Fair enough. But honest and genuine people can still be mistaken.

“I don’t think his making one mistake which has nothing to do with his arguments on climate change invalidates the rest of his book…”

Not directly. But I think finding mistakes should put readers on their guard. It makes me want to check a few more references in his book to see if what the reference says is what he says the reference says.

“…I mean can you show me any text – especially one the length of Plimer’s work – that is totally 100% flawless and free of even the slightest error or ambiguity?”

Of course I can’t. But Prof Plimer’s mistakes are far more than “…slightest error or ambiguity.” They’re absolute howlers. What would you have said if he’d made statements like that at one of his talks at your astronomical society?

@ Spectroscope, #38:

“already covered above”. In Phil’s previous articles, that is.

Not to my satisfaction.

My comment was a clarification of my reply to Chip in comment #17. It has nothing to do with answering you. For that, see my comment #23.

The rest of your comment doesn’t address the issues raised in #23.

@ Spectroscope, #70:

yes, I’m very serious.

Well, excuse me for being surprised that someone can visit a science blog and argue anti-science!

insults such as “denier” are invalid

That isn’t an insult but an observation of fact – a denier denies something, here established science.

The correct term for someone who disagrees with the politico-religious AGW orthodoxy is “skeptic”.

Skeptic organization are clear that skepticism is based on established science. As in AGW.

The rest of your claim here is just a rejection of argument, without addressing its points.

So … thankyou for helping prove my case

This you could only claim by stopping at that point and not addressing the subsequent elaboration. You are not trying to be serious, so there is no point in addressing your argument further.

The science on this is, as I noted, clear. Anyone really interested can read about it in for example IPCC 2007, which sums up the climate science known to that point.

… Messier Tidy Upper @10 asked how much longer the Earth spends at aphelion than at perihelion, which Brian partially answered. (But the AGW troll took over and most of his answer was about that…) To provide a slightly less partial answer, compare the time from the March equinox to the September equinox to the other “half” of the year. For this year (if I’ve counted days correctly) it’s 186 days 10 hours vs. 178 days 20 hours for the Sept.-Mar. half of the year. Because aphelion appears about in the middle of the Mar.-Sept. half year, it takes about 8 days longer. To elaborate on how much faster/slower the Earth moves in its orbit due to its ellipticity, that’s what the analemma (figure-8 shaped marking on a globe, usually in the middle of the Pacific Ocean) is all about.

Thanks (belated but sincere) – that’s exactly what I wanted to know. Much appreciated.

Great to have the explanation & extra info. from you & Wayne Robinson (# 78.) too.

@ 81. Buzz Parsec Says:

To try to get these comments even more off topic than Spectroscope has, I have often wondered whether Martians would have developed the Copernican model of the Solar System more quickly than us Earthlings, given that they could most likely observe the Moon orbiting the Earth without telescopes, and possibly also, being about 1/2 AU closer at opposition, been able to observe Jupiter’s moons as well.

I think that’s likely right – and the higher orbital eccentricity of the Martian orbit would likely help there too.

However, I could be wrong but I think the only place in the solar system where the Jovian moons can be seen with the unaided eye (Jovian system apart) is Ceres & maybe some other asteroids. I think Mars may be too far away still for even Ganymede and Callisto to be spotted without optical aid – but I’m not 100% sure …

Visualizing moving objects in 3D always makes my head hurt. I usually find that if I can imagine the right place to look from, it gets easier, but I haven’t found that yet.

To try to get these comments even more off topic than Spectroscope has, I have often wondered whether Martians would have developed the Copernican
model of the Solar System more quickly than us Earthlings, given that they could most likely observe the Moon orbiting the Earth without telescopes, and possibly also, being about 1/2 AU closer at opposition, been able to observe Jupiter’s moons as well.

You can believe whatever you want and obviously you think you are smarter than thousands of climate scientists, biologists, glaciologists, farmers and outdoorsmen who are observing the changes already underway due to global warming.

But you are making outrageous accusations about Dr. Mann, a noted researcher who publishes in respected peer-reviewed scientific journals. You are indulging in the politics of personal destruction by making utterly unfounded claims. It may be “strangle the messenger” in your case. However, most of the doofuses that generate and propagate the personality attacks are doing so under the (indirect) aegis of some fossil fuel companies. Think about that: why didn’t ExxonMobil go out in public denying AGW with their in-house scientists? They hire very bright people. They didn’t want their name associated with it, and so they money-laundered the funding of the doofuses through a chain of nonprofits.

You are also spamming this board with nonsense. Plimer’s notion that carbon dioxide at some point quits absorbing heat — where did that come from? — counters basic chemistry. Take any absorbing substance in a test tube, you add more absorbing molecules, more stuff will be absorbed. Even if you added so much carbon dioxide to our air that no sunlight gets to the ground, adding more CO2 would still cause more absorption at the top of the atmosphere.

Volcanic activity, tectonic changes, and orbital cycles all require tens of thousands or millions of years. They don’t act as fast as adding 38% more CO2 to our air. That’s why Plimer’s list is nonsense, it doesn’t apply to what’s happening in present decades.

AGW is not a theory. CO2 absorption of sunlight has been measured. Long ago, before research funding was available. AGW is an old theory and no scientist doing serious research has found any basic contradiction. Did you know the earth would be as cold as our Moon if there were no CO2 (and other greenhouse gases)?

Spectroscope, I note you quoted Professor Ian Plimer a couple of times. I’ll start my response by saying that it was thanks to Professor Plimer that I’m a skeptic, after seeing him on Australian television and buying his book “Telling Lies for God”. But in his book “Heaven + Earth” he makes some extraordinary claims about the Sun (about page 110-120 of the paperback: that the Sun was built on the remains of a supernova, that the Sun is a pulsar, and that the Sun primarily consists of metals such as iron. When someone makes claims like this in a book which is supposed to be a serious science text, it makes me doubt everything else he says, even if he was the person who effectively set me on the path to being a skeptic.

I’ve met Ian Plimer & talked to him personally as well as attending several talks he has given to the local astronomical society & he comes across as a very honest and genuine bloke. Given my own personal experience I am inclined to trust him.

I don’t think his making one mistake which has nothing to do with his arguments on climate change invalidates the rest of his book – I mean can you show me any text – especially one the length of Plimer’s work – that is totally 100% flawless and free of even the slightest error or ambiguity?

I don’t know that AGW is a Green Left conspiracy but I do think there may be a lot of exaggerating and spinning going on around it making it seem more certain and worse than it is.

I would venture a guess that this quite likely because the climatologists have a sub-conscious desire to boost the importance and excitement of their field. There are a couple of horror stories that Climatology could offer – ice age or frying planet & with the evidence suggesting the planet isn’t going into an ice age this century (which is actually by far the scarier scenario IMHON) they’ve gone for the opposite extreme. To say that the truth is most likely a prosaic matter of global average temperatures oscillating between slightly warmer and slightly cooler decades (eg. 1970′s cooler, 1990′s warmer etc ..) would probably make the lives of climatologists much less fun and interesting &, of course, also cause them to get a lot less grants than if the situation is presented as “OMG! We’re maybe all going DIE! You’d better fund us more so we can study this HUGE problem!”

I do think there is a big over-emphasis on Co2 and possible human causation rather than
considering that a lot of the factors here could lie in geology, astronomy, physics, etc .. Maybe the AGW is a phatom created by specialists focusing too narrowly on one aspect rather than looking at the bigger picture – including the bigger timescale?

I used to be absolutely sure the AGW was real. I am no longer so sure & would have to confess I am now skeptical as to its reality and severity. Listening to & reading Plimer’s book is one major reason for that.

I don’t think you would notice without keeping very careful observations. The Sun is about 3% closer now than in July, so is about 6% brighter. However, several things conspire to hide the difference in brightness. 1) changes in angle (the sun is much higher in the sky in summer, thus there is less atmospheric extinction.) I think this is a much bigger effect, either to hide the difference in the Northern Hemisphere, and to exaggerate it in the Southern Hemisphere. 2) Our eyes are logarithmic, hiding small differences in brightness. 3) Our eyes adapt to the prevailing light level. 4) We would be trying to compare current brightness of the Sun with our memory of how bright it was 6 months ago.

Also it depends on what you mean by “perceptible”. If you mean just looking up or around you and noticing, “Hey, it looks a little brighter outside right now than it did 6 months ago!”, almost certainly not. If you mean could you tell which of two Suns, one at July brightness and one at January brightness that you could directly compare, was brighter, I think it would be easy to see the difference. If you mean can we tell which is brighter using simple instruments (comparison sheets or a camera light meter) I think it would be pretty easy to tell it’s brighter now.

Messier Tidy Upper @10 asked how much longer the Earth spends at aphelion than at perihelion, which Brian partially answered. (But the AGW troll took over and most of his answer was about that…) To provide a slightly less partial answer, compare the time from the March equinox to the September equinox to the other “half” of the year. For this year (if I’ve counted days correctly) it’s 186 days 10 hours vs. 178 days 20 hours for the Sept.-Mar. half of the year. Because aphelion appears about in the middle of the Mar.-Sept. half year, it takes about 8 days longer.

To elaborate on how much faster/slower the Earth moves in its orbit due to its ellipticity, that’s what the analemma (figure-8 shaped marking on a globe, usually in the middle of the Pacific Ocean) is all about. The calender marked around the “8″ shows you how far north or south the Sun is on a given date (the vertical dimension of the 8), and how much “early” or “late” the Sun is on that date (the horizontal dimension). The earliness or lateness of the Sun is cumulative, about ten seconds a day, adding up to about 15-20 minutes at the extremes. The Earth revolves on its axis once a day (actually once every 23 hours and 56 minutes) with respect to the stars. This rotation period is extremely constant; it hardly varies at all. However, during the time it rotates once, it has also revolved almost 1 degree around the Sun (360/365.25 degrees, since it travels around the Sun once (360 degrees) in a year (365.25 days).) So it has to rotate for an additional 4 minutes to put the Sun at the same point in the sky from day to day. (23:56 + :04 = 24 hours for the “mean Solar day”)
This however is just an average. Since the Earth orbits faster at perihelion and is closer, it actually needs to rotate more than the additional 4 minutes to catch up with the Sun. On the other hand, at aphelion (in July) it is moving slower and is farther away, so it will over-rotate in the extra 4 minutes, and the Sun will not quite be at noon 24 hours after the previous noon. The Sun will be running late.

So over the course of the year, the Sun appears later and later, and then earlier and earlier and then later and later again and then earlier and earlier and repeats. (I’m not sure why the analemma is a figure 8, with two “earliest” and two “latest” dates, rather than just a circle or ellipse with only a single “earliest” and a single “latest” date each year, though. I’d probably flunk Astronomy 10 for not knowing this if I took it again and didn’t study )

If 99% climatologists agree on anthropogenic warming, I can try to research as much as I want on Google university, but still the consensus remains there.

I also wonder what scam this world-wide conspiracy would be after: less carbon fuels, less pollution, more green energy? Wow, that would really bring the Earth to doom and destruction…

So, the GW-debate is back again, although the topic had originally nothing to do with it. This reminds me of “Anaconda”, who always saw EU-topics in threads which had nothing to do with it.

Well, its not really relevant to my argument but I was responding to something somebody else said here regarding the degrees that are supposed to make a diference. AGW Alarmists seem to think 4 or even 2 degrees difference in temperature has catastrophic world-ending consequences – the fact that Earth’s temperature varies by that and more over the course of a year seems to have escaped their notice.

I’d like to post on specially dedicated threads here but on this issue the BA has been very reluctant to provide relevant threads largely ignoring what is the probably the worst scientific scandal of the century. Worse yet for fans of the BA, when he does deign to pay the Climategate scandal some attention he has come in on the side of the Warmists woo rather than the skeptical side in a disappointing display of how anyone can be blinded by their political biases – in the BA’s case towards the “Watermelon Green” left wing.

I don’t know the exact concentration of CO2 that is needed, but place yourself and any other animal of this planet in a room with enough CO2 and you and the animals will be dead rather soon. CO2 is a deadly poison for any animal that relies on oxygen.

Well only at certain super-high concentrations when oxygen is displaced. No, we can’t breathe an atmosphere with insufficent oxygen but hardly makes Co2 a threat at the levels we’ve got it or even much higher levels provided its still a mainly nitrogen-oxygen atmosphere.

Plants, on the other hand, depend on CO2 and as a byproduct they emit oxygen. A nice circle. It is true that CO2 levels have been higher in the past. But, as far as I know, they were higher when there were less plants on earth. When can that happen? During ice ages! So, we have an ice age, less plants, higher CO2 levels and the temperature can rise. Then the ice is receding, plants spread out, the CO2 level drops and the temperature can fall again. Seems logical, doesn’t it?

Yes. The key factor there is that Co2 levels have been higher in the past – much higher. The nonsense that Co2 levels are at unprecedented highs today due to Humans is totally false and absurd.

Moreover, we have historical & geological proof that the AGW end-is-nigh scenarios are humbug and utter rubbish & not to be taken seriously at all. Let alone used as an excuse to surrender our lives to overseas bureacrats, extremist Green ideologues and a reason to destroy our economy, culture, way of life and whole civilisation.

What is happening now? We are at the end of an ice age, so plants should spread out and should drop the CO2 level of the atmosphere. But what are humans doing? We rise the CO2 level in a period when it should drop AND we destroy large parts of the rain forest, so less CO2 can be processed. This seems to be the opposite of what “naturally” should happen.

Rainforest is over-rated. Its good sure but most of the biological life exists in the ocean and as plankton & bacteria. Chopping down abit of rainforest isn’t going to change our atmospheric composition – certainly not enough to be too harmful. Now that’s not to say we should destroy the rainforests – they are interesting places worth preserving for their own sake and we can learn much by studying them but nor should we make them out to be more significant than they really are.

Oh & humans are part of nature too don’t forget.

Don’t take my word for it, that is what I heard in a talk recently, but I am no expert in this field. But still, and here I go with Wayne Robinson: “Spectroscope, here is a little task for you. Ask yourself a few questions beginning with “What if…”. Just produce some worst case scenarios. They might not happen, but then ask yourself: Is it worth the risk?”

The risk of what?

Climate change is a natural and unavoidable part of living on this planet. The climate changes and that’s what its done throughout history. Reality is that nothing humans could do will affect the Earth’s climate* much one way or the other with the sole possible exception of all-out nuclear war creating a “nuclear winter.” So until we learn to alter Earth’s orbit, move the continents where we choose or change the light output from the Sun, we really & truly don’t have to worry. All we can do is adapt to natural climate change and that’s what Humans have done since we began existing and nothing new anyhow.

Now there is another “what if” factor here & that is what if we do what the Radical Greens and AGW Alarmist mob want? Suppose we tax carbon, handicap our economy, advantage our enemies, give them a fortune of our tax-payer dollars, institute schemes to trade Co2 emissions rights, etc .. Isn’t that too taking a risk? Indeed a lot *more* of a risk?

One we don’t need to take that will bring us in the West nothing but harm and have no environmental benefit anyway because the problem its trying to address doesn’t even exist?

Do *you* want to put on an AGW hairshirt for no valid reason, give up travelling by car, hand over your life to the lunatic Greens & UN bureacrats and people hostile to the best system of living humans have yet come up with – democratic capitalism? All because of an absurd myth that human Co2 is doing something that we know it isn’t doing? Would *you* surrender your quality of life and inalienable rights for a mob of liars with their own political manifesto that has historically been proven to fail everywhere its been tried from East Germany to Cuba to China?

If the “precautionary principle” says anything here it says we do NOT need to take any steps to address this non-problem at the cost of our society until we know *for sure* that there is very good reason to do so based on sound sceince – and the real science as oppsoed tothe CRU “tricked” science says that the AGW is demonstrably false baloney & we do NOT need to take any measures at all – *especially* not any that cause us economic and political harm.

Finally, if I’m wrong then I’d rather trust our technology and capitalist enterprise and ingenuity to solve (or at least adapt to) the problem through technological intelligent means rather than resort to going back to the caves & the miserable failure that is socialism as the green lobby prefers.

—————————————————————–

* Regional climate is another matter but even there it takes an awful lot to make any major change – we can add urban heat islands, create new artifical lakes with dams or divert rivers which alter local climates and so forth but that’s another topic entirely & not relevant here.

Its like going to a beach and seeing a highwater mark of wet sand and seaweed. That marks the furthest point of the tide when it was at its highest point and it is very much analogous here in that 1998 was when the Late 20th Century Warming peaked and has since begun to recede. We had a warm spell around the 1930’s, it cooled for a few decades to the 1970’s, its warmed to the 1990’s and temperatures are heading down again – that is climate fact and whether you can weather the fact it ain’t weather or not, it remains the stark reality contradicting any Alarmist spin.

was NOT meant to be in italics & is my comment & not TL,OM’s.

@Spectroscope ww . realclimate. org … ‘nough said!

RealClimate is a propaganda lobby site run by Mike Mann, the Alarmist “scientist” notorious for faking the “hockey stick” graph infamously used by Al Gore’s flawed well-known ‘Inconvenient Truth’ movie. (The truth is indeed inconvenient for the AGW Alarmists making that title unintentionally comical! )

The RealClimate propaganda site was among the organisations discredited by the Climategate scandal with leaked emails revealing they actively censor dissenting viewpoints and do NOT provide the facts or allow the facts to be provided by Climate change skeptics. It is a site with absolutely zero balance and zero credibility and anybody relying on it for information is badly misinformed.

*Now* enough has been said on that!

@ 23. Torbjörn Larsson, OM Says:

@ Spectroscopy: Oh, you were serious?!

Its *Spectroscope* actually not “spectroscopy” so you are already getting things wrong there TL,OM & yes, I’m very serious.

-A theory (or an observation) is commonly taken to be settled beyond reasonable doubt if it passes tests to a practical precision. There is no ‘provisional’ in science theories and facts. That is the falsified theory of inductionists, known to be wrong since 18th century or so. Falsification on the other hand passes tests, so is consistently a correct theory. There _is_ quantifiable uncertainty (used in tests), mistakes (bad tests) and so on, but under _no_ circumstances ‘provisional’ facts and theories. Inductionism is popular among fundamentalists, whether creationists or anti-scientists as climate science deniers or anti-vaxxers. Precisely because it obscures the meaning of facts and theories.

Que? I don’t follow you there. Also note that I did say insults such as “denier” are invalid and prove only that you are being rude as well as lacking in the ability to argue logically & fairly.

The correct term for someone who disagrees with the politico-religious AGW orthodoxy is “skeptic”.

One of the good things about science is that it is never settled – there are NO proven theories and even things like gravity and Einsteinan physics are open to reveiw and replacement by better ideas just as Einstein’s theory replaced Newtons. You can never say *any* theory is settled or proven & this applies triply or more so to the nonsense which is the AGW conjecture for reasons I have already explained.

For observations, especially unsupported by theory, practical (im)precision can amount to many sigma (5-9 are usually seen). As for theory, it depends on subject. In physics, I would say that 3 sigma is usually taken, at least if there are several other tests passed to similar (un)certainty. …

I have no idea what are you talking about here! What do you mean by sigma? Error bars? Uncertainty? Those are things that the AGW lobby tends to ignore & which contradict the supposed “certainty” of Gore’s AGW mob.

Observing phenomena that involves a lot of contingency, like our only universe, Earth or populations in medicine, can at times demand lower standards. For example, the difference between a healthy eye and a glaucoma eye is lower than 2 sigma in humans, with a great deal of overlap between distributions. The same goes for climate research, where “normal forced” and “anthropic forced” climates overlap for low forcing.

Again, I don’t get what point it is you are trying to make here, TL,OM.

Are you trying to point out the overlap between natural climate variation & the supposed human influence on our climate? And how that makes it difficult perhaps even impossible to tell thedifference between what’s “natural” and what’s “artificial” when it comes to our ever-changing climate?

That’s how it seems to be reading but it runs completely against the AGW Alarmists & supports what I’m saying which is the AGW idea is bunk. So … thankyou for helping prove my case I guess!

Nevertheless one _can_ observe the difference in model populations, i.e. running the models enough times to wash out individual contingency. – GIGO modeling isn’t used in science, as peer review uncovers such problems.

Well it may – *if* its allowed to but, as Climategate has revealed, the peer review process has been corrupted by the Warmer Alarmists who have resorted in their own words to distorting and changing the meaning of peer review.

If ‘peer review’ meant skeptics as well as believers asessing the climate computer models you may have a point but a mutual onanism circle of Alarmists each congratulating each other on how alarmingly scary their GIGO models are & trying to think of ever more far-fetched reasons to fear the sky falling in has zero credibility.

Computer modelling can be useful but it can also be little more than science fictional imagings & esp. when something as complex as chaotic as porrly understood and hard to predict as climate is involved. I do indeed think we don’t know enough about the myriad of factors both known and yet to be discovered to make the simplistic and already proven invalid models even vaguely approximate reality.

(Remember none of the Warmer Alarmists predicted temperatures to stabilise and cool post-1998 & Trenberth confessed to colleagues it was a “travesty” that they couldn’t find the predicted warming.)

Confusing weather (one year of noisy data) with climate (usually observed over 30 years, I believe – or at least, speaking of sun spots, over a solar cycle average).

Its like going to a beach and seeing a highwater mark of wet sand and seaweed. That marks the furthest point of the tide when it was at its highest point and it is very much analogous here in that 1998 was when the Late 20th Century Warming peaked and has since begun to recede. We had a warm spell around the 1930′s it cooled for a few decades to the 1970′s, its warmed to the 1990′s and temperatures are heading down agin – that is climate fact and whether you can weather the fact it ain’t weather or not, it remains the stark reality contradicting any Alarmist spin.

Cherry picking. Confusing established climate science with social debate.

Examples please? Where exactly, inyour opinion have I done this & please explain why you think so?

And on and on.

Or in other words you cannot find any actual flaws in my logic and are just trying to falsely imply that you can.

Specifics please if you can see any faults in my argument there why not say so specifically & in detail rather than using such vague and uninformative bits of rhetoric.

If you have any climate predictions from an alternative model that can compete with what climate scientists accept, you are welcome to publish your data.

Its already been published by other AGW skeptics – please read Ian Plimer’s comprehensive book or read the many other skeptical books that have been published such as Red Hot Lies: How Global Warming Alarmists use Threats, Frauds & Deception to Keep You Misinformed’ by Christopher C. Horner & ‘The Real Global Warming Disaster -Is the Obsession with Climate Change Turning Out to be the Most Costly Scientific Blunder inHistory’ by Christopher Booker. Or visit a huige number of skeptical websites such as Andrew Bolt’s or Anthony Watt’s & so on.

Absent that, you are just covering your eyes from established facts.

Sorry TL,OM, but the one hiding from established facts here is you & the other AGW believers & as you can see the facts are far from “established” and the contradictory reality is represented by a number of reliable sources and publications.

Re: sunspots question. We are now in Cycle 24 (Or at least the 24th cycle of sunspot increase since people started tracking these things.) Started late and there are still very few spots on the sun at present- sometimes days with none. It’s supposed to peak around 2012, with predictions of a lower peak than in past cycles. Stay tuned as they say. (Tons of absolute B.S. on sunspots if you do a web search. Maybe Phil can do a bit on the truth about sunspots sometime before 2012.)

Thanks for that reply – to my question there – too.

Because if the AGW skeptics are wrong & the extreme scenarios of the Warmers are right then we are stuffed.

10. Messier Tidy Upper Says:

Kepler observed that orbiting bodies sweep out equal areas in equal times, equivalent to the statement that a body’s orbital angular momentum is constant. To first order, the perihelion/aphelion difference is about 3% in distance (5 million km/150 million km or 1 part in 30), so we must move roughly 3% slower near aphelion, such that the product of orbital distance and orbital angular velocity remains unchanged.

Thanks for that.

What’s that extra time in terms of months / days / hours /seconds though is what I was asking. Afraid my maths isn’t really good enough to work that out.

Interesting fact noted there – back in 1951 the American Meteorological Society rejected the idea that CO2 could alter our climate. In the best skeptical tradition, however, they were willing to learn – and changed their minds.

Figuring out how much absorption takes place in the Earth’s atmosphere also requires handling absorption by all of the other species as well; methane is a more potent greenhouse gas than CO2, in fact. In the end, however, the people who model this kind of stuff do so in “Gorey” detail (pun intended), and all of the effects produced by this “radiative transfer” process are dealt with in their models. This is generally not done directly, as it is computationally expensive. Instead a detailed model that handles radiative transfer is run for varying amounts of the absorbing species and the results are then tabulated or “parameterized” for inclusion in a general global climate model. This same parameterization process takes place for most of the other physics in such models, e.g, for aerosols, soot and particulates, ocean/atmosphere CO2 exchange, CO2 uptake by plants, and so on, ad infinitum (or so it must seem to the poor modelers).

Details aside, the final point to make is that we now CAN model the way these complicated, inter-dependent and non-linear processes operate with some degree of confidence. It is not “useless” to try and determine an answer, any more than it is useless to try and calculate the trajectory of a space probe looping about Saturn. Sure, we can’t write out an exact analytic solution for the N-body orbit problem, but we can approximate the hell out of it, and we have the results to prove it. Check out the course correction logs for the Cassini mission if you don’t believe this. We don’t yet have that level of accuracy in our climate models, but they are getting there. To say that the results have no validity and should thus be ignored is a very ostrich-like behavior. And when was the last time you saw an ostrich flying a spacecraft or even listening to their iPod? Science works, mmm, yeah. What he said. -> http://xkcd.com/54/

Point is that living beings can not live without HO2, CO2 and even CO, the amounts of CO2 needed to pose a direct threath to ones live is so high that it is impossible to occur naturally unless you find your self in special circumstances like for example a volcanic eruption, in wich case you have more direct concerns that need attention before you would suffer the effects of a prolonged exposure to high levels of CO2.

Co2 in our atmosphere is not acting as a poison, the CO2 in your Coca Cola is not a posion, Co2 is only a posion in high levels for a prolonged time, a situation wich will in nature only occur under very special localised circumstances and not in every day live.