CO2 report – estimated to be "highest in 15 million years"

It sure does look like more ice hockey, but this is for CO2 not temperature… where is the data for temperature in their study? Surely if they can measure CO2 for 20 million years with their ice cores they think they can measure temperature and correlate the two into some relationship? Or am I mistaken about that?

Just curoius, but is splicing Mauna Loa data onto the end of ice core graph any different than splicing modern temperature data onto tree ring chronologies? Is that better science?
I weep for the future of science…

All I can see here is “correlation is cause”. Well, women wear short skirts when the sun is shining, but I don’t think women wearing short skirts causes the sun to rise in the morning.

“By analyzing the chemistry of bubbles of ancient air trapped in Antarctic ice, scientists have been able to determine the composition of Earth’s atmosphere going back as far as 800,000 years, and they have developed a good understanding of how carbon dioxide levels have varied in the atmosphere since that time. But there has been little agreement before this study on how to reconstruct carbon dioxide levels prior to 800,000 years ago.”
Also, isn’t it assuming a bit too much to say “Comparison of CO2 Levels in Earth’s History” when it’s a core sample taken from Antarctica, not from multiple places on the Earth? Is CO2 uniform across the atmosphere? As a gas one might think so but…
What is the error rate for such measurements over such a vast amount of time? What is the accuracy and what is the confidence level in the estimate?
How come this doesn’t jive with other studies of CO2 that I’ve seen? (At the moment I don’t recall the links to them.)
Maybe someone could compare this study with other studies of CO2 over the past 20 millions of years?
To the authors of the study: Where is the raw data? How come this important paper (assuming it’s important) isn’t available to the public as Open Science? Where is the raw non-manipulated data? How was the data adjusted, please show your work with a program that audits every tiny little adjustment and tweak that is made to the data, otherwise the work is suspect. Please show all the programs and steps involved in the preparation of this paper. Please show all your assumptions and provide a scientifically based justification and rationale for such assumptions and for your conclusions. Please provide all photos and video and film and audio recordings of your work in progress especially the videos documenting the proper or improper handling of the ice cores! What you don’t have documentary video to audit your ice core handling? If not why not? If so, please provide it. Please publish all of this forthwith for review by the public that funded your study. Thank you.

So what? For me as a geologist 15 mil years is not so long ago. I find it much more frightening that just recently / 10.000 years ago there was an Ice age.

O. Weinzierl (10:40:25) :
So what? For me as a geologist 15 mil years is not so long ago. I find it much more frightening that just recently / 10.000 years ago there was an Ice age.
That Train to Copenhagen might just get derailed due to an avalanche.
-of data by empirical results…

“By analyzing the chemistry of bubbles of ancient air trapped in Antarctic ice, scientists have been able to determine the composition of Earth’s atmosphere going back as far as 800,000 years, and they have developed a good understanding of how carbon dioxide levels have varied in the atmosphere since that time. But there has been little agreement before this study on how to reconstruct carbon dioxide levels prior to 800,000 years ago.”
Translation: “There has been little agreement but this study is what we believe. There will still be little agreement”
It’s nothing more than one interpretation of the ice core samples used. This is just an opinion piece and should not be classed as science.

Yes and it was 5-6C warmer 15 million years ago . . . so why is it not warming for the last decade? 300 million years ago the CO2 level was about the same as now but the temperature was 1C lower. 450 million years ago the temperature was lower than now but CO2 was 10 times higher. How did those things happen?
http://www.freerepublic.com/focus/f-news/1644060/posts

I believe her method is called the “Carbonite Clumped Isotope Thermometer”
From he University CV:
“The work that I’ve done with John Eiler at Caltech has demonstrated that the carbonate ‘clumped isotope’ thermometer offers unparalleled opportunities for addressing a range of questions in paleoclimatology and paleoceanography. This innovative method constrains carbonate growth temperatures based on the temperature-dependent “clumping” of 13C and 18O bonds within carbonate solids, independent of any solid-fluid equilibria.”
For her to construct a temp proxy using this method she must have statistical data that contains her statistical methodology, correlation co-efficients, error bars, etc… I would also like to know how she correlated temperatures from so long ago? Does her study suffer the same fate of the Birstlecone and Yamal tree rings( divergence problems?)? If this study is so important, the entire study should be in public archives.
Also, the results of her study run against what Dr Lindzen of MIT says about the behavior of CO2 doubling. Both cannot be right.

Shortened ‘codetech’:
“…fluffery…
…sheer falsehood…. The dishonest phrasing….woman is stupid or naive… or both.
…. absolutely retarded. …
… propaganda… fear mongering…. dishonesty…”
Humm – you don’t like what you read then? Then, to be taken seriously, please refute it with something more than such insult ridden invective.

Mann & Briffa are both in the Penalty Box for Illegal Use of the Stick, so the coach has sent in Aradhna Tripati to kill off the penalties.

Please forward the data to Steve McIntyre for debunkage…

Balony!
Has anyone stopped to think about this?
By far the majority of All GHG is put into the atmosphere NATURALLY.
Mankind only contributes a spit in the ocean of GHG.
So any increase in CO2 can be attributed to nature not man.
And since the entire amount of natural increase in CO2 is almost all naturally occuring, what exactly is the big wupp?
CO2 goes up and it goes down like ocean tides. The tiny amount we contribute to it could not possibly change the natural variation.
It is like spitting into the ocean and then claiming credit for the rising tide.

snip – Adolfo, a climate skeptic, has been banned for posting inflammatory commentary that violated blog policy on several occasions, then trying several different personages ( a total of five) to get around it. His comments are no longer welcome here due to this behavior.
– Anthony

Terryskinner (10:43:37) :
“Fantastic news:
Two periods of Earth History with the same CO2 levels but temperature very different and sea level very different. Conclusion: The level of CO2 does not determine either temperature or sea level.”
Yeah, that was the first thing that struck me, too. Assuming everything in the paper is true (big assumption), CO2 apparently doesn’t have much effect on climate any more–it has “lost” 5 to 10 degrees of warming ability in 15 million years. We can continue to fertilize the atmosphere with no adverse consequences! I was just about to call President Obama with the good news.
Then I realized that this is actually terrible news. If the warming effect of this essential climate-warming gas continues to decay at the same rate, the earth is doomed, DOOMED I tell you, to an eventual permanent ice age, no matter how much fossil fuel we burn!
Our only hope is that “greenhouse decay” makes Venus habitable before we all freeze here!

“During the Middle Miocene (the time period approximately 14 to 20 million years ago), carbon dioxide levels were sustained at about 400 parts per million, which is about where we are today,” Tripati said. “Globally, temperatures were 5 to 10 degrees Fahrenheit warmer, a huge amount.”
A clean thinker reads this as current temps aren’t anywhere close to what they were in the past at similar CO2 levels, therefore, temp & CO2 evidently arent that well correlated & there must be other more significant forcing mechanisms in play that need to be considered.
Of course, the author throws in the word “sustained” to imply that’s where we are heading. Proof please ? Is that too much to ask?

Give the woman a Nobel Prize, for creativity. Or, should that be a Nobrain prize?

R Taylor (10:59:21) :
You stated:
“Why does no-one pay attention to the lag of CO2 behind temperature? The only reasonable explanation is that temperature controls CO2. There is no empirical evidence that “carbon dioxide is a potent greenhouse gas.” We exceeded the highest CO2 in the last million years by 1910. On a 100-year time scale, the greenhouse effect in the atmosphere should be instantaneous. It isn’t there.”
1) Up until the last 100 years there has not been another species pumping gigatons of CO2 into the atmo on a yearly basis. Perhaps that’s what makes our situation unique. There is nothing “natural” about pumping out CO2 and paving over 25% of the landmass of the planet. I would not expect “climate” to react in a “normal” way.
2) Normally CO2 would lag temperature increases perhaps triggered by changes due to something like the Milankovitch cycle. But CO2 levels would inch up gradually over hundreds of years. But what man is doing to the atmo by loading up CO2 is not normal so the empiral evidence will be what we experience over the next 50-100 years.
3) The effect of changes in CO2 on temp should be instantaneous? That’s wishful thinking but not reality based. We may be only experiencing the beginning of the effects of higher levels of CO2. Our grandchildren will feel the brunt of any negative effects to the planet.
It’s similar to the USA economy. Accumulate trillions in debt and wish that it won’t have an impact on the next generation who is saddled with it. Are we willing to mortgage our children with the potential consequences of +3-5C over the next 100 years?
Shiny
William

Clearly the fact that C02 was rock steady proves that mankind’s evil activity has caused recent levels to skyrocket. We are evil, the science is settled. Of course since C02 drives temperature as everyone knows, (except for the evil denialists) that historical temperatures must also have also been rock steady. Any references to the MWP and LIA are obviously lies fabricated by the evil capitalist (oops, sorry about the spittle) dogs who will stop at nothing to destroy our planet.
Remember the simple facts that prove AGW is indisputable.
1. Hot –> it is AGW. (Everywhere there are no witnesses, except Texas!!!)
2. Cold –> it is AGW. (Everywhere else except Texas, Go Texas!!!)
3. Drought it is AGW. (Texas again!!!)
4. Flood –> it is AGW. (Jim Cantouri and Texas says so)
5. Less ice –> it is AGW. (Arctic) Look Texas doesn’t even have ice –> AGW
6. More ice –> it is AGW (Antarctic) (Flaw in data must adjust.)
These simple rules never fail. Proof positive, all skeptics will burn!!!

It used to be
end of ice age
temps up
co2 up
temps more up because of
temps down
co2 lagging behind for slow slide into next ice age
now it will be, for physics does not change
end of ice age
temps up
co2 up
temps more up because of
anthropogenic introduction of far more CO2 <<<<<<
temps even more up… to that of 15 million year ago level
clathrates kicking in
fried
how about that scenario?
biosphere collapse, societal collapse, war, hunger, thirst, nuke em

“conradg (11:19:11) :
I’m not a scientist, so I can’t question the study itself or its methods.”
That may be true, but you know at this point in time some of the qualified scientists seem out of touch with reality. (This doesn’t mean that all who have qualifications are like this.)
However, there are countless failed predictions by “experts” (*cough cough* Arctic sea ice minimum 2009), whilst many “non-scientists” who study climate as a hobby and who contribute here share interesting ideas and theories which are more worthwhile than the worn out hockey sticks and computer models which the “experts” constantly regurgitate on the table.

Gary Hladik (11:21:30)
You stated: “Our only hope is that “greenhouse decay” makes Venus habitable before we all freeze here!”
Unlike Earth, Venus does not generate a magnetic field. This is significant because Earth’s magnetic field protects its atmosphere from the solar wind. On Venus, however, the solar wind strikes the upper atmosphere and carries off particles into space. This has stripped away most of the water in the atmosphere of Venus leaving only 20 ppm of water vapor in the atmo.
Venus’ carbon dioxide-rich (96.5%) atmosphere is almost 100 times more dense than the Earth’s and acts like a blanket. As a result, Venus’ surface temperature is hotter than that of even Mercury, which is twice as close to the sun. The remaining portion of the atmo is 3.5% Nitrogen. Not much O2 to breath.
Without a magnetosphere and plate tectonics Venus will remain a hot very dead world. We may be capable of emulating Venus if we can get CO2 up over 1000ppm. Should we give it a try?
Shiny
William

CO2, too subtle.
Take the temperatures from Vostok, add a few years from a volcano in Hawaii, project into the future…
Nobel!

“In the last 20 million years, key features of the climate record include the sudden appearance of ice on Antarctica about 14 million years ago and a rise in sea level of approximately 75 to 120 feet.”
As a UCLA grad I am disappointed in the lack of logic in this phrase
I thought MELTING of ice on land caused sea levels to rise. Did the ice, which suddenly appeared on Antarctica come from outer space? and where did the water for the sea level rise come from.
I don’t think that these kind of “scientific” leaps of faith reflect well on the female gender.
Signing off: a sad UCLA engineer (of the female persuasion)

The global cooling news just keeps getting better.
California and Colorado ski resorts in a snow daze
http://travel.latimes.com/daily-deal-blog/index.php/california-resorts-i-5594/

william (11:43:39) : “Unlike Earth, Venus does not generate a magnetic field. This is significant because Earth’s magnetic field protects its atmosphere from the solar wind. On Venus, however, the solar wind strikes the upper atmosphere and carries off particles into space. This has stripped away most of the water in the atmosphere of Venus leaving only 20 ppm of water vapor in the atmo.”
Well duuhhhh. We’ll have to bring a lot of ice with us, won’t we? 🙂

Shoddy Journalism is correlated with recent increases in CO2. Image how bad the media was 15 million years ago….. 😉

See this graph on Co2 and temperature during the Cretaceous and early Tertiary which does not show much correlation.
I don’t understand why there was no “runaway greenhouse effect” when C02 was much higher than today? Where is the “tipping point?”
http://www.geocraft.com/WVFossils/PageMill_Images/image277.gif

william (11:30:42) : There is nothing “natural” about pumping out CO2 and paving over 25% of the landmass of the planet.
Have you ever been outside of NYC?

“Tripati’s new chemical technique has an average uncertainty rate of only 14 parts per million.”
It’s so nice to be certain!

The global warmers are manifestly not serious — if they were, the solutions they propose to global warming would be ones that would be more likely to work. For example: a crash program of space construction to give us the capability to build big flat panels in space to shade the earth if in fact it does start to warm up. The same technology has the added benefit of being easily converted to giant solar mirrors, diverting more solar energy onto the earth if another ice age begins, halting it in its track. If you’re serious about having an effect on the earth’s climate, this is the way to be thinking — not trying to monkey around with trace gasses in the earth’s atmosphere. Note that there is ample evidence that ice ages regularly occur and we are (more or less) due for another one soon, geologically speaking.

william:
1000 ppm? You’re not even remotely close to what it would take to emulate venus. Go for 100,000 ppm AND move the Earth closer to the sun, then maybe we’ll start to see some real effects. You should really consider learning more about physics.
25% of the landmass is paved now? I guess you never fly, do you? Flying (and actually looking out the window) is a humbling experience, as you realize just how miniscule our presence is on the planet.
And Hearndon, the entire article is wrong. All of it. I’d check that she spelled her name right if I cared. There is nothing to argue, since it has clearly left the Science building and taken a stroll over to the Fiction wing.
Just google “vostok”, and you’ll discover that the “straight line” of historical CO2 isn’t even remotely close.

Does it really tell us anything different than the Scotese graph. Both T and CO2 are at geologically low levels.
http://www.geocraft.com/WVFossils/Carboniferous_climate.html

For most of the last 800,000 years the Earth has been frozen in the deepest Ice Age in 250 million years. The global climate has not been anywhere close to “normal” but has been locked in ice and tundra over two-thirds of the Northern Hemisphere. Short, 10,000-year-long interglacial warmings every 100,000 years are frankly inadequate respites from the Reign of Ice.
The data in this study are from one the most inhospitable eras ever for Life. Over a quarter of the globe has been rendered biologically inert (most of the time). If CO2 had anything to do with it, then the CO2 levels have obviously (biologically, practically, ethically) been too low.
Life florished globally during the Miocene. The Earth was a bountiful garden with huge biodiversity of plants and animals including unimaginable (today) features such as boreal tropical forests.
Warmer is Better. Most people live where it’s warmer. Almost all foods grow better where it’s warmer. Biodiversity is highest where it’s warmer — there are more species per acre in Equatorial regions and progressively less toward the poles. Warmer means more evaporation and hence more precipitation — the Ice Ages have been a 2.5 million-year-long drought compared to the norm of geologic history.
I doubt CO2 has much effect on climate, based on my reading of various studies highlighted at WUWT. But I wish it did. I have no problem with turning up the thermostat to Miocene levels. It’s not going to happen, because the Ice Ages are due to plate tectonics (Antarctica over the S. Pole). But if we could do something to raise the temp a few degrees, then we should do so, and be industrious, happy, and thankful about it.

There are those of us who know that Climate Science has been hijacked by loonies who are at the tops of all the science organizations including the Climate Science department of Wikipedia.
I looked up Dr Robert Balling, said by a 1990 BBC programme (before the new Iron Curtain fell) to be an expert on UHI. Now it looks from his stuff as if he just does his best to stay out of trouble, otherwise he’d be out of academia altogether probably. And just a short Wiki article that’s slander because at least at one time he was an outspoken skeptic and critic.
In mythology the problem of Climate Science is described as the monster the Hydra, with hundreds of heads which all had to be cut off and cauterized, otherwise several more would spring in the place of the old heads. Joanne Rowling has given the Hydra a new lease of understanding with “Horcruxes”. In Climate Science, each Hockey Stick is another head of the Hydra, another Horcrux, IMO. Each one can only be “decapitated and cauterized” by its own specialists.
I still suspect that Jaworowski (if he’s still alive) and Segalstad regard the current CO2 hockey stick as seriously misbegotten. I am still sure that CO2 escapes from the depths of firn by solution and under pressure, and that CO2 levels recorded from deep ice cores are all too low. But on this point I am still no match for Ferdinand Engelbeen, whom I regard with affection and take seriously; he doesn’t think much of Segalstad.
Can anyone help spell out something in layman’s terms? Oh, and I’d like to see other CO2 measurements done at Mauna Loa, if such exist. And why did they choose volcanic outgassing Mauna Loa when non-volcanic islands are available?

“This record is the first evidence that carbon dioxide may be linked with environmental changes, such as changes in the terrestrial ecosystem, distribution of ice, sea level and monsoon intensity.”
The only thing this type of study and the associated non-journalism proves is that our schools are failing, including our universities. Sticking with the school theme – Lets examine this statement closely, class. This EVIDENCE MAY be LINKED with environmental changes… If that doesn’t just fill you full of confidence that they are correct, you are just being hard headed. I mean after all, who needs causal evidence when you MAY be able to potentially LINK two things together. And, yes, I know I’m occasionally shouting via text. I’m the last angry hippie and I want the world to know it!
I think Dr. Dean Edell summed up a ‘link’ the best when he said “You can link french fries with car accidents if you want, but you’ll never be able to prove they cause them.”

The most recent 50,000 years of the Vostok graph would produce a hockey stick too.
http://en.wikipedia.org/wiki/File:Vostok-ice-core-petit.png
And its data ends around 1950.
John M Reynolds

I have a problem with the “CO2 is a potent greenhouse gas” phrase. It really isn’t all that “potent” when you consider the overall mix of gasses in our atmosphere. That is another example of the “conventional wisdom” being passed off as fact.
CO2 is much less “potent” of a greenhouse gas than water vapor is. There is also a natural negative feedback in that if you introduce more CO2, plants absorb more of it through enhanced growth so the more CO2 you put into the atmosphere, the faster it comes out. Also, is that response linear? I don’t know. Maybe if you increase CO2 by 10% you get a 15% increase in plant growth so you end up pulling it back out faster than you are putting it in.
Would a 100% increase in CO2 result in more than a 100% increase in biomass creation? It would be something interesting to find out. One study in 2000 by Duke University found that loblolly pines grown in an ambient atmosphere of CO2 that is 50% above normal ambient were twice as likely to produce cones, produced 300% as many cones and 200% as many seeds per tree in addition to putting on more trunk mass.

C’mon, guys! Give her a break! Haven’t you seen her picture?
If she is discredited we’ll just get more Gavin Schmidt. No one wants that.

Okay, help me out here. Am I having a senior moment, seriously. I look at the graph and see that CO2 doesn’t cause temperature changes. Am I right…or wrong? Someone, please?

“We have shown that this dramatic rise in sea level [75 to 120 feet] is associated with an increase in carbon dioxide levels of about 100 parts per million, a huge change,” Tripati said.

And from 1880 to present, a sea level rise of about ten inches is associated with an increase in carbon dioxide levels of about 100 parts per million, i.e. chump change.
75 feet vs. 10 inches? Splain, Lucy!

Michael (11:49:56) :
The global cooling news just keeps getting better.
California and Colorado ski resorts in a snow daze
And in NZ, Mt Ruapehu has just announced an extended season.

Jaworowski et al 1992
http://www.co2web.info/np-m-119.pdf
DEPLETION OF CO2 IN SURFACE SNOW (source: http://www.greenworldtrust.org.uk)
An important finding of Raynaud and Delmas (1977) was the observation that in surface firn (up to 1 m depth) at the Pionerskaya and Vostok stations the concentration of CO2 in the interstitial air was 160 to 240 ppm, respectively, whereas at that time in the atmospheric air this concentration was reported to be 310 ppm. This demonstrates that, even in snow that was not subject to longer firnification and firn-ice transition processes, the CO2 content could have been reduced by up to 150 ppm, i.e. about 48% lower than in the ambient air of the same age. This important field experiment was never repeated in the later CO2 studies.
The striking feature of the glacier data used as an evidence for a recent man-made CO2 increase is that all of them are from ice deposited not in the last decades but in the 19th century or earlier. In these studies no information was presented on the recent concentrations of CO2 in firn and ice deposited in the 20th century. The results of CO2 determination in the pre-industrial ice are not compared with the CO2 content in recently deposited snow, firn or ice but with its current levels in the atmosphere. To justify such comparisons an assumption was needed that the entrapment of air in ice is purely a mechanical process, involving no chemical differentiation of gases. However, as appears from the discussion in this report, and as was demonstrated by Jaworowski et al. (1992), this assumption is wrong.

Re: Smokey (11:47:55)
[…Conclusion: they’re lying to us about the effect of CO2, which is a beneficial trace gas that is every bit as essential as H2O to life on Earth…]
Smokey, you are correct. They are either lying, or a bunch of people are all doing the same thing wrong. The GHE doesn’t even work the way that climate alarmists claim. Allow me to explain.
Lets take a look at a radiance plot from one of the stations in the SURFRAD network.
http://www.srrb.noaa.gov/cgi-bin/surf_check?site=desr&mos=June&day=2&year=2008&p1=dpsp&p5=dpir&p6=upir&ptype=gif
This is a plot of the observations of downwelling solar, downwelling IR and upwelling IR during a cloud-free clear-skies day at the Desert Rock, NV SURFRAD station. Do you notice anything odd? I notice that there is no day/night signal in the downwelling IR, even though upwelling IR increases up to 200 W/m^2, a 50% increase during daylight hours. How can that be? If the GHE worked the way the alarmists claimed (atmospheric GHG’s absorb upwelling IR and re-radiate half back towards the surface) there would have to be a day/night signal in the downwelling IR, but…there is none. That is because the GHE doesn’t work the way they claim.
Heinz Hug is correct. No tropospheric gas emits energy due to radiative decay, because the rate of collisional de-excitation is much more rapid than the radiative decay rate. In other words, IR-absorbing gas molecules lose any energy they gain to molecular collision, or conduction, to the surrounding gas molecules (~97% of which is O2 and N2) before they ever get a chance to radiate any of it. Convection and adiabatic cooling further serve to prevent radiative decay as the atmosphere loses KE as it rises.
Well then, if that’s true, where does the downwelling IR come from? All of the IR that downwells from the troposphere to the surface is the latent energies of condensation and fusion released by water vapor as it changes phase at altitude in the atmosphere (with half of those energies having been emitted upwards, of course). These are processes that are unaffected by the day/night cycle and explain why there is no day/night signal in the downwelling IR.
There is also a small amount of downwelling IR received at the surface due to stratospheric ozone because ozone radiates at wavelengths (wavenumber (^-cm) 1000-1100) that the troposphere is mostly transparent to, but it is very minor in comparison. (Stratospheric atmosphere densities are too sparse, and collisional de-excitation rates are too slow to prevent radiative decay).
Take a look at figure 1 in this paper.
http://esto.nasa.gov/conferences/estc-2002/Papers/B4P2%28Mlynczak%29.pdf
This is a color diagram depicting cooling (due to radiation) in the atmosphere from the surface to 100 mB across the IR spectrum of wavenumber (cm^-1) 0 to 2500. As the authors state: “This figure clearly illustrates that far-infrared emission by water vapor is responsible for cooling the atmosphere from the surface to around 200 mb. The bulk of the free troposphere cools radiatively in the far-IR portion of the spectrum.” The authors did not point out (and I don’t blame them, they do work for NASA, job security and all that) but I will, the lack of cooling (radiation) between wavenumbers (^-cm) 600 to 700, where CO2 is active. In fact there is no cooling (radiation) in the troposphere that can be attributed to anything but water vapor. Only water vapor radiates in the troposphere.
I would also like to point out in figure 1 the strongest cooling seen at ~300 mB. As water vapor rises through the atmosphere, if it fails to condense or encounter a nucleation seed, as it passes ~700 mB (where a temperature of 0C is generally encountered) it continues to rise as supercooled water vapor. Upon reaching ~300mB, where the temperature is ~ -40C, the water vapor undergoes spontaneous crystallization due to crystal homogeneous nucleation, releasing both of the latent energies of condensation and fusion all at once. This, together with the shift of the peak of the Plank function described by the authors is why the cooling signal is so strong there.
Well, there you have it. CO2 and some of the other trace gases in the atmosphere do absorb IR, they just don’t radiate any of it in the troposphere. Those trace gases have no effect on surface temperatures. The overall calculated average annual planetary surface temperature may have risen a bit in the last one hundred years or so, but it did not have anything to do with CO2, or any other trace gas.
AGW is pure bunk.

O. Weinzierl (10:40:25) :
So what? For me as a geologist 15 mil years is not so long ago. I find it much more frightening that just recently / 10.000 years ago there was an Ice age.
I am also a Geologist and even more frightening is the Four KNOWN Glaciations and Interglacials in the Pleistocene. Pray tell what caused THOSE temperature variations?

super critical (11:21:32) :
“I should like to propose an alternative interpretation; that the data reflects an absolute decrease in atmospheric O2.”
When we give the results of chemical analysis, it is always on a percent concentration basis (per mass or volume) of the total (100%), the total mass from which the sample comes is practically irrelevant. So when CO2 concentrations increase, it does indeed mean that atmospheric free oxygen had to have also decreased by the amount of O2 in the new CO2, assuming, of course, that all of the O2 for the combustion came from the atmosphere. In the case of burning hydrocarbons, this is almost always true. It is interesting to note that the H also bonds with O2. At the same time, the entire mass of the atmosphere is increasing, but only by the mass of the additional C & H atoms. Obviously, the extra H2O produced does not stay in the atmosphere very long, and in any case the amount is nearly null compared to the amount of water already on the surface of the planet (as is also the case of CO2 vs the total atmosphere). It is also interesting to note that the C & H atoms involved have not seen the light of day, so to speak, for a very long time, but they were also part of the atmosphere at SOME point in the distant past.
As for the ice core records, most people do not realize this, but CO2 is the only atmospheric constituent for which special sampling procedures have been developed. To quote from the abstract of the description of a newly developed dry extraction technique, this is because of the “well known water artifacts” when testing for CO2. Yes, I, for one, DO well know what the “artifacts” are when the ice starts to melt – higher concentrations of CO2. In other words, unless those results are being compared to “snowball earth”, they are totally invalid, and certainly not comparable to measurements taken in the tropics.

william 11:30:42
I’m interested in your claim that over 25% of the landmass of the planet is paved. Do you have any sources for this statement?

25% paved? Good lord, someone needs to get outside the city once in a while.
According to National Geographics, in the continental US, 20% of land mass is within 500 meters of a paved road. Within 500 meters!!! In the continental US!!! Add Alaska in and that number plummets.
What fraction of 1% do you think that number would be for Africa, China, South America.
25%… please.

The hockey stick (shown above) does not appear anywhere in the paper. I’d guess someone at UCLA news borrowed it from Wikipedia, or IPCC.
However, I was appalled to find
“These results show that changes in pCO2 and climate have
been coupled during major glacial transitions of the past 20
myr, just as they have been over the last 0.8 myr, supporting
the hypothesis that greenhouse gas forcing was an important
modulator of climate over this interval via direct and indirect
effects. Variations in pCO2 affect the radiative budget and
energy balance of the planet.”
When the graphs included had too few data points to determine whether temperature of CO2 leads:
“The data presented do not preclude alternative
mechanisms for driving climate change over the past 20 Ma;”

anna v says:

The site this appears in does not seem to be a geology site, it is rather a pot pouri site from biology to ….
I will be very surprised if it is peer reviewed. I spent some time on http://www.sciencemag.org/about/ and could find nothing about peer reviewing. Does anybody have a link to the acceptance policy?

Are you seriously telling me that you haven’t heard of Science? It and Nature are probably the two most prestigious interdisciplinary science journals in the world! Many scientists would probably sacrifice their first-born child to get a paper in there.

steve and tellboy
You need to do some reading over at http://pielkeclimatesci.wordpress.com/ and yes I mispoke I should have said man has altered significantly 25% of the surface of the earth on the way towards 50%. If you disagree with the effects that can have on climate then take it up with Peilke Sr and the hundreds of studies he’s highlighted on his blog.
And by the way I do get out of the city and all I see are shopping malls and commercial buildings going up where cornfields used to be. Oops those cornfields used to be natural prairies that covered the Midwestern United states, except they don’t exist anymore as they been ploughed under. Remember the dust bowl?
Increased CO2 = higher temperatures. Please provided the name of one reputable scientist that disagrees with that. Even McIntyre and McKitrick do not argue with AGW on first principles. It’s because it’s not arguable.
Shiny
William

William,
Actually, as I just pointed out in response to a question above, the added “gigatons” need to be reduced by the mass of the O2 in those new CO2 molecules, the O2 was already present in the atmosphere, as well as reducing it by the additional mass of O2 tied up as new water molecules. Please recalculate your results with these new assumptions, the previous results are not quite correct.
The new study in question is intimately tied to ice core measurements, which are very questionable.
Are you a “reputable scientist”?

I think this response should be noted! It’s by a retired Scientist, Fred H. Haynie, who took time to reseach AGW. This is what he found! He has a very interesting research from the results of Ice Cores!
http://www.kidswincom.net/climate.pdf
You can see my article here: http://www.globalwarminghoax.com/e107_plugins/forum/forum_viewtopic.php?1038
Mr. Haynie is looking for some Scientists to review his work! I hope someone here can get ahold of Him and help!

I just did a google “Aradhna Tripati UCLA”, as already predicted this article has been rapidly published – 7 google pages worth of hits already!
This young geologist is going places – a promotion is surely coming soon! I sense a high level position on Government Science Committees too.

man has altered significantly 25% of the surface of the earth on the way towards 50%.

And that is automatically a bad thing? Insects have “altered” pretty much 100% of the land surface. So have nematodes. But if it is “altered” by a non-human life form, then I suppose that is ok and “natural” whereas humans are not “natural” and any “alteration” caused by us is bad?
A being “alters” anyplace it exists. Any place it excretes waste is altered, the atmosphere that it breathes is “altered” any place it puts its foot is “altered” and anywhere it disturbs a plant or animal for food is “altered”.
Lets not forget that much of this “alteration” as allowed for much greater food consumption or health conditions. The condition of the human being was much worse only a couple of hundred years ago. During the Roman Empire, 85% of the people born did not make it to 35 years of age. That number didn’t change much until the early 1800’s.
Due to this “alteration” we have meat and a wide variety of vegetables to eat year round. Back in those days human diet was much worse and health was much worse. You ate only what grew in your local area when it was in season. There was no such thing as long term preservation such as canning or freezing of foods.
What tickles me most is when I hear a vegan talking about how bad our ecosystem is. They have the most unsustainable lifestyle there is and if it wasn’t for a system that uses a tremendous amount of energy to transport fresh veggies to them from around the world, they would be outside eating bark in the winter and would starve to death.
Sure, take things back to the way they were in the 18th century. Most of us would never live to see our 25th birthday. Some life that is. Yeah, we wouldn’t have much cancer and heart disease because we would die from something else much sooner.

Lashaffer and Smokey
I’m actually a climate skeptic and view the people who post at RC as those who worship on the altar of AGW. I consider myself a “warmer” and my views are consistent with Dr. Roy Spencer who also believes that increased CO2 causes warming. How much warming and understanding clouds and whether they are a +/- feedback is really the issue at this point. I find most of the comments here to be very similiar to those at RC in that you are at “polar” extremes on the topic as “deniers” of the possibility of AGW. I feel the truth is somewhere in the middle as Dr. Spencer does.
Shiny
William

Okay, here’s my problem. We’re fairly sure the Midieval, and the Roman Warm Periods were as Warm, if not warmer, than the present, right?
Then shouldn’t the CO2 levels, due to out-gassing from the warmer oceans, be about the same? Wattsupwiththat?

Seriously, is the gist of this extract, a claim by A. Tripati that the increase of 100 ppm of CO2 up to around 400 ppm could raise the sea levels by 75 feet, because she figures those were the facts 14 million years ago?
Hell’s teeth, her parents will have paid good money for her education and she comes up with that. They must be tearing their hair out in despair.

Makes sense to me. Temperatures were 5-10 deg F (very scientific we are) higher I’ll take 7.5, and sea levels were 75-120 feet higher I’ll settle for 100; and there was no ice anywhere.
Now just imagine how much land area was inundated by that 100 ft sealevel rise, so we have a considerable increase in the percentage of earth surface that is ocean, and an even bigger increase in the percentage that is open water (no ice), and the earth is 7 1/2 deg F hotter.
Surely that results in massive outgassing from an even bigger amount of ocean than we have now. I could believe that is enough to get the CO2 level up to 387 ppm.
Wonderful work Professor Tripati. So what does that mean for today; since 15 million years ago the earth was quite different from today, including its climate. Just think of how humid it might have been with even more ocean that was hotter.
Glad humans weren’t around to mess up that lovely place back then.

Aaron W
William is correct to say that c02 does have some heating effect – only it is a marginal one, or else an extraneous factor. When its saturation window closes then adding more doesn’t actually increase the temperature – it only shortens the absorbtion distance. That means that if there were 100ppm in the atmosphere, it would have th esame effect as 500ppm – only 500 ppm would just shorten the distance of absorbtion – it wouldn’t increase the temperature beyond 100ppm

“”” Joel Shore (14:02:33) :
anna v says:
The site this appears in does not seem to be a geology site, it is rather a pot pouri site from biology to ….
I will be very surprised if it is peer reviewed. I spent some time on http://www.sciencemag.org/about/ and could find nothing about peer reviewing. Does anybody have a link to the acceptance policy?
Are you seriously telling me that you haven’t heard of Science? It and Nature are probably the two most prestigious interdisciplinary science journals in the world! Many scientists would probably sacrifice their first-born child to get a paper in there. “””
Well Joel; the paper is actually in Sciencexpress; it hasn’t really been published in SCIENCE.
I’d send you a copy of the paper; but since it is likely copyrighted that wouldn’t be kosher; so you’ll have to get it yourself; well I’m sure your institution has access to it.

The trouble is, just as whether you believe in treenometers, ice cores can give you any finely resolved assessment of CO2 levels to, say within plus or minus a hundred years or two: and for that matter to any useful range of precision either. Personally I doubt it very much.
Kindest Regards

So the last time CO2 levels were this high temps were 5 – 7 degrees higher. This just begs for the next question: If CO2 levels drives temperature, why isn’t it hotter today? Obviously the direct linkage of CO2 levels and temperature doesn’t work. It would seem to me this research should be used by us “deniers” that in fact CO2 levels are pretty much bit players in driving global temperatures.

Al Gore’s investment company is based here in London, actually

RJK (15:19:18) :
So the last time CO2 levels were this high temps were 5 – 7 degrees higher. This just begs for the next question: If CO2 levels drives temperature, why isn’t it hotter today?
[…]

It’s very easy to understand.
At the Phaerozoic Eon scale, geological processes overwhelm the secular relationship between CO2 and temperature… Then from 1900-1977 and since 1998, local variability has obscured the secular relationship between CO2 and temperature.
😉

“We estimate the permeation coefficient for CO2 in ice is ∼4 × 10−21 mol m−1 s−1: Pa−1 at -23°C in the top 287 m (corresponding to 2.74 kyr). Smoothing of the CO2 record by diffusion at this depth/age is one or two orders of magnitude smaller than the smoothing in the firn. However, simulations for depths of ∼930-950 m (∼60-70 kyr) indicate that smoothing of the CO2 record by diffusion in deep ice is comparable to smoothing in the firn. Other types of diffusion (e.g. via liquid in ice grain boundaries or veins) may also be important but their influence has not been quantified.”
http://www.ingentaconnect.com/content/igsoc/jog/2008/00000054/00000187/art00012?crawler=true

In Britain girls wear shorter skirts in the winter. As a result of this more children are born the following autumn than at any other time of the year and humans are bad for the planet. The message is clear – mini skirts harm the environment. This UN backed study concludes that women should wear burkas and that a green-Marxist-Islamist ideology can save the planet, which is in line with George Monbiot’s activism and Respect Party.

Too soon to tell as others have noted. The implications aren’t clear.
We see only an abstract that isn’t too clear and a press release for UCLA news. The PR writer put in what he wanted to put in. And he selected quotes which may or may not mean anything. And he put in graphs he got from somewhere?
The first part of the actual abstract says she is using a boron/calcium ratio method to measure CO2 for 20 million years.
That is the science part. It may be successfully challenged or not. We don’t know yet.
The abstract continues with a second part that sounds like editorializing or off hand remarks about temperatures and glaciers and CO2 levels.
It isn’t clear if the second part is related to the paper or just seems like a good idea by the authors. And we won’t know until it is published.

william (14:31:06) :
Sorry to rain on your warming parade, william, but most industry in the US has left the building. Perhaps the leaders of this country want to save the Planet by making all US citizens peasants.
Now, with this .0001 increase in atmospheric C02 over 100 years, why don’t you post up your favorite pictures of the ocean showing us the 100 foot rise?
But I’ll do you the favor: Tomorrow I will drive by Battleship Row in the Suisun Bay and let you know how much the sea has risen.
And maybe you should check into Relative Humidity and see how much % of air is displaced at RH=50%.
Your displacement of 100ppm C02 is the equivalent of 1 x 10E-10 %.
Your CRH is astronomically insignificant.
Doesn’t sound like a planet cooker to me. If we do get to 1000ppm C02, the most likely thing to happen is the Earth will grow plants more abundantly, like it used to do before Ice Ages hit and brought much life to a screeching halt.
Al Gore has it upside down and inside out: A warming planet is likely to result is slightly less landmass, but an incredibly more abundant ecosystem.
Speaking of Ice Ages, have you stopped to ponder why the call it an Interglacial? It’s because the Ice never really left, it’s just temporarily receeded.
Now that is truly humbling. Man has zero control over the Ice. If it decides to trundle on down over the top of us, what are we to do about it? The very same thing we can do about warming into the next Global Tropical Paradise:
Absolutely nothing.

I can’t imagine that this discussion was significantly different 100 years ago, nor will it be 100 years hence, but I do believe that today’s “Chicken Little Climate Paranoia” on the part of the public was non-existent then and hope it will be so again in less than 10 years. The difference of opinions in what causes what regarding the weather is not the frightening aspect; it is that the most ignorant among us (politicians) have taken to the streets and are using the doom-and-gloom side of the argument to scare the public into supporting their crazy “solutions” to climate warming. It’s pure and simple extortion without regard to the real welfare of the people who elected them into office. (Yes, I know that the people are just as guilty for their choice at the ballot box.)

Robert, are you saying we can produce all the CO2 we want for 800 years???? Yes!!!! I pledge do my share of heavy breathing.

It is certainly difficult to separate the hyperbole from the salient. Dr. Timothy Patterson, Professor of Geology at Carleton College in Ottawa has published numerous articles about geology and climate as well as given many presentations on that subject. One presentation that might be relevant is:
http://www.tcsdaily.com/article.aspx?id=010405M
20 million years is relatively short geologically and the correlation [not causal relationship] between CO2 and temperature is fairly weak geologically. Temporally, the concentration increases of atmospheric CO2 follows temperature increases with an approximate 800 year lag.
According to Dr. Patterson, atmospheric concentration of C02 has been as much as 15 times present levels with temperatures approximately the same. Dr. Patterson has been a vocal critic of the CO2 theory of climate change.

Let me ask One More Time. Why weren’t CO2 levels as high during the MWP as Today?
Is it the lack of SUVs at King Arthur’s Court?
OR, is this run-up from 280 ppm all due to OUR SUVs?

william (13:47:07) : “…So what will it be, ignore the possibility that gigatons of CO2 added to the atmo every year is a problem or take some kind of reasonable preventive action to prevent some or all of the potential consequences that scientists are pointing out?”
The “preventive actions” proposed are neither reasonable nor are they proven to be preventive.

Smokey says:

All skeptics are saying is: “prove it.”… Empirical facts only, please.

Which is eerily similar to what “skeptics” of evolution are also saying. In fact Kent Hovind has a $250,000 challenge out “to anyone who can give any empirical evidence (scientific proof) for evolution.” ( http://www.kent-hovind.com/250K/challenge.htm ) And, he hasn’t paid up, which would seem to me by your logic to mean that evolution isn’t a very good theory either!

Wow I am really worried now,since I used to work in greenhouses with CO2 levels over 1,000 ppm.The plants never seem to complain,but then again they could be from Venus on vacation.Maybe that was why I had to visit the barber twice a month for haircuts?
Yes it is true that large greenhouses does have elevated CO2 in them because as growers knows,it greatly enhances growth and makes the plants look great! Recall those new bedding and vegetable plants newly arrived at the local nursery,how compact and dark green they are.Then when you take them home and plant them,they quickly loose that lustrous look.That is because they are now in LOW CO2 atmosphere,thus their robust health took a nosedive,to a lower level.
This paper may actually be accurate in the claims of CO2 levels in atmosphere over 15 million years,but fails miserably when trying to claim that it directly affect temperature changes.I see Bill Ellis has already exposed that,ROFLMAO!…… not even close.
I wonder how many people realize that at THIS time in history,the CO2 levels in the atmosphere are in the bottom 1% historically by volume,therefore very low levels at THIS time?
Talk about lack of historical proportions,sheesh!

CodeTech (12:12:16) : “And Hearndon, the entire article is wrong. All of it. I’d check that she spelled her name right if I cared. There is nothing to argue, since it has clearly left the Science building and taken a stroll over to the Fiction wing.”
Agreed, CodeTech….and agreed about the “criminal” nature of this nonsense. In any other field, someone would be sued for malfeasance.
Why do we put up with it in Science??? That mystery remains to be solved, but all of it is unacceptable.
And if public money is being used to fund any of this….then don’t even get me started…..
Chris
Norfolk, VA, USA

“Which is eerily similar to what “skeptics” of evolution are also saying. In fact Kent Hovind has a $250,000 challenge out “to anyone who can give any empirical evidence (scientific proof) for evolution.” ( http://www.kent-hovind.com/250K/challenge.htm ) And, he hasn’t paid up, which would seem to me by your logic to mean that evolution isn’t a very good theory either!”
Not REMOTELY simliar at all, Joel.
You are comparing….once again…apples…to blocks.
You have no business putting being skeptical of evolution and skeptical of AGW even in the SAME ROOM or mention them in the same sentence!!
MAJOR BS!
Chris
Norfolk, VA, USA

Joel Shore likes smearing people with the “you are all creationists” epithet:

Which is eerily similar to what “skeptics” of evolution are also saying. In fact Kent Hovind has a $250,000 challenge out “to anyone who can give any empirical evidence (scientific proof) for evolution.”

The big difference, Joel, is that the evidence for Evolution does not consist of a bunch of hastily cobbled-together computer simulations that have to be fudged to get the answers they want.
Fail.

Joel Shore (14:02:33) :
Are you seriously telling me that you haven’t heard of Science? It and Nature are probably the two most prestigious interdisciplinary science journals in the world! Many scientists would probably sacrifice their first-born child to get a paper in there.
Thank you,Joel, I only knew the published paper and did not recognize the site as being the same . There is an ancient greek proverb: ” it does not come alone” , talking about all age and mental deterioration :).
Nevertheless, I would still like a link to the peer review policy, if anybody has managed to find it. This paper the way it is presented in PR seems to be bizzare.

It’s getting that the Hockey stick shape is becoming a religious symbol to the Warminists….
They send young women to incense filled rooms armed with their hockey sticks and bones to shake rattles, while chanting arcane magiks, conjuring forth mystical graphs and statistics…. 😉
…. A rather creative field is this climate science. More an artform than science actually.

Wow, the amount of hostility to science is staggering in this blog. Apparently, [snip]
Reply: Change your tone or post elsewhere. ~ charles the moderator

Well, if the CO2 levels were the same as today, but the temperatures were 5 to 10F warmer, then that would be evidence that CO2 is not a climate driver.
Wouldn’t it?

Let me see, AGW skeptics are to Real Climate scientists as Creationists are to Evolutionists . . because neither Real Climate scientists or Evolutionists can prove that their theories are true . . . Joel shore.
Is there not a fallacy of reasoning here? If theory A cannot be proved and theory B cannot be proved then they must be either both true or both false. Therefore it is impossible to criticise theory A without also attacking theory B.
I think Joel should ask for a refund from his philosophy class.

Richard Sharpe says:

The big difference, Joel, is that the evidence for Evolution does not consist of a bunch of hastily cobbled-together computer simulations that have to be fudged to get the answers they want.

First of all, that isn’t what the evidence for AGW consists of either. Second of all, you can find very similar complaints made about evolution.
Look, my point is simply this: The case of evolution shows us that people can always make arguments claiming that there is not empirical evidence to support a scientific theory if these people have a strong enough desire not to believe the theory. It is simply impossible to provide compelling evidence to someone who has set their standard of evidence to a level that cannot realistically be met. If they set themselves or people like them as the judge and jury of the evidence then the scientists can argue from now to eternity and it ain’t going to change theses people’s minds.
And, in both cases, we see the same pattern: namely a dramatic divergence of views between the scientific community in the field and recognized scientific authorities (like NAS and AAAS) vs “skeptics” of the theory, with the scientific authorities finding the evidence quite compelling while those dead-set against it do not.
There are two ways to explain this divergence: Either there is massive conspiracy, fraud, or delusion in the scientific community OR there are some people, some of them scientists and engineers but only a few of them actively publishing in the field, who because of their own biases find it very difficult to accept the evidence. Which of these do you think sounds most reasonable?
savethesharks says:

You have no business putting being skeptical of evolution and skeptical of AGW even in the SAME ROOM or mention them in the same sentence!!

What about when Roy Spencer ( http://www.tcsdaily.com/article.aspx?id=080805I ) is in the room?

Phil, I get that absorbed IR will heat the temperature in the air. But to affect the weather (IE cold fronts, warm fronts, pressure gradients, etc), that warmed air would then have to change the temperature of the oceans such that the jet stream and water cycle is changed to a degree large enough to overcome the self-limiting parameters of climate zones. Warm air is a very inefficient way to warm an ocean. It can only warm the very top mm layer, which then evaporates it back into the air nearly at the same time. Please tell me how CO2-warmed air involves itself in this cycle. Please use peer-reviewed mathematical calculations showing that longwave radiation is a more powerful heat source than shortwave radiation on ocean temps and that equatorial wind and current oscillation is no longer largely responsible for SST variations.

pwl (10:36:53) :
How come this doesn’t jive with other studies of CO2 that I’ve seen? (At the moment I don’t recall the links to them.)
___________________
Please forgive me for being a grammar-Nazi, but it’s “jibe”, not “jive”.

Joel Shore (14:02:33) :
Are you seriously telling me that you haven’t
heard of Science? …Many scientists would probably
sacrifice their first-born child to get a paper in there.
Not to mention their scientific integrity!

i sure know its really gonna be great when all the leaders stop talking and outting into action all their most cherished objectives

Pamela Gray: You are getting yourself confused by trying to figure out how the heating occurs, which may be a subject of interest but is essentially irrelevant to the fact that the addition of greenhouse gases puts the earth – sun -space system out of radiative balance (i.e, the earth is receiving from the sun more energy than it emits back into space). The only way for this radiative balance to be restored is for the earth to emit more radiation back out into space and it does this by warming. Yes, the oceans have a large thermal inertia and explain why the process of restoring radiative balance takes a while.
However, no amount of worrying about how the solar and infrared radiation gets absorbed by the air, the oceans, etc. is going to get you around the First Law of Thermodynamics.
vrig: Your conclusions about how much fossil fuels are available are at odds with the peer-reviewed literature on this subject. See, for example, here http://www.sciencemag.org/cgi/content/abstract/sci;302/5652/1923 . The big player is coal, although there are also quite a bit of hydrocarbons when you count more exotic sources like the Canadian tar sands. That Science paper estimates the carbon in fossil fuel reserves as being 4000 gigatons of carbon (GtC) for conventional resources to 15,000 GtC for conventional plus exotic resources, which yields a range of concentration in the atmosphere from 1200 ppm to 4000 ppm. (I’m not sure exactly what their assumptions are concerning ocean and biosphere uptake of CO2.)

LOL: J.Hansford (23:52:23) :
It’s getting that the Hockey stick shape is becoming a religious symbol to the Warminists
Undoubtely a phallic symbol, as you indirectly suggest.

Joel Shore:
“And, in both [evolution and AGW] cases, we see the same pattern: namely a dramatic divergence of views between the scientific community in the field and recognized scientific authorities (like NAS and AAAS) vs “skeptics” of the theory, with the scientific authorities finding the evidence quite compelling while those dead-set against it do not. ”
Nonsense. There are no scientific positions taken against evolution. And for good reason – we have fossil evidence of a myriad of intermediate species, ordered sequentially in time showing a clear picture of how each form leads to the next and the next; we know how mutations in genes acting through environmental pressure favours the success of the most suitable phenotypes. But you know all that anyway.
Moreover, in order to dismiss evolution you would have to come up with an alternative explanation. Either a) all species were created by the Diety in the forms that have been layed down in the fossil record or b) . . . erhm, there is no explanation b). There is not. If you doubt this, try and think of any alternative explanation. Consequently, some form of evolution (gradual change or punctuated equilibrium) is the only theory that does not involve divine intervention.
Now we come to AGW. Can we think of any alternative explanation? Well, how about natural variation? Not only is this the alternative commensurate with natural law, but it fits with our understanding of an ever changing climate. Unless you believe in hockey sticks, that is.

Vincent says:

Yet, many scientists would disagree, including Lindzen, Spencer, Christy and Eschenbach. This naive extrapolation of the Clausius-Clapeyron equation is fundamental to the climate model forecasts of runaway warming, yet the resulting behaviour of clouds and convection as a function of this hypothesised warming is ignored completely.

Actually, I don’t think that many scientists still disagree about the effect of water vapor itself…although certainly clouds remain a source of uncertainty. And, clouds and convection are not ignored in the climate models, although as I said, there is a fair bit of uncertainty in regards to clouds. Nonetheless, in all the different climate models produced by all the different groups with all the different parametrizations of clouds, there has not been any that have managed to come up with a significant negative feedback involving clouds.

If the climate behaves in this way, then why should this feedback only kick in from levels of CO2 that humans have caused rather than previously?

They have. That’s the point. The sensitivity of the climate to past changes (such as the changes in forcings between the last interglacial and now) is what helps provide an estimate of the climate sensitivity…and supports the idea that the range that is seen in climate models is also the range that appears to operate in the real climate system.

John says:

While one might be right to point out that we wouldn’t really want a Carboniferous climate today, I find myself asking whether there is any evidence that, for example, the oceans became so acidic that they destroyed the shells of sea creatures or evidence of any of the other doomsday scenarios currently being thrown around.

It is not primarily the CO2 levels that matter as the rapidity of the rise. CaCO3 from limestone rocks acts to neutralize the oceans but it is a slow process relative to the rate at which we are increasing CO2 in the oceans. There is one possible past analog to the current situation, which is the PETM event that occurred about 55 million years ago when there was a large release of greenhouse gases and significant warming (although I don’t think they have good enough time resolution to say how rapid the greenhouse gas increase was relative to today). And, I believe that there were a lot of extinctions and changes in sea life around that time. I’m not really up on the literature for that event but there are a lot of papers about it over the last several years because of the analogy to our current “experiment”.

P Gosselin (02:03:37) :
If CO2 was steady for thousands of years, then why did temps fluctuate so much (Roman Optimum, MWP and LIA)?
Proves to me that CO2 is not a driver.

That’s the dichotomy.
If ice core-derived paleo-CO2 values are quantitatively correct – CO2 and temperature have only correlated for about 30 years out of the last 600 million years in a manner supportive of the AGW position.
If fossil plant stomata-derived paleo-CO2 values are quantitatively correct – A century-scale rise from 280ppmv to 380ppmv CO2 is wholly unremarkable and has been the norm in every warming period since the early Holocene; including the MWP, Roman Warming and Holocene Thermal Maximum.
So… Either CO2 didn’t cause the late 20th century warming; or the late 20th century rise in atmospheric CO2 levels was mostly caused by the late 20th century warming.
The fact that delta-CO2 lagged behind delta-T in the Pleistocene ice cores and that fossil plant stomata data suggest that Holocene CO2 levels have always risen to the mid to high 300’s ppmv… Coupled with the total non-correlation of temperature and CO2 throughout most of the Phanerozoic tells this geoscientist that the IPCC are barking up the wrong tree.

obviously joel, you were not paying attention to my post. The fact that Venus has an extremely long day precludes any reasonable similarity with Earth.
There has been no evidence to suggest that Venus had any significant water in the past as that would have undoubtedly helped reduce CO2 via inorganic processes. Since there is virtually no signficant power coming in to the surface from the Sun, there is no “greenhouse” effect present. The surface is just not being heated by large amounts incoming solar radiation there. Note that the actual greenhouse effect is really the blocking of convection rather than the radiative blocking of some fraction of IR.
As for CO2 doubling effects being closer to 3 or to 4 W/m^2 , it totally depends upon what altitude you desire to select for the comparison point. It also depends upon whether you take into account only absorption or whether you consider absorption and emission.
“…unlikely to be in the cards…” That’s a good laugh. At the Earth’s surface, there’s about 10 metric tons of atmosphere above you in every square meter column of atmosphere. To have the same amount of CO2 in our atmosphere as that of Venus would require the addition of over 90 metric tons of CO2 in every square meter atmospheric column over the surface of the Earth. Atmospheric pressure would have to become around 93 bar at the surface. It still would not be very close to the same thing as we’d need to more than triple the atmospheric nitrogen amount as well.
And more warmth leads to more water vapor cycle which leads to more convective heat transfer and leads to more cloud cover and greater albedo – reducing the incoming radiation reaching the surface . So What! Feel free to presume for no reason that we just happen to live with the one CO2 doubling range where by the effects are super amplified by h2o so the results are far greater than any additional CO2 doublings or any prior doublings. Just remember – as mentioned – there’s about 11 CO2 doublings (actually halvings) that one could have with similar consequences for power absorption AND the net results of all of these – plus all other effects of GHG gases amounts to a total of around 33 Kelvins rise. Essentially, all of this is due to h2o vapor with CO2 contributing a total of around 10% so it averages around 0.3 Kelvins per doubling for CO2 only. Considering that H2O is going to exist in the atmosphere regardless of the presence of any CO2 or minor variation in T, you now have the limitations of just how much of that positive feedback you want to claim for this rather unique CO2 concentration that is so much more sensitive LOL.
You cannot quantify CO2 averaged between clear sky and clouds. Clouds can essentially block IR totally – that means there is no CO2 blocking effect difference. What does it matter that CO2 would block 3.7 W/m^2 when you have practically 100% blocking due to cloud cover?
This of course brings up another major falacy. That is the presumption that this is a radiative only environment with a unique temperature required for radiative balance. If you consider a new variable, cloud cover fraction (for now a single number of some nonexistant typical average cloud) that can vary between 0 % and 100 %. If you plot incoming solar power versus outgoing IR, you will find that the intersection of those curves defines this balance point. I will not go into the details here of the details concerning how but suffice to say clear sky incoming solar is far greater than totally overcast sky incoming solar – as is outgoing IR. What it means though is that one can change the cloud cover and achieve radiative balance without changing the temperature even though there is a change in atmospheric absorption. IE, there’s not a unique temperature required which must rise if there’s an increase in CO2 absorption gases in the atmosphere.
BTW, another little tidbit concerns the fact that a small rise in ghg absorption also tends to cause a reduction in atmospheric layer temperatures in order to maintain energy balance due to the geometry of the system. Greater absorption causes greater emission for a given wavelength at a given temperature.

william (18:17:38) :
Ah. So you work in the steel industry? I have heard nothing from you about shutting that hugely CO2 polluting industry down.
According to your lights the industry you work in is destroying the planet. Have you no shame?
Honor dies where interest lies?

Vincent:

Nonsense. There are no scientific positions taken against evolution.

Well, there are plenty of people out there who are claiming there is no empirical evidence for evolution. And, there are indeed scientists (including Roy Spencer) who don’t believe in it. Of course, neither you nor I think they are correct but that doesn’t stop them from making these arguments. And, that is exactly my point. One cannot judge the state of the science by whether there are people vocally claiming that there is not the empirical evidence and so on and so forth.
That is why the scientific enterprise has evolved the way it has (pun sort of intended), with peer-review and bodies of scientists themselves set up to evaluate the current state of the science.
And, by the way, I am not claiming that the exact quantitative amount of uncertainty exists in evolutionary theory and in AGW. I agree that there are at this point larger uncertainties regarding climate sensitivity than would be true for analogous issues in evolutionary theory.
But, the basic point remains that the correct way for the science to be judged, including what uncertainties exist and how great they are, is within the scientific process itself and that lots of people screaming from the sidelines that “empirical evidence doesn’t exist” or what-have-you is more a measure of how the science interferes with their belief system than a measure of where the science actually is.