The Sun is estimated to have had a solar luminosity about 30% lower when the solar system was formed.
Now if I assumed that Earth's albedo was the same as it is today, what would have been the effective radiating temperature of the Earth at that time.
My solution: T_e = S/4*(1 - A)
I know that Earth's current albedo is A = 0.3.
T_e = S/4*(1 - 0.3)
T_e = ( (0.7)*(1370) ) / (4 (5.67*10^-8)) * (1-0.3) = 233K
233K <- would have been Earth's effective radiating temperature
Now if one assumes the magnitude of the greenhouse effect was the same then (now it is 33k) Earth's temperature would be:
233K + 33K = 266K
Assuming the math is right between those two would there have been liquid water on Earth? If there would be, how does one resolve this paradox? that is, given that albedo was the same, what element of the climate system could explain this?