The faint young Sun problem

J. F. Kasting, D. H. Grinspoon

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


The Sun was almost certainly much less bright during the early stages of its main-sequence lifetime. In the absence of some compensating factor, the Earth's mean surface temperature would therefore have been below the freezing point of water prior to ~2 Gyr ago. Geologic evidence for liquid water as early as 3.8 Gyr ago implies that the Earth was never this cold. This discrepancy can be resolved if the greenhouse effect of the early atmosphere was much larger than today. The most likely cause of an enhanced greenhouse effect is an increase in atmospheric carbon dioxide (CO2) concentrations by a factor of ~1000 or more compared to today. Such an increase could have resulted from feedbacks inherent in the carbonate-silicate geochemical cycle that controls the atmospheric CO2 level over long time scales. -from Authors

Original languageEnglish (US)
Pages (from-to)447-462
Number of pages16
JournalUnknown Journal
StatePublished - Jan 1 1991

All Science Journal Classification (ASJC) codes

  • Environmental Science(all)
  • Earth and Planetary Sciences(all)


Dive into the research topics of 'The faint young Sun problem'. Together they form a unique fingerprint.

Cite this