Inconsistency between geological evidence of liquid water on Earth and Sun's energy 3 Ga before remains as dilemma. Sun was only emitting 70% of its today's energy, and liquid water is essential for the emergence of Archean life.
Sagan, C., & Chyba, C. (1997). The early faint sun paradox: Organic shielding of ultraviolet-labile greenhouse gases. Science, 276(5316), 1217-1221.
Thanks, I think, the early atmosphere might be 1) escaped into space (where the earth was composed of hot and light weight gases just like hydrogen and helium, and were moving around with enough speed that they could overcome the pull of the earth's gravity) 2) was swept and blowed into space, via younger sun's solar-wind explosions. And 3) reaching certain critical points of ozone and oxygen emissions had caused the transformation of green orange and foggy atmosphere to clearer blue vivid sky!
A useful external website that might include some fine answers with graphic illustrations:
http://www.atmo.arizona.edu/students/courselinks/spring08/atmo336s1/courses/spring18/atmo170a1s1/1S1P_stuff/origin_evolution_atmosphere/origin_evolution_atmosphere.html
Thank You for Your valuable remark, dear Professor Dr. Kenneth, yes,, you are right Sir, I think that this illustration was prepared by one of the student on an academic spring course from Arizona, on the subject of the origin_evolution_atmosphere, and I found this paper with it's new and very useful conceptual manner, helping to get some hints, on understanding one of complexes scientific approach, in an easy abstract way!:)
Dear Dr. Kenneth M Towe, Thanks for Your valuable contribution, I'll read Your research paper, and I'll add it into our project's references list. Best Regards:)
Thanks for the useful explanations..
So, why do we need oxygen and ozone layer? We need the oxygen, to breath and to live,.. and we need ozone as a shelter and protection, for us, as human beings, against the harmful UV radiations. Similarly, Other creatures on earth might need CO2, CO2 layer, UV exposure or even extreme UV rays, just like us, it need it, to breath, to live and to breed.!:]
The ozone hole is a gift for the Stromatolite, I guess it was exist there since the beginning of the life on earth, it was wider before, but it was shrinking to its recent size during these billions of years, due to certain reasons! The stromatolite almost in an extinction era, due to this scarcity of UV radiation. This must be a Great pollution regarding to the Stromatolite, the elder living brother to the humans on earth!
Oh.. I see that, dear Dr. Kenneth M Towe. So, the "Ozone Hole" is completely a natural phenomenon, and there was no Ozone "hole". There was only the "thin" ozone layer, that become getting more stronger, with more and more of O2 emissions into the atmosphere, by photosynthesis process, the "thin" ozone layer was exists, since the beginning, since "the early Archean"! Thank you very much for correcting my info, Sir. And, Best Regards,..
Just thinking loudly.
What about the greenhouse gases?
CO2 level was not high enough to keep the Earth warm. Maybe just like Titan, methane had affected the planet temperature. Or sulfur released from volcanic activities.
What if the greenhouse gases block the UV? Would the formation of life be possible?
Are those possible/make sense?
Yes, those are trivial. But in my understanding, there is still lack of information in the scientific literature.
Why always we shall protect our selves from the UV rays, although, it have some benefits on the human body or organisms. In general, if the body can do good manner in tolerating and withstanding the natural UV ray, during and after an exposure that must be done over defined and controlled over and during portions of time, and do adjusted perfectly, without any side effects.
This might help in gaining benefits to the human body, for example, in controlling the growth processes to maintain the youths and vitality, as long as possible, or maybe to gain long age more than 200-300 years. Or simply, to live naturally on planet Mars!
That seems to be a huge advance for all humanity. We don't know yet, we might need less protection from UV after the needful adjustments in our bodies.
Although, it is fatal now, but, as Dr. Kenneth said Long-term protection would mean, withstanding exactly the UV-C rays even without any more protection. Therefore, the role of UV A B & C in driving growth on earth, must be studied and reviewed, and continuously.
"What is lacking in the scientific literature?"
Dr. Towe, this was for my previous response.
"Just thinking loudly. What about the greenhouse gases? CO2 level was not high enough to keep the Earth warm. Maybe just like Titan, methane had affected the planet temperature. Or sulfur released from volcanic activities. What if the greenhouse gases block the UV? Would the formation of life be possible? Are those possible/make sense?"
In this sense, the scientific literature seems a bit blurry rather than shiny. That is totally normal.
Yes, indeed. But understanding the factor which makes the Earth warm, with liquid water needs further research.