<blockquote>
<p>Carbon, nitrogen and water abundances at the surfaces of Earth and Venus are compared in order to investigate the distributions of these elements between fluid and solid envelopes in both planets. <strong>The atmosphere of Venus contains about twice more carbon (<span class="math-container">$\mathrm{1.25×10^{20}}$</span> kg of C) and nitrogen (<span class="math-container">$\mathrm{4.8×10^{18}}$</span> kg of N) than the atmosphere, hydrosphere and sediments of the Earth (<span class="math-container">$\mathrm{5.4×10^{19}}$</span> kg of C and <span class="math-container">$\mathrm{3×10^{18}}$</span> kg of N)</strong>. After scaling to the planetary masses, surface excesses of <span class="math-container">$\mathrm{1×10^{20}}$</span> kg of C and <span class="math-container">$\mathrm{2.7×10^{18}}$</span> kg of N are calculated for Venus relatively to the Earth. The simplest proposed explanation is the storage of 25 ppm of C and 0.7 ppm of N in the Earth mantle due to lithospheric subduction, a mechanism not operating on Venus. Following the same line of arguments, the Earth has an excess surface water of about <span class="math-container">$\mathrm{1.2×10^{21}}$</span> kg of H2O, when compared to Venus. Under the hypothesis of a primordial sizable water mass on Venus, thermodynamic modeling of mineral stabilities reveals that hydrous minerals are stable at the P–T conditions of both the surface and the deep crust of Venus, and thus could be the carriers of the missing Venusian water. A combination of crustal hydration and hydrogen escape processes may explain the present-day low amount and high deuterium/hydrogen (D/H) ratio (<span class="math-container">$\mathrm{2.5×10^{−2}}$</span>) of water in the Venusian atmosphere relatively to the Earth’s hydrosphere (<span class="math-container">$\mathrm{1.55×10^{−4}}$</span>). Alternatively, if the high D/H ratio of Venus only resulted from hydrogen escape, the reservoir of remaining oxygen must have been involved in the oxidation of a rock layer of about 50 km in depth.</p>
</blockquote>
<p><sub> From Christophe Lécuyer, Laurent Simon, François Guyot,
<em>Comparison of carbon, nitrogen and water budgets on Venus and the Earth,</em>
Earth and Planetary Science Letters, <strong>2000</strong>, DOI: <a href="https://www.sciencedirect.com/science/article/pii/S0012821X00001953" rel="nofollow noreferrer">10.1016/S0012-821X(00)00195-3</a>.</sub></p>

CC BY-SA 4.0
2024-12-06T19:00:06.410Z
Nice reference; this could benefit from some explanatory text
antlersoft
CC BY-SA 4.0
2024-12-06T09:40:23.917Z
2024-12-06T09:40:23.917Z
Nilay Ghosh
<p>Yes, Venus has much more carbon than Earth, primarily in the form of carbon dioxide (CO₂). About 96.5% of Venus's atmosphere is composed of CO₂, a potent greenhouse gas. This thick carbon-rich atmosphere traps heat, creating extreme surface temperatures of around 465°C (869°F). In contrast, Earth's atmosphere contains only about 0.04% CO₂, with much of the planet's carbon stored in rocks and oceans. Venus's extreme carbon content contributes to its runaway greenhouse effect, making it far hotter than Earth, despite being further from the Sun. The disparity highlights the differing atmospheric conditions of the two planets.</p>

CC BY-SA 4.0
2024-12-09T10:07:19.580Z
Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).
Community
CC BY-SA 4.0
2024-12-17T03:08:59.900Z
In the last part of this reply, it was stated that Venus is hotter than the Earth despite being farther from the Sun. I would like to clarify distances. Mercury is closest, followed by Venus then Earth. I think that the reply was meant to indicate that Venus is hotter than Mercury in spite of it being farther from the Sun, and it’s hotter than Earth despite Earth being farther than Venus.
Pogo
CC BY-SA 4.0
2024-12-09T09:25:52.330Z
2024-12-09T09:25:52.330Z
khushnuma
<p>Does Venus have more carbon (as an element) than Earth, and if so, why? Or it is basically the same amount?</p>

CC BY-SA 4.0
2024-12-04T05:56:02.590Z
Most of the carbon of both planets is in mineral form, in rocks, The big difference between Earth and Venus is that the atmospheric carbon of Earth has been captured by life.
James K
CC BY-SA 4.0
2024-12-04T10:35:13.673Z
@JamesK I think "atmospheric carbon captured by life" is a tiny factor. There is about 550 gigatons of carbon in the biosphere ([source](https://www.pnas.org/doi/10.1073/pnas.1711842115)), and maybe another 4,000-5,000 Gt if you include accumulated carbon in fossil fuels (e.g., [here](https://en.wikipedia.org/wiki/Carbon_cycle)).
Peter Erwin
CC BY-SA 4.0
2024-12-04T10:36:38.360Z
[cont'd]  The atmosphere of Venus, in contrast, has about $10^8$ Gt of carbon. The real difference is probably that Venus lost its oceans a very long time ago, and so CO2 added to the atmosphere by volcanism can't be removed the way it can on Earth.
Peter Erwin
CC BY-SA 4.0
2024-12-04T12:34:10.347Z
@PeterErwin You must also take into account carbonate rocks, that are not organic but also generated by lifeforms, from the remains of shells and exoskeletons. Probably most carbon fixated by organisms ended as carbonates.
ksousa
<planetary-atmosphere><venus><elemental-abundances>
Does Venus have much more carbon than Earth?
Anixx
# Does Venus have much more carbon than Earth?

(Asked by: username_0 on 2024-12-04)

Does Venus have more carbon (as an element) than Earth, and if so, why? Or it is basically the same amount?

**Tags:** planetary-atmosphere, venus, elemental-abundances
> **Comments:**
> **username_1**: Most of the carbon of both planets is in mineral form, in rocks, The big difference between Earth and Venus is that the atmospheric carbon of Earth has been captured by life.  
> **username_2**: @JamesK I think "atmospheric carbon captured by life" is a tiny factor. There is about 550 gigatons of carbon in the biosphere ([source](https://www.pnas.org/doi/10.1073/pnas.1711842115)), and maybe another 4,000-5,000 Gt if you include accumulated carbon in fossil fuels (e.g., [here](https://en.wikipedia.org/wiki/Carbon_cycle)).  
> **username_2**: [cont'd]  The atmosphere of Venus, in contrast, has about $10^8$ Gt of carbon. The real difference is probably that Venus lost its oceans a very long time ago, and so CO2 added to the atmosphere by volcanism can't be removed the way it can on Earth.  
> **username_3**: @PeterErwin You must also take into account carbonate rocks, that are not organic but also generated by lifeforms, from the remains of shells and exoskeletons. Probably most carbon fixated by organisms ended as carbonates.  

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## 2 answers

### Answer by username_4 on 2024-12-06. Score: 2

> Carbon, nitrogen and water abundances at the surfaces of Earth and Venus are compared in order to investigate the distributions of these elements between fluid and solid envelopes in both planets. **The atmosphere of Venus contains about twice more carbon ($\mathrm{1.25×10^{20}}$ kg of C) and nitrogen ($\mathrm{4.8×10^{18}}$ kg of N) than the atmosphere, hydrosphere and sediments of the Earth ($\mathrm{5.4×10^{19}}$ kg of C and $\mathrm{3×10^{18}}$ kg of N)**. After scaling to the planetary masses, surface excesses of $\mathrm{1×10^{20}}$ kg of C and $\mathrm{2.7×10^{18}}$ kg of N are calculated for Venus relatively to the Earth. The simplest proposed explanation is the storage of 25 ppm of C and 0.7 ppm of N in the Earth mantle due to lithospheric subduction, a mechanism not operating on Venus. Following the same line of arguments, the Earth has an excess surface water of about $\mathrm{1.2×10^{21}}$ kg of H2O, when compared to Venus. Under the hypothesis of a primordial sizable water mass on Venus, thermodynamic modeling of mineral stabilities reveals that hydrous minerals are stable at the P–T conditions of both the surface and the deep crust of Venus, and thus could be the carriers of the missing Venusian water. A combination of crustal hydration and hydrogen escape processes may explain the present-day low amount and high deuterium/hydrogen (D/H) ratio ($\mathrm{2.5×10^{−2}}$) of water in the Venusian atmosphere relatively to the Earth’s hydrosphere ($\mathrm{1.55×10^{−4}}$). Alternatively, if the high D/H ratio of Venus only resulted from hydrogen escape, the reservoir of remaining oxygen must have been involved in the oxidation of a rock layer of about 50 km in depth.

From Christophe Lécuyer, Laurent Simon, François Guyot,
*Comparison of carbon, nitrogen and water budgets on Venus and the Earth,*
Earth and Planetary Science Letters, **2000**, DOI: [10.1016/S0012-821X(00)00195-3](https://www.sciencedirect.com/science/article/pii/S0012821X00001953).

> **Comments:**
> **username_5**: Nice reference; this could benefit from some explanatory text  

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### Answer by username_6 on 2024-12-09. Score: -1

Yes, Venus has much more carbon than Earth, primarily in the form of carbon dioxide (CO₂). About 96.5% of Venus's atmosphere is composed of CO₂, a potent greenhouse gas. This thick carbon-rich atmosphere traps heat, creating extreme surface temperatures of around 465°C (869°F). In contrast, Earth's atmosphere contains only about 0.04% CO₂, with much of the planet's carbon stored in rocks and oceans. Venus's extreme carbon content contributes to its runaway greenhouse effect, making it far hotter than Earth, despite being further from the Sun. The disparity highlights the differing atmospheric conditions of the two planets.

> **Comments:**
> **username_7**: Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer).  
> **username_8**: In the last part of this reply, it was stated that Venus is hotter than the Earth despite being farther from the Sun. I would like to clarify distances. Mercury is closest, followed by Venus then Earth. I think that the reply was meant to indicate that Venus is hotter than Mercury in spite of it being farther from the Sun, and it’s hotter than Earth despite Earth being farther than Venus.  

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