Robust policy mixes for climate mitigation and macroeconomic sustainability in a Global-South context

We propose a methodology to explore the robustness of multi-objective policy mixes in a developing-country context. As a proof of concept, we apply this approach to climate-mitigation financing strategies for Colombia’s Nationally Determined Contribution. We assess their ability to remain within a safe operating space defined by twelve indicators, using the state-of-the-art macroeconomic model GEMMES-Colombia. To account for radical uncertainty regarding Colombia’s future macroeconomic environment, we sample a large parameter space. We generate policy mixes based on three resource-mobilisation levers (the share of green loan funding, the share of foreign financing in green loan funding, and green tax funding), using a multi-objective evolutionary algorithm. We analyse their performance, robustness under uncertainty, and vulnerabilities across different parameter configurations. We find that a policy mix with broadly balanced debt and tax financing, combined with a moderate share of dollar financing, is the most robust.