Australian Politics Forum - Arctic Ice continues to shrink

namnugenot

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Re: Arctic Ice continues to shrink
Reply #585 - Aug 12^th, 2012 at 12:07pm

muso wrote on Aug 11^th, 2012 at 6:31pm:

namnugenot wrote on Aug 11^th, 2012 at 3:45pm:

[quote author=455D5B47280 link=1316224167/580#580 date=1344657832]
I reject your assumption I do not accept basic atmospheric science. What I reject is that AGW, as it put into practice, is actual science.

So explain your understanding of how carbon dioxide acts as a greenhouse gas. That's starting with basic atmospheric physics. I want to find out exactly where (and why) you depart from the science that is taught in every physics department in the world.

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You see the beauty of AGW as a subject is that it is such a movable feast. It is an evolution of hypothesis and a selective and interpretive application of data to suit the observation that the earth is in a warming trend.

Not really. The observations are just confirmation of the consequences of the physical science. Don't get me wrong. The observations are certainly useful confirmations but they confirm the initial hypothesis which comes from the physical properties of the Carbon dioxide molecule, as well as the water molecule, methane, ozone, nitrous oxide etc..

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It has been doing so for about the last 18k years and is not controversial or disputed by myself.

Incorrect. It was actually a cooling trend prior to industrialisation, but that's probably irrelevent anyway given that there is a physical basis to the science.

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I also reject your view that the paleoclimate has nothing to offer science in illuminating the role of CO2.{/quote]
I didn't actually say that if you read my post. We can actually learn quite a bit from the paleoclimate without going back 150 million years plus in geological time, which is where the elevated levels of CO2 that you mention come in to play.

[quote]
I will however be on fairly solid ground in saying ancient CO2 obeyed the same physical laws as modern CO2. There is also I think general scientific agreement that CO2 was much higher, although as with all proxies this is far from exact, over most of the course of time that life has been reasonably widespread over the planet.

Of course it did, but there are many other factors apart from CO2. MOTR touched on the distribution of continents and the effects of ocean currents. I brought up the subject of solar output. There are many other factors that come into play, including the fact that there is less vegetation and less carbon sink, and the fact that we don't quite understand the orbital characteristics of the Earth say 150 million years ago and that a lot of the finer detail is missing in the older paleoclimate data. Many more proxies are available for the Quaternary period, such as lacustrine varve deposits, isotope analysis of ocean sediments and less reliable proxies such as tree ring data for even more recent data.

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Even ice cores have been considered to have underestimated the amount of CO2 in the atmosphere by looking at other proxies.

You've jumped several hundred million years ahead when talking about ice cores. They are only good for the last million years or so.

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However there is no monopoly on truth here and in the long run it is irrelevant.

The conservation of energy is a good start to understanding the implications of increased atmospheric CO2.

So the sun was only 70% of it's luminosity during the Cambrian? I think your timeline of the sun is missing a zero the true date holding that output was at 70% was 4.5 billion years ago not a tenth of that. Interestingly this periond is associated with the faint sun paradox for which various explanations have been proposed including greenhouse but still nothing conclusive.

When I mentioned the ice core data I had jumped ahead and these are coextensive with other data for the period, I think the oldest of the ice cores are put at less than 800k.

Well you say it was cooling pre-industrial I say it was warming albeit not as quickly as part of the overall trend. Long term trends are not that easy to pick at the start when there is always movement back and forth.

Conservation of energy the theory ridiculed by leading physicists of the day when proposed by Julius Mayer and now held as self-evidently true. Just shows that you can be in the majority and still incorrect. What I was actually talking about at this point was something different in any case, but no matter.

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Upton Sinclair

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Re: Arctic Ice continues to shrink
Reply #586 - Aug 12^th, 2012 at 12:21pm

namnugenot wrote on Aug 11^th, 2012 at 12:17am:

But your mountain is still snow capped! [/QUOTE[

Great response. Really highlights the fact that you don't have anything even approaching an alternative hypothesis for these observed changes.

[quote]You still havn't come up with a temperature for 7000ppm and 2000ppm either grandpa.

You haven't come up with a credible source for your claims. Extraordinary claims require extraordinary evidence, mon ami

Plimer's stated value of 4000 ppmv or greater is taken from Robert Berner's GEOCARB, a well-known geochemical model of ancient CO2. As the Ordovician was so long ago, there are huge uncertainties for that time period (according to the model, CO2 was between an incredible 2400 and 9000 ppmv.) Crucially, GEOCARB has a 10 million year timestep, leading Berner to explicitly advise against using his model to estimate Late Ordovician CO2 levels due its inability to account for short-term CO2 fluctuations. He noted that "exact values of CO2... should not be taken literally."

http://www.skepticalscience.com/co2-higher-in-past.htm

You could do well to go and bone up on the logarithmic relationship between CO2 and warming too.

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namnugenot

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Re: Arctic Ice continues to shrink
Reply #587 - Aug 12^th, 2012 at 12:32pm

Upton Sinclair wrote on Aug 12^th, 2012 at 12:21pm:

namnugenot wrote on Aug 11^th, 2012 at 12:17am:

But your mountain is still snow capped! [/QUOTE[

Great response. Really highlights the fact that you don't have anything even approaching an alternative hypothesis for these observed changes.

[quote]You still havn't come up with a temperature for 7000ppm and 2000ppm either grandpa.

You haven't come up with a credible source for your claims. Extraordinary claims require extraordinary evidence, mon ami

Plimer's stated value of 4000 ppmv or greater is taken from Robert Berner's GEOCARB, a well-known geochemical model of ancient CO2. As the Ordovician was so long ago, there are huge uncertainties for that time period (according to the model, CO2 was between an incredible 2400 and 9000 ppmv.) Crucially, GEOCARB has a 10 million year timestep, leading Berner to explicitly advise against using his model to estimate Late Ordovician CO2 levels due its inability to account for short-term CO2 fluctuations. He noted that "exact values of CO2... should not be taken literally."

http://www.skepticalscience.com/co2-higher-in-past.htm

You could do well to go and bone up on the logarithmic relationship between CO2 and warming too.

Who knocked on your coffin?

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muso

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Re: Arctic Ice continues to shrink
Reply #588 - Aug 12^th, 2012 at 12:44pm

namnugenot wrote on Aug 12^th, 2012 at 12:07pm:

So the sun was only 70% of it's luminosity during the Cambrian? I think your timeline of the sun is missing a zero the true date holding that output was at 70% was 4.5 billion years ago not a tenth of that. Interestingly this periond is associated with the faint sun paradox for which various explanations have been proposed including greenhouse but still nothing conclusive.

My whole point was that there is nothing much conclusive about the dim and distant past - including CO2 levels in the atmosphere. You can't really base any arguments on wooly data. By the way, I notice that you didn't volunteer an answer as to where you depart from Physics 101.

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When I mentioned the ice core data I had jumped ahead and these are coextensive with other data for the period, I think the oldest of the ice cores are put at less than 800k.

That's probably close enough. The Vostok station bores would approach that age. What other more reliable proxies are you referring to? I don't know of any.

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Well you say it was cooling pre-industrial I say it was warming albeit not as quickly as part of the overall trend. Long term trends are not that easy to pick at the start when there is always movement back and forth.

The data looks for all the world to show a decreasing trend between about 1000AD and the beginnings of industrialisation.

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« Last Edit: Aug 12^th, 2012 at 12:56pm by muso »

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namnugenot

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Re: Arctic Ice continues to shrink
Reply #589 - Aug 12^th, 2012 at 12:51pm

MOTR wrote on Aug 11^th, 2012 at 4:57pm:

namnugenot wrote on Aug 11^th, 2012 at 3:45pm:

muso wrote on Aug 11^th, 2012 at 2:03pm:

namnugenot wrote on Aug 11^th, 2012 at 12:17am:

But your mountain is still snow capped!
You still havn't come up with a temperature for 7000ppm and 2000ppm either grandpa.

It doesn't quite work that way. You're talking hundreds of millions of years ago. During most of the Mesozoic, for one thing there was significantly more vegetation than there is today. The carbon sinks were larger. For another thing, the sun's irradiance has also changed significantly. Estimates show that the sun only had 70% of its current output during the Pre Cambrian.

To determine climatical variations during that period is far from exact and estimates vary by several magnitudes.

It's quite illuminating that you would base your assumptions on such tenuous and tentative paleoclimate considerations when you don't accept basic atmospheric science.

Apart from that, you're comparing chalk and cheese.

I reject your assumption I do not accept basic atmospheric science. What I reject is that AGW, as it put into practice, is actual science. You see the beauty of AGW as a subject is that it is such a movable feast. It is an evolution of hypothesis and a selective and interpretive application of data to suit the observation that the earth is in a warming trend. It has been doing so for about the last 18k years and is not controversial or disputed by myself. To then in the circumstances point at a dimunition of arctic ice as the burning bush and say behold is the equivalent of cheap parlour tricks when there is natural variability within a number of timescales. I also dispute some of the body of work that proports to underline a warming where this is not supported by the data. To follow science you must be led by the data and not the other way around.
I also reject your view that the paleoclimate has nothing to offer science in illuminating the role of CO2. I will however be on fairly solid ground in saying ancient CO2 obeyed the same physical laws as modern CO2. There is also I think general scientific agreement that CO2 was much higher, although as with all proxies this is far from exact, over most of the course of time that life has been reasonably widespread over the planet. Even ice cores have been considered to have underestimated the amount of CO2 in the atmosphere by looking at other proxies.
Interesting analogy with chalk and cheese. One is a product of natural processes and lasts almost indefinitely whereas cheese is hand fashioned with a limited life before it become smelly and less than appetizing and then you are forced to go off and make a new one and repeat the cycle. I put the geological (long) record in the first category and anthropogenic AGW in the latter.
However there is no monopoly on truth here and in the long run it is irrelevant.

As close to a faith based position as you can find on this issue.

Got an alternative hypothesis yet, or are you still dodging that one.

Mmmm...you know in keeping with scientific best practice in actual fact I don't have to even put up any alternative...it is sufficient for me to show that yours is flawed, utilises poor or inappropriate methodologies, has been found to reach conclusions unsupported by the data or in some cases has been flat out fabricated.

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MOTR

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Re: Arctic Ice continues to shrink
Reply #590 - Aug 12^th, 2012 at 1:08pm

So you don't have an alternative hypothesis. What's your problem with disclosing that.

So you believe that the high levels of CO2 in the past refute The AGW hypothesis. How exactly, when you don't know the orbital forcings of the time, the workings of the ocean currents, the effect of less solar radiation, or even the temperature of the time.

Could you outline exactly how this refutes the AGW hypothesis. I'm absolutely gob smacked you think this kite will fly.

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muso Gold Member Offline Posts: 13151 Gladstone, Queensland Gender:	Re: Arctic Ice continues to shrink Reply #591 - Aug 12^th, 2012 at 1:09pm By the way, I found this useful summary graph showing a reconstruction of Paleoclimate: (The scale is logarithmic of course) Here is a link to the data source (Physics Forums). You can also find discussion of paleoclimate reconstructions there.
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muso Gold Member Offline Posts: 13151 Gladstone, Queensland Gender:	Re: Arctic Ice continues to shrink Reply #592 - Aug 12^th, 2012 at 1:11pm Upton Sinclair wrote on Feb 18^th, 2396 at 9:39am: You could do well to go and bone up on the logarithmic relationship between CO2 and warming too. I was waiting to see if he brought up that particular chestnut.
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progressiveslol

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Re: Arctic Ice continues to shrink
Reply #593 - Aug 12^th, 2012 at 1:36pm

Keeping aside the belief of greenhouse gases working as descrbed by scienctists, it boils down to the following

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What most people don't realize, partly because the media never explains it, is that there is no dispute over whether CO2 is a greenhouse gas, and all else being equal would result in a warming of the climate. The fundamental dispute is about water in the atmosphere, either in the form of water vapour (a gas) or clouds (water in liquid form). It is generally accepted that a warmer climate will result in more water evaporating from the land and sea and therefore resulting in a higher level of water in the atmosphere, partly because the warmer the air is the more water it can hold. All of the models used by the IPCC assume that this increase in water vapour will result in a positive feedback in the order of 3-4 times the increase in temperature that would be caused by the increase in CO2 alone.

Many scientists do not agree with this, or do not agree that we know enough about the impact of increased water to predict the outcome. Some scientists believe increased water will have a negative feedback instead, due to increased cloud cover. It all depends on how much, and a t what altitudes, latitudes and times of day that water is in the form of a gas (vapour) or a liquid (clouds). So if a certain increase in CO2 would theoretically cause a 1.0C increase in temperature, then if water caused a 3-4 times positive feedback the temperature would actually increase by 3-4C. This is why the warming predicted by the models is so large. Whereas if there was a negative feedback of 0.5 times then the temperature would only rise 0.5C.

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Upton Sinclair

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Re: Arctic Ice continues to shrink
Reply #594 - Aug 12^th, 2012 at 1:38pm

Cofgod wrote on Sep 24^th, 2011 at 11:37pm:

Now, what caused that period of Global Warming that ended the last ice age? I doubt that it was human activity and pollution considering that the earth's human population at the time numbered in just thousands, or maybe 1 or 2 million at the most.

A slight change in the way the Earth orbits the sun, known as the Milankovitch Cycle:

http://en.wikipedia.org/wiki/Milankovitch_cycles

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It must have been NATURAL global warming which caused the ice sheets to retreat 10,000 years ago and there is every reason to assume that the current retreat in ice sheets, should it actually be happening, is also as a result of natural warming and not human activity.

There's no need to assume anything. We know what caused the ice-ages to retreat, slight warming from changes in the Earth's orbit and the release of CO2 and other GHG's that amplify that warming. It's knowing about this relationship between CO2 and temperature that instructs our current understanding of the Earth's climate.

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namnugenot

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Re: Arctic Ice continues to shrink
Reply #595 - Aug 13^th, 2012 at 8:48am

MOTR wrote on Aug 12^th, 2012 at 1:08pm:

So you don't have an alternative hypothesis. What's your problem with disclosing that.

So you believe that the high levels of CO2 in the past refute The AGW hypothesis. How exactly, when you don't know the orbital forcings of the time, the workings of the ocean currents, the effect of less solar radiation, or even the temperature of the time.

Could you outline exactly how this refutes the AGW hypothesis. I'm absolutely gob smacked you think this kite will fly.

I have other hypotheses that has nothing to do with the validity of yours. Even if there was a total absence of proof against anthropogenic AGW, (which there's not), that does not prove your hypothesis. You can't cherry pick what suits you.

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namnugenot

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Re: Arctic Ice continues to shrink
Reply #596 - Aug 13^th, 2012 at 8:50am

muso wrote on Aug 12^th, 2012 at 1:09pm:

By the way, I found this useful summary graph showing a reconstruction of Paleoclimate:
(The scale is logarithmic of course)

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/All_palaeotemps.png/900...

Here is a link to the data source (Physics Forums). You can also find discussion of paleoclimate reconstructions there.

N ow there's a graph that's doesn't distort the true picture...not.

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namnugenot

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Re: Arctic Ice continues to shrink
Reply #597 - Aug 13^th, 2012 at 9:36am

namnugenot wrote on Aug 13^th, 2012 at 8:50am:

muso wrote on Aug 12^th, 2012 at 1:09pm:

By the way, I found this useful summary graph showing a reconstruction of Paleoclimate:
(The scale is logarithmic of course)

http://upload.wikimedia.org/wikipedia/commons/thumb/f/f5/All_palaeotemps.png/900...

Here is a link to the data source (Physics Forums). You can also find discussion of paleoclimate reconstructions there.

N ow there's a graph that's doesn't distort the true picture...not.

I mean you can't be serious...your just embarrassing yourself now.

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Upton Sinclair Senior Member Offline Australian Politics Posts: 496	Re: Arctic Ice continues to shrink Reply #598 - Aug 13^th, 2012 at 1:33pm namnugenot wrote on Aug 13^th, 2012 at 8:50am: N ow there's a graph that's doesn't distort the true picture...not. So THIS is why people like you get called deniers. You are shown evidence and you deny it. Nothing to see here folks!
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namnugenot

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Re: Arctic Ice continues to shrink
Reply #599 - Aug 13^th, 2012 at 3:07pm

Upton Sinclair wrote on Aug 13^th, 2012 at 1:33pm:

namnugenot wrote on Aug 13^th, 2012 at 8:50am:

N ow there's a graph that's doesn't distort the true picture...not.

So THIS is why people like you get called deniers. You are shown evidence and you deny it. Nothing to see here folks!

Evidence?...it's cringeworthy even by your standards.

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