Quantifying Climate Change over West Africa : Case Assessment of Temperature variability

Climate change has been one of the worlds major environmental challenges for the past few years and scientific evidence has shown its effects are unavoidable. With West Africa as the region of focus, this study quantifies the magnitude of change in temperature over 118 years (1901 - 2018). Explicitly, analysis on seasonal and decadal variabilities over West Africa, its demarcated areas, that is, GuineaCoast, Savannah, Sahel and Sahara regions and the trends in anomalies are performed using observational data from Climatic Research Unit (CRU -TS v4.03). Variables taken into consideration are maximum and minimum temperatures. Anomalies, Diurnal Temperature Ranges (DTR) and trend analysis using non-parametric Mann Kendall tests were calculated. Also, using 1901 1910 as referencedecade, deviations from the reference decade were computed to identify the magnitudes of change in temperature since that decade. Results show that West Africa has an annual minimum temperature increase of 0.0070 C and an annual maximum temperature increase of 0.0055 °C. For region specific temperature changes, Guinea Coast shows an annual minimum and maximum temperature change of a 0.0037 °C and 0.0027°C respectively, Savanna shows an annual minimum and maximum temperature change of 0.0074 °C and 0.0039 °C respectively, Sahel shows an annual minimum and maximum temperature change of 0.0092 °C and 0.0060 °C respectively and Sahara shows an annual temperature increase of 0.0072 °C and 0.0078 °C respectively. DTR shows that the gap between daily maximum and minimum temperatures are closing. This can be attributed to the more rapid increase in minimum temperature as opposed to maximum temperatures. These results have shown that the climate over West Africa is changing and zoning in on specific regions, those changes are still prevalent. Thus, precautionary measures must be taken with respect to the things that influence climate change. These include but not limited to the release of greenhouse gases into the atmosphere by anthropogenic means. This research's findings will be pivotal for studies in the attribution and track the temperature change precisely, heat waves in the region.