The Relationship between Climate Change, Variability, and Food Security: Understanding the Impacts and Building Resilient Food Systems in West Pokot County, Kenya

The Ripple Effect of Climate Change: Assessing the Impacts on Water Quality and Hydrology in Addis Ababa City (Akaki Catchment)

This research aimed to evaluate the effects of climate change on the hydrology and water quality in the Akaki catchment, which provides water to Addis Ababa, Ethiopia. This was performed using the soil and water assessment tool (SWAT) model and an ensemble of four global climate models under two Shared Socioeconomic Pathways (SSP) emission scenarios from Coupled Model Intercomparison Project Phase 6 (CMIP6). The climate data were downscaled and bias-corrected using the CMhyd tool and calibrated and validated using the SWAT-CUP software package. Change points and patterns in annual rainfall and temperature were determined using the homogeneity test and Mann-Kendell trend test. Water quality data were obtained from Addis Ababa Water and Sewerage Authority (AAWSA), and more samples were taken and analyzed in accordance with APHA recommended procedures. The SWAT model output was then used to assess the impacts of climate change on hydrological components and water quality. Rainfall increased by 19.39 mm/year under SSP2-4.5 and 12.8 mm/year under SSP8.5. Maximum temperature increased by 0.03°C/yr for SSP2-4.5 and 0.04°C/yr for SSP5-8.5. Minimum temperature increased by 0.03°C/yr under SSP2-4.5 and 0.07°C/yr under SSP5-8.5. This warming will augment the evapotranspiration rate which in turn will have a negative impact on the freshwater availability. Streamflow will increase by 5% under SSP2-4.5 and 9.49% under SSP5-85 which may increase sporadic flooding events. Climate change is expected to contribute to the deterioration of water quality shown by 61%, 36%, 79%, 115%, and 70% increased ammonia, chlorophyll-a, nitrite, nitrate, and phosphorus loadings, respectively, from 2022. The increase in temperature results in increases in nutrient loading and a decrease in dissolved oxygen. Overall, this research demonstrated the vulnerability of the catchment to climate change. The findings of this research can offer vital knowledge to policymakers on possible strategies for the sustainable management of water.

Agro-climatic sensitivity analysis for sustainable crop diversification; the case of Proso millet (Panicum miliaceum L.)

Current agricultural production depends on very limited species grown as monocultures that are highly vulnerable to climate change, presenting a threat to the sustainability of agri-food systems. However, many hundreds of neglected crop species have the potential to cater to the challenges of climate change by means of resilience to adverse climate conditions. Proso millet (Panicum miliaceum L.), one of the underutilised minor millets grown as a rainfed subsistence crop, was selected in this study as an exemplary climate-resilient crop. Using a previously calibrated version of the Agricultural Production Systems Simulator (APSIM), the sensitivity of the crop to changes in temperature and precipitation was studied using the protocol of the Coordinated Climate Crop Modelling Project (C3MP). The future (2040-2069) production was simulated using bias-corrected climate data from 20 general circulation models of the Coupled Model Intercomparison Project (CMIP5) under RCP4.5 and 8.5 scenarios. According to the C3MP analysis, we found a 1°C increment of temperature decreased the yield by 5-10% at zero rainfall change. However, Proso millet yields increased by 5% within a restricted climate change space of up to 2°C of warming with increased rainfall. Simulated future climate yields were lower than the simulated yields under the baseline climate of the 1980-2009 period (mean 1707 kg ha-1) under both RCP4.5 (-7.3%) and RCP8.5 (-16.6%) though these changes were not significantly (p > 0.05) different from the baseline yields. Proso millet is currently cultivated in limited areas of Sri Lanka, but our yield mapping shows the potential for expansion of the crop to new areas under both current and future climates. The results of the study, indicating minor impacts from projected climate change, reveal that Proso millet is an excellent candidate for low-input farming systems under changing climate. More generally, through this study, a framework that can be used to assess the climate sensitivity of underutilized crops was also developed.

Pearl Millet (Pennisetum glaucum) Seedlings Transplanting as Climate Adaptation Option for Smallholder Farmers in Niger

Pearl millet is the most widely grown cereal crop in the arid and semi-arid regions of Africa, and in Niger in particular. To determine an optimized management strategy for smallholder farmers in southern Niger to cope with crop production failure and improve cropping performance in the context of climate change and variability, multi-site trials were conducted to evaluate the impacts of transplanting on pearl millet growth and productivity. Eight treatments viz. T1-0NPK (100% transplanting without NPK), T1-NPK (100% transplanting + NPK), T2-0NPK (100% transplanting of empty hills without NPK), T2-NPK (100% transplanting of empty hills + NPK), T3-0NPK (50% transplanting of empty hills without NPK), T3-NPK (50% transplanting of empty hills + NPK), T4-0NPK (farmer practice without NPK), and T4-NPK (farmer practice + NPK) were included in the experiment. Compared to farmer practice, transplanting significantly reduced time to tillering, flowering, and maturity stages by 15%, 27%, and 11%, respectively. The results also revealed that T1-NPK significantly increased panicle weight, total biomass, grain yield, and plant height by 40%, 38%, 27%, and 23%, respectively. Farmers’ evaluations of the experiments supported these findings, indicating three substantial advantages of transplanting, including higher yield (37.50% of responses), larger, more vigorous and more panicles (34.17% of responses), and good tillering (28.33% of responses). An economic profitability analysis of the system revealed that biomass gain (XOF 359,387/ha) and grain gain (XOF 324,388/ha) increased by 34% and 22%, respectively, with T1-NPK. Therefore, it can be inferred that transplanting is a promising strategy for adapting millet cultivation to climate change and variability in southern Niger.