Climate Change Impact on Agriculture and Water Resources - A Review

Abstract

Climate change affects agricultural water requirement, water availability, water quantity and quality. Agriculture is most affected by climate change among other sectors because crop and livestock systems depend critically on climatic variables such as precipitation and temperature. The effect of climate change has been assessed in several special reports from international agencies the United Nations World Water Development (WWD), Food and Agriculture Organization of the United Nations (FAO), the International Food Policy Research Institute (IFPRI), and Intergovernmental Panel on Climate Change (IPCC) etc. These studies all share a common conclusion that climate change affects the availability, quality and quantity of water for basic human needs, thus threatening global food security. Following these global assessments and numerous local and regional studies, this study provides an overview of the state-of-the-art knowledge on the impact of climate change on agriculture and water resources, backed up by climatic data from Nigerian Meteorological Agency, Abuja. The results show that the atmospheric concentration of greenhouse gases (GHGs) is increasing. Consequently, the increasing concentration of GHGs resulted in changing global climate with increasing temperature. The rise in global average temperatures since 1860 now exceeds 0.6OC. In Nigeria, there is a decrease in rainfall (about 90 mm), while temperature increased (about 0.8OC) since 1960. This has led to increased evaporation and evapotranspiration and water stress resulting in the drying up of water bodies such as rivers and lakes. While climate change makes some countries experience an increase in water resources, the majority face serious water stress. The changes in climatic events such as temperature and rainfall significantly affect the yield of crops, because of their sensitivity to weather parameters, thereby causing huge economic impacts on countries that are highly dependent on Agriculture. More research and government policies should focus on a planned adaptation in agricultural water management to facilitate more consistent and more effective responses to climate change, with consideration of the linkage with non-agricultural water uses.