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Can CO2 in the Earth's atmosphere sublimate into a solid?

  1. Apr 17, 2017 #1
    CO2 becomes a solid at -78.5 C or -109.3 F. The coldest temperature ever recorded on earth was on Antarctica at -89.2 C or -128.6 F. So is it possible for CO2 to literally freeze out of earth's atmosphere under certain conditions?
    If not then why not?
  2. jcsd
  3. Apr 18, 2017 #2


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    Google is your friend. A simple search on 'co2 freezing temperature' tells you why not in the first link <link removed> shown !
    Last edited by a moderator: Apr 18, 2017
  4. Apr 18, 2017 #3
    On the topic of CO2 changing forms and leaving the atmosphere, I think its good for newcomers to read this about the topic https://en.wikipedia.org/wiki/Carbonate–silicate_cycle

    I am not calling you a newcomer, specifically. I'm posting this for readers who are interested in the ways CO2 changes forms. The carbonate-silicate cycle is important to understand when thinking of a topic like sublimation of CO2.

    I'm glad that it doesn't sublimate near atmospheric temp, otherwise 60 gigatons of carbon would become gaseous again whenever the temps rose. https://en.wikipedia.org/wiki/Carbon_cycle I'm also linking readers to the Wikipedia page on the Carbon Cycle. If you don't like Wikipedia, then you can read through the numerous well-regarded articles that these pages reference.

  5. Apr 18, 2017 #4


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    Unfortunately, that link is to an unacceptable source.
  6. Apr 18, 2017 #5


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    Beginner's mistake. Sorry about that. Also forgot to :welcome: Jim !

    Remains that
    if the CO2 vapour pressure is 1 atmosphere. With a partial pressure of around 0.0004 atm (0.3 mm Hg) that drops to about -137 C. (Exhaled air: 30 mm Hg, -110 C).
  7. Apr 18, 2017 #6


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    Liquid nitrogen is thought to be a component of noctilucent clouds. So that is one place in the atmosphere where you might find CO2 ice.

    Noctilucent Clouds form at an altitude of about 80 km from water ice. The temperatures can be very low, but the air pressure is also very low.

    Clouds of solid CO2 crystals have been observed in the Martian atmosphere. But there is very much less CO2 in the Earth's atmosphere. I would expect the minor presence of CO2 ice in noctilucent clouds would be masked by the water ice. Some CO2 might form in or on the surface of the water ice.

    I remember seeing a paper on N2 and CO2 in upper atmosphere clouds above the poles in winter. I will try to find it.
  8. Apr 20, 2017 #7
    The coldest atmospheric temperatures are in the mesopause layer, and although they are colder than dry ice, the <1 ATM vapor pressure lowers the temperature necessary to produce sublimation, and more insurmountably, the CO2 atmospheric concentration is too low to form other than miniscule solid particles -- otherwise we would sometimes find dry ice in Antarctica.
  9. Apr 20, 2017 #8
  10. May 2, 2017 #9
    A good salesman could sell dry ice in Antarctica to the gullible science types there.
  11. May 2, 2017 #10
    Atmospheric pressure is another factor. Under water at high pressures CO2 could solidify.
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