Fig. 4: Warming estimates from alternative model that includes interaction of heat and precipitation variables.
From: Yield reduction under climate warming varies among wheat cultivars in South Africa
Impacts are reported as the percentage change in mean yield under +1 to +3 °C warming scenarios relative to historical climate. Each 2-bar cluster shows estimates for a given scenario across different regression-model specifications. The preferred model (Supplementary Table 3) does not include an interaction between extreme heat (temperatures above 30 °C) and rainfall, while the low precipitation model does. Low precipitation is defined as a rainfall outcome below the 10th percentile of the in-sample rainfall distribution. We construct a dummy variable for this measure and then interact it with the extreme heat variable. Bars show 95% confidence intervals using standard errors clustered by province-year for n = 18,881 yield observations.
