Working Paper 8: Modeling potential impacts of future climate change in Mzimba District Malawi, 2040-2070

Historical data in Malawi indicates there has been climate change in the past and that farmer households have been affected. Climate models predict further changes in precipitation and temperature over Malawi in the future. However, most studies to understand the impacts of climate change in Malawi have focused on ex post assessments of weather events. Planning for future adaptations by Malawian farmers to a changed climate will require acknowledging that future climate patterns may deviate significantly from historical climate patterns. Little research has been done to assess ex ante (future) climate change and its potential impacts on and implications for farmer productivity, incomes, and poverty. This study investigates possible climate change patterns over the period 2040 to 2070 in order to assess the potential economic impacts for crop-livestock integrating and non-integrating farmers in Mzimba district in northern Malawi. Thirty year historical climate data were used with 20 Global Circulation Models (GCM) to generate plausible future climates. Future maize yields then were simulated using the APSIM crop model. The Trade-Off Analysis model for Multi-Dimensional Impact Assessment (TOA-MD) framework was used with the crop model results for economic analysis.

Results indicate that over the period 2040 to 2070 Mzimba district, relative to the present, will be warmer by be-tween 1°C and 3°C and slightly drier by 1.1 percent, but with considerable uncertainty in the GCM models. Maize produc-tivity is expected to increase by between 10 and 15 percent. On aggregate, 56 percent of farmers will register productivity gains – 55 percent of crop-livestock integrating farmers and 57 percent of non-integrating farmers. Mean net returns per hectare are expected to be higher among integrating farmers. Incomes per capita are predicted to increase by 5.2 percent – by 5.3 percent among integrating and by 5.1 percent among non-integrating farmers. Income-based poverty is predicted to decline by 4 percent – by 6 percent among integrating and by 2 percent among non-integrating farmers. The study recommends that in order to enable farmers in Mzimba to more effectively adapt to the changing climate, investment is needed in research to develop heat-tolerant maize varieties, and efforts should be made to enhance sustainable agricul-tural intensification, including crop-livestock integration.

By Arthur Chibwana Gama, Lawrence D. Mapemba, Patricia Masikat, Sabine Homann-Kee Tui, Olivier Crespo, and Elizabeth Bandason, 2014

This publication was supported by the MaSSP Bunda Grant Scheme Program.