Ron Smith, teaching Yale's Atmosphere, the Ocean and Environmental Change, uses a simple lab apparatus, a water tank with a controllable inflow and outflow, to teach the basic mathematics of system analysis. He walks through calculations for equilibrium and steady state, showing how water depth responds to changes in input flow, then plots inflow and depth against time to make the dynamics visible. The tank stands in for real Earth systems: a lake fed by a river, or the planet's overall heat budget, where energy in and energy out must balance for temperature to hold steady. Smith extends the analogy to the greenhouse effect, framing atmospheric warming as an increase to the heat input side of that budget rather than a separate phenomenon. The lecture is built around four chapters, moving from the tank experiment itself through steady-state calculations, system analogies, and graphing, giving students a physical model for reasoning about climate before the course turns to atmospheric chemistry and circulation.