A simple model for assessing climate control trade-offs and responding to unanticipated climate outcomes

We present MARGO, an idealized model of optimally-controlled climate change, which is complementary to both simpler conceptual models and more complicated Integrated Assessment Models. The four methods of controlling climate damage-mitigation, carbon dioxide removal (CDR), adaptation, and solar radiation modification (SRM)-are not interchangeable, as they enter at different stages of the causal chain that connects GHG emissions to climate damages.

Early and aggressive mitigation is necessary to stabilize GHG concentrations below a tolerable level. While the most cost-beneficial and cost-effective pathways to reducing climate suffering include deployments of all four controls, the quantitative trade-offs between the different controls are sensitive to value-driven parameters and poorly-known future costs and damages. Static policy optimization assumes perfect foresight and obscures the active role decision-makers have in shaping a climate trajectory.