http://www.permaculture.org.au/images/genetic_engineering2.jpg

We’re all excited that we’ve understood one little element of the puzzle, but can’t see how that single piece fits into a far bigger picture. Indeed, we don’t even realise there is a bigger picture. Worse, as we ‘cleverly’ mess with/manipulate that single piece, we discover knock on effects we didn’t anticipate.

When we step back, to look at/observe interactions/relationships/balance in natural systems, we see we don’t have to understand all the minutiae to know that we’re messing with a system that worked perfectly for thousands of years until now. We know the oceans are acidifying through increase in carbonic acid, we know this is from excess CO2 in the atmosphere. We know we’ve cut down far too many trees (releasing their CO2 and removing their CO2 sequestration services) and are releasing more CO2 into the atmosphere via fossil fuels than at any time in known history, etc. I find it fascinating when I hear, for example, denialists using the argument that we’re a ‘carbon starved world’ (http://permaculture.org.au/2009/3/31/capping-c02-emissions-will-steal-plant-food/ ), making me wonder how all the trees we had a few centuries ago could ever have survived. The few trees we have left now must be soooo happy all the other trees are gone. It’s the same mindset that has people removing ground cover and cutting down trees because they believe the plants are competing with them for water, then discovering after they’ve done so that everything around them dries up. This is complete reductionism and ignorance about natural systems and their services.

*sigh*

1.: In the video, I see three numbers: 23.4 degrees Celsius at the beginning, 31.2 degrees Celsius for the air bottle at the end, and 36.1 degrees Celsius for the CO2 bottle. Looking at the computer screen as shown at 01:56, which shows a cut-off graph, I think it is somewhat reasonable to assume that these are the final equilibrium temperatures.

That gives 7.8 Kelvins of heating for the air bottle, and 12.7 K for the CO2 bottle.

Now you write:

“Therefore, the contents of the carbon dioxide bottle will heat up 23.3% faster than the air bottle.

If you plot the rates of temperature increase in the two bottles and take the ratio of those rates, you will find that the entire effect is fully explained by the ratio of the molecular masses.”

from these numbers (and also, estimating slopes on the cut-off graph shown), I’d say that the ratio is certainly larger than 1:1.25. So, where is your 23.3% there?

2. Have you considered doing a simple check of your calculation against a materials property table? I’ll use the same source as you here, engineeringtoolbox.com:

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Thermal conductivity of air at NIST STP is 0.024 W/m K, that of CO2 is 0.0146 W/m K, giving us a ratio of 1.64, rather than 1.23. (Incidentally, that correct ratio is pretty close to the ratio of the temperature increases observed here – but for now, I’d consider that a coincidence, for that ratio will surely depend on the thickness of the insulating gas blanket.)

3. You are perfectly right that, all other things being equal, thermal conductivity goes with the inverse square root of the mass of the molecule. The noble gases obey that law somewhat
nicely: For Argon and Helium, mass ratio is about 10:1, and conductivity ratio is about 1:3. However, what you seem to be unaware of is that heat conductivity also is proportional to the molar specific heat capacity at constant volume. (Intuitively: the number of thermal degrees of freedom transported per particle.) Oxygen and Nitrogen are pretty close to the expected value of 5/2 R for a linear molecule (2 rotational + 3 translational degrees of freedom, each contributing k/2 per molecule), while CO2, due to excitations of internal degrees of freedom, has a larger Cv of about 3.4 R. That’s a factor 1.36 you just omitted. In addition to this, thermal conductivity is proportional to the mean free path of the molecule, which is inversely proportional to its cross-section. The CO2 molecule evidently has a much larger effective diameter than both N2 and O2, hence a smaller mean free path. Another factor you did not take into account when comparing air and CO2.

Just out of curiosity: may I ask what subject you did your PhD in?

Forgive me for not including it specifically in the previous post, but here is a reference where the calculation is shown in detail: http://www.chem.arizona.edu/~salzmanr/480a/480ants/collsurf/collsurf.html

For reference:

Air molecular mass:
http://www.engineeringtoolbox.com/molecular-mass-air-d_679.html

Carbon dioxide molecular mass:
http://en.wikipedia.org/wiki/Carbon_dioxide

Ideal gas law: http://en.wikipedia.org/wiki/Ideal_gas_law
Gives density as being proportional to the ratio of the pressure to the temperature. For the same initial conditions of pressure and temperature in the same size bottles, the density (and number) of molecules are the same.

Ratio of molecular mass: 28.97/44.01 = 0.6583

Kenetic theory of gases:
http://en.wikipedia.org/wiki/Kinetic_theory_of_gases
Gives the mean velocity as the square root of the ratio of the temperature to the molecular mass.

Inverse square root ratio of molecular mass:
sqrt(44.01/28.97) = 1.233

Number of collisions with a wall:
http://www.wikidoc.org/index.php/Kinetic_theory
Gives the number of collisions as being proportional to the product of the density and mean velocity. Since the initial densities are the same (see above), the ratio of the number of collisions is equal to the ratio of the velocities. At the same temperature, this is the ratio of the square root of the molecular masses, i.e., 1.233.

I fail to see how this is “quite wrong in more than one way”. Note also, that it is not I that am “quite wrong” in your assessment; it is J. Herapath who detailed the calculation in an 1816 paper entitled “On the Physical Properties of Gases” in the Annals of Philosophy (pp 56-60).

I think you have have a valid point here. While for the earth, radiation is the only cooling mechanism, we also have conduction and convection in this simple experiment.

So, if we strip out your numbers, which superficially appear very accurate, coming with 3 or even 4 digits, but unfortunately are quite wrong in more than one way, your basic claim as I understand it is that, in such a set-up, the non-air bottle will always heat to a higher equilibrium temperature than the air-filled bottle if we put in a heavy gas.

Hence, what we actually would have to compare in this experiment is the CO2 warming (relative to air) and the warming (also relative to air) produced by a non-IR-active gas of about the same molecular mass, heat capacity, and – preferentially, effective radius – as CO2.

Unfortunately, it is a bit difficult to actually do such a differential experiment here. Pondering over the periodic table, I don’t see an element or compound that could fit the bill. The closest analog may be Krypton, which, however, only has about 1/2 the heat capacity of CO2.

Perhaps the experiment should be re-done in such a way that the heat conduction playing field is leveled by also putting 50% helium into both the air and CO2 bottle then.

The gas inside the bottles impacts the bottle wall and exchanges energy with the surrounding atmosphere. Because of its increased mean speed, air molecules impact the walls 23.3% more often than the carbon dioxide molecules at the same temperature. Therefore, the contents of the carbon dioxide bottle will heat up 23.3% faster than the air bottle.

If you plot the rates of temperature increase in the two bottles and take the ratio of those rates, you will find that the entire effect is fully explained by the ratio of the molecular masses. Since the earth is not immersed in a surrouding medium it is not cooled in the same manner as the bottles, i.e., through bottle wall impacts.

Since the entire effect in the experiment you reference is fully explained by the molecular mass ratio and the bottle wall impact cooling mechanism, where is the radiative forcing effect necessary for global warming? The answer is that the experiment you reference and, apparently, rely upon for your argument is completely unable to discern a radiative forcing effect.

“explain how we can expect global temperatures to remain static whilst pumping billions of tons of extra greenhouse gases into the atmosphere”

An over simplified example of how global temperatures could only rise by a minor amount despite GHG emissions is that a slight, or localised, rise in temperature could lead to higher evaporation of water from the ground. This would lead to greater cloud cover in the atmosphere. Clouds very effectively reflect the sun’s energy before it ever enters to atmosphere (or at least the troposphere, which is the lower 10km of the atmosphere). Thus, higher GHG could have a minimal impact on temperature.

This is a believable hypothesis of how global temperatures can remain static despite GHGs. Water vapour may in fact be a negative feedback, contrary to what was said earlier. Unfortunately, cloud formation is one area of atmospheric science where science hasn’t yet been able to draw firm conclusions. All we know is that clouds potentially play a major part in global warming and that it is one of the biggest weaknesses of surrent climate change prediction models.

As I said at first, however, I think society does need to address GHG emissions. The climate is such a complicated, chaotic system that I think that scientists can not know exactly how it will be effected by GHG emissions other than to say they might have a big impact on climate and cause a lot of human suffering (disease, floods, and hightened international tensions). It is not a major impact on our society to significantly reduce our carbon dioxide production, it is just bad news for some powerful members of our society (e.g. the oil industry). People can have a very high standard of living, and our economies be very successful without emitting all these GHG. Therefore, as someone said earlier in this thread, it’s better that we are safe rather than sorry and not carry on introducing this unusually high level of carbon dioxide into the atmosphere. If we wait to see what the results are, it may be too late to avert incredible amounts of human suffering.

I think the issue at the heart of all this is: as a species, we both depend on nature as well as our technology for our survival. Now that is not such an extraordinary thing: pretty much most species need shelter, for example, and in the broadest sense most of them use some technological approach to provide that. And certainly all species need nature. It’s just that we seem to have difficulty reconciling the needs and characteristics of nature with our (present) technology. In that way, we are actually not that special. Part of that problem is that our present engineers often don’t watch and think enough before they design, but just throw massive concrete-steel-oil-and-gas solutions at problems. Concerning this particular issue, it is very enlightening to in particular study the work of the engineer John Todd on “Living Machines”. I think he found a very good way to demonstrate that one can indeed match up nature with technology in a sensible way.

Coming back to the analogy of the “jigsaw puzzle”: Nature desperately tries to tell us that we do something very basic very wrong. What is that key problem at the heart of the matter? The more I study Mollison’s work the more I get the idea he must have had some fairly profound insights into this. Take for example the poem at the beginning of “Permaculture One” that talks about people seeing “bamboo as a grass” and a different sort of people seeing “bamboo as a spear”. Note that the sort of global economy we have at present, and our present economic thinking, is still very strongly shaped by ideas from the cold war era. Both Communist and Capitalist thinking considered an economy as powerful (and hence desirable) that would be able to do a lot of advanced engineering in a short time-span. Bluntly, “having an economy that would be able to produce a lot of tanks in very short time-span, if needed” was regarded as a good thing on both sides. Landing a man on the moon? It all was about delivering a striking demonstration that a decentralized market economy with tens of thousands of supplier companies would be more effective at achieving a narrowly defined complex engineering goal than a planned economy could be.

But as such, both “philosophies” missed the most important point. Strength is NOT about acquiring the universal ability to bend things to your will if you don’t like them the way they are, and in particular “conflict” is NOT a game of chess where you have to use your resources in a clever way to obtain a strategic advantage over the enemy. Yet, this perspective is what I would call the common basis of capitalist and communist thinking. It occasionally becomes quite visible, such as in Thomas Schelling’s book “The strategy of conflict”.

There is a very different notion of “conflict” that regards such a situation as a product of some sort of confusion that can be traced back to an incomplete understanding of the issue at hand by all parties involved, and strives to come to a lasting solution by first clearing up that confusion. The key insight here is: when we think about conflict, then the concept of “violence” is a red herring that persistently distracts us from the perspective of having to work hard for a better understanding of the actual nature of the situation. Conflict really ultimately is a product of confusion: Forces clash which rather would have needed a design approach.

As long as we are stuck with thinking that is shaped by the idea of “progress” being all about increasing our capacity to use force to bend things to our will (“build more bombs”), and doing creative accounting to re-declare the destruction of valuable resources (Bill’s terminology would be “pro-creative assets”) as “production of wealth” (which actually at best is in the form of “degenerative assets”, hence actually liabilities, when seen in the right light), simple logic should tell us that we cannot be on the right track (in the sense that such an approach would quite automatically be self-defeating in the long run).

So, the question is not one about “shutting down the world economy” or “depriving the holy engineer of his magical weapon – fire”, which is the fear in the hearts of many people who are very strongly opposed to emissions reductions these days. It ultimately is all about setting the conceptual-philosophical basis of our economic thinking right, getting rid of the “creative accounting” that re-declares destruction as “wealth generation”, and instead generating real, lasting, stable wealth (fertile soil, clean water, stable forests, etc.) that can support both us, as people, as well as the co-evolutionary context that we depend on (including “that which is wild”). The “redistribution of surplus” aspect of the permaculture ethics is much less about “fair share” as it is about “switching over from reinvesting the surpluses generated by destructive economic activity to further speed up the destruction” to “reinvesting the surpluses from rehabilitiative economic activity to further speed up rehabilitation”.

It ultimately all boils down to “learning to see conflict as caused by confusion and resolving it through observation and profound design” superseding the idea of seeing “conflict as a need for the capacity to apply force”.

Nice idea, but does it work in practice? Well… does Permaculture actually work then? I’d pretty much say so.

Concerning these more abstract ideas, two other people apart from John Todd whose work certainly deserves to be studied, for they seem to have had profound insights into the nature of conflict and demonstrated the ability to productively use these insights to set up working solutions are Mohandas Gandhi, and Christopher Alexander.