The Assessment of Future Air Temperature and Rainfall Changes Based on the Statistical Downscaling Model (SDSM): The Case of the Wartburg Community in KZN Midlands, South Africa

Abstract

The agriculture sector in Africa is dominated by small-scale farmers who account for about 80% of the total farms. However, small-scale farmers are vulnerable to climate change and climate variability. Their high susceptibility to climate change emanates from their inadequate ability to adapt to climate change. As a result, small-scale farmers are generally adversely impacted by climate change due to over-reliance on rainfed agriculture and natural resources. This exposure and susceptibility, however, differ across the regions due to the heterogeneity in topography, climate, access to resources, farmer resilience and adaptation capacity. Therefore, site-specific studies are encouraged to increase the awareness, resilience and adaptation capacity at the local level. The study intends to analyse historical climate (air temperature and rainfall) data from a weather station that has not been employed for climate change studies and project possible future changes in the same climate parameters due to global warming for a localised agricultural community within the sugarbelt region of KwaZulu-Natal, South Africa. The study focuses mainly on air temperature and rainfall changes to inform local farmers about potential climate changes and possible impacts of the projected climate changes on the local agricultural productivity. This study was conducted in the KwaZulu-Natal midlands of South Africa, and the Representative Climate Pathways (RCP8.5 and RCP4.5) climate projection of the CanESM2 model were used for the projection of future air temperature and rainfall trends for the 2020s, the 2040s and the 2080s. According to the results, both minimum and maximum air temperatures will continue to increase for the entire study period. The RCP8.5 results indicate that maximum and minimum air temperatures will reach a maximum range of 1.72 to 3.14 °C and 1.54 to 3.48 °C, respectively. For the rainfall, the model projects a positive trend, although all the scenarios predict a declining trend for the near future (2020s) and an increase in the 2050s. These results indicate that, in the absence of adaptation the risk of small-scale farmers, particularly for sugarcane, which is largely planted in the area, the production losses will heighten and hence increase the likelihood of increased poverty, food insecurity and unemployment.