Effects of high CO2 levels on surface temperature and atmospheric oxidation state of the early Earth

Kasting, James F.; Pollack, James B.; Crisp, David

doi:10.1007/bf00053803

Cited by 222 publications

(191 citation statements)

References 67 publications

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“…However, improvements to the treatment of collision-induced absorption by carbon dioxide molecules have shown a decrease in the amount of warming possible by atmospheric CO 2 (Wordsworth et al 2010). In fact, the calculations by Wordsworth et al (2010) find that a 3 bar CO 2 atmosphere may be as much as 10 K cooler in their improved treatment of collision-induced absorption than the earlier model by Kasting et al (1984). This decrease in the expected amount of warming from atmospheric CO 2 outweighs any of the other improvements made to these radiative transfer calculations, so our calculations here can be considered as an overestimation of the greenhouse effect realizable by a dense CO 2 -H 2 O atmosphere.…”

Section: Methods: Energy Balance Model For Early Marsmentioning

confidence: 97%

Reduced albedo on early Mars does not solve the climate paradox under a faint young Sun

Fairén

Haqq-Misra

McKay

2012

A&A

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Context. The presence of liquid water on the surface of early Mars and Earth is difficult to reconcile with the reduced solar luminosity at 3.8 Ga. and before, which would have imposed mean temperatures below freezing all over both planets. For the case of Earth, it has been recently suggested the hypothesis that less continental area and limited cloudiness during the Archaean may have reduced planetary albedo and thereby increased surface warming by sunlight. Aims. Here we analyze whether this novel solution explaining warming conditions on the early Earth could be applied to early Mars. Methods. We use an energy balance climate model in our calculations. Results. Our results show that early Mars could have been kept warm as long as there was a nearly global ocean and relatively sparse cloud coverage. This result is internally inconsistent, and also incompatible with most of the observed geological evidence. Conclusions. Reduced albedo is not a suitable solution for the faint young Sun problem in the case of early Mars. The combination of climatic and geochemical models is essential for understanding the stability of liquid water during the Noachian.

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Section: Methods: Energy Balance Model For Early Marsmentioning

confidence: 97%

Reduced albedo on early Mars does not solve the climate paradox under a faint young Sun

Fairén

Haqq-Misra

McKay

2012

A&A

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“…The model is originally based on the one described by Kasting et al (1984a) and Kasting et al (1984b). Further developments are described by e.g.…”

Section: General Model Descriptionmentioning

confidence: 99%

The extrasolar planet Gliese 581d: a potentially habitable planet?

Paris

Gebauer

Godolt

et al. 2010

A&A

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Aims. The planetary system around the M star Gliese 581 contains at least three close-in potentially low-mass planets, Gl 581c, d, and e. In order to address the question of the habitability of Gl 581d, we performed detailed atmospheric modeling studies for several planetary scenarios. Methods. A 1D radiative-convective model was used to calculate temperature and pressure profiles of model atmospheres, which we assumed to be composed of molecular nitrogen, water, and carbon dioxide. The model allows for changing surface pressures caused by evaporation/condensation of water and carbon dioxide. Furthermore, the treatment of the energy transport has been improved in the model to account in particular for high CO 2 , high-pressure Super-Earth conditions. Results. For four high-pressure scenarios of our study, the resulting surface temperatures were above 273 K, indicating a potential habitability of the planet. These scenarios include three CO 2 -dominated atmospheres (95% CO 2 concentration with 5, 10, and 20 bar surface pressure) and a high-pressure CO 2 -enriched atmosphere (5% CO 2 concentration with 20 bar surface pressure). For all other considered scenarios, the calculated Gl 581d surface temperatures were below the freezing point of water, suggesting that Gl 581d would not be habitable then. The results for our CO 2 -dominated scenarios confirm very recent model results by Wordsworth et al. (2010). However, our model calculations imply that also atmospheres that are not CO 2 -dominated (i.e., 5% vmr instead of 95% vmr) could result in habitable conditions for Gl 581d.

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“…Kasting et al 1984;Kasting & Brown 1998) has shown that rainout of photochemically produced oxidants and reductants is also important in the atmospheric redox balance. Indeed, rainout of oxidants such as H 2 O 2 and H 2 SO 4 becomes significant at atmospheric O 2 levels that are substantially lower than those shown in figure 7b.…”

Section: Possible Cause Of the Mid-archaean Glaciationsmentioning

confidence: 99%

Palaeoclimates: the first two billion years

Kasting

Ono

2006

Phil. Trans. R. Soc. B

124

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Earth's climate during the Archaean remains highly uncertain, as the relevant geologic evidence is sparse and occasionally contradictory. Oxygen isotopes in cherts suggest that between 3.5 and 3.2 Gyr ago (Ga) the Archaean climate was hot (55-85 8C); however, the fact that these cherts have experienced only a modest amount of weathering suggests that the climate was temperate, as today. The presence of diamictites in the Pongola Supergroup and the Witwatersrand Basin of South Africa suggests that by 2.9 Ga the climate was glacial. The Late Archaean was relatively warm; then glaciation (possibly of global extent) reappeared in the Early Palaeoproterozoic, around 2.3-2.4 Ga.Fitting these climatic constraints with a model requires high concentrations of atmospheric CO 2 or CH 4 , or both. Solar luminosity was 20-25% lower than today, so elevated greenhouse gas concentrations were needed just to keep the mean surface temperature above freezing. A rise in O 2 at approximately 2.4 Ga, and a concomitant decrease in CH 4 , provides a natural explanation for the Palaeoproterozoic glaciations. The Mid-Archaean glaciations may have been caused by a drawdown in H 2 and CH 4 caused by the origin of bacterial sulphate reduction. More work is needed to test this latter hypothesis.

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Effects of high CO2 levels on surface temperature and atmospheric oxidation state of the early Earth

Cited by 222 publications

References 67 publications

Reduced albedo on early Mars does not solve the climate paradox under a faint young Sun

Reduced albedo on early Mars does not solve the climate paradox under a faint young Sun

The extrasolar planet Gliese 581d: a potentially habitable planet?

Palaeoclimates: the first two billion years

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