[jason_85 (OP)]

Hello, just joined, interesting forum! The reason I'm here is to get feedback on some articles I'm writing. Specifically, I'd like your commentary on this graph:



This graph is basically a plot of temperature against CO2 levels obtained from the EPICA project. It clearly shows CO2 lagging during the later stages of deglaciation, for which CO2 is supposed to be a driver. How can it be reconciled that CO2 lags behind temperature at a period for which it is supposed to be a driver? Specifically, why is it that an increase in CO2 does not cause a visible increase in temperature at a later time?

Thanks for your input.

[jason_85 (OP)]

I've already written about why newbielink:http://www.warmdebate.com/jason/why-do-carbon-dioxide-concentrations-lag-behind-temperature [nonactive], now I just want to be able to explain (with scientific references) why we can observe this lag and still state that CO2 can be responsible for increasing the extent of global warming.

[BenV]

Hi Jason, I've changed the subject of your post to be a question - please could you do this in future ast it helps to keep the forum tidy and easy to navigate?  Cheers.

I'm a zoologist myself, so can't help with your question, but welcome to the forum!

[frethack]

Before humans began larger scale perturbations of the atmosphere (pre-industrial era), CO2 acted as a feedback mechanism.  The amount of CO2 in the atmosphere was dependent on ocean temperatures, the number/size of volcanic eruptions, soil/biomass productivity, etc.  No serious paleoclimatologist believes that CO2 is the primary driver for deglaciation.  The overwhelmingly accepted thought is that orbital parameters (eccentricity, obliquity, precession) control glacial cycles, with CO2 being a feedback within the system.  As ocean temperatures warm, the waters ability to hold gases in solution is diminished, so oceans begin to de-gas CO2.  Biomass productivity goes up as air/sea temperatures warm, so animals and plants expand their domains, the plants taking in CO2 and the animals releasing CO2.  As these plants/animals die, microbes break down organic matter, increasing soil productivity, which gives off CO2.  Etc, etc, etc.

Basically, in short, oceans warm and life thrives, which gives off CO2.  This doesnt mean that it has no radiative effects.  By increasing the amount of greenhouse gasses (H2O, CH4, CO2, O3, etc.), the atmospheres ability to retain heat is enhanced, which helps warm the earth to some degree.  For instance, without the radiative effects of water vapor, the earth would be unable to sustain life, or even liquid water at its surface for that matter.

As of now, we pump CO2 into the atmosphere in very large quantities, which is going to have some effect on temperature.  The real debate is how much radiative forcing does CO2 provide compared to natural forcings. 

Im not in the "modern warming in entirely anthropogenic" camp.  In fact, my personal belief is that natural effects are playing a very large role in current climate, but any chemist or physicist will tell you that though CO2 is not the most efficient GHG, it will still provide more radiative heating as its concentrations increase

[jason_85 (OP)]

BenV: I'll keep that in mind and frame posts as questions from now on.

frethack: thanks for the info. That all makes sense, but if there was a feedback, shouldn't we see an effect on temperature following CO2 concentrations at points where temperatures are on the rise? In the graph I gave, where is the evidence that CO2 is exhibiting a secondary effect on temperature?

[frethack]

Therein lies the conundrum.  We *KNOW* through physics and chemistry that CO2 has radiative effects and is a GHG, but there is no research (that Ive ever read or heard of anyway) that states X amount of CO2 should provide Y amount of warming.  It is an unknown quantity, as far as I can tell.

For now, we can qualitatively say that CO2 traps heat in the atmosphere, and that higher concentrations will trap more heat (though there is evidence that this a logarithmic trend rather than a linear one), but there is no quantitative answer as to how much.

[frethack]

Another thing that I should have stated originally is that each of the individual data points comes with time/quantity error bars which are not shown.  The correlation between the graphs likely represents a "best fit" scenario by the author within those error bars.  Generally, the further back in time you go, the larger your error. 

d¹⁸O is a pretty poor recorder of temperature in ocean cores.  It really should be used more as a proxy for net evaporation, from which you can infer temperature, though this is not absolute.

[jason_85 (OP)]

So are you saying that there is no historic evidence that CO2 has any effect on temperature at all?

[frethack]

So are you saying that there is no historic evidence that CO2 has any effect on temperature at all?

No, what Im saying is that we know that CO2 has an effect on temperature, but we dont know with any certainty the magnitude of that effect.

[yor_on]

Well Mr Jason, what sites have we been up on now, if I may ask?
And gotten that 'ultimate unarguable proof' that CO2 ain't the 'man driven force' for Global Warming as those phreaky so called 'climate scientists' try to argue.

He**, it snows right outside our door, doesn't it?
Kind'a love it:)

I believe that when we see islands disappear under water we will still argue about the 'responsibility', although, perhaps not the Global warming in itself? But, I'm not sure of that either, considering how good we are on seeing only what we want to see. A pity that Earth don't share our argumentative logic, maybe she has a sense of humor though?

A simple answer is that climate scientists are not immortals. If they were, the answer to why there can be 'time lags' would be explained as they would have documented it in *real time*, instead of by looking at ice cores.

Another is that nobody knows all the ways nature/earth control its temperature through. There have been a lot of different activity through Earths 'life time' and we can only look at the remains. in that motto we are like forensic experts trying to reconstruct 'crimes' done some hundred of thousand or million years ago

It may seem that it's easy to find new evidence, but it's not, and Earth continues to consternate us with new 'relations'. What we do know is that there is a very close relation between CO2 and 'Global Warming' as you can see if you just look at your graph. And we also believe us to know that Methane releases can be a 'man killer' and that it already have happened two times, (without us existing that is:). And Methane have started to move big time now in the tundra and shallow waters of the arctic/antarctic, whats worse is that even if it oxidize away in a relatively short time (decades), it will do so into even more CO2. And that CO2 stays up there for, at the very least, 50 years, more probably a hundred too all of this is fairly new research for us humans, as we also are fairly new 'inhabitants' of our Earth.

"To repeat, the evidence that CO2 is a greenhouse gas depends mainly on physics, not on the correlation with past temperature, which tells us nothing about cause and effect. And while the rises in CO2 a few hundred years after the start of interglacials can only be explained by rising temperatures, the full extent of the temperature increases over the following 4000 years can only be explained by the rise in CO2 levels.

What is more, further back in past there are examples of warmings triggered by rises in greenhouse gases, such as the Palaeo-Eocene Thermal Maximum 55 millions years ago (see Climate myths: It's been far warmer in the past, what's the big deal?).

Finally, if higher temperatures lead to more CO2 and more CO2 leads to higher temperatures, why doesn't this positive feedback lead to a runaway greenhouse effect? There are various limiting factors that kick in, the most important being that infrared radiation emitted by Earth increases exponentially with temperature, so as long as some infrared can escape from the atmosphere, at some point heat loss catches up with heat retention."

===

Take a look at this post too.
lot's and lots of lags    

The History of Climate Change Science

[jason_85 (OP)]

Thanks for the input guys. This is something I really wanted to learn about, so while I was waiting I did some (lots) of research and wrote this article on the newbielink:http://www.warmdebate.com/jason/epica-ice-core-data-and-temperatureco2-relationships [nonactive]. Any comments would be appreciated, either here or on the article

Thanks again for the input.

[Geezer]

Thanks for the input guys. This is something I really wanted to learn about, so while I was waiting I did some (lots) of research and wrote this article on the XXX. Any comments would be appreciated, either here or on the article

Thanks again for the input.

So, (you thought) you were being a wise guy. Do you think we should ban you?

[frethack]

What is more, further back in past there are examples of warmings triggered by rises in greenhouse gases, such as the Palaeo-Eocene Thermal Maximum 55 millions years ago (see Climate myths: It's been far warmer in the past, what's the big deal?).

I would be very interested to see the source for this.  It is hypothesized that GHG's caused the PETM, but the temporal resolution in sediment cores is VERY low this far back in time.  Im at a loss to explain how anyone can tell if the rise in GHG's is lagging or leading the temperature rise, though in either case, it surely contributed to the warming.  It very well could be that GHG's are the main driver for the PETM, but I dont think that this can be claimed with any degree of certainty.  I could be wrong, but this exact topic was covered in a climate class a few semesters ago. 

Finally, if higher temperatures lead to more CO2 and more CO2 leads to higher temperatures, why doesn't this positive feedback lead to a runaway greenhouse effect? There are various limiting factors that kick in, the most important being that infrared radiation emitted by Earth increases exponentially with temperature, so as long as some infrared can escape from the atmosphere, at some point heat loss catches up with heat retention."

Id be very interested in reading this research as well.  It would be very useful to me.  An alternate view might be that, until recently (since industrialization), CO2 has not been the main driver in climate, but responds as a feedback mechanism to another forcing agent.

[yor_on]

Frethack

Test the first link I gave, that will give extensive information on 'time lags' and CO2. Don't miss the comments, they are often very good, both sides

As for the first quote, well it's a quote but I tend to agree to it too. A lot of people studying geology and Earth’s history says the same. At the Permian-Triassic extinction event . (Around 280 to 230 million years ago) and at the Paleocene-Eocene Thermal Maximum (63-40 millions years ago), the beginning of what life we know today, this 'Greenhouse scenario' seems to have happened twice already.

And at the Permian-Triassic extinction around 96 percent of all sea life and 70 percent of Earth’s land animals died, To be gone , never, ever, coming back, and furthermore, it is also the only known mass extinction of insects. 57% of all families and around 83% of all related gene groups/materials were killed. We’re still paying our dues for that one in reduced genetic materials etc, although it happened a quarter of a billion years ago. Here you can check the Permian–Triassic extinction event and the Paleocene–Eocene Thermal Maximum.

[frethack]

First, thank you for the links. 

Test the first link I gave, that will give extensive information on 'time lags' and CO2. Don't miss the comments, they are often very good, both sides

RealClimate is one of the sites that I frequent, and I do appreciate that you read to a greater depth than some.  Though there are subjects with which I agree with Dr. Schmidt and the RealClimate lot, I have some fundamental disagreements as well.  On the surface, this is a topic with which I generally agree.  You cannot base conclusions on one core (presuming that the above chart is from a single glacial core...which it does not state), and you must take resolution, dating errors, magnitude errors, idiosyncrasies from each individual core medium, etc. into account.  Im not sure that the article you posted above disagrees with my postings in this topic in any way.   

As for the first quote, well it's a quote but I tend to agree to it too. A lot of people studying geology and Earth’s history says the same. At the Permian-Triassic extinction event . (Around 280 to 230 million years ago) and at the Paleocene-Eocene Thermal Maximum (63-40 millions years ago), the beginning of what life we know today, this 'Greenhouse scenario' seems to have happened twice already.

I am very familiar with the PETM and the end-Permian extinction, and have studied mass extinctions in fairly good detail...especially relating to climate.  Im also very familiar with what geologists/climatologists have to say as I speak with them on a daily basis.  The resolution that can be attained from a sediment core that is 55ma, not to mention one that is 250ma, is very low.  In the case of the end-Permian extinction, you would be lucky to be able to resolve events at less than half a million years, which is certainly not enough to be able to make detailed assumptions on the timing of different causes and factors that contributed to the event.  Hypothesis range from deep ocean anoxia, to meteorite impact, to wild climate shifts from hothouse to icehouse conditions.  One VERY important thing that people forget is that in a complex system there is very rarely a single factor causing a major event.

[jason_85 (OP)]

This is something I really wanted to learn about, so while I was waiting I did some (lots) of research and wrote this article on the XXX

Oh my bad, I don't know what I was smokin when I wrote that. Anyway here's the link to my newbielink:http://www.warmdebate.com/jason/epica-ice-core-data-and-temperatureco2-relationships [nonactive]. It's by no means complete but more or less sums up my understanding of it.

[yor_on]

Ah Jason, quite nice link that one.
When I read you firstly I got this slight queasy 'Déjà vu' feeling, but it seems I did you a wrong there. A nice presentation indeed. Good on you.
==

Maybe you will like this one?
Climate sensitivity to the carbon cycle modulated by past and future changes in ocean chemistry. 

[yor_on]

Frethack, I agree to the 'forensics' involved can be both biased and deceptive depending on possible presumptions. But as for the correlation between CO2 and Global Warming? It's still there?

And when it comes to 'the driving effect' of CO2.
You don't seriously doubt that it exist, do you?

How, if so?
In your own words please.
You can link your sources, if you like.

[frethack]

By increasing the amount of greenhouse gasses (H2O, CH4, CO2, O3, etc.), the atmospheres ability to retain heat is enhanced, which helps warm the earth to some degree.

As of now, we pump CO2 into the atmosphere in very large quantities, which is going to have some effect on temperature.  The real debate is how much radiative forcing does CO2 provide compared to natural forcings. 

Im not in the "modern warming in entirely anthropogenic" camp.  In fact, my personal belief is that natural effects are playing a very large role in current climate, but any chemist or physicist will tell you that though CO2 is not the most efficient GHG, it will still provide more radiative heating as its concentrations increase

Therein lies the conundrum.  We *KNOW* through physics and chemistry that CO2 has radiative effects and is a GHG, but there is no research (that Ive ever read or heard of anyway) that states X amount of CO2 should provide Y amount of warming.  It is an unknown quantity, as far as I can tell.

For now, we can qualitatively say that CO2 traps heat in the atmosphere, and that higher concentrations will trap more heat (though there is evidence that this a logarithmic trend rather than a linear one), but there is no quantitative answer as to how much.

So are you saying that there is no historic evidence that CO2 has any effect on temperature at all?

No, what Im saying is that we know that CO2 has an effect on temperature, but we dont know with any certainty the magnitude of that effect.

These above are my own quotes from this thread.  No, I do not doubt that CO2 is a contributor to current and past climate, but I do believe that much more research is needed to determine what is natural and what is anthropogenic.  If you would like references, then I will provide references that Ive used in my own research thus far.  These are from very well respected peer reviewed sources, and very well respected authors.  These will allow you to google the abstracts.  If there is a paper you wish to read more in depth, I can email the PDF.

Poore, R. Z., T. M. Quinn, and S. Verardo (2004), Century-scale movement of the Atlantic Intertropical Convergence Zone linked to solar variability, Geophys. Res. Lett., 31, L12214, doi:10.1029/2004GL019940.

Poore, R. Z., H. J. Dowsett, S. Verardo, and T. M. Quinn, Millennial- to century-scale variability in Gulf of Mexico Holocene climate records, Paleoceanography, 18(2), 1048, doi:10.1029/2002PA000868, 2003.

Richey J, Poore R, Flower B, Quinn T (2007) 1400 yr multiproxy record of climate variability from the northern Gulf of Mexico. Geology: Vol. 35, No. 5 pp. 423–426

Bond, G., B. Kromer, J. Beer et al. (2001), Persistent solar influence on North Atlantic climate during the Holocene, Science, 294, 2130–2136.

Bond, G. C., W. Showers, M. Cheseby et al. (1997), A pervasive millennialscale cycle in North Atlantic Holocene and glacial climates, Science, 278, 1257–1266.G. C. Bond et al., Science 278, 1257 (1997).

Haug, G. H., K. A. Hughen, D. M. Sigman et al. (2001), Southward migration of the Intertropical Convergence Zone through the Holocene, Science, 293, 1304–1308.

G. Yancheva, N.R. Nowaczyk, J. Mingram, P. Dulski, G. Schettler, J.F.W. Negendank, J. Liu, D.M. Sigman, L.C. Peterson and G.H. Haug, Influence of the intertropical convergence zone on the East Asian monsoon, Nature 445 (2007), pp. 74–77.

A Test of Climate, Sun, and Culture Relationships from an 1810-Year Chinese Cave Record Pingzhong Zhang, Hai Cheng, R. Lawrence Edwards, Fahu Chen, Yongjin Wang, Xunlin Yang, Jian Liu, Ming Tan, Xianfeng Wang, Jinghua Liu, Chunlei An, Zhibo Dai, Jing Zhou, Dezhong Zhang, Jihong Jia, Liya Jin, and Kathleen R. Johnson (7 November 2008) Science 322 (5903), 940. [DOI: 10.1126/science.1163965]

 

[yor_on]

This confuse me somewhat. "No, I do not doubt that CO2 is a contributor to current and past climate, but I do believe that much more research is needed to determine what is natural and what is anthropogenic."

So if we look at the last two hundred years approximately.

---Quote—

Ice cores provide evidence for variation in greenhouse gas concentrations over the past 800,000 years. Both CO2 and CH4 vary between glacial and interglacial phases, and concentrations of these gases correlate strongly with temperature. Before the ice core record, direct measurements do not exist. .

Measurements from Antarctic ice cores show that just before industrial emissions started, atmospheric CO2 levels were about 280 parts per million by volume. From the same ice cores it appears that CO2 concentrations stayed between 260 and 280 ppm (Parts per million) during the preceding 10,000 years. However, because of the way air is trapped in ice and the time period represented in each ice sample analyzed, these figures are long term averages not annual levels. . .

Since the beginning of the Industrial Revolution, the concentrations of many of the greenhouse gases have increased. The concentration of CO2 has increased by about 100 ppm (i.e., from 280 ppm to 380 ppm).

The first 50 ppm increase took place in about 200 years, from the start of the Industrial Revolution to around 1973.

The next 50 ppm increase took place in about 33 years, from 1973 to 2006.

--End of quote--

And take a look here too. Greenhous effect CO2 and ppm:s.