How does the Faint Young Sun paradox challenge our understanding of early Earth’s climate?

Correct option is C

The correct answer is: (c) It suggests that early solar output was too weak to prevent global freezing
Explanation:
· The Faint Young Sun Paradox arises because about 4 billion years ago, the Sun’s luminosity was only ~70% of today’s.
· This weaker Sun should have left Earth frozen solid, yet geological evidence shows liquid water and a relatively warm climate existed.
· This paradox challenges climate models and suggests additional warming mechanisms (like greenhouse gases) were at play.
Information Booster:
· Term introduced by astronomer Carl Sagan and George Mullen (1972).
· Proposed solutions include higher concentrations of CO₂, CH₄, NH₃ in the early atmosphere.
· Geological evidence: ancient sedimentary rocks show presence of liquid water.
· Volcanic outgassing and reduced continental landmass may have influenced warming.
· The paradox is key in studies of early Earth habitability and astrobiology.