Quote:
Originally Posted by RWebb
Venus is indeed extra-super-hot because of greenhouse gas effects.
And... if Mars was larger, there is a possibility thay a green house effect could make it have an Earth-like climate.
Earth is nicely balanced -- or was.
I used to use all 3 planets as lecture examples for carbon cycles -- this was before we had the warnings re global warming.
I don't know what competone's problem is....
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http://en.wikipedia.org/wiki/Venus
Quote:
Venus has an extremely dense atmosphere, which consists mainly of carbon dioxide and a small amount of nitrogen. The atmospheric mass is 93 times that of Earth's atmosphere while the pressure at the planet's surface is about 92 times that at Earth's surface—a pressure equivalent to that at a depth of nearly 1 kilometer under Earth's oceans. The density at the surface is 65 kg/m³ (6.5% that of water). The enormously CO2-rich atmosphere, along with thick clouds of sulfur dioxide, generates the strongest greenhouse effect in the solar system, creating surface temperatures of over 460 °C.[20] This makes Venus's surface hotter than Mercury's which has a minimum surface temperature of -220 °C and maximum surface temperature of 420 °C, even though Venus is nearly twice Mercury's distance from the Sun and receives only 25% of Mercury's solar irradiance. Because of the lack of any moisture on Venus, there is almost no relative humidity (no more than 1%) on the surface, creating a heat index of 450 °C to 480 °C.
Studies have suggested that several billion years ago Venus's atmosphere was much more like Earth's than it is now, and that there were probably substantial quantities of liquid water on the surface, but a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of greenhouse gases in its atmosphere.[21] Thermal inertia and the transfer of heat by winds in the lower atmosphere mean that the temperature of Venus's surface does not vary significantly between the night and day sides, despite the planet's extremely slow rotation. Winds at the surface are slow, moving at a few kilometers per hour, but because of the high density of the atmosphere at Venus's surface, they exert a significant amount of force against obstructions, and transport dust and small stones across the surface. This alone would make it difficult for a human to walk through, even if the heat were not a problem.[22] Above the dense CO2 layer are thick clouds consisting mainly of sulfur dioxide and sulfuric acid droplets.[23][24] These clouds reflect about 60% of the sunlight that falls on them back into space, and prevent the direct observation of Venus's surface in visible light. The permanent cloud cover means that although Venus is closer than Earth to the Sun, the Venusian surface is not as well lit. In the absence of the greenhouse effect caused by the carbon dioxide in the atmosphere, the temperature at the surface of Venus would be quite similar to that on Earth. Strong 300 km/h winds at the cloud tops circle the planet about every four to five earth days.[25]
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So you are trying to tell us that burning fossil fuels on Earth will result in an atmosphere of nearly 100% carbon dioxide at a pressure approximately 92 times current atmospheric pressure?
Earth's atmosphere consists of approximately 0.038% carbon dioxide.
How many tons of fossil fuels would we have to burn to raise that carbon dioxide level in the atmosphere from 0.038% to 0.039%?
A few "back of the napkin" figures to demonstrate the nonsense behind "global warming" ideas:
A 0.001% increase in atmospheric carbon dioxide would represent approximately 5 trillion metric tons of carbon dioxide.
Current burning of fossil fuels is estimated to generate approximately 22 billion tons of carbon dioxide per year (U.S. Dept. of Energy number). Some claim that only half of that 22 billion tons is
not reabsorbed by plant life and remains in the atmosphere. Accepting that figure (I actually think much more is reabsorbed), CO2 in the atmosphere increases by about 11 billion tons each year.
So we can see that it would take approximately 470 years of current fossil fuel burning to raise CO2 levels from 0.038% to 0.039% of the atmosphere.
Now show me the lab experiments that demonstrate an increase of carbon dioxide from 0.038% to 0.039% in an oxygen-nitrogen mixture equivalent to earth's atmosphere, suddenly changes the heat transfer properties of that gas mixture -- preventing "heat loss" (as the "global warming" proponents claim) to a degree that it could increase overall atmospheric temperatures across the entire planet by a measurable amount?
The earth's surface atmosphere may be warming up, but any such warming has
nothing to do with the carbon dioxide being put in the atmosphere from the burning of fossil fuels.
The amount of carbon dioxide from the burning of fossil fuels is simply insignificant when measured against the amount of CO2 that exists naturally in the atmosphere.
There are real pollution issues relating to human activity, but "CO2 emissions" is not one of them.