An investigation of the Archean climate using the NCAR CCM

he Archean (2.5 to 3.8 billion years ago) is of interest climatically, because of the "Faint-Young Sun Paradox", which can be characterized by the Sun's reduced energy output. This lower energy output leads to a frozen planet if the climate existed as it does today but, the geologic record shows that water was flowing at the earth's surface 3.8 billion years ago. Energy Balance Models (EBMs) and one-dimensional radiative-convective (1DRC) models predict a frozen planet for this time period, unless large carbon dioxide concentrations (CO;A faster rotation rate may have existed in the Archean. The faster rotation rate simulations show warmer globally averaged surface temperatures that are caused by a 20% decrease in the total cloud fraction. The smaller cloud fraction is brought about by dynamical changes. A global ocean is a possibility for the Archean. A global ocean simulation predicts 4 K increase in global mean surface temperatures compared to the present-day climate control.;Experiments with the following conditions are then combined: rotation rate corresponding to a 14-hr day, 8...