- The article uses a simplified 'spherical cow' atmosphere model to explain global warming, focusing on CO₂ and water vapor.
- The Earth's surface temperature is determined by a balance between incoming solar radiation and outgoing longwave radiation, influenced by greenhouse gases.
- A key misconception addressed is that the 'CO₂ is saturated' theory is incorrect; adding more CO₂ still traps more heat by broadening absorption bands.
- Water vapor is a major greenhouse gas, but its concentration is dependent on temperature, creating a feedback loop that amplifies CO₂-induced warming.
- The model explains the role of the lapse rate (temperature decrease with altitude) in linking the temperature of the radiating atmosphere layer to the surface temperature.
- Doubling CO₂ concentration is predicted by simple and sophisticated models to cause several degrees of surface warming (e.g., 2–4°C or more).
- Venus serves as an extreme example of the greenhouse effect, with its thick CO₂ atmosphere causing a surface temperature of 737K.
- The article highlights unknowns, such as the water vapor continuum absorption spectrum and the complexity of modeling clouds and aerosols.