Assessing climate change projections and impacts on Central Malawi's maize yield: The risk of maladaptation

Malawi is listed as a Low-Income Food-Deficit Country (LIFDC) by the United Nations (UN), with high levels of poverty, malnutrition, and undernutrition. The maize grown in the Central Region of Malawi represents approximately a quarter of the total Malawian population's calorie intake, is a large source of local income, and a significant contributor to the country's Gross Domestic Product (GDP). While maize has been shown to be more resilient to climatic changes than many other grain crops, the predominantly rain-fed maize grown in Central Malawi has experienced many shocks from severe weather events in the past. Using the ensemble mean of 20 Regional Climate Models (RCMs), this study shows that temperatures in Central Malawi are projected to increase from the 1971-2000 baseline by between 1.4 and 1.6 °C by 2035 and 1.9 and 2.5 °C by 2055 under Representative Concentration Pathways (RCPs) 4.5 and 8.5 respectively, but precipitation projections are more uncertain. Using the UN Food and Agriculture Organization's (FAO) AquaCrop model, this study assesses the impact of future warming and three precipitation scenarios on two cultivars of maize planted on three separate dates in Central Malawi's summer planting season. The results indicate that if precipitation levels follow the ensemble average or maximum projection, then moving to a later planting date and a slower-developing cultivar may result in increasing yields compared to the baseline scenario. However, under a minimum precipitation projection, the results are less positive, with decreasing yields seen for both cultivars and all planting dates. The uncertainty around future precipitation therefore poses a significant risk of maladaptation and highlights the need for more robust precipitation projections in the area before climate model outputs are used as a primary driver for decision-making in Central Malawi's maize cultivation.