Climate change scenarios in Zambia: modeling farmers’ adaptation

Abstract

Background: At the center of the Sustainable Development Goals (SDG) by the United Nations is climate change. Analyzing adaptation processes is fundamental to enhance resilience in the poorest parts of the world. The analysis harmonizes top-down and bottom-up approaches by integrating general circulation models into the method of mathematical optimization. The article designs a quantitative farm planning model for rural Zambia and focuses on optimal allocation of land, labor and cultivation methods. Our research takes advantage of recent survey data of 277 Zambian households from 2018. The model simulates a baseline scenario, 2 climate change scenarios and 7 variations of farmers’ land availability, labor capacity and off-farm work possibility. This results in 21 possible future outcomes and farmer adaptations. Results: Climate change negatively affects future livelihoods at the study site. A dry climate decreases a farmer’s wealth by around 30% and a wet climate by nearly 20%. However, simulations show households are able to sustain their livelihood through adaptation processes at the farm level. Farmers’ variation in land size for crop cultivation indicates the strongest livelihood impacts in response to climate change. Increasing the land for cultivation is the best response, whereas a reduction of labor supply at the farm leads to households being more vulnerable to a changing climate. Off-farm employments reveal significant potential for climate change adaptation. An increase in work opportunities at a refugee camp nearby has a significant positive effect on rural livelihoods, without reducing the households’ farm production. The refugee camp, however, may imply future land competition. Conclusions: The study concludes climate change has a serious impact on farm yields and requires land and labor adjustments to prevent losses in wealth. Altering the cropping mix, reallocating planting times or changing farming techniques are meaningful instruments to respond to climate change at the study site. Agricultural intensification can increase the productivity per hectare and the mix of on- and off-farm work indicates income diversification as possible response to climate change. The analysis is specified to a rural farm context in Zambia, but is applicable to similar settings in sub-Saharan Africa and useful for local policy implementations towards climate change adaptation.