Topic: human influences

This lecture explains the physics and historical development of the greenhouse effect, including why rising concentrations of heat-trapping gases alter Earth's temperature. It addresses misconceptions about saturation and compares greenhouse forcing with other natural and human influences on the planetary energy balance. Measurements provide a basis for evaluating their relative contributions.

This lecture examines the composition of Earth's atmosphere and how it is reconstructed through time. It distinguishes abundant nitrogen and oxygen from trace gases whose concentrations respond strongly to human emissions. Measurements are used to compare natural changes with human influences relevant to climate.