How can anyone question man's significant role in global warming?

[Bystander]

"Not bad!" No, genuinely, pathetically awful --- might as well put the model quality issue out of its misery.

Tambora, 1815, 100 km³, 5-6 K temperature drop, implies Pinatubo at 10 km³ is going to result in a 0.5-0.6 K temperature drop if we apply a simple linear model (temperature drop is proportional to volume of eruption). A temperature drop between 0.5 and 0.7 K was observed. http://www.andaman.org/BOOK/originals/Weber-Toba/ch4_climate/textr4.htm Simple linear model predicts a climate effect within 0.05 K; compare this to the Goddard prediction that has been declared "Not bad!"

 

[Mk]

What about nonlinear? Why would it have to be linear?

 

[Bystander]

What about nonlinear? Why would it have to be linear?

Non-linear models are useful over the range of data to which they are fit. Extrapolate outside that range, and you're wasting time generating random numbers. Linear models "behave" when extrapolated outside the range of data to which they've been fit. Do they give "good" predictions? Depends on the quality of the data and the range of the extrapolation; fit a short, "noisy," data set and you're not going to get much more than "trend" information (this increases/decreases as that). Fit decent data, and you can extrapolate beyond the limits of the data by something like half the range of the data set and hang 10-20% uncertainty on the extrapolated values. Shove noisy data into a non-linear model and what do you get? A lot of unconstrained parameters, and no extrapolation capability --- not even trends. Shove decent data in and what? You may get an improvement in fit over the linear model (smaller residuals); do you get improved extrapolations? Only in the very few cases where the model accounts for every parameter of the system, and the data set is robust enough to constrain all the fit parameters.

 

[Skyhunter]

Standby to be surprised:

The first known accurate measurement of CO2 is:

Thenard, 1812 Traité élém. de chimie, 5 edit., vol1, p.303.

Value: 385,0 ppm

We also have:

W. Kreutz 1941, Kohlensäure Gehalt der unteren Luft schichten in Abhangigkeit von Witterungsfaktoren,” Angewandte Botanik, vol. 2, 1941, pp. 89-117
Average 1939-41: 438ppm.

(Current value ~381ppm)

The pile of ignored papers about measurements, before CO2 was structurally measured at Mauna loa, is about just under two feet high. Many are consistent with each other, showing two very weird short living decadal size spikes.

I wonder how it is possible that people still believe in mans significant role in global warming.

Well as your http://www.ipsl.jussieu.fr/GLACIO/hoffmann/hoffmannengl.html there is a huge problem with the credibility of these measurements, especially the 438ppm in 1939-1941.

A last comparison. Each year the entire terrestrial biosphere is exchanging about max. 60GTC with the atmosphere. That are all the leafs, stems, roots and champignons in the world (which of course is respired at the same time which is why the terrestrial biosphere is about in equilibrium). Now the scenario of Andre (720GTC within 16years) implies that the full global biosperic production is packed into little plastic bag and send into space so that no respiring flux comes back into our atmosphere. And this not for one year but effectively for each year between 1941 and 1957. An interesting hypothesis and a most interesting way of thinking. Thankyou for your contribution.

If you cannot explain where all that carbon went, why are you still advocating those data?

 

[Andre]

Skyhunter,

This is a most blatant example of ostrich politics. head in the sand. I can't explain it so, so it doesn't exist. Most of us can't explain Venus' enigmatic features, but it exists.

And those spikes most likely have existed, even after statistical processing, assuming that the largest environment noise errors apply. But for further confirmation, I have triggered the leaf stomata CO2 reconstruction people to see if they can replicate those spikes.

Where the spikes come and go? Well the oceans contain something like 70 times more CO2 than the atmosphere and it appears that the interchange between ocean and atmosphere is rather fast. A 200 ppm spike coming from the ocean would make that 69,5 times. Readsorption within some decade does not seem unreasonable if that spike event (which would sustain another pet idea) disturbed the balance.

 

[Skyhunter]

Where the spikes come and go? Well the oceans contain something like 70 times more CO2 than the atmosphere and it appears that the interchange between ocean and atmosphere is rather fast. A 200 ppm spike coming from the ocean would make that 69,5 times. Readsorption within some decade does not seem unreasonable if that spike event (which would sustain another pet idea) disturbed the balance.

Thank you,

You had offered no explanation in the other thread.

So you are suggesting that by some mechanism, the ocean releases carbon and then reabsorbs it in a very short time.

OK, nice to have a pet theory.

What does that have to do with AGW, and how is it relevant to this thread?

Has there been such an event recently?

Are you suggesting that the increase in CO₂ in recent years is natural , and not the result of a significant anthropogenic contribution?

Why don't we move past this and onto the broader discussion about what can be done about it. As Evo posted earlier, ill thought out solutions can create unintended consequences.

 

[culion]

Most of the discussions about global warming tend to go in circles after a relatively short time. The key question is how much of global warming is due to human forcings. It is not sufficient to simply claim that this is significant on the basis of unmeasured "consensus" which is of little importance in science. The climate has always changed and sometimes quite rapidly. However, actual changes are not consistent with the best available models that contain both human and natural driving forces. At this point, it looks like the effect of human activities is not substantial and should not be a major consideration in political and economic actions. Of course, other routes (e.g., conservation) might very well lead to the same end but would be done with the proper perspective with respect to the scope and rate of change of appropriate activities.

 

[Andre]

So you are suggesting that by some mechanism, the ocean releases carbon and then reabsorbs it in a very short time.

The pet idea is this:
Every once and a while oceanic methane hydrate enters unstable conditions, with either water pressure dropping (tectonic uprising) or more like changing ocean currents bringing too warm water over the clathrate field.

If such an event is more massive and more prolongued then in the bubble stream the water is also forced up. You can observe that in the aquarium. This deeper water contains much more CO2 than the surface waters, it is brought there by putrifying of sinking biologic remains as bystander kindly pointed out.

Now as this water is forced up, the pressure drops and just like opening the soda bottle, the CO2 is forced out of solution, entering the atmosphere. That's how you can get a sudden CO2 spike. When this process stops, obviously the CO2 will drop again, readsorpted in the ocean and other sinks, until the original equilibrium has been restored. I'm a bit amazed how quick that went in those two events but there was an unbalance. Anyway, the models may need new parameters.

What does that have to do with AGW, and how is it relevant to this thread?

Those CO2 spikes were in the order of magnitude comparable to the termination of the glacial periods. Yet there was no 5-10-15 degrees of warming. Perhaps half a degree at best, looking at the global warming data. But this may have had another cause. As cold seawater in that hydrate event spreads over the ocean surface and pushes the original warmer surface waters to unusual places, the normal weather patterns will be disturbed; think of El Nino.

Consequently, since nothing serious happened, it proves that climate is much more stable than assumed and there will be little or no climate change due to CO2 spikes

Has there been such an event recently?

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=3254&posts=13 is such an event on a small scale.

Are you suggesting that the increase in CO₂ in recent years is natural , and not the result of a significant anthropogenic contribution?

No, obviously, there has been a steady increase in the antropogenic CO2 emission added to the carbon cycle causing an unbalance unlike the spikes of the hydrate event. But in terms of climate this looks to be meaningless.

Why don't we move past this and onto the broader discussion about what can be done about it. As Evo posted earlier, ill thought out solutions can create unintended consequences.

Wise words and spot on. The world problems in two sentences: climate and indefinately sustainable energy. Both suggest a termination of fossil fuel use.

The first seems most acute and appears to call for immediate and strong action, which may result in maximum conversion attemps to natural renewable energy sources. However this could give a negative outcome, when the complete life cycle costs of those renewables exceeds the energy production. That would be surely ill thought out solutions creating unintended consequences.

But climate isn't an acute problem at all. The deadlines may or may not be set by peak oil or something giving us time to avoid ill thought out solutions.

Even if that time is shorter than we think, we cannot hold climate hostage for doing the right thing for the wrong course. Science should be based on finding the truth, not on supporting politics with convenient global warming theories.

 

[Sinimod]

"Not bad!" No, genuinely, pathetically awful --- might as well put the model quality issue out of its misery.

Tambora, 1815, 100 km³, 5-6 K temperature drop, implies Pinatubo at 10 km³ is going to result in a 0.5-0.6 K temperature drop if we apply a simple linear model (temperature drop is proportional to volume of eruption). A temperature drop between 0.5 and 0.7 K was observed. http://www.andaman.org/BOOK/originals/Weber-Toba/ch4_climate/textr4.htm Simple linear model predicts a climate effect within 0.05 K; compare this to the Goddard prediction that has been declared "Not bad!"

Actually 0.29 is a misquote. The Goddard Model was actually off 0.09.

 

[Bystander]

Better --- 'nother Cray and a few more millions, they'll get it to where it beats a first order linear model.

 

[Andre]

Thanks, Evo

 

[Evo]

I haven't had a chance to read through the thread since the surgery. Anyone reading for the first time will probably be scratching their head.

 

[Bystander]

You made it fairly clear that there were going to be "missing" antecedents to various posts --- it ain't all that bad.

 

[Andre]

Anyway, here is a big questioner of man's significant role in global warming.

http://www.cei.org/pdf/5478.pdf

 

[Skyhunter]

The pet idea is this:
Every once and a while oceanic methane hydrate enters unstable conditions, with either water pressure dropping (tectonic uprising) or more like changing ocean currents bringing too warm water over the clathrate field.

If such an event is more massive and more prolongued then in the bubble stream the water is also forced up. You can observe that in the aquarium. This deeper water contains much more CO2 than the surface waters, it is brought there by putrifying of sinking biologic remains as bystander kindly pointed out.

Now as this water is forced up, the pressure drops and just like opening the soda bottle, the CO2 is forced out of solution, entering the atmosphere. That's how you can get a sudden CO2 spike. When this process stops, obviously the CO2 will drop again, readsorpted in the ocean and other sinks, until the original equilibrium has been restored. I'm a bit amazed how quick that went in those two events but there was an unbalance. Anyway, the models may need new parameters.

Interesting theory.

Two things right off the top of my head are;

1. This much CO₂ in the atmosphere would alter the PH in the upper oceans, leaving other evidence. If it happened a mere 60-70 years ago the evidence should be easy to find. A radical change in ocean acidity would have a devastating effect on about any sea animals that have shells.

2. There have been no observed events on a scale like the one you described, the event you linked claims to be the first conclusive proof that such events can even release carbon into the atmosphere.

Those CO2 spikes were in the order of magnitude comparable to the termination of the glacial periods. Yet there was no 5-10-15 degrees of warming. Perhaps half a degree at best, looking at the global warming data. But this may have had another cause. As cold seawater in that hydrate event spreads over the ocean surface and pushes the original warmer surface waters to unusual places, the normal weather patterns will be disturbed; think of El Nino.

El Nino is a cyclical event, and part of a normal weather pattern.

Consequently, since nothing serious happened, it proves that climate is much more stable than assumed and there will be little or no climate change due to CO2 spikes

Unless you can prove that these events happened, there are no consequences, and you are making assumptions based on a theorized event that has little scientific credibility.

Wise words and spot on. The world problems in two sentences: climate and indefinately sustainable energy. Both suggest a termination of fossil fuel use.

The first seems most acute and appears to call for immediate and strong action, which may result in maximum conversion attemps to natural renewable energy sources. However this could give a negative outcome, when the complete life cycle costs of those renewables exceeds the energy production. That would be surely ill thought out solutions creating unintended consequences

.
Renewable clean energy sources are not going to devastate the world economy, as has been claimed by many of your denialist sources. In fact the opposite, new energy technologies are fast becoming the driving force behind cutting edge technological development. As more and more companies see the bottom line benefits, the funds used to sponsor such organizations as CEI will dry up.

But climate isn't an acute problem at all. The deadlines may or may not be set by peak oil or something giving us time to avoid ill thought out solutions.

Even if that time is shorter than we think, we cannot hold climate hostage for doing the right thing for the wrong course. Science should be based on finding the truth, not on supporting politics with convenient global warming theories.

What ill thought solutions?

People have been thinking about this for a long time, and there are many good solutions that can be implemented today. Like shifting transportation money from highways to public transit. Designing our cities around pedestrians instead of cars. Increasing CAFE standards, encouraging zero emission vehicles, etc, etc, etc.

I find the most alarmism comes from those crying about how doing anything to combat GW will harm the world economically.

 

[Mk]

I haven't had a chance to read through the thread since the surgery. Anyone reading for the first time will probably be scratching their head.

Heh. I scratched my head where that huge chunk went. I don't remember what was there anymore either!

 

[Andre]

Explanation here

https://www.physicsforums.com/showthread.php?t=133399

If you follow the link you may recognize the posts of Fred, which were plagiarized into this thread. Evo has spent hours to delete all that illegal copying.

I'm known over there as the "real Mike"

 

[Sinimod]

The Competetive Enterprise Institute (CEI) recently released their Working Paper on the internet "A Skeptics Giude to An Inconvenient Truth" (AIT) in which they purported to refute much of what was said in that publication and movie. At the beginning of this paper, the authors summarized claims of AIT as one sided, misleading, exaggerated, speculative, or wrong. The first and only statement CEI claimed is wrong is as follows:

(AIT) "Claims glaciologist Lonnie Thompson's reconstruction of climate history proves the Medieval Warm Period was "tiny" compared to the warming observed in recent decades. It doesn't. Four of Thompson's six ice cores indicate the Medieval Warm Period was as warm as or warmer than any recent decade."

To actually settle this part of the debate, one should read the Thompson et al., 2006 publication "Abrupt tropical climate change: Past and present." (http://www.pnas.org/cgi/content/full/103/28/10536)
Thompson et al 2006 states "annually and decadally averaged delta O18 and net mass-balance histories for the last 400 and 2, 000 yr, respectively, demonstrates that the current warming at high elevations in the mid- to low-latitudes is unprecedented for at least the last 2 millennia."

They go on to say "Today most glaciers outside the polar regions are retreating at accelerating rates." And further "A sequence of maps ducuments the rapid and accelerating retreat of the glacier front. In the last 14yr (1991-2005), Qori Kalis has been retreating ~10 times faster (~60 m/yr) than during the initial measurement period of 15yr from 1963 to 1978 (~6 m/yr)." And: "The accelerating retreat of the Qori Kalis terminus is consistent with that observed for six other glaciers in the Cordillera Blanca that have been monitored by the power company ElectroPeru."

It seems to me the last 2, 000 years would include the Medieval Warm Period (~AD 800-1, 300). I guess you can judge for yourself whose right on this one.

 

[Sinimod]

I meant to say 'the first statement CEI claimed was wrong.' Obviously there were others. Sorry for the oversight.

 

[Andre]

"annually and decadally averaged delta O18 and net mass-balance histories for the last 400 and 2, 000 yr, respectively, demonstrates that the current warming at high elevations in the mid- to low-latitudes is unprecedented for at least the last 2 millennia."

Whilst it has been established a some time ago that tropical glacier isotopes within the equinoxes have a very erratic meaning as can be seen http://home.wanadoo.nl/bijkerk/GNIP-isotope-temp.gif , the graph showing the annual temperature / isotope correlation factor for each weather station in the GNIP database with an r2>50%. And that's only seasonal precipitation, whereas we have discussed already that changes in seasonal precipation predominate the isotope signature, much more than temperature.

All isotope proxies fail to show the Holocene Thermal Optimum whilst other proxies show an amazing warming deep into the arctic (which the Greenland ice sheet survived with flying colors)

Forget isotopes in ice sheets and glaciers, we don't understand what thses are saying.

 

[Andre]

http://www.ipsl.jussieu.fr/GLACIO/hoffmann/Texts/hoffmannGRL2003.pdf confirms that by the way:

Isotope records from Andean ice cores provide detailed and high-resolution climate information on various time scales. However, the relationship between these valuable isotope records and local or regional climate remains poorly understood. Here we present results from two new drillings in Bolivia, from the Illimani and the Sajama ice caps. All four high altitude isotope signals in the Andes now available (Huascara´n, Quelccaya, Illimani and Sajama) show near identical decadal variability in the 20th century. Comparison with general circulation model results and
meteorological data suggest that the Andean high altitude records are primarily controlled by precipitation variability over the Amazon basin.

 

[Mk]

"annually and decadally averaged delta O18 and net mass-balance histories for the last 400 and 2, 000 yr, respectively, demonstrates that the current warming at high elevations in the mid- to low-latitudes is unprecedented for at least the last 2 millennia."

Way to do it Andre!

All isotope proxies fail to show the Holocene Thermal Optimum whilst other proxies show an amazing warming deep into the arctic (which the Greenland ice sheet survived with flying colors)

Um. What?
How could this be? Why? Precipitation?

 

[Andre]

It is very obvious that after the failed assisination attempt on the medieval warming period (Overpeck 1997) there is now an cleary coordinated attempt to bury the Holocene Thermal Optimum and probably the Eemian next, all for the political target to declare the current period as the warmest in hundreds of thousands of years or millions of years.

All about the Holecene Thermal Maximum here:

http://www.ukweatherworld.co.uk/forum/forums/thread-view.asp?tid=5124&start=1

also with several clear proxies showing that South America was significantly warmer as well. But Lonny Thompson is in the team that listened very carefully to Schneider

 

[Skyhunter]

Forget isotopes in ice sheets and glaciers, we don't understand what thses are saying.

Which is exactly what this abstact does.

Although the factors driving the current 18O enrichment (warming) may be debated, the tropical ice core 18O composite (Fig. 6A) confirms that it is unusual from a 2,000-yr perspective. Regardless of whether 18O is interpreted as a function of temperature, precipitation, and/or atmospheric circulation, the important message clearly preserved in these high-elevation ice fields is that the large-scale dynamics of the tropical climate system have changed.

http://www.pnas.org/cgi/content/full/103/28/10536

Supporting the point of the thread.

How can anyone question man's significant role in global warming?

 

[Andre]

Okay, so whenever:

18O is interpreted as a function of temperature, precipitation, and/or atmospheric circulation, the important message clearly preserved in these high-elevation ice fields is that the large-scale dynamics of the tropical climate system have changed.

which doesn't mean that you can interpret it as unpreceded warming in the Holocene. for that you'd need to have other proxies. So what else is new about South America and the Holocene Therman Optimum?

http://tinyurl.com/ezvgx

MH. Iriondo and NO. Garcia 1993. Climatic variations in the Argentine plains during the last 18,000 years,Palaeogeography, Palaeoclimatology, Palaeoecology Volume 101, Issues 3-4 , April 1993, Pages 209-220


Abstract
The last deglacial hemicycle was characterized by a general increase in temperature and precipitation in the region, with a few significant departures from this general trend. The present NE-SW climatic gradient was maintained throughout the entire period, except in the Upper Holocene. The following sequence of events is apparent if the present climate is taken as a reference base:

1. (a) 18,000–8500 yr B.P.: Arid and cool, with aeolian sand ad loess deposition. Patagonian fauna. Climatic isolines (temperature, precipitation, etc.) were located some 750 km northeast of their present positions.

2. (b) 8500-3500 yr B.P.: Humid subtropical, with Brazilian fauna. Pedogenesis and fluvial dynamics. Climatic limits migrated about 800/900 km southwest of their former positions...

http://tinyurl.com/lcnmy

Abarzúa et al 2004, Deglacial and postglacial climate history in east-central Isla Grande de Chiloé, southern Chile (43°S) Quaternary Research Volume 62, Issue 1 , July 2004, Pages 49-59


Abstract
Palynologic and stratigraphic data from Laguna Tahui (42°50′S, 73°30′W) indicate cool–temperate and humid conditions there between 14,000 and 10,000 14C yr B.P., followed by warmer and drier-than-present conditions between 10,000 and 7000 14C yr B.P....

,

http://tinyurl.com/gaxun

Ledru et al 1996 The last 50,000 years in the Neotropics (Southern Brazil): evolution of vegetation and climate Palaeogeography, Palaeoclimatology, Palaeoecology Volume 123, Issues 1-4 , July 1996, Pages 239-257


Abstract

In the “Lagoa Campestre” (Lake) of Salitre (19°S, 46°46′W, 970 m elev.),... .

The early Holocene, 9500 to 5000 yr B.P., is characterized by a more marked seasonal pattern and higher temperatures, reaching a maximum c. 5000 yr B.P...

Furthermore, Thompson could have cross checked the literature about the Medieval Warm Period in South America, being warmer than today or not and he could have found:

Rein B., Lückge, A., Reinhardt, L., Sirocko, F., Wolf, A. and Dullo, W.-C. 2005. El Niño variability off Peru during the last 20,000 years. Paleoceanography 20: 10.1029/2004PA001099.

The authors derived sea surface temperatures from alkenones extracted from a high-resolution marine sediment core retrieved off the coast of Peru (12.05°S, 77.66°W). The results indicated that the warmest temperatures of the past 20,000 years occurred during the late Medieval Period (AD 800-1250), and that they were about 1.5°C warmer than those of the Current Warm Period..

http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/studies/l1_perushelf.jsp

and

L Pérez-Cruz, 2006; Climate and ocean variability during the middle and late Holocene recorded in laminated
sediments from Alfonso Basin, Gulf of California, Mexico Article in Press, Quaternary Research Corrected
Proof -
Abstract
A laminated sequence (core BAP96-CP 24°38.12N, 110°33.24W; 390 m depth) from the Alfonso Basin in Bay of La Paz, southern Gulf of California, contains a record of paleoceanographic and paleoclimatic changes of the
past 7900 yr.

... Proxies indicate a warm scenario and the dominance of the Equatorial Surface Water in the Alfonso Basin from 2400 to 700 cal yr BP, suggesting the intensification of ENSO cycles.

suggesting that the current warm period is nothing unprecedent at al.

I keep wondering how people can think that man has a significant role in global warming.

Suppose that we can proof within a three sigma certainty that global CO2 levels were higher than today in the timeframe 1938-1949 and subsequently dropped against the increasing anthopogenic production, what would that say about the current climate paradigms?

 

[Skyhunter]

Okay, so whenever:
which doesn't mean that you can interpret it as unpreceded warming in the Holocene. for that you'd need to have other proxies.

Are you intentionally mis-characterizing the paper?

Three lines of evidence for abrupt tropical climate change, both past and present, are presented. First, annually and decadally averaged 18O and net mass-balance histories for the last 400 and 2,000 yr, respectively, demonstrate that the current warming at high elevations in the mid- to low latitudes is unprecedented for at least the last 2 millennia. Second, the continuing retreat of most mid- to low-latitude glaciers, many having persisted for thousands of years, signals a recent and abrupt change in the Earth’s climate system. Finally, rooted, soft-bodied wetland plants, now exposed along the margins as the Quelccaya ice cap (Peru) retreats, have been radiocarbon dated and, when coupled with other widespread proxy evidence, provide strong evidence for an abrupt mid-Holocene climate event that marked the transition from early Holocene (pre-5,000-yr-B.P.) conditions to cooler, late Holocene (post-5,000-yr-B.P.) conditions. This abrupt event, 5,200 yr ago, was widespread and spatially coherent through much of the tropics and was coincident with structural changes in several civilizations. These three lines of evidence argue that the present warming and associated glacier retreat are unprecedented in some areas for at least 5,200 yr. The ongoing global-scale, rapid retreat of mountain glaciers is not only contributing to global sea-level rise but also threatening freshwater supplies in many of the world’s most populous regions.

So what else is new about South America and the Holocene Therman Optimum?

http://tinyurl.com/ezvgx

Received 28 January 1992; accepted 25 May 1992. ; Available online 14 April 2003.

Not exactly new, but still relevant. Abstract does not contradict Thompson's article.

http://tinyurl.com/lcnmy
,

Again this abstract does not contradict Thompson.

http://tinyurl.com/gaxun

Nor does this one.

Furthermore, Thompson could have cross checked the literature about the Medieval Warm Period in South America, being warmer than today or not and he could have found:

Rein B., Lückge, A., Reinhardt, L., Sirocko, F., Wolf, A. and Dullo, W.-C. 2005. El Niño variability off Peru during the last 20,000 years. Paleoceanography 20: 10.1029/2004PA001099.

The authors derived sea surface temperatures from alkenones extracted from a high-resolution marine sediment core retrieved off the coast of Peru (12.05°S, 77.66°W). The results indicated that the warmest temperatures of the past 20,000 years occurred during the late Medieval Period (AD 800-1250), and that they were about 1.5°C warmer than those of the Current Warm Period..

http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/studies/l1_perushelf.jsp

Here you are being particularly misleading. That is not a quote by the authors you cite. It is a description of their paper from a non objective and questionable source.

and

L Pérez-Cruz, 2006; Climate and ocean variability during the middle and late Holocene recorded in laminated
sediments from Alfonso Basin, Gulf of California, Mexico Article in Press, Quaternary Research Corrected
Proof -
Abstract
A laminated sequence (core BAP96-CP 24°38.12N, 110°33.24W; 390 m depth) from the Alfonso Basin in Bay of La Paz, southern Gulf of California, contains a record of paleoceanographic and paleoclimatic changes of the
past 7900 yr.

... Proxies indicate a warm scenario and the dominance of the Equatorial Surface Water in the Alfonso Basin from 2400 to 700 cal yr BP, suggesting the intensification of ENSO cycles.

suggesting that the current warm period is nothing unprecedent at al.

And since you posted no link I have not read this paper, therefore I have no idea what it suggests.

I keep wondering how people can think that man has a significant role in global warming.

Well since the glaciers, which are the source of the cores that provide evidence for the temperatures of these warming periods are themselves melting, I find little difficulty believing it. If the MWP or the Holocene thermal maximum were warmer than today, those glaciers would have melted then as well.

Suppose that we can proof within a three sigma certainty that global CO2 levels were higher than today in the timeframe 1938-1949 and subsequently dropped against the increasing anthopogenic production, what would that say about the current climate paradigms?

But you cannot prove that, because there is no evidence other than atmospheric CO₂ measurements that have been discredited and stomata in conifers. A technique that holds promise for the future, but at this time has a high degree of uncertainty.

 

[Andre]

Thanks Skyhunter for your excellent demonstration of how the warmers fight way below the belt, your post is most exemplary of how it works:

Are you intentionally mis-characterizing the paper?

Polarizing a neutral sane scientific method (reproduction of results) into a personal attack since it implies: "are you a criminal" (ad hominem) and "how dare you attacking such a authority".

Obviously all the other remarks are doing the same. I hope that the intelligent readers here see trought the trick. I'm not going to lower myself into defending that I'm not a criminal. And you can think winning the discussion here, but the evidence remains firm that there was a distinct HTM and MWP in South America. There is one remark though:

because there is no evidence other than atmospheric CO2 measurements that have been discredited

Please show the evidence. So what is discredited? Do show, on what scientific grounds, those measurements have been discredited. After all, why should I allways need to carry the shiploads of evidence, why may adversaries always say anything they want?

 

[Andre]

Here, let me help, here are the discrediters:

G. S. Callendar, “Variations of the Amount of Carbon Dioxide in Different Air Currents,” Quarterly Journal of the Royal Meteorological Society, vol. 66, No. 287, October 1940, pp. 395-400

Callendar, G.S. (1938). "The Artificial Production of Carbon Dioxide and Its Influence on Climate." Quarterly J. Royal Meteorological Society 64: 223-40

Callendar, G.S. (1958). "On the Amount of Carbon Dioxide in the Atmosphere." Tellus 10: 243-48.

Keeling, C.D. 1960. The concentration and isotopic abundance of carbon dioxide in the atmosphere. Tellus 12:200-203.

Keeling C. D., 1958. The concentration and isotopic abundances of atmospheric carbon dioxide in rural areas, Geochim Cosmochim Acta. 13: 322-334.

Now let's scrunitnize why exactly those discredited values were wrong.

 

[Andre]

Here, let's even make it easier, here is a zipped scan of the key document, Callendar 1958

http://home.wanadoo.nl/bijkerk/Callendar-1958.zip

 

[Mk]

Are you intentionally mis-characterizing the paper?

Really, it doesn't matter if one does or does not. The only issue I see is respect, but science doesn't care about respect.

"The improver of natural knowledge absolutely refuses to acknowledge authority, as such." -- Thomas H. Huxley, on skepticism

 

[Skyhunter]

From your earlier post Andre, characterizing the Thompson article as;

an cleary coordinated attempt to bury the Holocene Thermal Optimum

But this is what the article says about the Holocene.

The third line of evidence for abrupt tropical climate change comes from a rooted, soft-bodied plant deposit discovered after it was exposed along the west-central margin of the rapidly retreating Quelccaya ice cap. The plant was identified as the wetland plant Distichia muscoides (Juncaceae), a dioecious mat- or cushion-forming plant (Fig. 7) that is well adapted to harsh diurnal freezing and thawing and often reaches the altitudinal vegetation limit, which is 5,100 m above sea level around the Quelccaya ice cap. The average of eight accelerator mass spectrometry 14C dates from two different laboratories places the calendar age of this plant deposit at 5,138 (±45) yr B.P. (Table 1). The recently exposed plant deposit provides strong evidence that temperatures were warmer in this region before 5.1 thousand years (ka) B.P. and that the current retreat of Quelccaya is unprecedented for the last 5 millennia.

Their conclusion based on the plant deposits exposed by the retreating glacier is evidence that during the Holocene, at the Quelccaya ice cap, it was at least as warm as it is now. Those plants don't grow on glaciers, so the glacier wasn't there 5138 years ago. And lacking evidence of any growth for the past 5 millenia, it would be safe to assume that the glacier has likely been there for 5000 years. And now it is melting. In fact glaciers are melting all over the world at astonishing rates.

I am sorry if you thought I was implying that you were deliberately mischaracterizing the article. And I certainly did not call you a criminal.

However, since the article does not dispute the warming during the Holocene. I wonder why you think it does?

Since Thompson et al did use other proxy data to support their conclusions, to imply otherwise is a mischaracterization.

I was simply asking if you were doing it intentionally.

I found nothing out of the ordinary with any of the literature you provided, nor on any other papers I found on the internet. Nowhere could I find a reading of 438ppm.

If you wish to refute something specific I would be happy to explore it with you. But if you want to joust with windmills, I will have to pass.

 

[Andre]

I'm a bit clueless about Thompsons glacier and I fail to see how his isotopes can say anything about the MWP and the HTM seeing the large unpredicable deviations of temperature in isotopes. So why is it here in the first place? anyway,

I found nothing out of the ordinary with any of the literature you provided,

Well how about the selection -data mining-criteria?

nor on any other papers I found on the internet. Nowhere could I find a reading of 438ppm.

Not everything is online and some libraries should be able to produce the relevant studies. I would recommend:

Duerst U, 1939, “Neue Forschungen über Verteilung und Analytische Bestimmung der wichtigsten Luftgase als Grundlage für deren hygienische und tierzüchterische Wertung,” Schweizer Archiv fiir Tierheilkunde, vol. 81, No. 7/8, August 1939, pp.305-3 17

Haldane, JBS 1936 Carbon Dioxide Content of Atmospheric Air, Nature, Apr 4 pp 575

Hock et al. 1952; Composition of the ground-level atmosphere at Point Barrow (Alaska) Journal of meteorology, Vol 9, 1952, S. 441

Kreutz W, 1941, Kohlensäure Gehalt der unteren Luftschichten in Abhangigkeit von Witterungsfaktoren, Angewandte Botanik, vol. 2, 1941,
pp. 89-117

Misra RK, 1950, Studies on the Carbon dioxide Factor in the Air and Soil Layers near the Ground, Indian Journal of Meteorology and Geophysics Vol I No4 pp275-286

So I plotted all available data of free air CO2 including back scans of graphs on a monthly average basis http://home.wanadoo.nl/bijkerk/fortiespike.GIF . And I accept certain accumulating error of some dozen ppmvs but even then, there is something to discuss. Anticipating some comments, I will wait elaborating.

 

[Skyhunter]

http://www.warwickhughes.com/agri/BeckCO2short.pdf is a short summary of the pre 1957 CO₂controversy, by those arguing against AGW.

They argue that some of the chemical measurements taken before 1961 are being ignored by Keeling, Callendar and the IPCC because these measurements don't fit AGW.

Looking at the data I must say that I agree with Keeling, Callendar, and the IPCC. Most, if not all climate scientists agree that the measurements made after 1957 using NDIR spectroscopy at Mauna Loa, are the most accurate and representative measurements of atmospheric CO₂ ever taken. These measurements do not show the wild fluctuations that are so prevalent with the measurements made using the chemical methods prior to 1957.

If you look at the two graphs, (Fig. 1 pg 4, Fig. 2 pg 5) the trend is stark and obvious.

It is not that the data does not fit a theory. It is that the data does not fit with what we now know about the physics of CO₂ concentrations in the atmosphere. What was a common trend for 150 years is no longer observable now that scientists are using methods that are ~30 times more accurate.

Are we to assume, that when we gained the ability to measure atmospheric CO₂ accurately, it just stopped fluctuating wildly and coincidentally coincided with levels that are recorded in the glaciers?

If global CO₂ concentrations were as high as 420 PPM, the upper ocean would become much more acidic as the CO₂ was absorbed into the oceans in the form of carbonic acid. The effects of ocean acidification would last for tens of thousands of years.

http://www.physorg.com/news11008.html

Barring some new evidence that CO₂ levels do fluctuate wildly, I feel confident in ignoring the pre 1957 measurements that showed high levels of CO₂, especially since there were other measurements taken pre 1957 that fit with modern, more reliable evidence.

In short, we now know that global atmospheric CO₂ content does not fluctuate wildly.

In order to question man's significant role, one needs to deny overwhelming evidence.

 

[Andre]

Nice circular reasoning Skyhunter.

For instance:

Callendar "knows" that the anthropogenic CO2 production causes an increase of the atmospheric CO2.

He cherry picks the few data that would 'proof' that claim, and refuting the majority of data without any substantiation (for instance for being of more than 10% off his selected base line).

So now we "know" empirically that background CO2 level in the atmosphere reacts inert. "In short, we now know that global atmospheric CO2 content does not fluctuate wildly." So we cannot accept rates off changes of some 20 ppm per year, suggested by the rejected measurements of Buch (Ireland) Duerst (Switserland), Kreutz (Germany), Misra (India) and Hock et al (Alaska).

But we know that because Callendar had ordered it so to be, closing the circle. Why would CO2 not be able to change with those rates?

http://www.carleton.edu/departments/geol/DaveSTELLA/Carbon/carbon_intro.htm

Check fig 7 for 1994, Fossil fuel burning was 5GtC/yr, release of CO2 by warm ocean waters was 90 GtC/yr, uptake of CO2 by cold surface water was -90GtC/yr, downwelling of cold surface water moves 96.2 GtC/yr, upwelling at the equator 105,6 GtC/yr etc etc

We could consider the atmosphere a very tiny overflow buffer of CO2 for the oceans. Change anything significant in the oceans and your carbon dioxide balance budget can change dozens of GtC/year, more than enough to have an annual fluctuation of 0,000020 volume parts.

Anyway, there is a pet mechanism that could create havoc in the oceans every so often. Apparantly this happened on a large scale 14,500 and 11,600 years ago and on much smaller scales around 350AD, around 1830AD and around 1940AD apparently with little action in between.

 

[Andre]

I understand that's difficult to accept the high measurements without access to the actual references.

The most comprehensive of those sampling was done by Kreutz (1941) in the weather station just outside the (then relatively small) town of Giessen, Germany. His report in German is a masterpiece of advanced heavy literature and hence difficult to read. Therefore an impression of the contents:

His objective was to find correlations and dependencies of CO2 with weather phenomenons. For that he started continuous sampling, first about every two hours to establish a diurnal pattern and later three times a day for continuation. Sampling was done on four different heights simultaneously, ground level, 0.5 meter 2 meters and 14 meters (on the observation tower) and it started as of August 1939, his report includes sampling up to Jan 1941, despite the continuation of sampling there was never a second report.

Kreutz did some interesting discoveries. The average CO2 levels were highest at the 14 meters sampling location, even slightly higher than at ground level. The two meter point gave the lowest CO2. Correlating these series he found that ground level showed the highest diurnal variation, 14 meters the lowest, which made him conclude that the soil was a clear CO2 source as were the “industries and the cities” apparently at the 14 meter level. For the rest he struggled with temperatures, moisture, inversions, precipitation forms, etc, etc, but the awkward spike, centred on august 1940, spoiled everything. Most notably is the role of the wind. CO2 levels were highest with westerly winds whereas strong winds seem to either decrease or increase the CO2 level at random. But most noteworthy his overall average value was about 430 ppm and he was the first to realize that the mainstream value of 0.03% was actually too low.

To validate Kreutz observations on the anthropogenic factor, a number of evolutions is currently taken place. For a general assessment of the anthropogenic factor in cities, there are a few studies available which show consistently average values about 30 ppmv higher in downtown metropolises compared to the standard of Mauna Loa. A second factor is the assessment of the values of the 6-7 modern measuring stations in Germany in rural sites against Mauna Loa, to see if the background CO2 level is much different (it isn’t). A third assessment would require a detailed historical reconstruction of the anthropogenic CO2 production around Giessen in that time. After all, there was a war going on. Preliminary result is only the proximity of a railway (500 meters) but then again the reconstructed 1940 fossil fuel consumption of Germany was only a fraction of today.

The conclusion would be that no matter what you try and which error margins you want to apply, the back ground natural CO2 level in 1940 was higher than today. Of course the awkward August spikes beg for an explanation. Kreutz did not mention any increase in human activities in that period and suspected an unusual soil production. There is an interesting riddle to solve. Suggestions have included possible contamination of the chemicals needed for titration and increased war activities. It was the time of the battle of Britain of course, some 800km away but nowadays a multitude of fuel is consumed by the local commercial airlines and no trace of a spike like that.

And Callendar 1958? He probably had never heard of Kreutz when he cherry picked his CO2 values let alone that he was willing to decipher the text, then again, he would have rejected the result anyway because it exceeded his standard of accepting only values with less than 10% aberration. But if he would have been a little bit more objective, we may not have had the global warming hype of today.