Venus has a vastly greater atmospheric mass than Earth due to runaway greenhouse effects and lack of carbon sinks
the verdict
CONTESTED
contested - the weight sits with the supporting side
refutedsupported
the weight of evidence
3 sources for · 0 against
While sources confirm that Venus has a much thicker and denser atmosphere than Earth, they do not provide sufficient comparative proof establishing that the difference in atmospheric mass is due to runaway greenhouse effects and a lack of carbon sinks.
Abstract The atmospheres of the terrestrial planets are known to have been modified as a consequence of the impact degassing and atmospheric erosion during the late accretion. Despite the commonality of these processes, there are distinct gaps – roughly two orders of magnitude – between the abundances of noble gases and nitrogen in the present-day atmospheres on Venus, Earth, and Mars. The element partitioning on planetary surfaces is thought to be significantly different between the three planets ∼ 4 Ga: the runaway greenhouse on Venus, the carbon-silicate cycle and ocean formation on Earth, and the CO2-ice and H2O-ice formation on Mars. Consequences of element partitioning for the atmospheric evolution during the late accretion onto Venus, Earth, and Mars are investigated with a numerical model. We set upper limits to the partial pressures of CO2 and H2O on Earth and Mars, which corresponds to the state of phase equilibrium and carbon-silicate cycle. The final N2 mass shrinks by ∼ 40% and ∼ 15% for Earth and Mars, respectively. The effect of element partitioning is found to be insufficient to reproduce the gaps. For Venus, the survival of the primordial atmosphere through the late accretion may partially account for the present-day atmosphere. Whereas on Mars, the atmospheric escape due to solar extreme UV and wind may have also influenced the atmospheric evolution.
To better understand the mechanisms of global warming, we developed a one atmospheric layer model for Earth and a multiple atmospheric layer model (N = 111) for Venus. Earth’s greenhouse gas atmosphere has an average of 78.9% absorption efficiency of terrestrial radiation (f = 0.789), while we assume Venus’ atmosphere has a near 100% absorption efficiency (f = 1) due to its denser, CO2-rich atmosphere. Viewing the atmospheric layers as blackbodies, we modeled the surface temperature of Earth and Venus, both of which are able to predict the respective actual planetary temperatures. The consistency (δ < 1%) between the modeled surface temperature and the observed surface temperature of these two planets suggest that the multiple layer greenhouse gas atmosphere mechanism could explain Venus’ runaway global warming and scorching temperature. The results of these two models suggest that if Earth continues to experience uncontrolled greenhouse gas emissions, global warming and its negative outcomes may be further exacerbated.
Venus is the second planet from the Sun. Similar in size and mass to Earth, Venus has no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. The atmosphere is composed mostly of carbon dioxide and has a thick cloud layer of sulfuric acid that spans the whole planet. At the mean surface level, the atmosphere reaches a temperature of 737
Venus is the second planet from the Sun. Similar in size and mass to Earth, Venus has no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. The atmosphere is composed mostly of carbon dioxide and has a thick cloud layer of sulfuric acid that spans the whole planet. At the mean surface level, the atmosphere reaches a temperature of 737 K (464 °C; 867 °F), making it the hottest planet in the solar system and also a pressure 92 times greater than Earth's at sea level, turning the lowest layer of the atmosphere into a supercritical fluid. From Earth, Venus is visible as a star-like point of light, appearing brighter than any other natural point of light in the sky, as either the brightest "morning star" or "evening star".
Venus orbits closer to the Sun than the Earth does. The orbits of Venus and Earth make the two planets approach each other in synodic periods of 1.6 years. In the course of this, Venus comes closer to Earth than any other planet. In interplanetary spaceflight from Earth, Venus is frequently used as a waypoint for gravity assists, offering a faster and more economical route. Venus has no moons and a very slow retrograde rotation about its axis, a result of competing forces of solar tidal locking and differential heating of Venus's massive atmosphere. As a result, a Venusian day is 116.75 Earth days long, about half a Venusian solar year, which is 224.7 Earth days long.
Venus has a weak magnetosphere; lacking an internal dynamo, it is induced by the solar wind interacting with the atmosphere. Internally, Venus has a core, a mantle, and a crust. Internal heat escapes through active volcanism, resulting in resurfacing, instead of plate tectonics. Venus may have had liquid surface water early in its history with a habitable environment, before a runaway greenhouse effect evaporated any water and turned Venus into its present state. There are atmospheric conditions at cloud layer altitudes that are the most similar ones to Earth in the Solar System and have been identified as possibly favourable for life on Venus, with potential biomarkers found in 2020, spurring new research and missions to…
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