Faint Young Sun Paradox Remains

The Sun was fainter when the Earth was young, but the climate was generally at least as warm as today; this is known as the `faint young Sun paradox’. Rosing et al. [1] claim that the paradox can be resolved by making the early Earth’s clouds and surface less reflective. We show that, even with the strongest plausible assumptions, reducing cloud and surface albedos falls short by a factor of two of resolving the paradox. A temperate Archean climate cannot be reconciled with the low level of CO2 suggested by Rosing et al. [1]; a stronger greenhouse effect is needed.

(Submitted on 26 May 2011 (v1), last revised 30 May 2011 (this version, v2))

Colin Goldblatt, Kevin J. Zahnle

Comments: 3 pages, no figures. In press in Nature. v2 corrects typo in author list in original submission

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Atmospheric and Oceanic Physics (physics.ao-ph)

DOI: 10.1038/nature09961

Cite as: arXiv:1105.5425v2 [astro-ph.EP]

Submission history

From: Colin Goldblatt [view email]
[v1] Thu, 26 May 2011 23:11:39 GMT (4kb)
[v2] Mon, 30 May 2011 15:54:48 GMT (4kb)