[chris (OP)]

Ben Luckie has been in touch from Australia to say:

From all the CO2 that makes its way into our atmosphere does this extra amount of molecules pushing on the already existing molecules in our atmosphere cause the atmosphere to heat up creating a secondary action of warming by default molecule interaction and thus adding to global warming.  Somewhat like to the effect of warmer humid air before a storm breaks as the air molecules are pressed closer together but on a global scale.

Thanks for the great programme.
cheers
Ben

What does everyone think?

[alancalverd]

CO2 plays almost no part in atmospheric physics on this planet.

The "warm humid air" before a storm is actually less dense than the cold dry air that follows it. The classic storm front is caused by rapidly moving cold air literally overtaking the warm stuff, which then accelerates upwards and dumps huge quantities of energy as the water vapor first condenses then freezes into towering cumulonimbus clouds. 

The recent general warming of the earth's atmosphere has had two effects: to increase carbon dioxide release from the activity of coldblooded animals, and to reduce storm activity by reducing the temperature differentials between polar and tropical air. 

Physics and meteorology are often very different from journalism!

[PhysBang]

Sure. It plays almost no role, except roles that people might actually care about.

[chiralSPO]

CO2 plays almost no part in atmospheric physics on this planet.

That is demonstrably false. While I agree it is not the most important player, the claim that "CO₂ plays almost no part in atmospheric physics on this planet" is indefensible. CO₂ plays a significant role in determining the temperature of the atmosphere, and therefore plays a significant role in the physics involved in weather patterns, stratification, and mixing processes.

Now, on to the OP. I don't think that the CO₂ can change the temperature of the atmosphere in this way. Energy is conserved, so to increase the temperature of the atmosphere, there must also be a source of that energy. The sun is this source, and CO₂ influences how quickly the energy from the sun leaves the Earth, once it has gotten here.

[jeffreyH]

Let's be fair to Alan. The carbon cycle is balanced and doesn't tend to runaway.
http://www.columbia.edu/~vjd1/carbon.htm

[Bored chemist]

CO2 plays almost no part in atmospheric physics on this planet.

Come on; you can say that , or you can have a tag line that says "helping to stem the tide of ignorance".
But both?

[alancalverd]

Yes, both. According to the Intergovernmental Panel on Climate Change (and who am I  to argue with them?) the principal determinant of atmospheric temperature is water.

I set out one of the means by which this occurs, in my reply above. But just because every meteorologist, sailor, aviator or farmer understands it, apparently isn't good enough for the deniers in this forum. 

[PhysBang]

I really don't give a **** if this forum bans me, but what the **** do the Naked Scientists stand for if they allow this kind of wilful deception?

[PhysBang]

Let's be clear about what the IPCC actually says, so we can go on towards marginalizing ********MOD*******EDIT**************

From the IPCC report "Climate Change 2013: Physical Science Basis":

Is CO2 important?
Page 121: "Unequivocal evidence from in situ observations and ice core records shows that the atmospheric concentrations of important greenhouse gases such as carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) have increased over the last few centuries."

Does CO2 effect the climate?
Page 297: "Both anthropogenic climate change and anthropogenic ocean acidification are caused by increasing carbon dioxide concentrations in the atmosphere."

Does CO2 effect glacial cycles?
Page 400: "Such close linkages between CO2 concentration and climate variability are consistent with modelling results suggesting with high confidence that glacial–interglacial variations of CO2 and other GHGs explain a considerable fraction of glacial–interglacial climate variability in regions not directly affected by the NH continental ice sheets (Timmermann et al., 2009; Shakun et al., 2012)."


On Radiative Forcing, the capacity of a factor to influence the climate:
Page 56: "Forcing by CO2 is the largest single contributor to the total forcing during the Industrial Era and from 1980–2011."
Later, same page: "Carbon dioxide is the largest single contributor to historical RF from either the perspective of changes in the atmospheric concentration of CO2 or the impact of changes in net emissions of CO2."

[alancalverd]

I might point out that correlation is not causation and assertion is not proof, but as the last contributor's attitude is beneath contempt, I won't bother.

Anyone who knows enough to discuss science without resorting to childish insults is recommended to read the IPCC's first executive summary in which it was admitted that water was the principal greenhouse gas but, there being no means of measuring or assessing its historical distribution, there would be no attempt to model it.   

[alancalverd]

I rest my case.

[chiralSPO]

PhysBang's word choice aside, the IPCC quotes provided, are quite relevant, and do counter Alan's claims quite deftly. Alan, we understand that CO₂ is not as major a player as water, but that doesn't mean that CO₂ is insignificant. We are significantly changing the concentration of CO₂ in the atmosphere, and that is having a significant effect on atmospheric physics, and will continue to have an increasing role unless we reverse the trend. Since both CO₂ trends and H₂O trends are largely self-reinforcing (not self-regulating), and reinforce each other, I see no reason not to focus more on the parameter that we have changed, and less on the system's responses (treat the disease, not the symptom).

[jeffreyH]

I would suggest that changes in the water cycle drive changes in the carbon cycle. So not knowing what is happening in the water cycle leaves research in a very poor state.

[jeffreyH]

Have a look at a hydrologists point of view.
http://www.hydrologiraadet.no/wp-content/uploads/2015/09/Modelling2015_Blyth.pdf

[Bored chemist]

I rest my case.

You have rested your case on the lie that " water is the biggest contributor" means the same as "CO2 plays almost no part".

Which shows that your case rests on anything but  valid evidence.
If you were interested in science you would recognise that it's now time to change your viewpoint.

[Bored chemist]

I might point out that correlation is not causation and assertion is not proof,

Nobody said they were.
Another thing that's "not proof" is a straw-man.