Climate change

[Sibling Zono (anon1mat0)]

Regarding odds, I never win when the odds are 1 in 5 why would I win with 1 in 10k? 
--
Thanks to a related thread in omnia I did a bit of research on the subject, and while I lean on the anthopogenic wagon, there are certain arguments that merit review. On the same token I agree with Bluenose in that we have to be as honest as possible regarding the unknowns.

To name one argument, one skeptic mentioned that the ability of CO2 as a greenhouse gas has a ceiling and he sugested that such ceiling had been reached already. The consequence of that argument is that adding more CO2 wouldn't change climate any further (his example was that in a greenhouse after certain point it was pointless to have a thicker glass).

I never got to voice the thought that I got considering it:
If that is true then we are royally screwed; either our current abrupt warming is NOT anthropogenic and there absolutely nothing we can do to stop it, or, it is athropogenic but we already did the damage and there is little to none that we can do about it.

Perhaps one of our more chemically savy siblings [size=0]*cough*Swatopluk*cough*[/size] can shed some light on that one.

[Swatopluk]

Oh, that would require a whole essay, overflowing with equations etc.

Let's try to make it short, risking abit of oversimplification.

Effect 1
Any linear filter (i.e. most substances not specially engineered to act otherwise) absorb a certain percentage of radiation per length. This depends on the wavelength and the stuff involved and its concentration.
e.g. substance A absorbs 40% in the first centimetre. In the second centimetre it absorbs 40% of what is left and so forth. It will not absorb everything in the first 2.5 centimetres.
The transmission is inversely proportional to the concentration, i.e. double the conc. and the transmission will half.
This is called the Lambert-Beer law.

Effect 2
The above quoted linear law is not valid above a certain limit, then it becomes non-linear. That means the "law of diminishing returns" begins to affect the effect.

The argument quoted in the post above could (ab)use both those effects depending on the claim about the greenhouse gas distribution in the atmosphere. If we would assume the gases to form a layer proportional in thickness to the total amount then one could argue that the logaritmic relationship will make any added gas less effective than the same amount added before. If we would assume a homogeneous distribution than the argument would run that the concentration has alredy reached the less than linear increase region thereby having the same "diminished returns".
I think that both assumptions (layer model, non-linear region) are bogus and even if they were valid they ignore that the effect would only be diminished in its increase, not its total.
Like Bush's claim that the US in on the right course because the increase rate of new debts is shrinking (this year only 8 gazillions compared to last year's 10 more debts added).

One thing not discussed above is the pressure valve effect. The greenhouse gases (esp. water vapour) are mainly critical because the close a gap in the absorption spectrum thereby acting like a control valve. If it is too far open, the engine is not working (=> ice age), if it is too tight the boiler will explode (=>it will get too hot down here for our way of life).

Unfortunately this is not discussed enough in public.

I admit, I extremly oversimplified the matter and a physics teacher would rip me to shreds if I talked that way in an exam.

The "hurricanes are proof for global warming" meme is already used as a straw man by both sides of the discussion.
The lack of a Katrina this year is used to discredit gw as a whole ("if there was gw we would have 2 Katrinas this year and 3 next year")
on the other hands false predictions were made that the "1 yesteryear, 2 today, 3 to-morrow" would prove gw. Both views are of course against the scientific consent that climate change effects are visible only over a prolonged time period and mainly in statistic probabilities and long term averages. But try to explain that to the editors of a daily newspaper that want a "Katrina ate my dog's homework" headline not a "your probability to suffer from trimethyamineuria is increased from 1:12345.67 to 1:122345.67 in the next decade"

[goat starer]

a good article from the BBC on the overuse of catastrophic language in relation to climate (in the wake of yesterdays Climate 'Chaos' demo in London) and the worry that this could devalue the argument appeared today...

http://news.bbc.co.uk/1/hi/sci/tech/6115644.stm

an older one linked below on the media...

http://news.bbc.co.uk/1/hi/sci/tech/5236482.stm

It should be noted hovever that that scintists are firm in the opinion that climate change is happening and will be serious but that the use of language is irresponsible in terms of reflecting the issue and maintaning public trust!

[Sibling Zono (anon1mat0)]

Oh, that would require a whole essay, overflowing with equations etc.
[snip]
I admit, I extremly oversimplified the matter and a physics teacher would rip me to shreds if I talked that way in an exam.

Your explanation is perfect for the layman among us. Thanks.

I knew it was a good idea to call you to this thread.

[Bluenose]

Picking up on where I left off before I went away.

First, thank you Swato for you simple explanation of the importance of CO₂ in the greenhouse effect, plus the points you and Goat Starer made about overstating the effects of global warming.  This latter is a point I have made here and elsewhere, but alas, what
passes for public debate generally misses the point.

I would like to discuss my thoughts about global warming here by referring to what is usually known as chaos theory.  Unfortunately in the media this is usually "explained" by using the "butterfly effect" example in which a butterfly flapping its wings in Outer Mongolia "causes" a hurricane in the Gulf of Mexico or some such proposition.  The problem with this is that it does nothing to explain the important points about chaotic systems, that is non-linear systems, which includes a great many systems including classical ones like the orbits of the planets.

To explain my point, and at the risk of boring those who are already familiar with chaos theory, I would like to repeat a different example that illustrates what I am getting at.  Then i will bring it back to the climate and discuss the implications of that I am talking about for global warming.

Lets us conduct an experiment in which we know all the starting parameters and see how well we can predict its behaviour.

We start with two spherical fairly strong magnets mounted on non-magnetic stands above a flat surface marked out in a grid.  One magnet is painted blue and the other red.  Directly above the mid point between the magnets we suspend on a long string a steel ball bearing.  In our experiment we can conduct it in a vacuum, so wind resistance is not a factor and we can assume a perfect, frictionless string, since we can run the experiment in a computer if we want to.  The point is, we can describe all the forces in action and the positions of all components to within the boundaries of quantum uncertainty, and this experiment yields the same results.

To start we move the ball bearing to a point directly over the middle of one of the squares on the flat surface and let it go.  The ball bearing will describe a path around one or both of the magnets, perhaps a figure of eight course or whatever and when it comes to rest we paint the starting square with the colour of the magnet that the ball bearing comes to rest against.

Now what would you suppose would be the likelihood that if the first square ends up blue, that adjacent squares would also be blue?  Certainly you would think that there are likely to be more blue than red.  However, what actually happens is that there is no predictive power in what colour nearby squares may be for any square in question.  The pattern is completely random, and the kicker is, it is random at any scale!  We can go down right to the quantum level and still not achieve predictability.  Oh, we can predict with reasonable accuracy the first few movements of the ball bearing.  For example, if the previous one described a path around one magnet and then swung around the second and then back round the first and then orbited the second a few times before stopping next to it, a ball released from an adjacent position is likely to follow more or less the same path for the first movement or two, or even three, but then it is likely to depart from the previous course, and even if it ends up against the same magnet, it may well not follow the same course eventually to get there.

This is an important point about chaotic system, the lack of predictability beyond the immediate future.  The weather has now for some time been recognised as a non-linear (chaotic) system.  This is why weather predictions work OK for a few days, but once they get about a week out or so their accuracy is much less than perfect.  As we know more about the weather we will improve our ability to predict it by a small factor, but in the end there is a limit to just how far into the future predictions can be made with much more than random accuracy.

So considering the climate system, it seems to me that many of the people clamouring about climate change and the anthropogenic cause of it, seem to "forget" (if they know to start with) that making predictions about how a non-linear system will behave beyond the immediate future is an invalid exercise.  We don't even know all the factors involved sand as I have shown even if we did, our predictions are nothing more than wishful thinking if we expect reality to reflect those results.  The mathematical models that are all being used are similar to those that sometimes get used to predict the positions of the planets in the distant past or future.  Certainly the models yield results.  Its just that the real system is extremely unlikely to give the same results.

So what does this all mean for global warming?  Well IMO, we need to do a lot more basic science.  the more we know about how the system works, the better we can make predictions and the longer the predictive window will be.

We can use the limited predictive window as a guide to what we should do.  Certainly it seems likely that human induced increases in the level of CO₂ could be a factor.  It makes sense to look at ways of reducing that output.  Of, course, reducing carbon output will also have other beneficial effects such as reducing outputs of pollutants and so on, so it is a good idea anyway.

However, it is a big mistake to assume we have more than a very tenuous grasp on what is going on in the climate.  We should remember that the planet has been significantly glaciated over the last two or three million years and that glaciation over the long term seems related to continental drift.  When the continents are lumped together we have little glaciation, when they are spread apart as they are now the tendency is for glaciation.  We are currently in an interglacial period and based on the history of thelast few million nears we are nearing the end of it.  Just what effect our little input into the climate may have is not clear.  The common consensus is that we might trigger a "thermal runaway" and increased greenhouse effect as per all the doomsayers.  However, I urge caution, because we might have few years in the sun and then plunge into another ice age.

Finally, we do not even know for sure that the observed warming is in fact caused by humans.  Until we do better understand the climate we are being very brave, and perhaps a little arrogant, to claim it is all down to humans.  The system could be getting warm all on itsown and what we do make not the slightest jot of difference.  I say instead of getting all excited about hurricanes or hundred year droughts (or even thousand year droughts) we really should be doing as much as possible to understand just what is going on.  In the end, though, we would be wise to remember that even if we ever understand everything about the climate, we will still not be able to predict its behaviour in the long term.

Sibling Bluenose

[Swatopluk]

As long as it does not just serve as a "stay the course" excuse, I'd agree. I think we know at least that we potentially sit in a gunpowder magazine and that until we can be sure that we are wrong we should refrain from playing with matches too much.
That is, we should try to at least stop the increase of manmade CO₂ release and if possible reduce it to a sustainable level by investing in alternatives. Additionally, as some of my chem profs used to say: Oil and (to a degree) Coal are far to precious to just burn. Better use them differently first (making e.g. polymers) and burn those after use (provided we get rid of halogenated ones). That's both more efficient and more clean.

[Bob in a quantum-state-of-faith]

As long as it does not just serve as a "stay the course" excuse, I'd agree. I think we know at least that we potentially sit in a gunpowder magazine and that until we can be sure that we are wrong we should refrain from playing with matches too much.
That is, we should try to at least stop the increase of manmade CO₂ release and if possible reduce it to a sustainable level by investing in alternatives. Additionally, as some of my chem profs used to say: Oil and (to a degree) Coal are far to precious to just burn. Better use them differently first (making e.g. polymers) and burn those after use (provided we get rid of halogenated ones). That's both more efficient and more clean.

Why burn at all?    With proper procedures, all polymers are completely recyclable.  In that way, you'd have high-quality feedstocks for your polymer-manufacturing facilities.

At present, most plastics are stamped with the type [of plastic].  I've seen some discussion of micro-tags embedded into the plastic matrix.  It was originally developed for explosive tracing, but it could easily be used to identify the type and quality of the polymers, so that a machine could sort the different types for a very high-quality end-product.

It seems such a waste to simply burn it-- especially considering the vast quantity of PAPER (basically cellulose) waste we generate each year. Now THAT I can see as a simple heat-fuel. 

[Swatopluk]

At least according to one of my technical chemistry profs in most cases the recycling of plastic has a worse total energy balance than its use as "white coal". One problem is that there are still too many mixed polymers (i.e. those only consisting of C,H,O mixed with those also containing N,P,Cl etc.). Even the "pure" ones usually contain problematic additives. The first step should be towards "clean" distinctions and to the avoidance of plastics where not strictly necessary (a lot of wrapping for example could be done as well with other, renewable materials. Just compare the US with Europe in the production of "wrapping waste" (and Europe is far from perfect in that area).
At least until now polymer recycling is combined with a loss of quality, i.e. with each recycling the product range shrinks.
There is still a lot to do (and not enough done).

[Swatopluk]

"Condoms don't belong in schools and neither does Al Gore"
http://www.rightwingwatch.org/2007/01/condoms_dont_be.html

A school bans outright the showing of Al Gores "An Inconvenient Truth" because of creationist complains

[Sibling Zono (anon1mat0)]

There is a part of me that believes that the people with such beliefs should gather together and make a region/zone of their own. The amish are a good example, and they don't interfere with everybody else.

If they just could be a little *selfish* and leave *salvation* just for themselves... 

[Sibling Chatty]

Move 'em all to Idaho. They've got a good representation there already.

[Swatopluk]

Do we need a second Utah ?

[Sibling Chatty]

Utah's getting crowded, and the non-Mormons are getting numerous.

I'm not sure there's much to miss in Idaho, and it'll be a shorter move for some of the nutcases in the northwest quadrant of the country, which seems to be overaking the South as nutcase territory.

As long as we can have potatoes at a reasonable price...who is gonna miss Idaho?

[ivor]

The Princess of Darkness says you can get good potatoes from Maine so we don't really need Idaho.

[Scriblerus the Philosophe]

Lol.
I hear Idaho is beautiful, so why don't persuade them to go live somehwere sterile enough to be ugly and/or useless. South Dakota or something. More then enough grass elsewhere on the plains to let them have that and leave the rest of us in peace.

As the spawn of two generations of geologists, I was always told that a lot of what's happening is a result of post-ice age warming. The rest is us, of course, but that that ice was recent enough for the planet to still be warming up.