Life and Atmosphere
It is undeniably true that life and atmosphere are so related to eachother. For without a proper
atmosphere life would wither and without life a different atmosphere would surround the
planet. Just think of all the green plants which produce oxigen (O2).
It is overall thought that no O2 was present at the formation of life. It was released in atmosphere
later. It has been long recognized that the source of this release was photosyntheses (a proces
which releases O2), followed by organic carbon burial; which is a term used for the burial of
carbon based organisms and their carbon contained waste materials. Yet O2 concentrations
allready rose about 2 billion years ago, when algae, which are capable of photosynthesis, just
began to form. The precise timing of this increase and the reasons why have not been
explained.
But some feel that life has an even bigger impact on the atmospere than recycling amounts of
gas. The "Gaia Hypothesis" is one of the most contreversial ideas (Rampino & Caldeira, 1994).
It holds that living organisms on Earth actively regulate atmospheric composition and climate
in respect to the increasingluminosity of the Sun. As in most cases there are people who support
the strong version or the weak and everything inbetween.
Strong Gaia proposes that life maintains planetary conditions at an optimum for living
organisms. And Weak Gaia states that biological processes and feedbacks affect global climate.
This weak version is acceptible for most scientists. The biosphere cannot be ignored as major
important in recycling energy and matter during Earth's history.
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