Clarifying Misunderstandings Regarding Venus's Climate and CO2's Role
WEF article "Venus was once Earth-like, but climate change made it uninhabitable"
Introduction
In response to the claims made in the WEF article about Venus's climate and the role of carbon dioxide (CO2) in its atmosphere, it's important to address the manipulative inaccuracies and provide a more accurate understanding.
The assertion that Venus had oceans, rain, and snow akin to Earth is not accurate. Venus is much closer to the sun and has a surface atmosphere pressure 92 times higher than Earth's. At 1 bar, the observed temperature is around 30°C, in line with expectations. However, in the early days, the pressure was even higher, potentially as high as 1000 bars, thus looking more like a gas planet from outside. Under such intense pressure, the surface temperature on Venus would likely have soared to thousands of degrees Celsius, rendering it even too hot to maintain a solid surface as we find on Earth.
The dominant effect for the high temperature is simply fundamental physics and a well know relation.
P V = N k T
This elegant little law applies to any gas and for the physical conditions on any planet. So around ~500°C at surface (90 bars) and ~30°C at 1 bar is expected. Jupiter showed 153C at 22 bars, the last measurement point of NASA’s amazing Galileo spacecraft before disintegrating in Jupiter atmosphere 78 minutes after start of the final death plunge September 21, 2003.
Simple 1/r2 temperature model demo
With no atmosphere (vacuum), a simple interplay exists: incoming solar flux E=A=W/m² (as function of distance to sun) and thermal radiation E = B x T4
Equilibrium writes as:
A = B x T4
To resolve B, we use -18°C for earth (the reported no atmosphere value). A is expressed relative to earth (set to 1).
We can resolve B as knowing the T (-18°C)
A = B x T4 —>B = A / (-18+273)4 = 2.36E-10
and use this as constant for all planets as simplification. This gives us following results. The 1 bar observed T follows an inverse square law (~1/r2) and nicely matching the model. As expected, the sun is the dominant parameter.
The fallacy of WEF is the a 92 bar comparison with 1 bar for the earth. That is what makes it look like an outlier.
Venus' surface temperature stands as an anomaly owing to its exceptionally thick atmosphere (92 bar). On the other hand, Mars, enveloped by a 95% CO2 atmosphere (in contrast to Earth's mere 0.03%), retains its chilliness by receiving a mere 44% of Earth's solar flux and possessing a scanty atmosphere.
A noticeable deviation (see kink below) appears for Earth—a distinct characteristic. The greenhouse effect acts as our safeguard against frigid demise. Enveloping 70% of our world, water (H2O) reigns supreme as the primary greenhouse molecule, exhibiting extensive absorption across a wide infrared spectrum. In sharp contrast, carbon dioxide (CO2), present in mere trace amounts at 0.04%, assumes a marginal role.
The earth’s climate is all about water. Oceans, clouds, rain, vapor and their complex interplay.
Adding more data, including the gas planets, their moon and pluto, we get the following: a nice agreement with expected and not “greenhouse runaway effects”.
Discussion
The assertion that the temperature on Venus is a consequence of a runaway greenhouse effect is misleading, often tied to a manipulated narrative aligned with certain climate agendas. Rather, the explanation is more straightforward: temperature elevation correlates with pressure increase. This principle is not unique to Venus but holds true even for Jupiter, a gas giant planet. For instance, at a pressure of 22 bar on Jupiter, the recorded temperature reaches approximately 153°C. At 92 bar, we would likely have seen similar values as on Venus. 500°C.
In conclusion, the article from the World Economic Forum (WEF) proves to be profoundly manipulative (as expected from this organization) in its comparison of surface temperatures, juxtaposing the extreme pressure of 92 bars on Venus (at 0.7 AU distance) with the 1 bar on Earth (at 1 AU distance).
There's no doubt that when Venus was formed, the planet and it's atmosphere were very hot due to it's compression and increased pressure caused by it's own gravity.
Venus' solar flux is fixed by the distance between the Sun and Venus via the inverse square law.
(I'm assuming variation in Solar emissive power and orbit are insignicant).
Incoming power I = S * πr^2
S is solar irradiance
πr^2 is area exposed to the sun
You describe outgoing radiation E = B x T^4. It's commonly written as:
W = ε σT^4, the Stefan Boltzman equation where:
ε is emissivity
σ is the Stefan Boltzman constant
W Power per square meter.
Total emitted power E = W * 4πr^2
4πr^2 is the surface area of a sphere
Net power:
P = I - E = S * πr^2 - ε σT^4 * 4πr^2
Once Venus was created, 4.5 billion years ago, E > I meaning more energy is emitted than radiated.
The result of this, as energy is lost, is that Venus and it's atmosphere cooled down.
The cooling process would continue until incoming and outging energies balance.
I = E
S * πr^2 = ε σT^4 * 4πr^2
(this is where πr^2 cancels out)
S = ε σT^4 * 4
T^4 = 1/4 * S / ε σ
Take the quartic roots on both sides and you get Venus' effectice temperature of -47C.
There is no way the heat from the creation of Venus 4.5 Billion years ago can explain the difference between the effective (-47C) and actual surface temperature of 464C).
The heat generated at the creation of Venus dissipated Billions of years ago.
So the answer to the question of what causes the excessive temperatures on Venus is not atmospheric pressure.
The obvious cause is the GHG effect.
There's no doubt that when Venus was formed, the planet and it's atmosphere were very hot due to it's compression and increased pressure caused by it's own gravity.
Venus' solar flux is fixed by the distance between the Sun and Venus via the inverse square law.
(I'm assuming variation in Solar emission power and orbit are insignicant).
Incoming power I = S * πr^2
S is solar irradiance
πr^2 is area exposed to the sun
You describe outgoing radiation E = B x T^4. It's commonly written as:
W = ε σT^4, the Stefan Boltzman equation where:
ε is emissivity
σ is the Stefan Boltzman constant
W Power per square meter.
Total emitted power E = W * 4πr^2
4πr^2 is the surface area of a sphere
Net power:
P = I - E = S * πr^2 - ε σT^4 * 4πr^2
Once Venus was created, 4.5 billion years ago, E > I meaning more energy is emitted than radiated.
The result of this, as energy is lost, is that Venus and it's atmosphere cooled down.
The cooling process would continue until incoming and outging energies balance.
I = E
S * πr^2 = ε σT^4 * 4πr^2
(this is where πr^2 cancels out)
S = ε σT^4 * 4
T^4 = 1/4 * S / ε σ
Take the quartic roots on both sides and you get Venus' effectice temperature of -47C.
There is no way the heat from the creation of Venus 4.5 Billion years ago can explain the difference between the effective (-47C) and actual surface temperature of 464C).
The heat generated at the creation of Venus dissipated Billions of years ago.
So the answer to the question of what causes the excessive temperatures on Venus is not atmospheric pressure.
The obvious cause is the GHG effect.