Greenhouse effect and global warming Flashcards
Explain the Faint Young Sun Paradox
The Faint Young Sun Paradox shows apparent contradiction of observations of liquid water in early earth’s history and sun’s output only 70% as intense as it is now.
Draw evolution of main gas volumes in atmosphere over time
See notes
Calculating equilibrium surface temperature (equation 1)
Te = ((1-A)Fs/4sigma)^1/4
Calculating energy emitted (equation 2)
E = 4(pi*r^2)sigma(Te)^4
Calculating energy absorbed (equation 3)
E = (1-A)(pi*r^2)(Fs)
Calculating solar constant (equation 4)
Solar Constant (Fs) = Solar output / 4pi(radius of orbit)^2
Explain radiative forcing
Similar to the greenhouse effect, its the climate influence on the balance of incoming and outgoing energy in a planet-atmosphere system
List molecules that cause the radiative forcing
Long-lived greenhouse gases:
Carbon Dioxide Nitrous oxide Methane Halocarbons Ozone Stratospheric water vapour
Explain radiative forcing (positive feedback system)
Radiation emitted by our planet has mid IR wavelengths.
Mid IR emission from planet -> molecules in atmosphere absorb IR -> absorption = vibrationally excited molecules -> collisions convert vibr E to trans E between molecules warming the atmosphere -> warmed atmosphere = warm surface -> Mid-IR spectrum moves to shorter wavelengths with increased intensity -> cycle repeats
Causes for different temperatures for Venus, Mars and Earth
Venus - Too hot, thick atmosphere, much radiative forcing
Earth - Just right, dissolution of CO2 in water + trapped in rocks
Mars - Too cold, thin atmosphere, little radiative forcing
List all the consequences of global warming
- Loss of ice = rise sea level
- Change in regional climate = severe weather = agriculture
- Changes in ocean acidity/ecosystems
- Heat stress
- Diseases
- Air pollution
- Stratospheric ozone
