In a stellar evolutionary model, one is to imagine a faint sun only being able to keep the earth at below freezing and wouldn’t warm up for another 2-3 billion years while assumptions in geology claim that water was plentiful and not frozen about 3-4 billion years ago! This problem has riddled scientists for decades.
In 1972, Carl Sagan and George Mullen hypothesized a “super” greenhouse effect that would have prevented the earth from freezing. So scientists began to look for evidence confirming it but a new study found evidence to the contrary…
“A team led by earth scientist Minik Rosing of the University of Copenhagen analyzed iron-bearing rocks in southwestern Greenland that were 3.8 billion years old. They focused on two minerals, magnetite and siderite, that can provide a bellwether of the CO2 concentrations in the atmosphere. Too much CO2, and magnetite can’t form, whereas the opposite is true for siderite.”
“Based on the ratio of the minerals, the team reports in tomorrow’s issue of Nature that CO2 levels during the Archean could have been no higher than about 1000 parts per million—about three times the current level of 387 ppm and not high enough to compensate for the weak sun.”
The articles goes on to say, that it’s premature to discard the greenhouse hypothesis, claiming temperatures back then were at least as high as they are today. The greenhouse hypothesis is the only mechanism known to man that could keep the planet warm, there is none other so naturally they would hang on to it. Also, scientists who are caught in up the evolutionary story tend to act as if they know this or that, but there is no basis for any of it, but rather say it’s a “long chain of further refinements of our understanding.” Did you see much understanding of what they are talking about and how close they think they are to rescuing their theory? To have a chain of understanding there must be solid links!