ESS101C
Prof.
Jin-Yi Yu
Faint Young Sun Paradox
qSolar luminosity was much weaker
(~30%) in
the early part of Earth’s history (a faint young Sun).
qIf Earth’s albedo and greenhouse
effect
remained unchanged at that time, Earth’s mean surface temperature would be well below the freezing point of water during a
large portion of
its 4.5 Byr history.
qThat would result in a
“snowball” Earth,
which was not evident in geologic record.
(from The Earth System)