AST101H1 Lecture Notes - Lecture 15: Runaway Greenhouse Effect, Carbon Cycle, Cool Earth

• School: UTSG
• Department: Astronomy & Astrophysics
• Course: AST101H1
• Professor: Bryan Gaensler

Document Summary

Stability of earth"s climate: venus has experienced a runaway greenhouse effect but not earth. Too warm > more precipitation > more co2 from atmosphere dissolves in rainwater > co2 concentration decreases in the atmosphere > weakened greenhouse effect will cool earth down. Too cool > less precipitation > rainwater dissolves less co2 from the atmosphere > more co2 builds up in the atmosphere > strengthened greenhouse effect will warm earth up. 400,000 years: the last decade has been the hottest ever recorded. Atoms or molecules escaping into space (permanent) In a gas, individual atoms and molecules are moving in random directions: temperature is the average speed of the particles (not all particles move at the same speed, cold gas: slow speeds; hot gas: high speeds. The atmosphere of mars: the atmosphere of mars is much thinner than that of earth, earth: 1 atmosphere vs mars: 0. 006 atmosphere (co2 95%, nitrogen 2. 7%)