Global Temperature Change, baseline in History

[Dancing David]

I would like this thread to not denigrate, so I would like to ask at the start that the evidence and the analysis is what is discussed. Please avoid accusations and name calling.


I would prefer that this thread not go to a moderated status.

One of the huge issues in the issue of the potential for accelerated global warming is the baseline of the data. We have very accurate records for a very short period of history. Bepending on the data it might be 30, 150, 350 or 900,000 years BP(before present set at 1950).

This is of course a crucial point to the discussion, the question that it resolves to is :
Does the introduction of fossil fuel technology and the release of CO₂ and other pollutants like methane have a substantial impact on glabal temperature and climate?

So then it comes down to;
What is the baseline to decide what is a 'normal' cycle of climate change without human intevention?

Things to discuss and there are many more:

• 
  Data sets, proxies and extrapolation of historical temperature.
  
  Solar cycles.
  
  Milakanovic cycles.
  
  Vulcanism.
  
  Antartica moving over the South Pole (65 mya).
  
  Biological impactors on climate (preindustrial human and others).
  
  Issues of analysis of data.

Hopefully we can have a discussion without resorting to 'nanny nanny boo boo boo'.

 

[mhaze]

http://www.sciencedaily.com/releases/2007/03/070315101129.htm

 

[BobK]

I suggest this graph as a starting point for discussing the length of a climate cycle. Looks to be a pretty regular 11 degree cycle and therefore a reasonable basis for a 'normal' climate cycle.
Vostok Ice core

 

[Dancing David]

http://www.sciencedaily.com/releases/2007/03/070315101129.htm

Certainly an interesting point, however not one that leads to a baseline for determining what happened in the past. there are ways of discussing global climate without taking an average, although that is commonly done. One could also compare the trends at various measurement sites for example.

So while that is a fine philosphical point I am not sure it responds to the OP.

 

[Dancing David]

I suggest this graph as a starting point for discussing the length of a climate cycle. Looks to be a pretty regular 11 degree cycle and therefore a reasonable basis for a 'normal' climate cycle.
Vostok Ice core

And if I recall that goes back to 450,000 BP which is fairly decent, but only encompasses two ice age cycles.

The Vostok core also points out some of the problems in the Milankovic cycles.
http://en.wikipedia.org/wiki/Milankovitch_cycles


which can not account solely for the driving of climate change, which is why other mechanisms are most likely involved as well.

This from a wiki page as well:
http://en.wikipedia.org/wiki/Image:Atmospheric_CO2_with_glaciers_cycles.gif#file

 

[mhaze]

And if I recall that goes back to 450,000 BP which is fairly decent, but only encompasses two ice age cycles.

The Vostok core also points out some of the problems in the Milankovic cycles.
http://en.wikipedia.org/wiki/Milankovitch_cycles


which can not account solely for the driving of climate change, which is why other mechanisms are most likely involved as well.

This from a wiki page as well:
http://en.wikipedia.org/wiki/Image:Atmospheric_CO2_with_glaciers_cycles.gif#file

Just a cautionary note: This could easily or may have already gone past the ability to use Wikipedia as a reference. Although it is a great reference, it's easy to slide right past it's boundaries of knowledge in these obscure little areas.

Further, the Wiki pages on climate change are ran by some notorious warmers who have locked out changes, McConnally for example. On a controversial subject such as long term temperature reconstructions (EG subject of the "hockey stick") there would be no reason to assume a lack of bias on the part of McConnally, him being part of the hockey stick "Team".

In general, then some of the Wikipedia pages on climate change have stagnated.

 

[Dancing David]

Just a cautionary note: This could easily or may have already gone past the ability to use Wikipedia as a reference. Although it is a great reference, it's easy to slide right past it's boundaries of knowledge in these obscure little areas.

Further, the Wiki pages on climate change are ran by some notorious warmers who have locked out changes, McConnally for example. On a controversial subject such as long term temperature reconstructions (EG subject of the "hockey stick") there would be no reason to assume a lack of bias on the part of McConnally, him being part of the hockey stick "Team".

In general, then some of the Wikipedia pages on climate change have stagnated.

Um, I think it is a well known fact that wiki is what it is , and is prone to many errors, but it is an easy reference to the opening of a debate on a subject.

I am sorry but the hockey stick is not part of this discussion, it is more recent than the historcal baseline.

I don't want this to denigrate into another political discussion.

Please bring your knowledge and resources (and they seem considerable) to bear upon the question of establishing what we know about the historical baseline of climate.

 

[lomiller]

One of the huge issues in the issue of the potential for accelerated global warming is the baseline of the data.

There is no single “baseline” climate for the earth. We have been in roughly the same pattern of climate since Panama shut the gap between North and South America 5 million years ago. Since that time there hasn’t been any sustained period where the planet was more then 2-3 deg warmer then today. We are, however, close to the level of CO2 emissions that could take us over that level, and while artificial CO2 emissions get worked into the earths bio-systems within a few hundred years it takes millions to actually remove them.

What we need to concern ourselves with isn’t some baseline it’s the climate we have adapted our civilization to. Human civilization postdates the end of the last ice age and has never experienced a major climate shift. The other thing we need to be wary of is the speed at which climate is changing. A global climate change over a few thousand years gives biological systems time to adjust, but much faster changes can be real trouble.

 

[lomiller]

Just a cautionary note: This could easily or may have already gone past the ability to use Wikipedia as a reference. Although it is a great reference, it's easy to slide right past it's boundaries of knowledge in these obscure little areas.

Wikipedia may not be prefect but it is a good tool for gauging the “established” view. Climate science isn’t exactly a candidate for something to slide by based on obscurity.

Further, the Wiki pages on climate change are ran by some notorious warmers who have locked out changes, McConnally for example. On a controversial subject such as long term temperature reconstructions (EG subject of the "hockey stick") there would be no reason to assume a lack of bias on the part of McConnally, him being part of the hockey stick "Team".

There is no controversy. Mann’s hockey stick has won out. There are a dozen reconstructions backing and every major science organization in the world backing it up while Manns critics are batting zero. (Unless you count Loehle’s poorly received paper published in the pseudo-journal Energy and the Environment. For those not familiar with that particular publication it’s roughly the equivalent of the Creationist/ID “peer review” journals we see from time to time.)

 

[a_unique_person]

http://www.sciencedaily.com/releases/2007/03/070315101129.htm

He's basically saying that because you can't measure the 'global average', any measurement is useless.

There are two simple ways around this, which have been mentioned previously, because scientists have usually thought about such things before people on blogs do.

Use anomolies. Then you just have to measure changes at one point. Average all those changes, and you have a measurement that's quite good.


Recall that the earth is a chaotic system, but overall, as a body, it absorbs and re-emits radiation. That can also be measured.

That even a chaotic system, with enough samples, will have a representative value for temperature, if you have enough samples and they are taken over a long enough time. They won't ever give you the 'average' temperature, if what you want is the average of all places on the earth at ground level, but they will let you detect and measure warming or cooling.

These aren't any more meaningless than the temperature gauge on your car dashboard. What does it measure? One single point on the whole engine. Is it an important measurement? Definitely.

 

[mhaze]

He's basically saying that because you can't measure the 'global average', any measurement is useless.

There are two simple ways around this, which have been mentioned previously, because scientists have usually thought about such things before people on blogs do.

No, he is commenting on wrong methods that are actually being used. Yes there are ways around this.

For example, just look at ice cores. Period. Don't mix air temperatures and historical ice cores. Then there is an argument "You are only looking at ice, not the planet as a whole". Well, duh....

It's the mixing of liquid and gas measurements of temperature along with the mixing of different proxies that generate the errors, which then compound and are not properly quantified.

Still, a simple answer is compare only like to like, and be aware of the limitations of your method and test measurements. The great error in the "multiproxy tabulations" really is the obscuration of these simple truths, well, several layers of it, to be precise.

But there certainly should not be any problem in looking separately in the same study at several series of proxies and striving to reach a qualified conclusion - combining them together algebraically is where the errors propagate.

 

[lomiller]

No, he is commenting on wrong methods that are actually being used.

No, he is literally saying there is no such thing as global mean temperature.

Discussions on global warming often refer to 'global temperature.' Yet the concept is thermodynamically as well as mathematically an impossibility

 

[balrog666]

No, he is literally saying there is no such thing as global mean temperature.

Yes, he is indeed.

 

[mhaze]

No, he is literally saying there is no such thing as global mean temperature.

Quote:
Discussions on global warming often refer to 'global temperature.' Yet the concept is thermodynamically as well as mathematically an impossibility

I understand that and he is correct. That's why I said he was commenting on wrong methods that were actually being used (otherwise, why write on the subject he wrote on - Answer - Apparently "climate scientists" don't know or understand the concepts).

Temperature is the wrong metric for the condition of the planet, heat content is the correct metric, and one does not parallel the other. The heat content of the oceans is 2000x that of the atmosphere, and the cryosphere acts as a set of huge "batteries".

Re read my prior post. I suggest reasonable methods around the problem, which do not require computation of a global mean temperature, and which are relevant to the question of the thread.

 

[mhaze]

...Please bring your knowledge and resources (and they seem considerable) to bear upon the question of establishing what we know about the historical baseline of climate.

The 2007 IPCC AR4 is online in HTML now (google will find it, I forget the link), which makes cut and paste easy. This would be a preferred reference over wikipedia, which as I mentioned has stagnated, and which often only references the 2001 IPCC documents.

 

[a_unique_person]

I understand that and he is correct. That's why I said he was commenting on wrong methods that were actually being used (otherwise, why write on the subject he wrote on - Answer - Apparently "climate scientists" don't know or understand the concepts).

He's correct, but he's wrong. We cannot measure every point, but no one can do that with any system. A good sample is more than sufficient.

Temperature is the wrong metric for the condition of the planet, heat content is the correct metric, and one does not parallel the other. The heat content of the oceans is 2000x that of the atmosphere, and the cryosphere acts as a set of huge "batteries".

I'll leave that as an exercise for him to carry out. In the meantime, biological systems are more than well aware of what the temperature is.

 

[CaveDave]

SNIP...
I don't want this to denigrate into another political discussion.SNIP...

===========

Denigrate \Den"i*grate\, v. t. [L. denigrare; de- + nigrare to
blacken, niger black.]
1. To blacken thoroughly; to make very black. --Boyle.
[1913 Webster]

2. Fig.: To blacken or sully; to defame. [R.]
[1913 Webster]

To denigrate the memory of Voltaire. --Morley.
[1913 Webster]

Or

denigrate
v 1: belittle; "Don't belittle his influence" [syn: {minimize}, {belittle},
{derogate}]
2: charge falsely or with malicious intent; attack the good
name and reputation of someone; "The journalists have
defamed me!" "The article in the paper sullied my
reputation" [syn: {defame}, {slander}, {smirch}, {asperse},
{calumniate}, {smear}, {sully}, {besmirch}]

===========

Perhaps you intended:

===========

Degenerate \De*gen"er*ate\, v. i. [imp. & p. p. {Degenerated};
p. pr. & vb. n. {Degenerating}.]
1. To be or grow worse than one's kind, or than one was
originally; hence, to be inferior; to grow poorer, meaner,
or more vicious; to decline in good qualities; to
deteriorate.
[1913 Webster]

When wit transgresseth decency, it degenerates into
insolence and impiety. --Tillotson.
[1913 Webster]

2. (Biol.) To fall off from the normal quality or the healthy
structure of its kind; to become of a lower type.
[1913 Webster]

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

HTH

Dave

 

[fsol]

No, he is commenting on wrong methods that are actually being used. Yes there are ways around this.

For example, just look at ice cores. Period. Don't mix air temperatures and historical ice cores. Then there is an argument "You are only looking at ice, not the planet as a whole". Well, duh....

It's the mixing of liquid and gas measurements of temperature along with the mixing of different proxies that generate the errors, which then compound and are not properly quantified.

Still, a simple answer is compare only like to like, and be aware of the limitations of your method and test measurements. The great error in the "multiproxy tabulations" really is the obscuration of these simple truths, well, several layers of it, to be precise.

But there certainly should not be any problem in looking separately in the same study at several series of proxies and striving to reach a qualified conclusion - combining them together algebraically is where the errors propagate.

I wonder why you haven't pointed that out to biocab yet.

 

[Travis]

http://www.scotese.com/climate.htm

 

[Dancing David]

There is no single “baseline” climate for the earth. We have been in roughly the same pattern of climate since Panama shut the gap between North and South America 5 million years ago. Since that time there hasn’t been any sustained period where the planet was more then 2-3 deg warmer then today. We are, however, close to the level of CO2 emissions that could take us over that level, and while artificial CO2 emissions get worked into the earths bio-systems within a few hundred years it takes millions to actually remove them.

Hello, and a belated welcome to the forum.

I am NOT saying that global warming is not occuring, I am trying to have a discussion without the politics.

It seems to me that the baseline is very important.

What data and evidence leads you to make the above statements?

I am not disagreeing with them, I am asking what they are?

I mean for this to be a discussion of the data and evidence.

There are other factors than the CO₂ while that one is VERY impotant.

I believe that AGW is real and that it is likely related to CO₂ emissions. However there are other factors as well:
-the increase in sunspot activity suggest something very interesting
-a lack of really messy volcanos as well.

So I am trying to talk about the data, I believe that CO₂ is an issue that should be addressed, and the burning coal has lots and lots of issues.

So please to show us the data that support your statements.

What we need to concern ourselves with isn’t some baseline it’s the climate we have adapted our civilization to.

Excuse me, but what gives you permission to come and tell me what threads that i will start and that i won't?

Human civilization postdates the end of the last ice age and has never experienced a major climate shift.

See there you go again, human civilization is as old as the tools that we can find, climate change is an amorphous term.

You need to label and define the usage of your terms more carefully. Drought is a major climate shift , is it not?

The other thing we need to be wary of is the speed at which climate is changing. A global climate change over a few thousand years gives biological systems time to adjust, but much faster changes can be real trouble.

That shows a lack of understanding of history, what led to the extinction of the megafauna in North America/ (Hint: temperature cycles that ran hundreds of years.)

So welcome to the forum and welcome to the thread, please show the data that explains your conclusions, I believe it is there, I would like to see it.