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Originally posted by Sarah77:
Is there a well rounded paper which comes to any conclusion or did the subject become marred in politics and big business wrangling before this was possible.
As I beleive has already been mentioned publictations such as Nature magazine will contain 'rounded' articles. This particular publication however deals with a lot of 'raw' science, direct from the researchers published papers. This means that in many cases there is a lot of technical information which is difficult for the 'lay' reader to interpret.
Also the papers publised will often only deal with an aspect of this particular issue. One article for instance may only deal with measurements made of the proportion of particular isptopes of oxygen in atmospheric CO2 samples, and related this to the proprtion of CO2 from geological sources. It is also common for an article to refer to other published material as a source for certain information, or to back-up any assumptions made.
So finding a single accessible article in such a publication is not easy.
Publications such as Science magazine and New Scientist are more accessible, but they tend to be more in the business of reporting about scienctific issues than a rigorous discussion of the actual science itself. Both of these magazines do contain items which explain the science, which they do very well, but as their expected readership is people interested in science as opposed to scientists proper, you wouldn't find anything definitive there.
Unfortunately, the subjuct of climatology is quite a complex one, and draws on a number of different traditional 'hard' sciences in an attempt to describe what actually goes on in the atmosphere of a given planet. The problem here is that a planets atmosphere is a very complex system with lots of different things affecting each other. That means that you can't write a single equation which can be aplied to the whole thing.
Much of the argument centers around how accurate the various computer models are, and whether the models include enough of the factors which might have an effect on the way the model behaves.
Unfortunately one of the problems is that we don't really know which factors are important until they are included in the comouter model, but we can't yet include every possible factor.
What has to be done instead is to look at how reasonable it is to assume that something has a significant effect and leave out stuff which we believe will have no effect or such a small effect that it can be reasonable ignored. This is why things that some people think are important like cosmic rays are left out. There simply does not appear to be no connection between how many cosmic rays reach the earth and the weather.
Another problem is because of the 'positive feedbacks' which occurr. That is just a way of saying that when something increases, (or decreases) it has an effect which tends to increase (or decrease) it further. This amplifies the changes in these quantities.
The amount of CO2 in the atmosphere along with a number of other gases is one such factor subject to positive feedback. If there is a temperature rise the amount of CO2 in th eatmosphre increases due to the fact that the oceans can't dissolve as much of it anymore, so a greater proportion stays in the air. Water vapour (as a gas not clouds) work in much the same way, and the two actually reinforce each other.
According to the models increasing something like the CO2 concentration even by a modest amount can have a much bigger effect than would be expected were it not for these positive feedbacks, so much so that human CO2 is likely to have an unexpectedly large effect.
The surprising thing is that CO2 is actually quite a rare gas in the atmosphere. We don't actually breathe out a huge amount with every breath, and as it's rather soluble, lots gets washed out by rain.
Many of those who say that CO2 is not very important argue that becuse the models don't include everything, the models could be wrong, or simply not accurate enough. They argue that such small temperature changes that the models predict could easily arise out of small innacuracies, and that these inaccuracies can be amplified by the very positive feedbacks that are built into the models themselves.
Another argument is that the models are just plain wrong. That these amplifying mechanisms just plain don't exist, and that climate change is caused by something other than what is in the air.
There is an obvious difficulty in testing these models, and that is we have only one planet handily close to test the models against. What we have to do is look at historical temperature data and finf out what we can about the content of the atmosphere, volcanic activity, what the Sun was doing etc, and see if the model gives the right results.
We have a bit of a problem here as accurate scienific instruments have only been aroung for one or two hundred years, and the means of accurately measuring gases in small concentrations is also quite a recent development. So to find out what the weather was like we need to look at archeological data etc, which is agrguably open to some interpretetion.
This is another angle used to attack current theory. If the historical data cannot be relied upon, how can we know that the models are correct?
It is also not helped by arguments which are designed to appeal to 'common sense', such as the 'CO2 lags temperature' argument which is used to convince us that CO2 is not the cause. But as I have already pointed out, it is no surprise that CO2 'lags' temperature, in the historical record for reasons already explained. It has to be pointed out that 'common-sense' is no guide when it comes to science, it doesn't even work well in our oeveryday lives, especially when compared to carefully thinking things through!
(The initial cause of the temperature rise could be one of a number of other mechanisms, such as the fact that the Earths angle of tilt is continually changing, but once the temperature rise has started CO2 is one of the gases which keeps the rise going until it tops-out at a new high. This 'lag' phonomenon is commonly observed in engineering, and are characteristic 'self-stoking' feedback systems.)
The question is, who do we believe?
Possibly it might help you to note that most of those who are against the current theory actually don't often agree among themselves as to what the cause of global heating is. (That is among those who agree insofar as global warming is occurring at all!) It is also worth pointing out that many of those who oppose the theory do not actually work in the area of climate research, and much their 'work' has not been peer-reviewed before publishing it. (Which is the scientific equivalent of marking their work. It's how science is done, few real scientists would publish a paper without having their work checked for possible mistakes. It may not be fun having your mistakes pointed out by other scientists, but that's a whole lot better than publishing tripe!)
Compare that with the general agreement among professional climatologists who not only agree that it is occurring but agree that CO2 is significant. Futheremore they are quite happy to let other scientists go over their work and point out any possible weaknesses.
As to your question about why is it we are singling out poor old carbon. The answer is two-fold. First, when you add the amount of CO2 that we estimate we hae added to the air to the computer models, (and any other stuff we might have added as well!) we get temperature rises which are about the same as the ones we can actuall measure today. And secondly is simply that it's the only factor that we have any major influence on!
It is of course possible that it's all just hokum, but it is carefully studied hokum, and you would have to beleive that the large number of honest researchers have agreed amongst themselves to promote hokum. So at least it's honest hokum.
In fact the only critic of the reliability of the comoputer models that personally I can afford credibilty is Freeman Dyson, who is arguably one of the best thinkers of the 20th century, and a highly respected physicist and mathemetician. He points to 'fudge factors' in the models which have been put in to aproximate some of the physics apparently too hard to model accurately. Even he does not go so far as to say the whole thing is 'hokum' but he does say that while such fudging exists the models should be regarded as suspect, and may not be terribly reliable. That's just good science.
So I suppose for me it boils down to whether or not the fudges have been replaced. I don't recall any references to Dyson in the program, and his view on the subject would certainly carry a lot of weight in support of the programs basic theme, (And he's not a person who is shy of speaking his own mind!) so maybe he's changed his view on that. (He's easy enough to contact, so maybe I'll ask him.)
Or maybe I wasn't listening.
