Unformatted text preview: 7 2/19/2008 The Freeze-Fry: The Freeze, cont. (2) Freeze?!
Ice continued to expand until Earth's Earth s surface was frozen LongLong-term freeze: ~10 million years? BUT, continued volcanic outgassing builds up CO2 in atmosphere Due to ice cover, CO2 is not removed cover by weathering (of rocks) or by photosynthesis The Freeze-Fry: The Fry FreezeCO2 imbalance in other direction... Continued volcanism causes CO2 levels to rise Eventually, CO2 levels became very high Earth warmed up--perhaps very rapidly up--perhaps Cf. enhanced greenhouse effect Ice melted near equatorial regions Albedo decreased, accelerating the warming , g g Evaporation increased, increasing water vapor in the atmosphere 8 2/19/2008 The Freeze-Fry: The Fry, cont. FreezeGreenhouse effect became even stronger, stronger, accelerating th warming l ti the i CO2 levels now very high Atmosphere is incredibly hot (possibly ~50C = 122F) ~50 122 "Hothouse world"
Various feedback systems (biogeochemical) would eventually re- t bili th E th re-stabilize the Earth system t Wouldn't all this cause a mass extinction on a grand scale? millions of years ago (Ma)
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- Spring '08
- Geology, Cambrian, Cambrian Explosion, Snowball Earth, Ediacaran fauna