http://www.manchester.ac.uk/aboutus/news/display/?id=10798
Life evolved on Earth during the Archean, between 3.8 and 2.4 billion years ago, but the weak Sun should have meant the planet was too cold for life to take hold at this time; scientists have therefore been trying to find an explanation for this conundrum, what is dubbed the ‘faint, young Sun paradox’.
“During the Archean the solar energy received at the surface of the Earth was about 20 to 25 % lower than present,” said study author, Dr Ray Burgess,
“We measured the amount and isotopic abundances of nitrogen and argon in the ancient air,” said Professor Marty. “Argon is a noble gas which, being chemically inert, is an ideal element to monitor atmospheric change. Using the nitrogen and argon measurements we were able to reconstruct the amount and isotope composition of the nitrogen dissolved in the water and, from that, the atmosphere that was once in equilibrium with the water.”
The researchers found that the partial pressure of nitrogen in the Archean atmosphere was similar, possibly even slightly lower, than it is at present, ruling out nitrogen as one of the main contenders for solving the early climate puzzle.
Dr Burgess added: “The amount of nitrogen in the atmosphere was too low to enhance the greenhouse effect of carbon dioxide sufficiently to warm the planet. However, our results did give a higher than expected pressure reading for carbon dioxide – at odds with the estimates based on fossil soils – which could be high enough to counteract the effects of the faint young Sun and will require further investigation.”
By citation i mean give me a link to a peer-reviewed journal where the estimate of solar strength is published. Thanks
I missed the link in your earlier response. Thanks
Okay, read the last sentence in the quote from Dr. Burgess. Problem solved.
Dr Burgess added: “However, our results did give a higher than expected pressure reading for carbon dioxide – at odds with the estimates based on fossil soils – which could be high enough to counteract the effects of the faint young Sun and will require further investigation
Does “Evolution” or “Darwinism” as a theory “qualify” within the scientific constraints long defined by the scientific community ?
Is it, “Falsifiable” ?
Is it “Observable” ?
Is it “Repeatable” ?