Global Warming Cont...

[Guisslapp]

The positive feedback loop stops after the first lap.

Why would a positive feedback loop do that?

[saltydawg]

Why would a positive feedback loop do that?

Because it's not really a loop. Saltydawg made a mistake when he used that word and is going to be whipped with a wet noodle.

[arkansasbob]

Because it's not really a loop. Saltydawg made a mistake when he used that word and is going to be whipped with a wet noodle.

if it's not a loop, then what is it?

[TechsasDawg]

...Saltydawg made a mistake when he used that word and is going to be whipped with a wet noodle.

At the Doubletree???

TD

[saltydawg]

if it's not a loop, then what is it?

a postive or negative feedback.

[randerizer]

randerizer, I requested Gavin A. Schmidt to give his expert opinion on your post.

His response is as follows:
"Nonsense I’m afraid. CO2, CH4, and CFC and N2O gas concentrations from ice cores have been replicated against ice cores in vastly different accumulation environments (temperatures/snow depths), against the instrumental record, with cores from Greenland and Antarctica. There is no depth affect visible in the results, and there has been plenty of modelling of the important processes (firnification, gas age/ice age differences etc). Vague doubts based on no information do not stack up against the actual science."

Except that I have seen coring processes in action, I have had to interpret way more core-based compositional data than Gavin Schmidt has ever seen, and I have seen firsthand the problems (impossibilities) of getting an accurate gas concentration from a sample that is unearthed.

I have also worked extensively on modeling underground phenomena, and I think he is being 100% dishonest to even imply that "plenty of modeling" is sufficient to close the book on other aspects I described.

I'm sorry, but your Gavin Schmidt boy is full of shit here.

[saltydawg]

Except that I have seen coring processes in action, I have had to interpret way more core-based compositional data than Gavin Schmidt has ever seen, and I have seen firsthand the problems (impossibilities) of getting an accurate gas concentration from a sample that is unearthed.

I have also worked extensively on modeling underground phenomena, and I think he is being 100% dishonest to even imply that "plenty of modeling" is sufficient to close the book on other aspects I described.

I'm sorry, but your Gavin Schmidt boy is full of shit here.

What kind of material are you coring and how deep is it?

[randerizer]

What kind of material are you coring and how deep is it?

A wide range of rocklike materials at a wide range of fluid compositions (and fluid properties) at a wide range of depths (let's say 50ft-15000ft).

To reiterate, it is my view that the data collected from ice cores is flawed because it doesn't account for:

1) Diffusion
2) Permeability (to gas and water -- in the case of water, this should also be combined with issue 1)
3) Changes in the internal structure and/or ice cores, e.g. by local subsurface river formation, faults, etc. Basically limited geological interpretation around the ice cores and application of those geological interpretations to a reasonable simulation of the various fluid flows/ice changes in the areas including the ice cores
4) Losses of gases from cores associated with unearthing the sample (depressurization).

[randerizer]

Not that I necessarily trust wikipedia on this issue, but a selection to reinforce the validity some of my arguments:

http://en.wikipedia.org/wiki/Ice_core#Coring

Ice relaxation (e.g., depressurization -- which leads to less gas being present in the sample once unearthed)


Deep ice is under great pressure. When brought to the surface, there is a drastic change in pressure. Due to the internal pressure and varying composition, particularly bubbles, sometimes cores are very brittle and can break or shatter during handling. At Dome C, the first 1000 m were brittle ice. Siple dome encountered it from 400 to 1000 m. It has been found that allowing ice cores to rest for some time (sometimes for a year) makes them become much less brittle.
Decompression causes significant volume expansion (called relaxation) due to microcracking and the exsolving of enclathratized gases.[5] Relaxation may last for months.[6] During this time, ice cores are stored below -10 °C to prevent cracking due to expansion at higher temperatures. At drilling sites, a relaxation area is often built within existing ice at a depth which allows ice core storage at temperatures below -20 °C.
It has been observed that the internal structure of ice undergoes distinct changes during relaxation. Changes include much more pronounced cloudy bands and much higher density of "white patches" and bubbles.[7]
================================================== ========
Core contamination

Some contamination has been detected in ice cores. The levels of lead on the outside of ice cores is much higher than on the inside.[12] In ice from the Vostok core (Antarctica), the outer portion of the cores have up to 3 and 2 orders of magnitude higher bacterial density and dissolved organic carbon than the inner portion of the cores, respectively, as a result of drilling and handling.[13]




Core contamination, or specifically the movement of materials from outside the core inwards, which occurs during the drilling process, indicates that:
1) the ice cores in question do exhibit some permeability (which leads to something being able to enter the rock -- also strongly suggests that something can EXIT the core or FLOW THROUGH the core)

2) the composition of materials in the ice core is likely NOT an accurate reflection of the composition within the ice core before extraction.


================================================== ======

Dating cores

"Deeper into the core the layers thin out due to ice flow and high pressure and eventually individual years cannot be distinguished."

-- I would argue that this hints strongly that subsurface changes are at work that are not correctly accounted for in the analysis... The word "flow" in terms of the subsurface should be a clear signal...

[saltydawg]

A wide range of rocklike materials at a wide range of fluid compositions (and fluid properties) at a wide range of depths (let's say 50ft-15000ft).

To reiterate, it is my view that the data collected from ice cores is flawed because it doesn't account for:

1) Diffusion
2) Permeability (to gas and water -- in the case of water, this should also be combined with issue 1)
3) Changes in the internal structure and/or ice cores, e.g. by local subsurface river formation, faults, etc. Basically limited geological interpretation around the ice cores and application of those geological interpretations to a reasonable simulation of the various fluid flows/ice changes in the areas including the ice cores
4) Losses of gases from cores associated with unearthing the sample (depressurization).

Thanks for your input. While climate scientists like to refer to ice cores when discussing past atmospheric CO2 levels, they really are not necessary to understanding the impact of the current rise of CO2 from burning fossil fuels.

[randerizer]

Thanks for your input. While climate scientists like to refer to ice cores when discussing past atmospheric CO2 levels, they really are not necessary to understanding the impact of the current rise of CO2 from burning fossil fuels.

Correct -- they have nothing to do with the impact of increased CO2.

But they sure have a lot to do with establishing that fossil fuel burning does ANYTHING to move the atmospheric CO2 dial. If REAL historical CO2 levels are higher than where we are at now, and the cycles are consistent with our current cycles, then human CO2 emissions basically mean jack to the overall temperature cycle

[saltydawg]

Correct -- they have nothing to do with the impact of increased CO2.

But they sure have a lot to do with establishing that fossil fuel burning does ANYTHING to move the atmospheric CO2 dial. If REAL historical CO2 levels are higher than where we are at now, and the cycles are consistent with our current cycles, then human CO2 emissions basically mean jack to the overall temperature cycle

Not really. Carbon isotopes determine the percentage of CO2 in the current atmosphere that comes from burning fossil fuels. And that analysis shows that most of the increase in atmospheric CO2 levels comes from burning fossil fuels. Of course, deforestation plays a role too.

As far as the impact of CO2 on surface temperatures, looking at past cycles doesn't mean much since they were all natural. What we have here is the un-natural dumping of billions and billions of tons of CO2 into the atmosphere in a matter of decades in a world that is totally dependent upon the current shoreline and agricultural systems. Who cares if there was massive climate change 500,000 years ago. If we have massive climate change today there are going to be a lot of unhappy campers.

[randerizer]

Not really. Carbon isotopes determine the percentage of CO2 in the current atmosphere that comes from burning fossil fuels. And that analysis shows that most of the increase in atmospheric CO2 levels comes from burning fossil fuels. Of course, deforestation plays a role too.

As far as the impact of CO2 on surface temperatures, looking at past cycles doesn't mean much since they were all natural. What we have here is the un-natural dumping of billions and billions of tons of CO2 into the atmosphere in a matter of decades in a world that is totally dependent upon the current shoreline and agricultural systems. Who cares if there was massive climate change 500,000 years ago. If we have massive climate change today there are going to be a lot of unhappy campers.

Would be interested to know how they tag the carbon in CO2 from fossil fuel sources to distinguish it from other sources. Are you suggesting that CO2 from fossil fuels shows up with a different dating than CO2 from volcanoes, CO2 from exposed reef systems, etc.? Or are you just indicating that CO2 from ALL of these sources is increasing relative to what is already in the atmosphere (i.e., we are seeing a net increase in CO2 in the atmoshpere)?

The latter doesn't tell me anything about fossil fuel use, deforestation, etc., without a bulletproof understanding of the global carbon cycle in the absence of humans. I would suggest that our inability to properly account for highs and lows in historical CO2 levels (or rather our complete dismissal of the real magnitudes of those highs and lows) suggests that we have very little knowledge of the current state of the CO2 cycle.

[saltydawg]

Look at these numbers.

http://cdiac.ornl.gov/ftp/ndp030/global.1751_2005.ems

Houston, we have a problem.

[Guisslapp]

a postive or negative feedback.

Do you understand the difference between positive and negative feedback?