The Faint Young Sun Problem

Systems Notation

Positive Feedback Loops
(Destabilizing)

Positive Feedback Loops
(Destabilizing)

Negative Feedback Loops
(Stabilizing)

Runaway Greenhouse: F_IR and F_S

The Carbonate-Silicate Cycle

Negative Feedback Loops
(Stabilizing)

Model pCO₂ vs. Time

pCO₂ from Paleosols (2.8 Ga)

Geological O₂ Indicators

The Universal Tree of Life

Slide 13

Slide 14

Slide 15

CH₄-Climate Feedback Loop

CH₄-Climate Feedback Loop

Titan’s Organic Haze Layer

The Anti-greenhouse Effect

Archean Climate  Control Loop

Huronian Supergroup (2.2-2.45 Ga)

Snowball Earth Glaciations

Model pCO₂ vs. Time

Late Precambrian Geography

Triggering a Snowball Earth episode

Slide 26

Recovering from a Snowball Earth episode

Slide 28

How did the biota survive the Snowball Earth?

Snowball Earth
Ice Thickness

Ice Thickness (cont.)

Heat Flow Through Semi-transparent, Ablating Ice

Comparative Heat Fluxes

Ice Transmissivity

Heat Fluxes (cont.)

CONCLUSIONS

CONCLUSIONS (cont.)

CONCLUSIONS (cont.)