A Climate That Came and Went: Limit Cycles and the Changing Weather of Ancient Mars

The paper proposes that early Mars may have undergone episodic limit cycles, long cold periods interrupted by short warm intervals triggered by volcanic CO₂ buildup and enhanced greenhouse gases. Using a simplified climate model, Haqq-Misra shows that these warming spikes align with the timing of valley networks and delta formation. The study suggests Mars’ wet features may reflect transient, not sustained, warm climates driven by cyclic atmospheric processes.