global warming: salvaging fact from heaps of BS

[SkepticLance]

To Mr Skeptic

Good point. I guess today's reality is mainly lack of precision. There have been times in the past when they have also been inaccurate, in that (eg Antarctica) they modelled warming when the reality was cooling.

 

At this point, I cannot be sure enough of either to trust in the predictions (whether conditional or not) of global climate models.

[iNow]

I don't have to be able to tell you where every single raindrop is going to fall in order to accurately tell you that my entire driveway is going to get wet during the next storm.

 

You've proven that you're not even willing to look at the data and reconsider your position, as your mind is already made up and you've been digging your heels in. That's unfortunate, but is your perogative.

[Mr Skeptic]

To Mr Skeptic

Good point. I guess today's reality is mainly lack of precision. There have been times in the past when they have also been inaccurate, in that (eg Antarctica) they modelled warming when the reality was cooling.

 

But that says nothing about the model's accuracy nor precision! For example, if a model predicts an increase in temperature of .5 degrees plus or minus 1 degree, and a cooling of .5 degrees is observed, then the model was, in fact accurate. However, its precision was rather low. If the model predicted an increase of .50000 degrees plus or minus 0.00001 degrees, but a cooling of .5 degrees is observed, then the model was very precise, but not very accurate. If the temperature increased by .50000 degrees, then the model was both accurate and precise. Again, if the model was given a weak oceanic current, when the current was in fact strong, then the model may or may not have been correct, regardless of what it predicted and what actually happened. However, if the correct inputs are given, then you can compare the outcome and the corrected prediction to tell whether or not the model was accurate.

 

What you seem to want is a model that is accurate, precise, and has been given correct inputs.

[npts2020]

I am not sure if this is really adding to resolution but a couple of things really bother me about the debate on this thread. Firstly, is the idea that any significant number of climatologists are somehow profiting from their studies other than "making a paycheck" when most would stand to make far more if their research came to the opposite conclusion. The few people I have had a chance to talk with that make that "paycheck" have all told me they would like for their study to contradict scientific convention on global warming but that the effects were generally worse than predicted and none were better. (How much money would big corporations give to somebody who could actually disprove the science behind global warming rather than raise doubts with gobbledygook?) The second thing is that people have spent a lot of effort arguing about computer modeling. Computer models (climate change ones anyway) are predictions of outcomes using many complex variables and can be tweaked to get almost any result. Having said that, the valid variables all fall within relatively narrow ranges, making nearly all of the models conclude that humans are causing climate change (using the same logic of being at a craps table and rolling snake-eyes (2) 98 out of 100 times and concluding the dice are loaded). Before there was even a computer model, former presidential candidate Barry Commoner wrote several books mostly about energy use and climate change, imh non-scientist opinion "The Closing Circle" and "The Poverty of Power" are the best and describe dead-on what is going on climatewise some 30 years later. BTW Mr. Commoner does propose solutions as do many who are strong believers in the sciece behind climate change, its just that many skeptics dont like them. Just my two cents.

[scalbers]

To Mr Skeptic

Good point. I guess today's reality is mainly lack of precision. There have been times in the past when they have also been inaccurate, in that (eg Antarctica) they modelled warming when the reality was cooling.

 

At this point, I cannot be sure enough of either to trust in the predictions (whether conditional or not) of global climate models.

 

Actually one doesn't really need to have a super accurate climate model to understand the basic physical processes going on, and that we are on a course of action that is too slow to adequately deal with the global warming issue. There is basic physics of CO2 radiation transfer, amplification of the greenhouse warming by water vapor, and the time it takes for CO2 to be removed for the atmosphere & oceans as well as the time it takes society to change. It is pretty clear to me that these factors all add up to the notion that we should accelerate our actions. These concepts should be fairly straightforward to grasp as I have mentioned them in different forms several times in this thread.

[swansont]

I really do not care whether you believe that climate models are inaccurate because of poor computer resolution as iNow said, or because of unknown factors as I have been saying. The point is that climate models are not accurate. If you agree with that point, I am happy.

 

I am off to Australia tomorrow for a week, so won't be able to continue your debate for that period.

Cheers.

 

And we're back to "All models are wrong. Some are useful." Saying that models aren't accurate is true; infinite accuracy and precision will never be achieved, but then, that's true of any scientific model, and some of them are certainly useful. You have to quantify what accuracy/precision/resolution is required of the model. Otherwise the objection is so open-ended as to be useless.

[xnebulalordx676]

I don't buy into this warmer temperature of the planet earth has been created by humans and their carbon footprint. Carbon is not all powerful and neither are humans. I don't think those two forces combined have such power to knock the planet apart.

I trust Al Gore be some sort of pawn to get everyone to spend more on green devices for large corporations that are now trying to break into the hippie market.

 

Allow me to explain the problem I have with all of this: Ages ago the "green movements" did not even know about carbon footprints or have activities based on this theory. There was no such talk as they went about the simple businesses of picking garbage out of streams etc. since this was a noticeable improvement or the right thing to do.

 

Then everything became based on carbon discussions and "green movements" were coerced to add this debate as a extra without long papers of scientific proof. The only long papers that exist on this subject seem to emanate from Al Gore and his government approved science wave riders for the future of multinational corporation profit enthusiasts. There's not yet enough definition to blame man yet in my book.

 

But wait there's more. I also think another ice age will strike before the earth overheats but I won't get into that right now.

[iNow]

Mass extinction event, here we come. It really is too bad that the stupid seem to outbreed the educated.

[swansont]

Mass extinction event, here we come. It really is too bad that the stupid seem to outbreed the educated.

 

They're breedin' while we're readin'

[SkepticLance]

It would appear that nebulalord has not read all the objectively and empirically obtained data on current warming, and has been influenced into some erroneous conclusions. This does not mean he is stupid - just misled.

 

The extinction event is currently under way. Sadly, it does not affect certain humans who really need their genes weeded from the population. Instead, they go on to become politicians.

[iNow]

Misled by stupid people then. Whatever.

[xnebulalordx676]

The sad thing being that most of this thread allow this themselves to be swayed by an unproven theorem about how carbon from humans must have some footprint thats warms this huge earth that they don't even fill up half of. Get real!

 

I had no idea I was surrounded by such insolence. I shall persevere and cope somehow.

[Edtharan]

I don't buy into this warmer temperature of the planet earth has been created by humans and their carbon footprint. Carbon is not all powerful and neither are humans. I don't think those two forces combined have such power to knock the planet apart.

First of all, you don't have to be "all powerful" to cause global warming. You just need to be powerful enough.

 

Now the physics of carbon dioxide (and certain other gasses like Methane and water vapour) are well known. We know that they scatter infra-red radiation.

 

We also know that sunlight warms the ground and the oceans and that they re-emit that light as infra-red.

 

Without the CO2 (and other greenhouse gasses), this infra-red radiation would radiate straight out into space. However, if you scatter it, then some will scatter back down onto Earth, where it will heat the ground and the oceans.

 

This is basic physics, and there are no scientists that would actually dispute this (and it can easily be seen in a lab). Other gasses will scatter other frequencies of light, it is why the sky is blue in the day time. There are gasses that scatter blue light. So we know that this does occur.

 

The Earth has some natural greenhouse gasses and if it didn't Earth would be an ice ball (the temperature would be less than 0 degrees C. About -20 C IIRC).

 

So we know that there are gasses that trap heat (energy) in the Earth's atmosphere and oceans.

 

But what happens if we were to increase the concentrations of those gasses?

 

Well the Earth, before we made changes to the greenhouse gasses, would have reached an equilibrium (it would change over time, but the equilibrium would be reached faster than it would change). The amount of energy coming in would have been matched by the amount leaving.

 

This is because the amount of energy falling onto the Earth is constant (or close enough to), but the amount radiated out is dependent on the amount of energy contained on the Earth. So the hotter the Earth, the more is actually emitted from the Earth.

 

But, if the amount of greenhouse gasses are increased (or decreased) then the level of Equilibrium changes. This means that if you increase CO2 (and other greenhouse gasses), then you will get warming.

 

Looking at ice core samples, we know that CO2 has increased from around 270 parts per million (pre-industrial) to around 385 parts per million (yes that is around 140% of its pre-industrial levels).

 

That is a significant increase.

[swansont]

The sad thing being that most of this thread allow this themselves to be swayed by an unproven theorem about how carbon from humans must have some footprint thats warms this huge earth that they don't even fill up half of. Get real!

 

You do understand that "footprint" is a metaphor, right?

 

And that a theory is not the same as a theorem?

 

And that theories are not proven in the same sense that theorems are?

[scalbers]

Another anecdote about CO2 driving global warming is very warm conditions at the time of the dinosaurs (e.g. greenery in Antarctica) when CO2 values were roughly 2000ppm. So carbon can be pretty powerful. Clearly it is we humans that are causing the present increase in carbon as well. So both carbon and humans are powerful enough.

Edited October 4, 2008 by scalbers

[JohnB]

On a side note. Co2 blocks the IR in certain wavelengths, this we know.

 

However it is not a one way thing. Logic tells me that increased CO2 must also block some of the suns IR from reaching earth, giving a negative forcing.

 

This is not something that is mentioned much, if at all. Does anybody have any information on this?

[swansont]

On a side note. Co2 blocks the IR in certain wavelengths, this we know.

 

However it is not a one way thing. Logic tells me that increased CO2 must also block some of the suns IR from reaching earth, giving a negative forcing.

 

This is not something that is mentioned much, if at all. Does anybody have any information on this?

 

Yes, that certainly happens. But the blackbody curve at ~5800 K is mainly in the visible part of the spectrum, while the blackbody curve at ~300 K is peaked at around 10 microns, meaning a much smaller fraction of the incoming radiation is blocked. This is the basis of the greenhouse effect.

[insane_alien]

in laymans terms, most of the light from the sun is not absorbed while most of the IR emitted from earth IS absorbed.

[JohnB]

That's what I thought.

 

It just doesn't seem to get into the calculations anywhere. It's like water vapour.

It must block IR in both directions. Because we are dealing with extremely low changes in RF, under 0.7%, I doubt any factor can be ignored.

 

From the graph above, it's obvious that no matter the increase in water vapour, there will be no change at some wavelengths as the WV is already blocking the IR. However, an increase would progressively block the circa 900 and 1150 bands.

 

Note that this blocking is happening at the top (sort of) the atmosphere where it will be radiated out into space. It strikes me that it should be factored in, but it doesn't seem to get a mention. It just seems odd.

[scalbers]

I think the absorption of solar IR would be a slight factor, though much of it would continue to be reradiated downward to the surface as IR.

 

The main point remains that there would be more increased IR radiating down from the CO2 (both day and night) compared with the solar IR being blocked (only during the day). Note the back radiation (and atmospheric absorption) arrow in this diagram - http://www.euronet.nl/users/e_wesker/gh.gif

 

I actually loosely think of a second argument about what greenhouse gases can do. If hypothetically all wavelengths were blocked by CO2 in the upper atmosphere, then there may be a net warming at the ground. This would be due to the adiabatic temperature changes between the level where radiation is absorbed/emitted (up in the atmosphere) and the ground, where the pressure is higher.

 

It's also true that water vapor is often omitted in the discussion and how it has an important amplifying effect on global warming.

Edited October 5, 2008 by scalbers

[insane_alien]

John, it isn't factored in when people do basic 'back of the envelope' calculations. but if you were to look at the global models used to predict what will happen in the future then you will see it factored in.

[xnebulalordx676]

I know about the metaphor.

And You are trying to get all serious about terminology with those two terms that are not all that separate with me on thread labeled... "BS"? Please quit trying to appear so fancy. ty.

You do understand that "footprint" is a metaphor, right?

 

And that a theory is not the same as a theorem?

 

And that theories are not proven in the same sense that theorems are?

[JohnB]

I_A. I don't doubt that it is factored in in the GCMs, it's just it isn't mentioned in the literature. I find that odd.

I think the absorption of solar IR would be a slight factor, though much of it would continue to be reradiated downward to the surface as IR.

You mean the heat would flow from the cold upper atmosphere to the warm surface? This concept does not sit easily with me for some reason.

 

We do need to consider slight factors. Since we are talking about a change of circa 2 W/M-1 out of the 324 reaching the surface and given that the 324 is barely a quarter of the 1300 odd that hits the TOA, I would suggest that "slight factors" are exactly what we are dealing with.

[DrP]

You are trying to get all serious about terminology with those two terms that are not all that separate with me on thread labeled... "BS"?

 

I'm not getting drawn into any of these conversations - I have just been following this thread for sometime now and I'm enjoying the discussion taking place. FYI, xnebblah..67whatever - the thread is not labled BS - it is labled SEPARATING/SALVAGING the BS from from FACT... so of course people are going to try and be precise with any terminology - how else can they seperate the BS from the Fact unless we are speaking the same language?

[npts2020]

JohnB: Heat does not flow from a "colder upper atmosphere to a warmer surface". As the upper atmosphere warms (but still colder than the surface) there is less difference in temperature between the two. The rate of heat transfer is related to the difference in temperature between source and sink (in this case surface and upper atmosphere). As you heat the sink (upper atmosphere) less heat is transferred away from the surface causing surface temperatures to rise till again reaching equilibrium at some higher temperature.