Guest post by Steven Goddard
There are still people who insist that changes in CO2 can explain the pattern of glacial and interglacial periods. This article will present several arguments demonstrating that is incorrect, based on the ice core data below.
Click for larger image
The most obvious reason is that CO2 lags temperature. Changes in ocean temperature have driven the changes in atmospheric CO2, as explained here. CO2 is not the driver.
Now consider the earth 20,000 years ago. Temperatures were low – about 8C cooler than the present. Due to the cold ocean temperatures, levels of atmospheric H20 (the primary greenhouse gas) were low. CO2 levels were also low, at about one half current levels. The earth’s albedo was very high due to extensive ice cover which had much of North America and Europe buried in ice. Using the popular “CO2 and feedbacks explain everything” theory, all of these negative feedbacks should have driven earth further and further into an irrecoverable ice age. Cold ocean water should have continued to absorb more CO2 from the atmosphere.
Atmospheric H2O should have continued to decline due to lower vapor pressures over the cooling oceans. Albedo should have continued to increase due to expanding glaciers further from the poles. All of these negative feedbacks should have caused temperatures to decrease further, and the death spiral should have continued. But none of these things happened. Instead, the earth warmed very quickly. CO2 was absolutely not the driver, and positive/negative feedbacks had to be in balance.
Consider the earth 14,000 years ago. CO2 levels were around 200 ppm and temperatures, at 6C below present values, were rising fast. Now consider 30,000 years ago. CO2 levels were also around 200 ppm and temperatures were also about 6C below current levels, yet at that time the earth was cooling. Exactly the same CO2 and temperature levels as 14,000 years ago, but the opposite direction of temperature change. CO2 was not the driver.
Now consider 120,000 years ago. Temperatures were higher than today and CO2 levels were relatively high at 290 ppm. Atmospheric H20 was high, and albedo was low. According to the theorists, earth should have been warming quickly. But it wasn’t – quite the opposite with temperatures cooling very quickly at that time. CO2 was not the driver.
If CO2 levels and the claimed lockstep feedbacks controlled the climate, the climate would be unstable. We would either move to a permanent ice age or turn into Venus. Warmer temperatures generate more CO2. Increased CO2 raises temperatures. Warmer temperatures generate more CO2 …… etc. It would be impossible to reverse a warming or cooling trend without a major external event. Obviously this has not happened.
An exercise to get people thinking for themselves. If the temperature at some point in the past was 4C cooler than now and CO2 levels were 240 ppm, was the temperature going up or down? There are ten points on the graph that match those conditions. Half of them have rapidly rising temperatures and half have rapidly falling temperatures. It becomes abundantly clear that there has to be another degree of freedom which is dominant in controlling the glacial cycles.
In the ice core record, temperature drives CO2 – not the other way around. Sometimes the earth warms quickly at 180 ppm CO2. Other times it cools quickly at 280 ppm CO2. Again, CO2 is not the driver of glacial cycles – there has to be a different cause.
UPDATE:
The use of the term “negative feedback” in this article is the commonly understood meaning – i.e. feedbacks that drive temperature down. Technically speaking, this usage is incorrect. From a viewpoint of semantics, a negative feedback would be one that works against the current trend. This semantic difference has no relevance to the logic being presented in the article.
There is no evidence in any timescale: decadal, century, milenial or geologic that CO2 levels significantly contribute to temperature change. The satellite records show this, the ice core data shows this as do longer geologic records.
As many have observed, as CO2 levels have continued to rise over the last decade, temperatures have fallen contrary all GCM expectations. The 20th century showed no consistent relationship between the two with periods of increase and decline over the period. As others have pointed out on this thread, careful (nonGoreon) analysis of the ice core data fail to demonstrate the defensive CO2 amplification position.
During the Cretaceous and Jurassic geologic periods CO2 levels were as much as 5 times greater than the current levels — no tipping point there! During the Miocene the world was about 10°F warmer and the CO2 concentration was significantly less. During the Pleistocene CO2 increases were accompanied by global cooling.
Historic and geologic data are inconsistent with GW theory. Imagine what climate scientists would be saying were it the other way round — it the world really looked like their discredited models.
As a lurker here interested in the subject (AGW) I think its important to point out that while AGW scientists may not believe that the CO2 is the ‘primary driver’ of rising temperatures, the ‘public relations department’ of AGW theory proponents is putting out something completely different. Chock it up to our sound-bite culture, but to those of us outside the circle of the ‘settled debate’ it sure seems like the primary talking point is something along the likes of:
“We’re killing ourselves with CO2, now stop eating beef, buy a Prius, ride a bike to work, and don’t breathe hard while doing it.”
Typically the people saying this then get back into their Gulfstream G-IV and jet off to the next city to say the same thing to another group of people. After buying their carbon-credits to off-set the trip, of course.
So maybe what you (AGW scientists) have is more of PR problem. But it sure seems like the debate is anything but ‘settled’.
Just one man’s opinion.
Todd
Let’s assume John Philip is correct,
Historically CO2 does not ‘drive’ the changes in temperature, in the sense of initiating them, but does act as a powerful feedback once they are underway,
If CO2 is a powerful positive feedback during the warming part of the glacial/interglacial cycle, then it must be an equally powerful negative feedback at equal concentrations during the cooling part of the cycle.
Which means there must be an even more powerful positive feedback (or forcing) overcoming CO2 during the cooling phase.
The even more powerful feedback is then mysteriously absent during the warming phase. This is a far too ad hoc explanation for me.
Bill Illis notes that Hansen says in a recent paper,
“Basically, warming will be slower than originally thought, but most of the ice sheets will still melt and the albedo feedback from the lack of ice will push us to +6.0C from a doubled CO2 within 1,500 years.”
So a trace gas with trump the Milankovitch cycle. How silly is this going to get.
What I’m interested in now is does our ‘ice age’ (interglacials and glacials … all relatively cold) that we live in correspond to the length of time the Super Massive Black hole in the center of the galaxy has been asleep?
http://biocab.org/Carbon_Dioxide_Geological.jpg
http://www.pbs.org/wgbh/nova/blackhole/program.html
No time for Hansens paper, the politics of AGW is getting boring … and my Jack Russel wants to play.
Steven Goddard (06:07:38) :
What the Vostok cores show is that there is 0% correlation between CO2 levels and the direction the temperature is moving. You can pick any CO2 level on the graph, and find an equal number of points where the temperature is going up, and where it is going down.
You seem to have a misunderstanding of the term “forcing”. The forcing is the CHANGE in net irradiance at the top of the atmosphere, relative to some reference level.
250 ppm of CO2 could be a positive forcing (causing temperatures to increase), if CO2 levels 500 years earlier were 200 ppm. Or 250 ppm of CO2 could be a negative forcing if CO2 levels 500 years earlier were 300 ppm. This is exactly what your graph shows.
Alexander Harvey (05:07:27) :
Here is a longer Benthic Carbonate reconstruction:
http://en.wikipedia.org/wiki/File:Five_Myr_Climate_Change.png
Visually I notice the appearance of greater variance or amplitude with lower tempertures.
Is this real or an artifact of the reconstruction? Anyone know?
If it is not an artifact then does it imply that the climate is more stable when temperatures are warmer? (Less positive feedback?)
If so, does that imply Climate Sensitivity has declined with increasing temperatures?
A very good question. Perhaps the more stable temperatures 45M years ago when it was warmer than now suggest that higher temperature is closer to the earth’s long term optimum. Maybe if we had a study of a period with much higher temperatures at a similar resolution we might see bigger amplitude variance there too. Of course, the optimum might change with the distribution of the landmass. As might the degree of variance at other temperatures. Greater biomass may have a greater dampening effect on temperature swings too.
Complicated innit? :o)
Regardless of one’s persuasion concerning what CO2 actually forces, one must agree that changes in H2O force more.
Regardless of what one believes about the validity of paleoCO2 data, one must agree that when the planet was 8C cooler, the atmosphere contained much less H2O vapor, and that H2O vapor change slightly lags temperature change.
If a<b, then why are we hung up on a? If “greenhouse effect” is of serious concern, we should be principally concerned about the increase in pan humidity associated with the trends in irrigation over the last century.
Or, perhaps both are of small import as “greenhouse” gases, in support of the thesis of this thread (though I believe it can be shown that other properties of water are strong drivers of the glacial cycle…a topic for another thread).
A couple of (very) cold winter (certainly in Canada and apparently in Europe) in the face of growing CO2 can’t scientifically be used as evidence of AGW supporters being wrong. However, the general public and our news media up here have quietened on the subject (BBC is an exception – maybe they need to turn their thermostats down). Also, the global warming “consensus” is feeling the need to fight rearguard actions – although still showing confidence in their hot world scenarios, we are beginning to see the semantic phase: “oh we didn’t actually say that”… “of course there will be temporary reversals” (Dr. Hansen predicted a world record temperature being recorded in the next 2-3 years and this was two years ago … I apologize for not having the exact links but it is in Hansen’s blog in a few places) … “oh dear, the ice extent sensors have underestimated ice extent by half a million sq km…. the Hadley Centre (weather people in UK), once leading champions of AGW are now telling the media to temper down their extravagant AGW rhetoric. … And what about slurs against WUWT:
Didjeridust”
“This is just a way of trying to give the simple minds among the readers here the impression that there actually is people in the “AGW camp”, the “Alarmists”, “Climate hysterics” or whaetever, that holds this view.
“Science Blog of the year” – Yeah, right!”
Like the feedbacks and forcings of CO2, we are likely to see the same type of forces at work in the debate going forward. Dr. Hansen and others are already extending the “best before” date by several decades. If the AGW consensus turns out to be wrong, don’t expect any mea culpas. What happens to these types of debates if they go wrong is that gradually they melt away around the edges and those who have taken the most irretrievable stances die of old age.
Let us be grateful for WUWT it is one of the better avenues for preventing the “consensus” from closing off debate. Its award is well deserved, witness the fact that the heavyweights in the AGW feel the need to respond immediately to damaging posts – degraded satellite sensors (NSIDC), Norways Nansen group explaining downward revisions of ice extent, NASA’s quick response to errors in measuring world temp (mixing months in the record) . Both sides of the debate facilitated here is clearly read religiously every day. They have handed out Nobel Prizes for much less than this.
But Steven, the AGW scientists are now saying that CO2 is both a negative and a positive feedback mechanism as well as a forcing. So regardless of the initial natural cause of a temperature change in the past, CO2 will make it worse, whether it goes up or down. So if it is going up, CO2 will make it go up more. If it is going down CO2 will make it go down more. If we have new circumstances and temperature was stable and perfect (IE no natural forcings in action), a sudden change is initially caused by and made worse by CO2, which explains the dire circumstances we are now in, and yes, even when it gets colder instead of warmer. I know it is complicated and there are other far more educated scientific web sites that will help explain this to you.
There is work afoot to replace burying nuclear reaction waste (a deadly substance that only due diligence by knowledgeable people have saved us from) with sequestered CO2 instead because it is such a harmful gas. I tell ya. If they hadn’t banned that substance in hairspray, we would all be dead now from skin cancer. Nuclear waste and CO2 are just as deadly. We should be thanking these people instead of childishly arguing with them;
Alexander Harvey (05:07:27) :
Visually I notice the appearance of greater variance or amplitude with lower tempertures.
Is this real or an artifact of the reconstruction? Anyone know?
If it is not an artifact then does it imply that the climate is more stable when temperatures are warmer? (Less positive feedback?)
Indeed, climate is more stable during warm periods than during cold one’s. That has to do with albedo: the change of land from vegetation to ice sheets and back is a very strong feedback in both directions, which strengthens any small change in orbital caused insolation. But that is a lot less when most of the ice sheets are already melted, thus less feedback in warmer periods.
And clouds may be involved as temperature regulator, once the vapor pressure reaches a maximum (like hurricanes forming when seawater reaches 28°C, dissipating energy to cooler places and to space).
About CO2 as “strong” feedback: The ice ages indeed show that CO2 is NOT a strong feedback, as no effect is measurable from 40 ppmv drop at the end of the Eemian, neither any response from temperature on CO2 changes during the LGM-Holocene transition. Thus CO2 is NOT a strong driver of temperature either, even if we are responsible for the 100 ppmv increase in the past 150 years.
The average 3°C/2xCO2 of the current GCM’s is already much too high, let it be the 6°C/2xCO2 proposed by Hansen e.a. This is not supported by evidence form the ice cores.
Hansen was the first to introduce the 3°C/2xCO2, because he missed a feedback factor, as the ice ages – interglacials show a larger temperature variation than calculated from albedo changes. Thus CO2 must give a strong feedback. But any other feedback (an underestimate of the albedo feedback or of cloud feedback – nobody knows the cloud cover of the ice ages…) could do the job as well.
Steven Goddard’s statement,
“Whatever drives glacial cycles must be a very strong force, and it is not CO2.”,
describes the crucial issue in climate change. I’ve been following this debate since the mid 90’s and it seems to me that the discovery of the CO2 lag in the Vostok cores marked a drastic turning point in the debate.
If I remember right, in the 90’s AGW proponents were adamant that Milankovitch cycles were not significant drivers of climate change. Their arguments regarding Milankovitch cycles seemed valid at the time and still seem valid now. In other words, the Milankovitch cycles seem inadequate to provide climate forcing sufficient to overcome the proposed theoretical influence of CO2. Now, the AGW crowd seem to love Milankovitch cycles. Am I imagining this? Memory plays tricks.
Solar variability continues to be denied as a factor in the AGW arguments. If one accepts their earlier arguments regarding Milankovitch cycles and their continuing arguments involving solar variability then there is a clear implication of some other factor not currently identified. This factor is capable of causing large rapid shifts in temperature. It seems that any prudent researcher concerned with the effects of rapid climate change would be giving some thought to this possibility. Um…the precautionary principal would seem to suggest that somebody ought to be covering that base. Of course, this presumes that the researchers are really concerned about the future well-being of humanity.
Anyway, is the following statement true? There is an unknown factor which causes large worldwide temperature swings but climate scientists are not interested in finding out what it is.
I found and downloaded the CO2 and Temperature data over the last 100 million years from Berner, Pagani and Zachos (all coauthors on Hansen’s latest paper) and plotted these on the same graph.
As you can see, the temperature and CO2 history of the planet is complicated. While there is a small correlation between temperatures and CO2, there is much more reason to believe this link is not very strong and there are often very contradictory trends in the two measures.
CO2 is certainly not the main driver of temperatures.
Those of you who have spent some time at Global Warming Art looking at separate historical CO2 and Temperatures plots will want to see this.
http://img10.imageshack.us/img10/4364/tempvsco2100m.png
The ice core data goes back over 400,000 years but how far in the past do they stop or become unviable and force us to use actual CO2 measurements? Since CO2 concentrations are significantly higher today than in any of the ice core data, is there a problem with melding measured CO2 values with ice core values? Is there degradation in the CO2 levels appearant in the ice cores that we are not ajusting for? Or has man really pumped out so much CO2 that we truly are in a whole new ball game and this time it is different? Being a CO2 sceptic, I don’t think so, but this chart shows gives me a better understanding why some people do.
Bill
Look there is NO coloquial use of the term “negative feed back” – it can only have one meaning. Feed back that reduces the effect of disturbances.
E.G. wiki:
Negative feedback feeds part of a system’s output, inverted, into the system’s input; generally with the result that fluctuations are attenuated. Many real-world systems have one or several points around which the system gravitates. In response to a perturbation, a negative feedback system with such point(s) will tend to re-establish equilibrium.
There is the negative feedback on ebay – with a different meaning.
I have not seen it used to mean negative forcing until the misuse in the Telegraph article and here.
If technical authors do not understand this what hope is there?
Mike
If the CO2/methane/temp changes had been in lockstep (the greenhouse radiational effects are instantaneous), it prb’ly would’ve convinced me & alot of others that CO2 drives climate.
Wonder if the phrase “we gotta get rid of those ice-core time lags” was ever uttered?
Bill,
Thanks for the link to the Hansen paper.
Now I am struggling a little with his use of the words forcing and feedback (slow and fast).
Now CS is defined in terms of temperatures and radiative forcings and those forcings are defined in terms of Net Irradiance.
Now the net irradiance changed little betwen the LGM and the Holocene, he states that equilibria existed in both periods. So only true forcings (effects not due to the change in temperature) can be included in the calculation. The sun and GHG that changed from some other reason than temperature.
Feedbacks (effects due to the change in temperature should not be included).
I would have thought that would have ruled out most or all of the -3.5 figure (ice ,veg, etc) and the CO2 part of the -3 figure leaving about 0.75 W/m^2 as the forcing giving a CS of ~6 degC/(W/m^2) or ~20C per CO2 doubling,
Now I can see what he is saying, he has two points on the NI(T) function [Net Irradiance function] seperated by 6.5 W/m^2 and 5 degC and he draws a straight line between them and extropolates to higher temperatures which is okay if that straight line represents physical reality but if in getting from A to B the CS =1/NI(T) was nearly vertical their is no justification of the extrapolation.
I will be willing to accept that people may have a very different concept also called CS but I think the argument will still hold but would require many more words to explain.
Alexander Harvey
Al Gore’s movie ends with, “Are you ready to change your life?” What does Mr. Gore ask you to change? Reduce your “carbon footprint.”
My son’s 9th grade science teacher stated emphatically that AGW was real, humans are going to kill the planet unless we stopped the carbon.
I, for one, have taken a modified version of the Al Gore pledge. I promise to try to be successful enough to put as much carbon into the air as Mr. Gore does. Heated swimming pools, world wide travel, exotic foods flown in for large parties – must be fun.
—-
Mr. Goddard takes hard data, points out interesting patterns that indicate that CO2 simply can’t be “the thing” that drives the temperature. Nick, et. al. focus on the few comments regarding the “who” in the public discussions and not on the “what”. I wonder why that is.
Oops correction,
Having used the term Net Irradiance I went on to use it where I shouldn’t of:
Now I can see what he is saying, he has two points on a flux function F(T) seperated by 6.5 W/m^2 and 5 degC and he draws a straight line between them and extropolates to higher temperatures which is okay if that straight line represents physical reality but if in getting from A to B the CS =1/F(T) was nearly vertical their is no justification of the extrapolation.
Such is life!
Alex
Sandw15,
Excellent comments!
Chris V,
You are now proposing that the polarity of CO2 forcing is dependent is dependent on CO2 levels “500 years earlier?” You better call up your local climate modeler and explain that to him, because I can assure you that GCM radiative transfer models do not have any component of distant past CO2 levels as part of their calculation.
thefordprefect,
You apparently have no disagreement with the logic, as you have decided to pursue a nonsensical argument around semantics. Negative is normally interpreted as making things smaller. (You may remember that from primary school mathematics.) This could mean the trend gets smaller, or it could mean the temperature gets smaller. In this case of a declining temperature regime, the meanings are opposite.
The problem with the BBC segment was that the term “negative feedback” was used incorrectly by either definition. I’m sure you think you are being clever, but rest assured – you are not.
george h. wrote:
“As many have observed, as CO2 levels have continued to rise over the last decade, temperatures have fallen contrary all GCM expectations. ”
If temperatures have fallen over the last decade, why were all the years since 2000 warmer than 1999?
Bill Yarber (08:48:47) :
The ice core data goes back over 400,000 years but how far in the past do they stop or become unviable and force us to use actual CO2 measurements? Since CO2 concentrations are significantly higher today than in any of the ice core data, is there a problem with melding measured CO2 values with ice core values? Is there degradation in the CO2 levels appearant in the ice cores that we are not ajusting for? Or has man really pumped out so much CO2 that we truly are in a whole new ball game and this time it is different?
The ice core data are going back to 800,000 years nowadays. There is no adjustment of the ice core data necessary, the bubbles still contain the atmosphere as it was many thousands of years ago. If there was diffusion of CO2 through the ice, the CO2 measurements would level out over time, but the oldest and youngest glacial/interglacial ratio remains the same.
And yes, we have pumped twice the amounts of CO2 into the atmosphere than what is measured in ice cores and the atmosphere (with an overlap of about 20 years for the Law Dome ice cores). The other halve is sequestered by oceans and the biosphere.
If the increase has a real (or even dangerous) impact, that is the multibillion euro(*) question.
(*) because of the devaluation of the dollar some expressions need an economic upgrade…
Jeff:
You’re confusing an anomaly with the trend.
Here’s the trend: click [the green line]
Sandw15,
“Anyway, is the following statement true? There is an unknown factor which causes large worldwide temperature swings but climate scientists are not interested in finding out what it is.”
If a “climate” scientist is someone whose research has benefited by the AGW theory, then, in my opinion you are correct. One merely accepts AGW and proceeds to calculate the impact on whatever piece of science may be their specialty. Just climb on the hay wagon and sing to the tune. Who cares why the worldwide temperature swings.
Those interested in finding out what “it” is are people like Steven and yourself.
But look what Al Gore and the IPCC did. I stand in awe. They trumped difficult to understand and oftentimes contradictory science and packaged their overly simplistic version of it in snippets that support their desired new socio-economic model. Now we have a world of lemmings following the Goracle.
So Steven, keep it up. Perhaps at some point we will have a Goracle too, but one who understands how to extract the CO2 following temperature information in your plot, as well as the logic that shows that temperatures move up and down in grand steps through the same CO2 concentrations, and who can communicate with nine year olds around the planet, who can then teach their parents.
I think that the next thing the Academic-Political complex will tell us is that CO2 production leads to runaway coolening, so they have to tax us for it.
Steven Goddard (09:46:19) :
Chris V,
You are now proposing that the polarity of CO2 forcing is dependent is dependent on CO2 levels “500 years earlier?” You better call up your local climate modeler and explain that to him, because I can assure you that GCM radiative transfer models do not have any component of distant past CO2 levels as part of their calculation.
No, you misunderstood me. I was commenting on this statement you made:
What the Vostok cores show is that there is 0% correlation between CO2 levels and the direction the temperature is moving. You can pick any CO2 level on the graph, and find an equal number of points where the temperature is going up, and where it is going down.
The DIRECTION the temperature is moving depends on the CHANGE in the CO2 forcing. As long as your starting temperature is near equilibrium, increasing CO2 will cause temperatures to rise, and decreasing CO2 will cause temperatures to fall.
The ABSOLUTE CO2 levels do not determine the temperature TREND. The CHANGE in the CO2 levels does.
“The ABSOLUTE CO2 levels do not determine the temperature TREND. The CHANGE in the CO2 levels does.”
So a forcing is a derivative, and a feedback is an exponent?
I am reminded of Wittgenstein’s maxim that most philosophical conundrums are founded in a confusion over the limitations of language, particularly the fact that ambiguity cannot be avoided, proven axiomatically by Goedel.
The idiocy that is AGW is unavoidably enabled and continued thru climate jargon.