10.2 Venus Atmosphere

Venus has an extreme greenhouse atmosphere with surface temperature of 465°C and 92 bar pressure. Sulfuric acid clouds completely enshroud the planet.

Extreme Conditions

92 bar

Surface pressure

465°C

Surface temperature

96% CO₂

Main constituent

Runaway Greenhouse

Venus is a cautionary tale of the runaway greenhouse effect:

  • • All water vapor in atmosphere (no liquid oceans)
  • • CO₂ not sequestered in carbonates
  • • Surface hot enough to melt lead
  • • Earth could have gone this way with slightly higher solar flux

Super-rotation

Venus's atmosphere rotates 60× faster than its surface (4-day "year" in upper clouds vs 243-day actual rotation). Mechanism still not fully understood.