*3.2. Future Climate Projections*

The intra-annual changes in temperature and precipitation for the study area under the two future projected climate change (RCP 4.5 and RCP 8.5) scenarios are presented in Figure 4a–d. From the results obtained, it was clear that elevated CO2 concentration would significantly increase temperatures in the future. The monthly average temperature was projected to increase by 1.0, 1.6, and 2.9 ◦C for the 2010–2039, 2040–2069, and 2070–2099 periods respectively, for RCP 4.5 scenario relative to baseline. Under the RCP 8.5 scenario, the average monthly temperature increased by 2.3, 3.0, and 5.0 ◦C for the three future time periods as shown in Figure 4a,b. The highest temperature increase was expected

for the RCP 8.5 scenario towards the end of the century. Results further revealed that summer months were likely to experience increased temperature particularly the month of October during the mid and end of the century. In addition, the results presented in Figure 4c,d show the variations in intra-annual predicted precipitation for the Olifants catchment for RCP 4.5 and RCP 8.5 respectively. As indicated in Figure 4c, a slight increase in precipitation for the RCP 4.5 scenario was expected for the early-term in the month of August and September and a decrease was expected for other months. For the mid-term and far-term, an average increase in precipitation was expected for the months of July and August, with the remaining part of the months expected to be dry. A precipitation decline between 3.2 to 51.4% was predicted for RCP4.5 with the mid-term expected to be the driest. The results presented in Figure 4d show a decreasing trend in most of the months in the mid and end-term for the RCP 8.5 climate change scenario. However, a slight increase was projected for the months of July, August, and September in the early term. The end-term was projected to be the driest period for the RCP 8.5 scenario, a decrease in precipitation ranging between 2.5 to 58.7% was anticipated. The summer months of October to February for both climate change scenarios were expected to experience a greater decline in precipitation during the early-term, mid-term, and end-term respectively. Based on the outcome of the climate analysis, the decline in the projected precipitation during the summer months and an increasing trend in temperature will have implications for future crop production, as most of the crops in the catchment are planted during this period.

**Figure 4.** Olifants catchment future monthly climate departure from observed climate: (**a**) temperature anomaly for representative concentration pathways (RCP) 4.5 and (**b**) for RCP 8.5; (**c**) and (**d**) showing precipitation anomaly for RCP 4.5 and RCP 8.5 for the period 2010–2039, 2040–2069, and 2070–2099 respectively.
