Not in reality it doesn't. If that were so Volk, you'd have a uniform distribution over the Earth with hotspots. However, that isn't the case. Why doesn't High and Low pressure get filled? Why do they move across the surface? Because this isn't a uniform liquid with normal fluid dynamics. Its far more complicated than that.
OK, Freen, A) If what you are saying was true, the atmospheric composition should vary greatly over the earth's surface. Not just CO2 level, but O2 levels and nitrogen levels. They don't, the relative concentrations of all gases over the earth's surface are pretty much stable relative to each other, all over the globe. O2 levels in the atmosphere don't spike very much over areas of high plant activity, and they don't sink much over areas of low plant activity. Oh, and B ) Areas of high pressure and low pressure do get filled, what the hell do you think wind is? It's the movement of air from high to low pressure.
Also, if what you were saying were true. Why would water vapor levels vary? Obviously, it rained today. So we have a lot of water vapor. However, we don't find much over the desert. The concentration of water vapor there is low compared to say, Europe. Yet you don't see the mean flow of water vapor moving towards a desert.
Because unlike all the other atmospheric gases, the amount of water vapor air can hold varies with temperature, and thus it can be transported around and then dropped by the various small and large scale movements of the earth's atmosphere, that occur on short timescales of days and weeks. The residency time of water vapor in the atmosphere is very short, the residency time for all the other atmospheric gases is much much longer.
The example you're thinking of only works when you have one gas or maybe a few. The fact is the atmosphere is huge. It takes a lot of something in one place to really move around and get going.
The gas laws don't change because there are more gases in the mix. While the atmosphere is indeed huge, it is also very well mixed. The world over, the composition of the atmosphere is about 76% Nitrogen, 23% Oxygen, 1% Argon and trace amounts of everything else. Those are obviously not exact values, but as approximate figures, they work. The concentration of CO2 is about .002%, moving toward .003%, and that is pretty much the same the world over.
Volcanic ash when spewed into the atmosphere can make its way around the world. But it doesn't go everywhere, and it doesn't go to areas of "low concentration".
A) Volcanic ash is not a gas, it's particulate matter, so it behaves by different rules.
B ) The gases released by volcanoes do spread out over the whole world, moving from areas of high concentration to low concentration.
All of whom face the threat of loosing credibility and funding for attempting to refute global climate change. Even if the facts were that clear, there is ABSOLUTELY NO REASON to have an attitude, like yours, that discourages scientific discussion and investigation in the matter, which IS HAPPENING.
I'm expressing disappointment at your intellectual dishonesty bjorn. You presented an opinion that scientific inquiry into the subject has been tainted by politics. When in fact, the verdict had already been in for years before Gore ever made his stupid movie. You're trying to make the case that everything we know about global warming has been found out since Gore's movie, but even a cursory look at research into global warming shows that the majority of the data is substantially older than 2005. I remember reading about global warming in Discover magazine over 10 years ago. Nearly all the real serious debates about global warming was over and done with in the scientific community by the end of the 1990's, and certainly by 2005. So once again bjorn, BS!
It is said that when Rincewind dies, the occult ability of the human race will go UP by a fraction. -Terry Pratchett