New Study: Faint young Sun paradox resolved by assuming CO2 did not control temperature — Published in Geophysical Research Letters
Study finds that the 'Faint young Sun problem' has become 'more severe" because to solve the problem using conventional greenhouse theory would require CO2 to comprise 0.4 bar or about 40% of young Earth atmosphere, far greater than CO2 partial pressures today [0.014 bar or 28 times less] or those estimated for young Earth [0.06 bar].'
‘Our results suggest that currently favored greenhouse [gas] solutions could be in conflict with constraints emerging for the middle & late Archean [young Earth]’