Test students' ability to analyze coupled climate–carbon cycle feedbacks and their influence on long-term atmospheric CO2 trajectories, including identification and mechanistic understanding of key processes (CO2 fertilization, ocean uptake, permafrost and soil carbon release), interpretation of coupled model output (transient vs equilibrium responses), computation and use of diagnostic metrics (feedback factors, climate–carbon sensitivity), design of sensitivity experiments and scenario comparisons, and evaluation of uncertainties and implications for long-term mitigation pathways.