming practiced in flood-prone areas and on the banks of rivers and lakes in arid or semi-arid environments essentially depends on the soil water stock after the flood has receded. During these last few decades, this coveted agriculture is increasingly challenged by severe water constraints, due to increased hydrological hazards and development projects aimed at controlling floods. These challenges are difficult to anticipate, and are the subject of a great deal of uncertainty regarding the sustainability of development projects in the concerned areas. In this study, recent hydraulic data of the Senegal River were analyzed to understand the constraints related to the river management in flood-prone areas. Satellite imagery analysis techniques were used to estimate flooded areas and establish relationships with the river regime. Agricultural practices implemented by farmers were also analyzed to evaluate the resilience of this cropping system to the risk of water stress. The results confirmed many constraints of different importance related to the objectives assigned to the management of dams under multiple water use context. It clearly came out that the water resource management rules relegate flood-recession agriculture to the lowest priorities. In addition, there are safety issues related to unexpected effects of flooding on the water structures and in the nearby inhabited localities of flood-prone areas. Knowing some characteristics of the flooding and of the river’s levels and their relationships can be useful within the framework of an organized climate service that would help farmers and communities to better anticipate constraints.
Mamadou Sall; Jean-Christophe Poussin; Aymar Bossa; Ramatoulaye Ndiaye; Madiama Cissé; Didier Martin; Jean-Claude Bader; Benjamin Sultan; Andrew Ogilvie. Water Constraints and Flood-Recession Agriculture in the Senegal River Valley. Atmosphere 2020, 11, 1192 .
AMA StyleMamadou Sall, Jean-Christophe Poussin, Aymar Bossa, Ramatoulaye Ndiaye, Madiama Cissé, Didier Martin, Jean-Claude Bader, Benjamin Sultan, Andrew Ogilvie. Water Constraints and Flood-Recession Agriculture in the Senegal River Valley. Atmosphere. 2020; 11 (11):1192.
Chicago/Turabian StyleMamadou Sall; Jean-Christophe Poussin; Aymar Bossa; Ramatoulaye Ndiaye; Madiama Cissé; Didier Martin; Jean-Claude Bader; Benjamin Sultan; Andrew Ogilvie. 2020. "Water Constraints and Flood-Recession Agriculture in the Senegal River Valley." Atmosphere 11, no. 11: 1192.
Climate change is already affecting agro-ecosystems and threatening food security by reducing crop productivity and increasing harvest uncertainty. Mobilizing crop diversity could be an efficient way to mitigate its impact. We test this hypothesis in pearl millet, a nutritious staple cereal cultivated in arid and low-fertility soils in sub-Saharan Africa. We analyze the genomic diversity of 173 landraces collected in West Africa together with an extensive climate dataset composed of metrics of agronomic importance. Mapping the pearl millet genomic vulnerability at the 2050 horizon based on the current genomic-climate relationships, we identify the northern edge of the current areas of cultivation of both early and late flowering varieties as being the most vulnerable to climate change. We predict that the most vulnerable areas will benefit from using landraces that already grow in equivalent climate conditions today. However, such seed-exchange scenarios will require long distance and trans-frontier assisted migrations. Leveraging genetic diversity as a climate mitigation strategy in West Africa will thus require regional collaboration.
Bénédicte Rhoné; Dimitri Defrance; Cécile Berthouly-Salazar; Cédric Mariac; Philippe Cubry; Marie Couderc; Anaïs Dequincey; Aichatou Assoumanne; Ndjido Ardo Kane; Benjamin Sultan; Adeline Barnaud; Yves Vigouroux. Pearl millet genomic vulnerability to climate change in West Africa highlights the need for regional collaboration. Nature Communications 2020, 11, 1 -9.
AMA StyleBénédicte Rhoné, Dimitri Defrance, Cécile Berthouly-Salazar, Cédric Mariac, Philippe Cubry, Marie Couderc, Anaïs Dequincey, Aichatou Assoumanne, Ndjido Ardo Kane, Benjamin Sultan, Adeline Barnaud, Yves Vigouroux. Pearl millet genomic vulnerability to climate change in West Africa highlights the need for regional collaboration. Nature Communications. 2020; 11 (1):1-9.
Chicago/Turabian StyleBénédicte Rhoné; Dimitri Defrance; Cécile Berthouly-Salazar; Cédric Mariac; Philippe Cubry; Marie Couderc; Anaïs Dequincey; Aichatou Assoumanne; Ndjido Ardo Kane; Benjamin Sultan; Adeline Barnaud; Yves Vigouroux. 2020. "Pearl millet genomic vulnerability to climate change in West Africa highlights the need for regional collaboration." Nature Communications 11, no. 1: 1-9.
Food security is a crucial issue in the Sahel and could be endangered by climate change and demographic pressure during the 21st century. Higher temperatures and changes in rainfall induced by global warming are threatening rainfed agriculture in this region while the population is expected to increase approximately three-fold until 2050. Our study quantifies the impact of climate change on food security by combining climate modelling (16 models from CMIP5), crop yield (simulated by agronomic model, SARRA-O) and demographic evolution (provided by UN projection) under two future climatic scenarios. We simulate yield for the main crops in five countries in West Africa and estimate the population pressure on crop production to assess the number of available cereal production per capita. We found that, although uncertain, the African monsoon evolution leads to an increase of rainfall in Eastern Sahel and a decrease in Western Sahel under the RCP8.5 (Representative Concentration Pathway) scenario from IPCC, leading to the higher temperature increase by the end of the 21st century. With regard to the abundance of food for the inhabitants, all the scenarios in each country show that in 2050, local agricultural production will be below 50 kg per capita. This situation can have impact on crop import and regional migration.
Dimitri Defrance; Benjamin Sultan; Mathieu Castets; Adjoua Famien; Christian Baron. Impact of Climate Change in West Africa on Cereal Production Per Capita in 2050. Sustainability 2020, 12, 7585 .
AMA StyleDimitri Defrance, Benjamin Sultan, Mathieu Castets, Adjoua Famien, Christian Baron. Impact of Climate Change in West Africa on Cereal Production Per Capita in 2050. Sustainability. 2020; 12 (18):7585.
Chicago/Turabian StyleDimitri Defrance; Benjamin Sultan; Mathieu Castets; Adjoua Famien; Christian Baron. 2020. "Impact of Climate Change in West Africa on Cereal Production Per Capita in 2050." Sustainability 12, no. 18: 7585.
The Paris Climate Agreements and Sustainable Development Goals, signed by 197 countries, present agendas and address key issues for implementing multi-scale responses for sustainable development under climate change—an effort that must involve local, regional, national, and supra-national stakeholders. In that regard, Continental Carbon Sequestration (CoCS) and conservation of carbon sinks are recognized increasingly as having potentially important roles in mitigating climate change and adapting to it. Making that potential a reality will require indicators of success for various stakeholders from multidisciplinary backgrounds, plus promotion of long-term implementation of strategic action towards civil society (e.g., law and policy makers, economists, and farmers). To help meet those challenges, this discussion paper summarizes the state of the art and uncertainties regarding CoCS, taking an interdisciplinary, holistic approach toward understanding these complex issues. The first part of the paper discusses the carbon cycle’s bio-geophysical processes, while the second introduces the plurality of geographical scales to be addressed when dealing with landscape management for CoCS. The third part addresses systemic viability, vulnerability, and resilience in CoCS practices, before concluding with the need to develop inter-disciplinarity in sustainable science, participative research, and the societal implications of sustainable CoCS actions.
Tiphaine Chevallier; Maud Loireau; Romain Courault; Lydie Chapuis-Lardy; Thierry Desjardins; Cécile Gomez; Alexandre Grondin; Frédéric Guérin; Didier Orange; Raphaël Pélissier; Georges Serpantié; Marie-Hélène Durand; Pierre Derioz; Gildas Laruelle Goulven; Marie-Hélène Schwoob; Nicolas Viovy; Olivier Barrière; Eric Blanchart; Vincent Blanfort; Michel Brossard; Julien Demenois; Mireille Fargette; Thierry Heulin; Gil Mahe; Raphaël Manlay; Pascal Podwojewski; Cornélia Rumpel; Benjamin Sultan; Jean-Luc Chotte. Paris Climate Agreement: Promoting Interdisciplinary Science and Stakeholders’ Approaches for Multi-Scale Implementation of Continental Carbon Sequestration. Sustainability 2020, 12, 6715 .
AMA StyleTiphaine Chevallier, Maud Loireau, Romain Courault, Lydie Chapuis-Lardy, Thierry Desjardins, Cécile Gomez, Alexandre Grondin, Frédéric Guérin, Didier Orange, Raphaël Pélissier, Georges Serpantié, Marie-Hélène Durand, Pierre Derioz, Gildas Laruelle Goulven, Marie-Hélène Schwoob, Nicolas Viovy, Olivier Barrière, Eric Blanchart, Vincent Blanfort, Michel Brossard, Julien Demenois, Mireille Fargette, Thierry Heulin, Gil Mahe, Raphaël Manlay, Pascal Podwojewski, Cornélia Rumpel, Benjamin Sultan, Jean-Luc Chotte. Paris Climate Agreement: Promoting Interdisciplinary Science and Stakeholders’ Approaches for Multi-Scale Implementation of Continental Carbon Sequestration. Sustainability. 2020; 12 (17):6715.
Chicago/Turabian StyleTiphaine Chevallier; Maud Loireau; Romain Courault; Lydie Chapuis-Lardy; Thierry Desjardins; Cécile Gomez; Alexandre Grondin; Frédéric Guérin; Didier Orange; Raphaël Pélissier; Georges Serpantié; Marie-Hélène Durand; Pierre Derioz; Gildas Laruelle Goulven; Marie-Hélène Schwoob; Nicolas Viovy; Olivier Barrière; Eric Blanchart; Vincent Blanfort; Michel Brossard; Julien Demenois; Mireille Fargette; Thierry Heulin; Gil Mahe; Raphaël Manlay; Pascal Podwojewski; Cornélia Rumpel; Benjamin Sultan; Jean-Luc Chotte. 2020. "Paris Climate Agreement: Promoting Interdisciplinary Science and Stakeholders’ Approaches for Multi-Scale Implementation of Continental Carbon Sequestration." Sustainability 12, no. 17: 6715.
Climate services have been criticised in the past for their tendency to only disseminate results from climate research, rather than to seek to understand and tailor to the needs of their target audiences. Two surveys have been conducted within two projects, ISIpedia and CLIMAP, to assess users’ needs for climate and climate impacts information of all countries (with a foremost focus on West Africa) and for Senegal. The joint analysis of the results showed that climate and climate-impact information is very relevant for West African respondents’ activities but a number of barriers prevent existing climate services from fully fulfilling the role they could play in this respect. Consistently across both surveys, the respondents highlighted the irrelevance or the incompleteness of the information that current climate services provide, which is mostly related to the lack of high-resolution information or high uncertainties, as the biggest barriers. Both surveys showed that the lack of training to understand the provided information is also an important barrier, which calls for the organisation of capacity-building activities to ensure the uptake of the information by their target audiences. Overall, the survey responses demonstrated the importance of stakeholder engagement to ensure the usefulness of climate services in West Africa. In addition, appropriate integration of the existing climate services within the national contexts as well as their dissemination within the ecosystem of information portals and products appear to be essential to ensure their effectiveness.
B. Sultan; Q. Lejeune; I. Menke; G. Maskell; K. Lee; M. Noblet; I. Sy; P. Roudier. Current needs for climate services in West Africa: Results from two stakeholder surveys. Climate Services 2020, 18, 100166 .
AMA StyleB. Sultan, Q. Lejeune, I. Menke, G. Maskell, K. Lee, M. Noblet, I. Sy, P. Roudier. Current needs for climate services in West Africa: Results from two stakeholder surveys. Climate Services. 2020; 18 ():100166.
Chicago/Turabian StyleB. Sultan; Q. Lejeune; I. Menke; G. Maskell; K. Lee; M. Noblet; I. Sy; P. Roudier. 2020. "Current needs for climate services in West Africa: Results from two stakeholder surveys." Climate Services 18, no. : 100166.
Climate model projections generally indicate fewer but more intense tropical cyclones (TCs) in response to increasing anthropogenic emissions. However these simulations suffer from long-standing biases in their Sea Surface Temperature (SST). While most studies investigating future changes in TC activity using high-resolution atmospheric models correct for the present-day SST bias, they do not consider the reliability of the projected SST changes from global climate models. The present study illustrates that future South Pacific TC activity changes are strongly sensitive to correcting the projected SST changes using an emergent constraint method. This additional correction indeed leads to a strong reduction of the cyclogenesis (−55%) over the South Pacific basin, while no statistically significant change arises in the uncorrected simulations. Cyclogenesis indices suggest that this strong reduction in the corrected experiment is caused by stronger vertical wind shear in response to a South Pacific Convergence Zone equatorward shift. We thus find that uncertainty in the projected SST patterns could strongly hamper the reliability of South Pacific TC projections. The strong sensitivity found in the current study will need to be investigated with other models, observational constraint methods and in other TC basins in order to assess the reliability of regional TC projections.
C. Dutheil; M. Lengaigne; M. Bador; J. Vialard; J. Lefèvre; N. C. Jourdain; S. Jullien; A. Peltier; B. Sultan; C. Menkès. Impact of projected sea surface temperature biases on tropical cyclones projections in the South Pacific. Scientific Reports 2020, 10, 1 -12.
AMA StyleC. Dutheil, M. Lengaigne, M. Bador, J. Vialard, J. Lefèvre, N. C. Jourdain, S. Jullien, A. Peltier, B. Sultan, C. Menkès. Impact of projected sea surface temperature biases on tropical cyclones projections in the South Pacific. Scientific Reports. 2020; 10 (1):1-12.
Chicago/Turabian StyleC. Dutheil; M. Lengaigne; M. Bador; J. Vialard; J. Lefèvre; N. C. Jourdain; S. Jullien; A. Peltier; B. Sultan; C. Menkès. 2020. "Impact of projected sea surface temperature biases on tropical cyclones projections in the South Pacific." Scientific Reports 10, no. 1: 1-12.
Achieving food security goals in West Africa will depend on the capacity of the agricultural sector to feed the rapidly growing population and to moderate the adverse impacts of climate change. Indeed, a number of studies anticipate a reduction of the crop yield of the main staple food crops in the region in the coming decades due to global warming. Here, we found that crop production might have already been affected by climate change, with significant yield losses estimated in the historical past. We used a large ensemble of historical climate simulations derived from an atmospheric general circulation model and two process-based crop models, SARRA-H and CYGMA, to evaluate the effects of historical climate change on crop production in West Africa. We generated two ensembles of 100 historical simulations of yields of sorghum and millet corresponding to two climate conditions for each crop model. One ensemble is based on a realistic simulation of the actual climate, while the other is based on a climate simulation that does not account for human influences on climate systems (that is, the non-warming counterfactual climate condition). We found that the last simulated decade, 2000–2009, is approximately 1 °C warmer in West Africa in the ensemble accounting for human influences on climate, with more frequent heat and rainfall extremes. These altered climate conditions have led to regional average yield reductions of 10–20% for millet and 5–15% for sorghum in the two crop models. We found that the average annual production losses across West Africa in 2000–2009 associated with historical climate change, relative to a non-warming counterfactual condition (that is, pre-industrial climate), accounted for 2.33–4.02 billion USD for millet and 0.73–2.17 billion USD for sorghum. The estimates of production losses presented here can be a basis for the loss and damage associated with climate change to date and useful in estimating the costs of the adaptation of crop production systems in the region.
Benjamin Sultan; Dimitri Defrance; Toshichika Iizumi. Evidence of crop production losses in West Africa due to historical global warming in two crop models. Scientific Reports 2019, 9, 1 -15.
AMA StyleBenjamin Sultan, Dimitri Defrance, Toshichika Iizumi. Evidence of crop production losses in West Africa due to historical global warming in two crop models. Scientific Reports. 2019; 9 (1):1-15.
Chicago/Turabian StyleBenjamin Sultan; Dimitri Defrance; Toshichika Iizumi. 2019. "Evidence of crop production losses in West Africa due to historical global warming in two crop models." Scientific Reports 9, no. 1: 1-15.
Climate change directly threatens food security in West Africa through a negative impact on productivity of the main staple food crops. However, providing consistent future crop yield projections in the region remain challenging because of uncertainty in the response of the regional climate to the CO2 increase and in the response of the cultivated crop to this altered climate with more CO2 in the atmosphere. Here, we analyse a set of idealised climate simulations to investigate the effect of CO2 concentration increase on the West African monsoon and potential impacts on crop yields of maize. On the one hand, simulations with prescribed SST and quadrupled CO2 concentration are analysed to study the atmospheric response to direct radiative forcing induced by increasing CO2 concentration, not mediated by ocean heat capacity. On the other hand, simulations with prescribed SST augmented by 4 K are analysed to study the atmospheric response to the global ocean warming expected as a consequence of the increasing CO2 radiative forcing. We show that if CO2 concentration increase has a positive impact on crop yield due to the fertilisation effect, it also has a direct effect on the monsoon which acts to increase (decrease) rainfall in the Eastern (Western) part of the Sahel and increase (decrease) crop yields consequently. Finally, we show that SST warming acts to reduce rainfall and increase local temperatures leading to strong reduction of crop yield. The reduction of crop yield is more important in the Eastern part of the Sahel where the warming is more intense than in the Western part of the Sahel. Overall, positive effects are weaker and more uncertain than the negative effects in the analysed simulations.
Benjamin Sultan; Ben Parkes; Marco Gaetani. Direct and indirect effects of CO 2 increase on crop yield in West Africa. International Journal of Climatology 2018, 39, 2400 -2411.
AMA StyleBenjamin Sultan, Ben Parkes, Marco Gaetani. Direct and indirect effects of CO 2 increase on crop yield in West Africa. International Journal of Climatology. 2018; 39 (4):2400-2411.
Chicago/Turabian StyleBenjamin Sultan; Ben Parkes; Marco Gaetani. 2018. "Direct and indirect effects of CO 2 increase on crop yield in West Africa." International Journal of Climatology 39, no. 4: 2400-2411.
Maize (Zea mays) is one of the staple crops of West Africa and is therefore of high importance with regard to future food security. The ability of West Africa to produce enough food is critical as the population is expected to increase well into the twenty-first century. In this study, a process-based crop model is used to project maize yields in Africa for global temperatures 2 K and 4 K above the preindustrial control. This study investigates how yields and crop failure rates are influenced by climate change and the efficacy of adaptation methods to mitigate the effects of climate change. To account for the uncertainties in future climate projections, multiple model runs have been performed at specific warming levels of + 2 K and + 4 K to give a better estimate of future crop yields. Under a warming of + 2 K, the maize yield is projected to reduce by 5.9% with an increase in both mild and severe crop failure rates. Mild and severe crop failures are yields 1 and 1.5 standard deviations below the observed yield. At a warming of + 4 K, the results show a yield reduction of 37% and severe crop failures which previously only occurred once in 19.7 years are expected to happen every 2.5 years. Crops simulated with a resistance to high temperature stress show an increase in yields in all climate conditions compared to unadapted crops; however, they still experience more crop failures than the unadapted crop in the control climate.
Ben Parkes; Benjamin Sultan; Philippe Ciais. The impact of future climate change and potential adaptation methods on Maize yields in West Africa. Climatic Change 2018, 151, 205 -217.
AMA StyleBen Parkes, Benjamin Sultan, Philippe Ciais. The impact of future climate change and potential adaptation methods on Maize yields in West Africa. Climatic Change. 2018; 151 (2):205-217.
Chicago/Turabian StyleBen Parkes; Benjamin Sultan; Philippe Ciais. 2018. "The impact of future climate change and potential adaptation methods on Maize yields in West Africa." Climatic Change 151, no. 2: 205-217.
In the West African Sahel, two paradoxical hydrological behaviors have occurred during the last five decades. The first paradox was observed during the 1968–1990s ‘Great Drought’ period, during which runoff significantly increased. The second paradox appeared during the subsequent period of rainfall recovery (i.e., since the 1990s), during which the runoff coefficient continued to increase despite the general re-greening of the Sahel. This paper reviews and synthesizes the literature on the drivers of these paradoxical behaviors, focusing on recent works in the West African Sahelo/Sudanian strip, and upscaling the hydrological processes through an analysis of recent data from two representative areas of this region. This paper helps better determine the respective roles played by Land Use/Land Cover Changes (LULCC), the evolution of rainfall intensity and the occurrence of extreme rainfall events in these hydrological paradoxes. Both the literature review and recent data converge in indicating that the first Sahelian hydrological paradox was mostly driven by LULCC, while the second paradox has been caused by both LULCC and climate evolution, mainly the recent increase in rainfall intensity.
Luc Descroix; Françoise Guichard; Manuela Grippa; Laurent A. Lambert; Gérémy Panthou; Gil Mahé; Laetitia Gal; Cécile Dardel; Guillaume Quantin; Laurent Kergoat; Yasmin Bouaïta; Pierre Hiernaux; Théo Vischel; Thierry Pellarin; Bakary Faty; Catherine Wilcox; Moussa Malam Abdou; Ibrahim Mamadou; Jean-Pierre Vandervaere; Aïda Diongue-Niang; Ousmane Ndiaye; Youssouph Sané; Honoré Dacosta; Marielle Gosset; Claire Cassé; Benjamin Sultan; Aliou Barry; Okechukwu Amogu; Bernadette Nka Nnomo; Alseny Barry; Jean-Emmanuel Paturel. Evolution of Surface Hydrology in the Sahelo-Sudanian Strip: An Updated Review. Water 2018, 10, 748 .
AMA StyleLuc Descroix, Françoise Guichard, Manuela Grippa, Laurent A. Lambert, Gérémy Panthou, Gil Mahé, Laetitia Gal, Cécile Dardel, Guillaume Quantin, Laurent Kergoat, Yasmin Bouaïta, Pierre Hiernaux, Théo Vischel, Thierry Pellarin, Bakary Faty, Catherine Wilcox, Moussa Malam Abdou, Ibrahim Mamadou, Jean-Pierre Vandervaere, Aïda Diongue-Niang, Ousmane Ndiaye, Youssouph Sané, Honoré Dacosta, Marielle Gosset, Claire Cassé, Benjamin Sultan, Aliou Barry, Okechukwu Amogu, Bernadette Nka Nnomo, Alseny Barry, Jean-Emmanuel Paturel. Evolution of Surface Hydrology in the Sahelo-Sudanian Strip: An Updated Review. Water. 2018; 10 (6):748.
Chicago/Turabian StyleLuc Descroix; Françoise Guichard; Manuela Grippa; Laurent A. Lambert; Gérémy Panthou; Gil Mahé; Laetitia Gal; Cécile Dardel; Guillaume Quantin; Laurent Kergoat; Yasmin Bouaïta; Pierre Hiernaux; Théo Vischel; Thierry Pellarin; Bakary Faty; Catherine Wilcox; Moussa Malam Abdou; Ibrahim Mamadou; Jean-Pierre Vandervaere; Aïda Diongue-Niang; Ousmane Ndiaye; Youssouph Sané; Honoré Dacosta; Marielle Gosset; Claire Cassé; Benjamin Sultan; Aliou Barry; Okechukwu Amogu; Bernadette Nka Nnomo; Alseny Barry; Jean-Emmanuel Paturel. 2018. "Evolution of Surface Hydrology in the Sahelo-Sudanian Strip: An Updated Review." Water 10, no. 6: 748.
The objective of this paper is to present a new dataset of bias-corrected CMIP5 global climate model (GCM) daily data over Africa. This dataset was obtained using the cumulative distribution function transform (CDF-t) method, a method that has been applied to several regions and contexts but never to Africa. Here CDF-t has been applied over the period 1950–2099 combining Historical runs and climate change scenarios for six variables: precipitation, mean near-surface air temperature, near-surface maximum air temperature, near-surface minimum air temperature, surface downwelling shortwave radiation, and wind speed, which are critical variables for agricultural purposes. WFDEI has been used as the reference dataset to correct the GCMs. Evaluation of the results over West Africa has been carried out on a list of priority user-based metrics that were discussed and selected with stakeholders. It includes simulated yield using a crop model simulating maize growth. These bias-corrected GCM data have been compared with another available dataset of bias-corrected GCMs using WATCH Forcing Data as the reference dataset. The impact of WFD, WFDEI, and also EWEMBI reference datasets has been also examined in detail. It is shown that CDF-t is very effective at removing the biases and reducing the high inter-GCM scattering. Differences with other bias-corrected GCM data are mainly due to the differences among the reference datasets. This is particularly true for surface downwelling shortwave radiation, which has a significant impact in terms of simulated maize yields. Projections of future yields over West Africa are quite different, depending on the bias-correction method used. However all these projections show a similar relative decreasing trend over the 21st century.
Adjoua Moise Famien; Serge Janicot; Abe Delfin Ochou; Mathieu Vrac; Dimitri Defrance; Benjamin Sultan; Thomas Noël. A bias-corrected CMIP5 dataset for Africa using the CDF-t method – a contribution to agricultural impact studies. Earth System Dynamics 2018, 9, 313 -338.
AMA StyleAdjoua Moise Famien, Serge Janicot, Abe Delfin Ochou, Mathieu Vrac, Dimitri Defrance, Benjamin Sultan, Thomas Noël. A bias-corrected CMIP5 dataset for Africa using the CDF-t method – a contribution to agricultural impact studies. Earth System Dynamics. 2018; 9 (1):313-338.
Chicago/Turabian StyleAdjoua Moise Famien; Serge Janicot; Abe Delfin Ochou; Mathieu Vrac; Dimitri Defrance; Benjamin Sultan; Thomas Noël. 2018. "A bias-corrected CMIP5 dataset for Africa using the CDF-t method – a contribution to agricultural impact studies." Earth System Dynamics 9, no. 1: 313-338.
By using a detailed agricultural and climate dataset over Burkina-Faso and simple assumptions regarding the form of an insurance contract, the authors investigate the potential economic efficiency for farmers of a weather-index insurance system in this country. To do so, the results of more than 3000 simulated contracts applied to 30 districts, 21 yr (1984–2004), and five crops (cotton, millet, sorghum, maize, and groundnut) are explored. It is found that such an insurance system, even based on a simple weather index like cumulative rainfall during the rainy season, can present a significant economic efficiency for some crops and districts. The determinants of the efficiency of such contracts are analyzed in terms of yield/index correlations and yield variability. As a consequence of these two main determinants, the farmer's gain from an insurance contract is higher in the driest part of the country. In the same way, maize and groundnuts are the most suitable to implement an insurance system since their respective yields show a large variance and a generally high correlation with the weather index. However, the implementation of a real weather-index insurance system in West Africa raises a number of key practical issues related to cultural, economic, and institutional aspects.
Alexis Berg; Philippe Quirion; Benjamin Sultan. Weather-index drought insurance in Burkina-Faso: assessment of its potential interest to farmers. 2018, 1 .
AMA StyleAlexis Berg, Philippe Quirion, Benjamin Sultan. Weather-index drought insurance in Burkina-Faso: assessment of its potential interest to farmers. . 2018; ():1.
Chicago/Turabian StyleAlexis Berg; Philippe Quirion; Benjamin Sultan. 2018. "Weather-index drought insurance in Burkina-Faso: assessment of its potential interest to farmers." , no. : 1.
Symposium on Social Theory and the Environment in the New World (dis)Order ; International audience ; In West Africa, agriculture, mainly rainfed, is a major economic sector and the one most vulnerable to climate change. A meta-database of future crop yields, built up from 16 recent studies, is used to provide an overall assessment of the potential impact of climate change on yields, and to analyze sources of uncertainty. Despite a large dispersion of yield changes ranging from -50% to +90%, the median is a yield loss near -11%. This negative impact is assessed by both empirical and process-based crop models whereas the Ricardian approach gives very contrasted results, even within a single study. The predicted impact is larger in northern West Africa (Sudano-Sahelian countries, -18% median response) than in southern West Africa (Guinean countries, -13%) which is likely due to drier and warmer projections in the northern part of West Africa. Moreover, negative impacts on crop productivity increase in severity as warming intensifies, with a median yield loss near -15% with most intense warming, highlighting the importance of global warming mitigation. The consistently negative impact of climate change results mainly from the temperature whose increase projected by climate models is much larger relative to precipitation change. However, rainfall changes, still uncertain in climate projections, have the potential to exacerbate or mitigate this impact depending on whether rainfall decreases or increases. Finally, results highlight the pivotal role that the carbon fertilization effect may have on the sign and amplitude of change in crop yields. This effect is particularly strong for a high carbon dioxide concentration scenario and for C3 crops (e.g. soybean, cassava). As staple crops are mainly C4 (e.g. maize, millet, sorghum) in WA, this positive effect is less significant for the region. (C) 2011 Elsevier Ltd. All rights reserved.
Philippe Roudier; Benjamin Sultan; Philippe Quirion; Alexis Berg. The impact of future climate change on West African crop yields: What does the recent literature say? 2018, 1 .
AMA StylePhilippe Roudier, Benjamin Sultan, Philippe Quirion, Alexis Berg. The impact of future climate change on West African crop yields: What does the recent literature say? . 2018; ():1.
Chicago/Turabian StylePhilippe Roudier; Benjamin Sultan; Philippe Quirion; Alexis Berg. 2018. "The impact of future climate change on West African crop yields: What does the recent literature say?" , no. : 1.
Ben Parkes; Benjamin Sultan; Philippe Ciais; Xuhui Wang. Erratum to “Modelling fertiliser significance in three major crops” [Eur. J. Agron. 90 (2017) 1–11]. European Journal of Agronomy 2018, 93, 135 .
AMA StyleBen Parkes, Benjamin Sultan, Philippe Ciais, Xuhui Wang. Erratum to “Modelling fertiliser significance in three major crops” [Eur. J. Agron. 90 (2017) 1–11]. European Journal of Agronomy. 2018; 93 ():135.
Chicago/Turabian StyleBen Parkes; Benjamin Sultan; Philippe Ciais; Xuhui Wang. 2018. "Erratum to “Modelling fertiliser significance in three major crops” [Eur. J. Agron. 90 (2017) 1–11]." European Journal of Agronomy 93, no. : 135.
The objective of this paper is to present a new data set of bias-corrected CMIP5 global climate models (GCMs) daily data over Africa. This dataset was obtained in using the Cumulative Distribution Function Transform (CDF-t) method, a method that has been applied on several regions and contexts but never on Africa. Here CDF-t is used over the period 1950–2099 combining historical runs and climate change scenarios on 6 variables, precipitation, mean near-surface air temperature, near-surface maximum air temperature, near-surface minimum air temperature, surface down-welling shortwave radiation, and wind speed, which are critical variables for agricultural purposes. Evaluation of the results is carried out over West Africa on a list of priority users-based metrics that was discussed and selected with stakeholders and on simulated yield using a crop model simulating maize growth. Bias-corrected GCMs data are compared with another available dataset of bias-corrected GCMs, and the impact of three different reference datasets on bias-corrections is also examined in details. CDF-t is very effective in removing the biases and in reducing the high inter-GCMs scattering. Differences with other bias-corrected GCMs data are mainly due to the differences between the reference datasets. This is particular true for surface down-welling shortwave radiation, which has impacts in terms of simulated maize yields. Projections of future yields over West Africa have quite different levels, depending on bias-correction method used, but they all show a similar relative decreasing trend over the 21st century.
Adjoua Moise Famien; Serge Janicot; Abe Delfin Ochou; Mathieu Vrac; Dimitri Defrance; Benjamin Sultan; Thomas Noël. A bias-corrected CMIP5 dataset for Africa using CDF-t method. A contribution to agricultural impact studies. 2017, 1 -32.
AMA StyleAdjoua Moise Famien, Serge Janicot, Abe Delfin Ochou, Mathieu Vrac, Dimitri Defrance, Benjamin Sultan, Thomas Noël. A bias-corrected CMIP5 dataset for Africa using CDF-t method. A contribution to agricultural impact studies. . 2017; ():1-32.
Chicago/Turabian StyleAdjoua Moise Famien; Serge Janicot; Abe Delfin Ochou; Mathieu Vrac; Dimitri Defrance; Benjamin Sultan; Thomas Noël. 2017. "A bias-corrected CMIP5 dataset for Africa using CDF-t method. A contribution to agricultural impact studies." , no. : 1-32.
Land Use Land-Cover Change (LULCC), such as deforestation, affects the climate system and land-atmosphere interactions. Using simulations carried out within the LUCID (Land Use and Climate, IDentification of robust Impacts) project framework, we first quantify the role of historical land-cover change induced by human activities on surface climate in West Africa. Focusing on two contrasted African regions, we find that climate responses of land-use changes are small but they are still statistically significant. In Western Sahel, a statistically significant near-surface atmospheric cooling and a decrease in water recycling are simulated in summer in response to LULCC. Over the Guinean zone, models simulate a significant decrease in precipitation and water recycling in autumn in response to LULCC. This signal is comparable in magnitude with the effect induced by the increase in greenhouse gases. Simulated climate changes due to historical LULCC could however be underestimated because: (i) the prescribed LULCC can be underestimated in those regions; (ii) the climate models underestimate the coupling strength between West African surface climate and leaf area index (LAI) and (iii) the lack of interactive LAI in some models. Finally, our study reveals indirect atmospheric processes triggered by LULCC. Over the Western Sahel, models reveal that a significant decrease in solar reflection tend to cool down the surface and thus counteract the atmospheric feedback. Conversely, over the Guinea zone, models reveal that the indirect atmospheric processes and turbulent heat fluxes dominate the climatic responses over the direct effects of LULCC.
Souleymane Sy; Nathalie De Noblet-Ducoudré; Benjamin Quesada; Ibrahima Sy; Amadou Moctar Dieye; Amadou Thierno Gaye; Benjamin Sultan. Land-Surface Characteristics and Climate in West Africa: Models’ Biases and Impacts of Historical Anthropogenically-Induced Deforestation. Sustainability 2017, 9, 1917 .
AMA StyleSouleymane Sy, Nathalie De Noblet-Ducoudré, Benjamin Quesada, Ibrahima Sy, Amadou Moctar Dieye, Amadou Thierno Gaye, Benjamin Sultan. Land-Surface Characteristics and Climate in West Africa: Models’ Biases and Impacts of Historical Anthropogenically-Induced Deforestation. Sustainability. 2017; 9 (10):1917.
Chicago/Turabian StyleSouleymane Sy; Nathalie De Noblet-Ducoudré; Benjamin Quesada; Ibrahima Sy; Amadou Moctar Dieye; Amadou Thierno Gaye; Benjamin Sultan. 2017. "Land-Surface Characteristics and Climate in West Africa: Models’ Biases and Impacts of Historical Anthropogenically-Induced Deforestation." Sustainability 9, no. 10: 1917.
Les épisodes de sécheresse et de canicule comptent parmi les catastrophes naturelles qui causent le plus de dégâts et qui touchent le plus de personnes au monde. Une augmentation de leur fréquence et de leur intensité dans de nombreuses régions, sous différentes latitudes, semble être une conséquence attendue du réchauffement climatique. De fait, il est crucial de mieux caractériser ces événements, de les comprendre et d’essayer d’en atténuer les conséquences, voire de les anticiper (cf. I.7)...
Benjamin Sultan; Yamna Djellouli. 4. Sécheresse et canicule : incidence et prise en compte. Le développement durable à découvert 2017, 218 -219.
AMA StyleBenjamin Sultan, Yamna Djellouli. 4. Sécheresse et canicule : incidence et prise en compte. Le développement durable à découvert. 2017; ():218-219.
Chicago/Turabian StyleBenjamin Sultan; Yamna Djellouli. 2017. "4. Sécheresse et canicule : incidence et prise en compte." Le développement durable à découvert , no. : 218-219.
International audienceWe present work using two long term climate datasets to show that nitrogen fertiliser is an important aspect of yield projection for three major crops. The ability of linear models using climate variables as predictors to accurately project the yield of maize, rice and wheat over multi-decadal scales is improved with the addition of fertiliser as an input. Highly productive nations including Argentina, India, Poland and South Africa show significant improvement in yield simulations and show that fertiliser use should not be discounted when estimating yield variability. The use of nitrogen fertiliser in the generalised linear models improves yield forecast by 18% using the Princeton climate dataset and 23% using the WFDEI climate dataset. This work therefore supports the use of additional predictors than climate for improving the ability of statistical models to reconstruct yield variability
Ben Parkes; Benjamin Sultan; Philippe Ciais; Xuhui Wang. Modelling fertiliser significance in three major crops. European Journal of Agronomy 2017, 90, 1 -11.
AMA StyleBen Parkes, Benjamin Sultan, Philippe Ciais, Xuhui Wang. Modelling fertiliser significance in three major crops. European Journal of Agronomy. 2017; 90 ():1-11.
Chicago/Turabian StyleBen Parkes; Benjamin Sultan; Philippe Ciais; Xuhui Wang. 2017. "Modelling fertiliser significance in three major crops." European Journal of Agronomy 90, no. : 1-11.
The reference evapotranspiration (ET0) is an integrated climatic variable from which many crop models derive simulated crop yields. In most of these models, different equations are parameterized leaving the choice of the equation to the user. However, the impact of the choice of the ET0 equations on crop yield prediction has been little studied. The present study proposes a sensitivity analysis of the impact of the choice of the ET0 equation on simulated millet yields using SARRA-H crop model over 12 Senegalese stations representative of the Sudano-Sahelian climate conditions of West Africa. Priestley-Taylor, a modified Priestley-Taylor and Hargreaves equations lead to simulated yields up to 19% than those calculated using the Penman-Monteith equation. Despite high biases in wind speed, among the tested methods, the Penman-Monteith method remains the most robust to derive ET0 and yield over the major part of Senegal, Hargreaves equation being more appropriated under dry climates. The choice of ET0 formulation introduces uncertainties representing 8% of baseline yield regardless of precipitation changes; for wet conditions these uncertainties approach 30% of the overall climate change impact. The choice of ET0 equation is increasingly important, with local temperature changes out to 4 °C, while extreme changes above 6 °C depend less on the ET0 equation.
Johanna Ramarohetra; Benjamin Sultan. Impact of ET0method on the simulation of historical and future crop yields: a case study of millet growth in Senegal. International Journal of Climatology 2017, 38, 729 -741.
AMA StyleJohanna Ramarohetra, Benjamin Sultan. Impact of ET0method on the simulation of historical and future crop yields: a case study of millet growth in Senegal. International Journal of Climatology. 2017; 38 (2):729-741.
Chicago/Turabian StyleJohanna Ramarohetra; Benjamin Sultan. 2017. "Impact of ET0method on the simulation of historical and future crop yields: a case study of millet growth in Senegal." International Journal of Climatology 38, no. 2: 729-741.
The ability of a country or region to feed itself in the upcoming decades is a question of importance. The population in West Africa is expected to increase significantly in the next 30 years. The responses of food crops to short term climate change is therefore critical to the population at large and the decision makers tasked with providing food for their people. An ensemble of near term climate projections are used to simulate maize, millet and sorghum in West Africa in the recent historic and near term future. The mean yields are not expected to alter significantly, while there is an increase in inter annual variability. This increase in variability increases the likelihood of crop failures, which are defined as yield negative anomalies beyond one standard deviation during a period of 20 years. The increasing variability increases the frequency and intensity of crop failures across West Africa. The mean return frequency between mild maize crop failures from process based crop models increases from once every 6.8 years to once every 4.5 years. The mean return time frequency for severe crop failures (beyond 1.5 standard deviations) also almost doubles from once every 16.5 years to once every 8.5 years. Two adaptation responses to climate change, the adoption of heat-resistant cultivars and the use of captured rainwater have been investigated using one crop model in an idealised sensitivity test. The generalised adoption of a cultivar resistant to high temperature stress during flowering is shown to be more beneficial than using rainwater harvesting by both increasing yields and the return frequency of crop failures.
Ben Parkes; Dimitri Defrance; Benjamin Sultan; Philippe Ciais; Xuhui Wang. Projected changes in crop yield mean and variability over West Africa in a world 1.5 K warmer than the pre-industrial. 2017, 2017, 1 -24.
AMA StyleBen Parkes, Dimitri Defrance, Benjamin Sultan, Philippe Ciais, Xuhui Wang. Projected changes in crop yield mean and variability over West Africa in a world 1.5 K warmer than the pre-industrial. . 2017; 2017 ():1-24.
Chicago/Turabian StyleBen Parkes; Dimitri Defrance; Benjamin Sultan; Philippe Ciais; Xuhui Wang. 2017. "Projected changes in crop yield mean and variability over West Africa in a world 1.5 K warmer than the pre-industrial." 2017, no. : 1-24.