On Dec 21, 3:49 pm, archytas <[email protected]> wrote: > Come on Chaz - most of Mars' atmosphere did one when the magnetic > field collapsed.
Er - 'one' what? The point I was making is that the numpties on the other NGs who support AGW assume that more CO2 necessarily means more heat, but there has to be a limit to the amount of heat according to the band with of the radiation. After a while more does not mean more. Venus, I seem to remember has loads of CO2 and is > unpleasantly hot - though not, as I understand because of the CO2. CO2 plays a role but there is much more besides, including a range of acids. > There is loads of quantitative research, it's just that the media > thinks no one can be arsed with any of it. You are conflating a 'tiny > amount' of CO2 with its trace presence on a scale of vastness you > don't grok. Grok? Your point has a compelling logic - when I put it to non- > scientists their heads start to nod. It's reasonable initial > thinking, but fades when the facts come out. > The essential argument starts with the properties of CO2 as a > molecule. Light generally doesn't affect it much, but three > frequencies of infrared make the molecule bend because it absorbs > them. All this kind of stuff is known as the result of experiments - > in my day you'd go to some volume of The Handbook of Physics and > Chemistry for the data. We can measure the amount of sunlight hitting > the Earth, know the Earth's size and can apply standard black body > calculations. These leave a discrepancy between the Earth's > theoretical temperature and actual measurements, so either black body > is bolloxs or we look for a model to explain this. This leads to > greenhouse theory (which in conjunction with orbital forcing brings > the sums back in order. Small experiments done by other than BBC > patronising goons give the basic figures which can them be expanded > into the estimates of total greenhouse gases, of which CO2 is a minor > but substantial part. The models are quite complicated and have to > take collisions between molecules into account. The sums are > basically what the IPCC has put out. Most people are simply so poor > at science they can't get this far. > The models may be wrong. Orbital forcing, for instance, is thought to > vary the amount of sunlight hitting certain latitudes by as much as > 25% (hence the ice ages), which is obviously big in comparison with > CO2 effects, though the amplification model of greenhouse warming may > be enough to prevent the 'next' ice age. Let's hope so. The models bouncing around in the mid 1970s resulted in a bif ice-age scare. I imagine you are old enough to remember it. WIth a background in archaeology I know only too well that we are currently in an interstadial and the next ice-age is fast becoming a little overdue. > The role of CO2 in this is > marginal, but marginal effects often amplify. 96% of sweet FA is, of > course, much more marginal than parts per million in a lot. Spark > plugs are a negligible weight in my car, but the sod won't run without > them. Not a very good analogy, you might as well have mentioned the cigarette lighters. > > There is a wider point similar to yours as to whether the marginal > effects are enough given the percentage variations in the models, but > this really starts in quantitative review and qualitative questions as > to whether the models are right even in the sense of being approximate > enough. Somewhere in this Chaz, is something like me trying to teach > the electro-chemistry of rusting to 12 years old who don't know what > iron is (one classic answer because I'd just done something explosive > with magnesium to wake them up, was that rusting happens because of > the magnesium - you must have had similar classics in your own > teaching). I still get the feeling that the world and the necessary factors that contribute to this issue are still beyond the ability of scientists and their models. Coupled with the will to succeed and the necessity to continue keep getting the grants, tends to press a certain direction for assumptions upon which models are designed. GW seems to be the new Kuhnian paradigm and I can't help but think that the next generation will look back in amusement as we do with eugenics, social Darwinism and phogistan. Or they could be fried to a crisp! > Sue and I started a conversation to establish what we really knew > about 'global warming' and the answer was pretty alarming and not far > off sweet FA. We found a few papers and a book, had a bit of a read, > noticing we were excluding the vast majority of Internet bull. Our > conclusion so far is that the real arguments are still in the margins > of a load of hot air. We didn't find reason to doubt the CO2 basics > though - it lets sunlight in because it doesn't absorb those > frequencies, but does absorb the bounce back infrared and this is > retained in a complex collision network and stays in part of the > atmosphere. This is a confirmation of basic science. The models hang > together and the sums work. The questions are not about basic CO2 > absorption, but there are questions about the complex models of > exchange and balances. One would hope these scientific arguments are > defeasible, subject to change on new facts and new models. Many > papers are, in fact, of the 'you left this out' or 'what if' kind. > They themselves have to be subject to being bagged-off. I'm afraid > this is the fate of your initially interesting conjectures, a bit like > the creationist asking 'where are the transition fossils then, evil > atheist bastard?' Oddly I was called a 'creationist' for doubting the CO2 science! But then I do not expect any sense from a person that did not really understand my question. - the answer being 'over there, have a look'. You > just don't know enough here. What's really interesting is that the > case hasn't been made properly and concisely even for people like us. > Answers to your question start with getting to grips with black body > radiation, the sums of that and then looking about in basic science > for reasons to change the sums to retain the basic science - this > information is widely available, both in qualitative modelling and as > the spreadsheet sums. > > On 21 Dec, 10:50, chazwin <[email protected]> wrote: > > > > > All the stuff that is out there point to CO2 as a GHG, but none of it > > has quantitative information. > > What worries me is the tiny amount of CO2, what the limits are due to > > the narrowness of the radiation spectrum it can absorb, is CO2 able to > > change the properties of the air as a whole or does the temperature > > change rely on its concentration. > > There seems to be an implication that CO2 prevents heat leaving. Would > > Mars not be hotter with nearly 96% CO2? There has to be limits. > > > On Dec 21, 1:41 am, archytas <[email protected]> wrote: > > > > The work on this is not new - a Swede called Arenheus (spelling) did > > > the work around 1900. This from Wiki: > > > Arrhenius developed a theory to explain the ice ages, and first > > > speculated that changes in the levels of carbon dioxide in the > > > atmosphere could substantially alter the surface temperature through > > > the greenhouse effect.[3] He was influenced by the work of others, > > > including Joseph Fourier. Arrhenius used the infrared observations of > > > the moon by Frank Washington Very and Samuel Pierpont Langley at the > > > Allegheny Observatory in Pittsburgh to calculate the absorption of CO2 > > > and water vapour. Using 'Stefan's law' (better known as the Stefan > > > Boltzmann law), he formulated his greenhouse law. In its original > > > form, Arrhenius' greenhouse law reads as follows: > > > if the quantity of carbonic acid increases in geometric progression, > > > the augmentation of the temperature will increase nearly in arithmetic > > > progression. > > > This simplified expression is still used today: > > > ÄF = á ln(C/C0) > > > Don't mistake any of this with 'greenhouse science' - it's basic > > > physics and chemistry and works at the bench in every experiment we do > > > in stuff like how much heat comes out if we lob a sliver of magnesium > > > in an acid etc. - stuff you will have done - and in stuff like > > > creating Bose-Einstein Condensates in which to trap light as matter > > > (Lene Hau). You should grok after a trip to Wiki. This question is > > > at the level of trying to get 12 year olds into a chemical explanation > > > of how rusting takes place, not at all easy as scientific > > > understanding is as rare as rocking horse droppings. > > > > On 21 Dec, 00:57, archytas <[email protected]> wrote: > > > > > I'd start at New Scientist Chaz. > > > > > On 20 Dec, 10:44, chazwin <[email protected]> wrote: > > > > > > I have searched in vain for any evidence that CO2 is a significant > > > > > greenhouse gas. > > > > > According to radiometric dating of Carbon isotopes it is thought the > > > > > the amount of CO2 has increased from 0.028% - 0,038% in the last 100 > > > > > years. > > > > > Unless Carbon has some magical properties is seems unlikely that such > > > > > tiny concentrations should cause any significant increase in > > > > > temperature, even-though it is a greenhouse gas. > > > > > Can any one help me find the scientific evidence? > > > > > I don't want to the political answer, nor the circumstantial answer, > > > > > nor any sceptic/denier/doubter information as I have heard it all. > > > > > What I want is the basic physical science of carbon that suggests that > > > > > a 0,01% increase can be held responsible for a proposed 1 degree > > > > > increase in temperature. -- You received this message because you are subscribed to the Google Groups "Epistemology" group. 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