Agricultural Productivity and Climate Change : An Evidence of a Non-linear Relationship in Sub-Saharan Africa

This paper focuses on the relationship between agricultural productivity and climate change in sub-Saharan Africa. The main objective is to justify the observed upward trend in agricultural productivity as the temperature is increasing and rainfalls are decreasing. We argue that the relationship between agricultural productivity, temperature, and precipitation is non-linear. Specifically, there are thresholds from which the effect of temperature on agricultural productivity is exceeded by the effect of precipitation. We hypothesize that even if precipitation is decreasing, its level over a year is still sufficient for its positive effect on agricultural productivity to outweigh the negative effect of rising temperatures. Using data from the FAO database on seven different groups of crops, we estimate a Panel Smooth Transition regression model and results show that there is a non-linear relationship between agricultural productivity, temperature, and precipitation. On average, the effect of temperature on agricultural productivity is exceeded by the effect of precipitation observed over a year. We recommend that countries in Sub-Saharan Africa invest in agricultural research to find irrigation techniques that will mitigate the future effects of scarcity of rainwater owed to extremely hot temperatures