Earth is about the same size as Venus, but temperatures are much cooler here. The primary difference between Earth and Venus is that we have oceans which absorb CO2 and form limestone – CACO3. Without the massive limestone deposits we have on Earth, the atmosphere would be much denser and temperatures would be much higher.
Venus is too close to the Sun to have liquid water. The water evaporated away, so volcanic CO2 kept accumulating, and their atmosphere became 100X more dense that of Earth.
The world’s leading climatologist – James Hansen – based his PhD dissertation on the idea that Venus was hot because of aerosols. Carl “Reefer Madness” Sagan later convinced him that Venus was hot because of a “runaway greenhouse effect” and now Hansen says the exact opposite – that Chinese aerosols make earth cool.
In order to become the world’s leading climatologist, you have to demonstrate that you have no clue about atmospheric physics.
IMO, at Tallblokes site, Stephen Wilde has very convincing arguments about atmospheric temperature profiles and how they are controlled by the gas laws and gravity. Atmospheric makeup is not important.
http://tallbloke.wordpress.com/2012/02/25/stephen-wilde-the-myth-of-backradiation/
“Without the massive limestone deposits we have on Earth, the atmosphere would be much denser and temperatures would be much higher.”
Er, that’s not quite true, as using the gas law, PV = nRT, you calculate both the temperature of Earth and Venus without considering the density.
It’s the water cycle, with its convection of warm, humid air to altitude, that carries 85% of the energy from the surface to altitude. That’s what makes us cooler.
Venus is not a greenhouse because sunlight does not reach the surface due to the permanent cloud deck. It’s high temperature is due to the high moles per liter and the 90 atmospheres of barometric pressure, not the density—that is to say that the 95% CO2 is not a factor—the universal gas law only considers the moles per liter and NOT the identity of the gas.
Pretending that these two planets are very similar is to misrepresent the reality.
It appears that this post flew right over your head. Please hit the reset button and try again. Density is a function of V and n, and thus P.
ummmm…
When you are cold you get closer to the campfire or make the campfire hotter and it feels and is warmer for you… not much other explanation is required.
The comparison is apples and oranges unless distance is taken into account. Closer to the campfire = warmer temps.
awwww someone beat me to it…
You have no idea what you are talking about.
Sagan’s Mars dust generating high vacuum reaction chamber was so leaky that it outgassed a world of carcinogenic vapors.
As Jack Charlton used to say “Put em under preasure”
Speaking of pressure, I can hear that observation deck creaking.
I hope it’s not outsourced Chinese steel.
It looks like a toto seat.
Appropriate as that deck would scare the crap right out of me.
I agree with Steven that the primary reason for the difference is the ocean. Not because it’s ability to absorb co2 reduces the radiative effect, but mostly because it means our atmosphere has a much smaller mass than that of Venus, where the surface pressure is 93 times higher than Earth’s.
Tallbloke, Steven said, “Without the massive limestone deposits we have on Earth, the atmosphere would be much denser and temperatures would be much higher.
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Pretty much in agreement with you.
Hansen keeps changing his mind. 14C is now the old/new 15C average global temperature.
http://www.americanthinker.com/2012/11/fourteen_is_the_new_fifteen.html
At my old house which sat on limestone soil, it’s my fault that I released too much CO2 into the air when I accidently dropped a limestone rock into vinegar.
“Why Doesn’t my Aunt have a Penis?”
“Does your Uncle have an opinion on this?”
“Unfortunately, she has the wrong genus,
But with a skilled hand, she’ll look more like Enos
And never again experience lenis”