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.
Steven Goddard,
How can you be so simplistic as to take Al Gore’s claims on face value?
“there is one relationship that is far more powerful than all the others and it is this. When there is more carbon dioxide, the temperature gets warmer”
Clearly, what Al meant depends upon what the meaning of the word “is” is.
[/sarc]
Molon was absolutely right about the negative/positive feedback distinction, and if anyone is going to use that term they should either use it properly or make it explicit that they using it colloquially (i.e. wrongly).
It’s not a mistake I would make and I immediately tune out when I see someone else making it. It is a big deal–almost worth blogging about.
Bill D (22:35:08) : All of the science that I have read says that sun cyles drive the long term glacial cycles
I assume you meant to say ‘insolation cycles due to orbital mechanics’ since solar cycles don’t have any known 100,000 or 40,000 year periodicities…
Warming increases rates of bacterial degredation on land and in water, as well as making stronger thermal statification in the oceans. Thus, warming can lead to less CO2 burial in the ocean and more CO2 release from soils. Right now the tundra is a major reservoir of organic carbon. If warming and melting continue, releases from this source will increase.
And what about the effect of growing 25 to 50 TONS per acre per year of plants (as demonstrated in Eucalyptus, Willow, and Poplar groves)? Hmm? How about that 40% increase in growth rate demonstrated from higher CO2 levels?
Please balance your CO2 books on plant dynamics. Warmer and higher CO2 results in much greater biosequestration over most of the earth surface. Look beyond the tundra…
Yes, this matters a great deal. Just where do you think all that coal and oil came from in the first place… See peat bogs for a modern example of the process still at work.
The one question we need to ask is this –
“Can the climate get COOLER when there are high(er) levels of CO2 in the atmosphere?”
This needs to be asked – and answered – clearly, loudly and often. The answer, clearly and unequivocally, from historical data, is YES.
I question if the historic interglacial CO2 peaks were in the 290 range (as on the graph). The ancient atmospheric CO2 has not been directly measured. Rather, ice core measurements have been “adjusted” by a “factor”. I question the “factor”.
Could be that current CO2 levels are not any higher than recent ancient interglacial levels. A bit OT for this thread, but it is something I think about every time I see that graph.
So, here I am lurking around, not being particularly scientifically minded (leaning toward Psychology rather than a hard science because that’s just how my mind works) and I see statements like Nicks, and wonder…
You see, the last 20 years of the AGW hype have been premised on the idea that CO2 drives the climate. To state, now, that this has never been stated in the precisely worded way Nick asks for is rather like turning to a large haystack and saying “But there isn’t a straw in there that’s exactly 111.762 mm with a diameter of 16 mm, therefore the entire haystack doesn’t exist”.
It’s a clever bit of obfuscation to say that nobody has made a precise statement but it rather misses the point; the claim has been that CO2 drives climate. The proof is lacking, and the claim falsified by the data.
Back to lurking!
We look forward to Mr Goddard’s next post where, having single-handedly shown how the world’s assembled climate and coral experts are mistaken he goes on to demonstrate that chickens cannot actually lay eggs because the chickens ‘lag’ the eggs… 🙂
The same argument was advanced by Viscount Monckton, and the counterargument elegantly expressed by Dr Stephan Harrison, Senior Lecturer in Physical Geography at the University of Exeter
He says that during glacial/interglacial transitions, increases in atmospheric C02 follow rather than precede warming, and argues that this nullifies the present causal link between high levels of CO2 and observed warming. Of course it doesn’t. Warming at glacial/interglacial timescales is driven by orbital forcing, with C02 playing an important feedback on global temperatures. This is entirely different to the situation that exists today, where changes in insolation amounts or patterns are insufficient to explain the warming we see. Either Monckton knows this (in which case his arguments should be dismissed as pure propaganda) or he doesn’t know this, in which case his understanding of the science is woeful.
Are we getting hung up on semantics here? 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, which explains the ‘lag’. Not a difficult concept really.
Others adressing the issue include the Royal Society see misleading argument No 3,, RealClimate, (read the letter by Professor og Geosciences Jeff Severinghaus) its a New Scientist Climate Myth, and it is currently No 11 in the skeptical science list of arguments.
Reply: Tone it down ~ charles the moderator
“We look forward to Mr Goddard’s next post where, having single-handedly shown how the world’s assembled climate and coral experts are mistaken”
Oh, really sir. Assembled where?? How many are feeding on the public teat?? How many are really Climate Scientists??
or just politically appointed advocates who are not being held accountable?? Why are so many other Climate Specialists now forging a publicly visible rebuttal?? Do you regard political activists hijacking public policy through bad science to be a moral issue or a “feedback” of some sort.
regards
Steven Goddard (00:06:50)
It’s worth putting back Gore’s previous sentence from that part of his film you quoted from:
“The relationship is very complicated. But there is one relationship that is more powerful than all the others and it is this. When there is more carbon dioxide, the temperature gets warmer, because it traps more heat from the sun inside.”
Of course it would have been better if Gore had said “all else being equal, when there is more carbon dioxide, the temperature gets warmer….”. That would accord with scientific understanding. In any case I suspect that everyone that is interested in this subject will know that orbital variations “drive” the ice age cycles and are amplified by CO2/albedo (and water vapour!) feedbacks.
A more serious point is your assertion:
That’s rather “Gore-like” in its omissions! First it’s incorrect since we simply don’t know what the CO2 levels were at the time of the late-Ordovician glaciation nearly 450 million years ago.Unfortunately we don’t have any paleoCO2 proxies contemporaneous with that event. Secondly it’s very well characterised that the solar constant was around 5% weaker then (late-Ordovician) than now, and so the threshold for significant glaciation was much higher then than now. So whereas widespread glaciation can occur on Earth now with CO2 levels around/below 500/600-ish ppm of CO2, during the late-Ordovician greenhouse gas levels would have to be much higher (greater than 2000 ppm and perhaps as high as 3500 ppm CO2 [***]) to suppress significant glaciation.
e.g. D. L. Royer (2006) CO2-forced climate thresholds during the Phanerozoic Geochimica et Cosmochimica Acta 70, 5665–5675
“So whereas widespread glaciation can occur on Earth now with CO2 levels around/below 500/600-ish ppm of CO2…”
then why-o-why are people so adamant we have to get back to 280 or so and that the 380 we currently have is close to or beyond a ‘tipping point’? We are currently STARVED of co2 and 280 is dangerously low for the health of life as we go into the next glaciation. I have seen NO studies that quantify the loss of life as CO2 was depleted from the atmosphere as the globe cooled. All scientists have been interested in is extinctions! Well, if a few individuals of a species survive and therefore don’t go extinct that doesn’t make killing off most of them due to co2 starvation okay does it?
This makes the one-sided arguments of warmers rather specious and empty.
The problem is the relationship that is “more powerful than alln the others” is also clearly dead wrong from the vary data set he is pointing at.
Claiming minor problems with what someone else says does not alter this HUGE deliberate falsehood.
Why are paleo proxies OK for the AGW folks to abuse but not ok when the evidence in them disputes it?
Roy and Molon: I absolutely agree – proper use of the term negative feedback is important.
On feedback Ferdinand gives a good summary too, until it comes to GCM’s and modern times. Now CO2 is not a feedback – it’s a forcing. We’re injecting it into the atmosphere.
Ozzie John and cohenite – foiunavon above has summarised the standard theory of Ice Ages. AGW theory doesn’t say that past warmings were caused by CO2, and I don’t believe they were. It just says that the present unique circumstances, in which large amounts of fossil carbon are being added to the atmosphere, will cause warming.
In fact CO2 change was never a good explainer of Ice Ages. It would only raise the question – what drives the CO2 change (then)?
“Now CO2 is not a feedback – it’s a forcing.”
All right, a feedback in AGW-speak changes the amplitude, got it. So one can’t model more than quadratic functions? Seems that a forcing could go negative in non-linear systems.
“Wrapping Greenland in reflective blankets”
http://www.telegraph.co.uk/earth/environment/climatechange/4689667/Wrapping-Greenland-in-reflective-blankets.html
A Centifugal governor is a mechanical device that automatically determines the power output of a steam engine and is an example of system control via negative feedback http://en.wikipedia.org/wiki/Centrifugal_governor
The phrase “Dangerous negative feedback” is an oxymoron with a dissemblance rating of genius level.
John PhiliP quotes:
What warming?
CO2 is a minor forcing agent, overwhelmed by other factors. Our planet is proving it to those who simply open their eyes: click
Nick Stokes (03:41:51) :
“In fact CO2 change was never a good explainer of Ice Ages. It would only raise the question – what drives the CO2 change (then)? ”
How about temperature?
John Philip (03:24:53) :
Are we getting hung up on semantics here? 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, which explains the ‘lag’. Not a difficult concept really.
Explain the concept please because I find it difficult. The difficulty I have is that I feel I have to believe it before I can understand it. Would that be correct?
David Porter
How about temperature? Well, it’s temperature that you’d be trying to explain, so that won’t do. Although it’s not too far off – heat vaporising CO2 which causes heating … is the kind of positive feedback mechanism which can promote oscillation from relatively weak drivers. But you still need a driver – orbital aberrations have the right kind of frequency.
I think the role of CO2 in this kind of feedback should not be overstated – water vapor is probably more significant.
” Bill D (22:35:08) :
Thus, warming can lead to less CO2 burial in the ocean and more CO2 release from soils.”
O.K., on the last point; where and when did the carbon become entrapped in the soil?
Organic material is sequestrated in the soil during growth, are you suggesting that during a cold period there is more entrapped, which is released when things heat up?
Can you model the time-line for the entrapment of carbon and its release on the same time scale as presented by the author.
John Philip (03:24:53) :
The whole point John is that the “powerful feedback” part is entirely unproven. The Stefan-Boltzmann law gives a very weak feedback effect of about 1 degree for doubling of CO2. Anything beyond that requires invoking even more powerful feedbacks such as water vapor, and discounting potential negative feedbacks such as clouds.
Steven’s post illustrates this nicely: if CO2 was such a powerful feedback then how come the ice core record shows that it seems to be almost completely overwhelmed by other effects?
The simple fact is we still have very little understanding of the relative strengths of the different feedbacks and how they are influenced by the climate state, despite Al Gore’s and the alarmist industry’s vociferous claims to the contrary.
Steve Goddard has excelled himself again. Posts like this will have all those so called ‘scientists’ quaking in their boots!
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?
These are not statements, just questions; as I sure do not know. If it is an artifact it needs sorting as it is very suggestive of a real difference in the temperature stability between warm and cold periods.
Alexander Harvey
Looks like a place to post this, note 100,000 years pattern in graft.
The Fermi telescope and NASA’s Swift satellite detect “in the order of 1,000 gamma-ray bursts a year, or a burst every 100,000 years in a given galaxy,”
http://news.yahoo.com/s/afp/20090219/sc_afp/sciencespaceastronomy;_ylt=AgMlEZoKo9cB4K9JUXloNxVxieAA;_ylu=X3oDMTE5djBmdHJiBHBvcwMzBHNlYwN5bi1tb3N0LXZpZXdlZARzbGsDaHVnZWdhbW1hLXJh
For the opposite point of view on CO2 and the ice ages …
You have to read Hansen’s latest paper published recently in Open (Access) Atmosphere Science Journal (but was rejected by Science and even NASA would not put out a news release on it)).
The long list of coauthors includes all the paleoCO2 experts.
He is bumping up the long-term equilbrium warming estimate to +6.0C for a doubled CO2 based on his current understanding of how the ice ages work, the now-slower-than-thought ocean thermal response time, the causes of the Antarctic glaciation (now I know why foinavon keeps bringing this up) and the Eocene thermal maximum.
Here is the full paper.
http://www.columbia.edu/~jeh1/2008/TargetCO2_20080407.pdf
The published one is here (just small changes and authors added).
http://arxiv.org/abs/0804.1126
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.
This all depends on his current understanding of how the ice works and his misunderstanding of Pangani’s CO2 estimates during the Antarctic glaciation.
“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.”
1500 years.??????? good grief!! this looks like a “get out”
Look back 1500 years and see how far humanity has come technologically. Just look back 100 years !!
The EcoDruids are in panic mode as shown by the Steig Affair
and that noteworthy attempt to involve the last man standing in this sordid affair of AGW, Antartica.
regards
tty (01:45:59)
The Ordovician occured during the Palaeozoic era.
M White (03:50:08) :
“Wrapping Greenland in reflective blankets”
I wonder if academics, like Dr. Box, ever think about the practical aspects of their proposals. It does explain why academics, like Dr. Box, should remain in institutions and not venture into the private sector.
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. This is the exact opposite of what Al Gore was claiming.
As far as Dr. Hansen goes, he put this claim in his Illinois Wesleyan presentation.
Chief instigator of climate change was earth orbital change, a very weak forcing.
http://www.columbia.edu/~jeh1/2008/illwesleyan_20080219.pdf
This claim is self-contradictory. The “chief instigator” would have to be the strongest influence in the system, because it has to be able to overcome the combination of all of the other feedbacks in order to reverse the direction which the temperature is moving. 15,000 years ago CO2 was low, H20 was low, and albedo was high – yet the temperature started rising quickly. Changes in the earth’s orbit had to be able to overwhelm the combination of CO2 forcing + H2O forcing + albedo forcing, all of which were working to lower temperature further at the time.
I taught a class of 10 year olds on Friday. The class was not about global warming, but one of the children raised the subject.
If you want the names of people who believe that Al Gore’s giant CO2 graph proves that rising CO2 leads to rising temperatures, go to any public school and talk to the brightest children. They all have been brainwashed to believe this.
Whether or not AGW is a serious concern, the Vostok graph tells us nothing about it. All that it shows is that there is a relationship between temperature and CO2 levels.
For clarity, I asked Anthony to add the following addendum to the article, but I don’t know if he is busy with CA today.
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.