(Note: this originally published on Dr. Spencer’s blog on April 25th, and I asked if I could reproduce it here. While I know some readers might argue the finer points of some items in the list, I think it is important to keep sight of these. – Anthony)
by Roy W. Spencer, Ph. D.
There are some very good arguments for being skeptical of global warming predictions. But the proliferation of bad arguments is becoming almost dizzying.
I understand and appreciate that many of the things we think we know in science end up being wrong. I get that. But some of the alternative explanations I’m seeing border on the ludicrous.
So, here’s my Top 10 list of stupid skeptic arguments. I’m sure there are more, and maybe I missed a couple important ones. Oh well.
My obvious goal here is not to change minds that are already made up, which is impossible (by definition), but to reach 1,000+ (mostly nasty) comments in response to this post. So, help me out here!
1. THERE IS NO GREENHOUSE EFFECT. Despite the fact that downwelling IR from the sky can be measured, and amounts to a level (~300 W/m2) that can be scarcely be ignored; the neglect of which would totally screw up weather forecast model runs if it was not included; and would lead to VERY cold nights if it didn’t exist; and can be easily measured directly with a handheld IR thermometer pointed at the sky (because an IR thermometer measures the IR-induced temperature change of the surface of a thermopile, QED)… Please stop the “no greenhouse effect” stuff. It’s making us skeptics look bad. I’ve blogged on this numerous times…maybe start here.
2. THE GREENHOUSE EFFECT VIOLATES THE 2ND LAW OF THERMODYNAMICS. The second law can be stated in several ways, but one way is that the net flow of energy must be from higher temperature to lower temperature. This is not violated by the greenhouse effect. The apparent violation of the 2nd Law seems to be traced to the fact that all bodies emit IR radiation…including cooler bodies toward warmer bodies. But the NET flow of thermal radiation is still from the warmer body to the cooler body. Even if you don’t believe there is 2-way flow, and only 1-way flow…the rate of flow depends upon the temperature of both bodies, and changing the cooler body’s temperature will change the cooling rate (and thus the temperature) of the warmer body. So, yes, a cooler body can make a warm body even warmer still…as evidenced by putting your clothes on.
3. CO2 CANT CAUSE WARMING BECAUSE CO2 EMITS IR AS FAST AS IT ABSORBS. No. When a CO2 molecule absorbs an IR photon, the mean free path within the atmosphere is so short that the molecule gives up its energy to surrounding molecules before it can (on average) emit an IR photon in its temporarily excited state. See more here. Also important is the fact that the rate at which a CO2 molecule absorbs IR is mostly independent of temperature, but the rate at which it emits IR increases strongly with temperature. There is no requirement that a layer of air emits as much IR as it absorbs…in fact, in general, the the rates of IR emission and absorption are pretty far from equal.
4. CO2 COOLS, NOT WARMS, THE ATMOSPHERE. This one is a little more subtle because the net effect of greenhouse gases is to cool the upper atmosphere, and warm the lower atmosphere, compared to if no greenhouse gases were present. Since any IR absorber is also an IR emitter, a CO2 molecule can both cool and warm, because it both absorbs and emits IR photons.
5. ADDING CO2 TO THE ATMOSPHERE HAS NO EFFECT BECAUSE THE CO2 ABSORPTION BANDS ARE ALREADY 100% OPAQUE. First, no they are not, and that’s because of pressure broadening. Second, even if the atmosphere was 100% opaque, it doesn’t matter. Here’s why.
6. LOWER ATMOSPHERIC WARMTH IS DUE TO THE LAPSE RATE/ADIABATIC COMPRESSION. No, the lapse rate describes how the temperature of a parcel of air changes from adiabatic compression/expansion of air as it sinks/rises. So, it can explain how the temperature changes during convective overturning, but not what the absolute temperature is. Explaining absolute air temperature is an energy budget question. You cannot write a physics-based equation to obtain the average temperature at any altitude without using the energy budget. If adiabatic compression explains temperature, why is the atmospheric temperature at 100 mb is nearly the same as the temperature at 1 mb, despite 100x as much atmospheric pressure? More about all this here.
7. WARMING CAUSES CO2 TO RISE, NOT THE OTHER WAY AROUND The rate of rise in atmospheric CO2 is currently 2 ppm/yr, a rate which is 100 times as fast as any time in the 300,000 year Vostok ice core record. And we know our consumption of fossil fuels is emitting CO2 200 times as fast! So, where is the 100x as fast rise in today’s temperature causing this CO2 rise? C’mon people, think. But not to worry…CO2 is the elixir of life…let’s embrace more of it!
8. THE IPCC MODELS ARE FOR A FLAT EARTH I have no explanation where this little tidbit of misinformation comes from. Climate models address a spherical, rotating, Earth with a day-night (diurnal) cycle in solar illumination and atmospheric Coriolis force (due to both Earth curvature and rotation). Yes, you can do a global average of energy flows and show them in a flat-earth cartoon, like the Kiehl-Trenberth energy budget diagram which is a useful learning tool, but I hope most thinking people can distinguish between a handful of global-average average numbers in a conceptual diagram, and a full-blown 3D global climate model.
9. THERE IS NO SUCH THING AS A GLOBAL AVERAGE TEMPERATURE Really?! Is there an average temperature of your bathtub full of water? Or of a room in your house? Now, we might argue over how to do the averaging (Spatial? Mass-weighted?), but you can compute an average, and you can monitor it over time, and see if it changes. The exercise is only futile if your sampling isn’t good enough to realistically monitor changes over time. Just because we don’t know the average surface temperature of the Earth to better than, say 1 deg. C, doesn’t mean we can’t monitor changes in the average over time. We have never known exactly how many people are in the U.S., but we have useful estimates of how the number has increased in the last 50-100 years. Why is “temperature” so important? Because the thermal IR emission in response to temperature is what stabilizes the climate system….the hotter things get, the more energy is lost to outer space.
10. THE EARTH ISN’T A BLACK BODY. Well, duh. No one said it was. In the broadband IR, though, it’s close to a blackbody, with an average emissivity of around 0.95. But whether a climate model uses 0.95 or 1.0 for surface emissivity isn’t going to change the conclusions we make about the sensitivity of the climate system to increasing carbon dioxide.
I’m sure I could come up with a longer list than this, but these were the main issues that came to mind.
So why am I trying to stir up a hornets nest (again)? Because when skeptics embrace “science” that is worse that the IPCC’s science, we hurt our credibility.
NOTE: Because of the large number of negative comments this post will generate, please excuse me if I don’t respond to every one. Or even very many of them. But if I see a new point being made I haven’t addressed before, I’ll be more likely to respond.
PS Konrad, I said earlier “Konrad, I think you badly underestimate the “Church of Radiative Climastology”
Let me amend that that to “Konrad, I think you improperly conflate science with politics/environmentalism/ego/religion.” The BASIC science of the “Greenhouse effect” is sound, which of course was Dr Spencer’s initial point — the IR properties of gases in the atmosphere have a warming effect on the surface. This is NOT your “Church of Radiative Climastology”!
What is less certain is how much additional warming there would be from further increases in CO2. It is also a challenge to quantify the warming of the globe over time.
What is even less certain is what should be done about it. And THIS is your “Church of Radiative Climastology”. All of the objections you list are down here — none relate to fundamental science. You are engaging in pure strawman and ad hominem tactics that only detract from your scientific message.
This comment is focused on Spencer’s #7 about relationship of atm CO2 and GMT.
Has nature performed a controlled experiment for us? Look at the two periods in the last ~75 years that I describe as follows:
A) The ~20 year period spanning approximate the 1940s and 1950s where there was a pause / plateau in atm CO2 (ice cores) while there was a decrease in GMT (instrumental).
B) The ~15 to ~17 year period that precedes April 2014 where there was an increase in atm CO2 (Mauna Loa) while there was a pause / plateau in GMT (instrumental and satellite).
In period A the control in nature’s experiment was atm CO2 because it was relatively unchanged during the period. In period B the control was GMT because it was relatively unchanged during the period.
What does nature’s controlled experiment imply? I think it implies that between delta atm CO2 and delta GMT it is not observed that atm CO2 change must cause GMT change on those timescales.
Cites showing A and B available.
John
JohnWho:
I do not understand what you are trying to say at May 4, 2014 at 7:07 am.
Say whatever you want: I would be grateful if it were to include additional information.
I have repeatedly explained my view and my reasons for it.
Richard
JohnWho says:
May 4, 2014 at 7:07 am
Has anyone looked at the past data and determined that every time temp went up 1 degree C we saw a subsequent rise of X ppm of CO2 and every time temp drops 1 degree C we saw a subsequent drop in ppm of CO2?
Yes, the ice core data of Vostok over 420,000 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/Vostok_trends.gif
the response is quite linear at 8 ppmv/°C. The main deviation from the average is due to the long lag of CO2 during a glaciation.
Meanwhile the Vostok data are confirmed by the 800,000 years Dome C ice core.
The 8 ppmv/°C also holds for shorter periods like the MWP-LIA transition: ~6 ppmv/0.8°C with a lag of ~50 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_1000yr.jpg
Based on the 8 ppmv/°C, the maximum contribution of the warming since the LIA is 8 ppmv, the rest of the 100+ ppmv rise is human.
On very short term (seasons to 2-3 years) CO2 shows a response to the temperature variability of 4-5 ppmv/°C. Some think that the recent rise in CO2 is mainly/all natural, which implies a response of over 100 ppmv/°C…
Ferdinand Engelbeen says:
May 4, 2014 at 1:16 am
“Bart, as said so many times, the CO2 rate of change is responding to the variation, and its long term response is not more than 8 ppmv/K over very long term.”
This is self-contradicory, Ferdinand. You explicitly say “the rate of change”, yet your sensitivity has no units of time. We do not know the entire frequency response which dominates over long periods of time. We do not even know if the system is stationary over the long term. But, our best, most moden, most direct, most accurate measurements show that, in the current era, there is an integral relationship between temperature and CO2.
“…to attribute the slope in rate of change to an unknown process…”
It isn’t attributed to an unknown process. The slope in the rate of change of CO2 is due to the slope in temperature.
Ferdinand Engelbeen says:
May 4, 2014 at 1:25 am
“…9 GtC/year human emissions, 4.5 GtC/year increase in the atmosphere, 4.5 GtC/year net uptake by the natural carbon cycle…”
The flawed “mass balance” argument in yet another guise. It is very frustrating that, at times, you appear to understand that these figures are meaningless without knowledge of the power of the sinks, but then you turn around and assert again that it is unqualified proof of what you want the explanation to be.
Ferdinand Engelbeen says:
May 4, 2014 at 1:56 am
“That does NOT imply that the slope in rate of change is from the same process.”
It does. You cannot arbitrarily pick and choose which parts of the temperature record influence the rate of change of CO2, and which do not.
“Your attribution of the whole slope in rate of change has no proven physical cause…”
You don’t have to know the physics of trains to know that you better get out of the way of that big light coming at you when the Earth starts rumbling. You are approaching the problem backwards. First, you take observations, and then try to fit your theories to them.
“It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts.” -Sherlock Holmes
“The graph using the same units for both is here:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/dco2_em4.jpg“
As said many times, your graph is misleading because you fit the entire series, without trying to determine if the least squares slope is diverging over time. But, even then, your plot clearly shows that emissions are currently accelerating, while concentration is steady.
Ferdinand Engelbeen says:
May 4, 2014 at 2:19 am
I could say the same.
– It is impossible for the variation in CO2 to reflect the variation in temperatures without reflecting the slope
This is a hard piece of evidence. It is a mathematical necessity. Yours are “soft”.
– There are many potential explanations for the 13C/12C ratio.
– We must weigh the most modern, most direct, and most accurate measurements most heavily in any assessment.
– You have the wrong units – the observations show that there is an integral relationship.
richardscourtney says:
May 4, 2014 at 6:21 am
Most CO2 emission to the atmosphere is ‘natural’. If the ‘natural’ emission is unchanged then there would be no rise in atmospheric CO2 caused by the anthropogenic CO2 emission If any one sink were able to sequester all of the small additional CO2 emission from the anthropogenic sources.
Richard, some 97% of all emissions is natural, 3% human, but all natural sinks together are 98,5% of total emissions. No matter what any individual sink does (even if it was 10 times human emissions), the sum of all sinks is less than the sum of all sources (natural + human), but more than the natural sources alone.
Thus while some sinks and their variability may be much larger than the human emissions, ans able to remove all human emissions at once, still about halve the human emissions stay in the atmosphere (as quantity, not as original molecules). Already over 50 years.
John Whitman says:
May 4, 2014 at 8:07 am
In all periods since 1900, CO2 levels in the atmosphere simply follow human emissions without much influence of temperature beyond the 2-3 years influence of ocean currents like ENSO or volcanic eruptions like Pinatubo:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/temp_emiss_increase.jpg
and
http://www.ferdinand-engelbeen.be/klimaat/klim_img/acc_co2_1900_cur.jpg
The influence of T on CO2 is modest, not more than 8 ppmv and hardly visible in the increase of CO2. The influence of CO2 on T is even more problematic and invisible in the natural variability of T.
Ferd.
And as the oceans begin to cool they will once again be able to absorb the extra emissions and over time be able to even reduce the level of co2 in the atmosphere as has happened countless times in geological history and this sudden rise will be smoothed out in ice core samples thousand of years from now and not look like anything different then any other event.
The ability of the environment to control co2 goes up and down with temps as proven by the fact that co2 levels fall even as plant life ability to absorb it shrinks during an ice age, it is the ocean temp that control co2 and more precisely the change in ocean temp the creates the lagging response as the systems correct them selves to the changing environment.
Bart says:
May 4, 2014 at 8:45 am
This is self-contradicory, Ferdinand. You explicitly say “the rate of change”, yet your sensitivity has no units of time. We do not know the entire frequency response which dominates over long periods of time.
The short term response is transient to the long term response. The frequency response between a few decades (MWP-LIA) to multi-millennia is not more than 8 ppmv/K, the short term response is less.
It isn’t attributed to an unknown process. The slope in the rate of change of CO2 is due to the slope in temperature.
Bart, if there is no change in the average carbon cycle, then the full short term variability is entirely from the short term temperature variability. If there is an increase in e.g. upwelling over time, that will have zero influence on the short term variability, but will show an increase of CO2 over time and even, combined with an increase in temperature, an influence on the slope of the rate of change.
The point is that the processes involved in the variabilty and the process that causes the slope of the rate of change are completely independent of each other. Both may be influenced by temperature (changes), but that is in different ways for different processes.
Thus you can’t assume that the the short term variations and the long term trend are caused by the same process.
The flawed “mass balance” argument in yet another guise. It is very frustrating that, at times, you appear to understand that these figures are meaningless without knowledge of the power of the sinks
There is knowledge that the natural sources and sinks didn’t increase much over time, despite increasing human emissions. Which means that the sinks can’t accomodate with the speed of the increase. But it was my reaction to Richard, who was violating the mass balance…
It does. You cannot arbitrarily pick and choose which parts of the temperature record influence the rate of change of CO2, and which do not.
Even if the slope of the rate of change is caused by increased deep ocean upwelling combined with temperature, that is a different process than what influences the short-term variation, which is mainly temeprature/vegetation driven and opposite to the long-term trend.
That is the basic error that you make (and the reason that either amplitude or slope don’t match).
Bob Boder says:
May 4, 2014 at 9:13 am
The long term temperature influence on CO2 is not more than 8 ppmv/°C. To remove the current excess 100+ ppmv, you need a drop of 12°C, which is what is seen between an interglacial and a glacial period, but we are currently in an interglacial. For the current temperature, the “normal” CO2 level is ~300 ppmv, while we measure 400 ppmv.
Any one-way increase of 100 ppmv in 160 years would be noticed in every ice core over the past 800,000 years…
Ferdinand:
I am writing this for the benefit of onlookers.
At May 4, 2014 at 1:25 am you quoted my true statement made at May 4, 2014 at 12:12 am which said of your (and the IPCC) assertion
And you disputed that true statement by replying
Ferdinand Engelbeen:
At May 4, 2014 at 10:33 am you assert
NO! It would not!
But such changes would be noticed in stomata data and they are.
Richard
Ferd
And if one looks at co2 rise from your view co2 would rise during an ice age not fall because the natural environment would lose it ability to absorb co2 that from your view comes from where? A series of Forrest fires a dry spell a magic fairy. Co2 rises after an increase in temperature and falls during a degrees why?
Co2 is constantly being produced by natural sources and absorb by nature sources as tempatures rise the absorption is impeded as it falls it increases.
Where is your evidence that shows that 100 ppm increase would show in the core samples as an increase over 100 year period.
Bob Boder says: May 3, 2014 at 6:06 pm
“Question to everyone, does anyone here think that co2 in the atmosphere is causing the oceans to warm?”
Good question and with an easy answer from my part, no. If atmosphere were a closed system, it could be debated. But it’s not. It shares an open interface with space, which leads me to the following:
On the Moon the temperature can reach 253 degrees F (123 C) or dip to -243 F (-153 C). Makes one wonder how the CO2-glaciers can form in the insignificant pressure of GHC-enveloped Mars http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA13985.
Bob Boder says:
May 4, 2014 at 10:53 am
Bob, the pre-industrial CO2 levels were an equilibrium between atmosphere, oceans and the biosphere. Short term responses are dominated by the biosphere: seasons to 2-3 years. Long term responses are dominated by the (deep) oceans. Oceans and biosphere in general are reacting in countercurrent to temperature: CO2 is released from warmer oceans, but warmer temperatures (and vegetation) and more land area will give more plant growth. The long term equilibrium was 8 ppmv/°C over the past 800,000 years. Nowadays we are 100 ppmv above that long-term equilibrium. That is not caused by temperature…
The resolution of ice cores depends of the local accumulation rate. That varies between 10 years for some coastal cores to 600 years for the Vostok ice core. The distribution of a one-year CO2 peak in the atmosphere can be calculated (and is measured) in any ice core. Here for the Law Dome high-resolution ice cores:
http://courses.washington.edu/proxies/GHG.pdf
Fig.11 shows that 10% of a 1-year pulse in the atmosphere stil is measureable in the ice core (~10 year resolution). The current increase is 100 ppmv in 160 years. If you spread the average 80 ppmv increase from that period over 600 years, that still is a ~20 ppmv increase. The accuracy and repeatability of the ice core CO2 measurements is 1.2 ppmv (1 sigma), more than good enough to detect a 20 ppmv increase.
richardscourtney says:
May 4, 2014 at 10:49 am
I have addressed that issue here but you have studiously avoided it.
Richard, I have addressed that many times in the past to no avail. The seasonal swings are enormous, but the processes involved in the seasonal changes are mainly temperature dependent and limited in capacity. They react on temperature but less on pressure and thus can’t cope with any extra CO2 in the atmosphere. The processes which remove any excess CO2 out of the atmosphere are mainly pressure dependent, enormous in capacity, but slower in reaction speed…
And as said in my reaction to Bob Boder, all ice cores can detect a one sided increase as we have seen over the past 160 years. Variations and absolute CO2 values in stomata data must be taken with a grain of salt, because they reflect local changes in CO2 levels, not “background” changes.
Ferd
There is no pre industrial equilibrium the atmospheric co2 was coming of a low due to the little ice age and started to rise prior to the industrial period and again you theory only makes sense if co2 rises during a cooling trend which it clearly doesn’t
Your ice core assertion is wrong as well as both Richard and Bart have pointed out to you time and again. Stomata data states otherwise.
F.Englebeen:
what is it that makes ice core samples an objective metric of true atmospheric co2 concentration rather than being anomalies in proxies?
in other words, how is this not attaching a short and recent instrumental record onto a long proxy record?
gnomish says:
May 4, 2014 at 12:16 pm
CO2 levels in ice cores are direct measurements in ancient air bubbles enclosed in the ice, not proxy based on some derived metric. That is an advantage above any kind of proxy.
The disadvantage is that the air mix in the bubbles is from several years: while the snow is compacting into ice, the pores between the snow/firn crystals remain open with the atmosphere. Thus there is an exchange between the air inbetween the ice and the atmosphere over many years.
For e.g. the high accumulation Law Dome ice cores, at bubble closing depth (~72 m) the ice is already 40 years old, but the average gas age is only 7 years older than in the atmosphere and the bulk of the mix is from ~10 years around the average, with a long small tail up to 40 years old.
For the low accumulation Vostok ice core, the difference in age between ice and gas is even many thousands of years and the ~bulk of the air mix (resolution) is from 600 years air.
Thus while CO2 levels are real measurements, they are a mix from several years, thus fast peaks may go unnoticed, depending of the resolution. Despite that, they give a good insight of the past changes, as one can stack the different ice cores with different resolution, the farther back into the past, here over the past 10,000 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/antarctic_cores_010kyr.jpg
or the last 1,000 years:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/antarctic_cores_001kyr.jpg
or even an overlap with the South Pole direct measurements:
http://www.ferdinand-engelbeen.be/klimaat/klim_img/law_dome_sp_co2.jpg
Bob Boder says:
May 4, 2014 at 12:14 pm
There is no pre industrial equilibrium the atmospheric co2 was coming of a low due to the little ice age and started to rise prior to the industrial period
The little ice age – current warming is good for 8 ppmv rise in CO2, not 100 ppmv. For some the (small) rise in CO2, but mainly in CH4 is already caused by increased land use change by humans.
again you theory only makes sense if co2 rises during a cooling trend which it clearly doesn’t
I have no theory, I only look at the data, which show that short term variation caused by temperature is dominated by changes in vegetation and long term changes are dominated by the oceans. The short term changes are 4-5 ppmv/°C the long term are ~8 ppm/°C. In both cases higher temperatures = more CO2 and vv.
Currently we have flat tempertures and record increases of CO2, halve the amounts which humans emit. Tell me how that can be natural…
Your ice core assertion is wrong as well as both Richard and Bart have pointed out to you time and again. Stomata data states otherwise.
Ice core measurements are direct measurements of ancient are, but smoothed. Stomata data are proxies with a lot of problems like a variable “land bias” over the centuries. BTW, stomata data are calibrated over the past century against direct measurements, firn and… ice core CO2 levels.
Ferdinand Engelbeen:
At May 4, 2014 at 1:37 pm you assert
Nonsense!
Ice is NOT a sealed glass bottle.
All ice surface is coated in a liquid layer (i.e. water) at all temperatures down to -40°C (this is why ice is slippery). And ice crystals have a liquid coating. Gases dissolve in water and do so preferentially.
The firn takes decades to seal and will be dissolving gases as it does so. So, there is no reason to suppose the composition of air trapped in resulting ice will be representative of atmospheric composition, and there is good reason to suppose the trapped air will not have the same composition as the atmosphere.
And then there is movement of ionic solutions in liquid crystal surface layers of the resulting ice.
The ice core data and the stomata data are each indicative and each is useful, but neither is directly comparable to results of atmospheric measurements.
Richard
Ferdinand Engelbeen:
At May 4, 2014 at 10:49 am I complained that you have “studiously avoided” the indications of the dynamics of the seasonal variation in atmospheric CO2.
Your reply at May 4, 2014 at 12:05 pm falsely asserts
That is not true. As in this thread, you have studiously avoided it.
You merely assert
And that assertion pretends the indications of the dynamics of the seasonal variation do not refute your untrue assertion that the seasonal changes are significantly “limited”.
As I have repeatedly explained – and you have repeatedly ignored – the dynamics of the seasonal variation indicate that the sinks can easily sequester ALL the CO2 emitted to the atmosphere, and the issue to be resolved is why they don’t when they clearly can.
Richard
Ferdinand Engelbeen:
It would help if you were to read the information in the thread. For example at May 4, 2014 at 1:52 pm you demand
I told you that here and I subsequently linked you to it when you later failed to grasp the point.
Richard
richardscourtney says:
May 4, 2014 at 2:03 pm
You are completely out of current knowledge of what ice core measurements can and do measure. At -40°C there is no liquid water at the ice-air surface and there is no liquid water inbetween ice crystals, except where salts/dusts are present.
But even so, any migration in the ice cores would be noticed as a fading away of the quite constant 8 ppmv/°C ratio between CO2 and temperature proxy for each interglacial 100,000 years back in time. Which is not the case.
Modern measurements include complete sublimation of the samples and cryogenic separation of all components, which shows all CO2, hidden or not and decomposes any clathrates present in the ice. The sublimation method and the in general used grating method show the same CO2 levels.
Moreover, there is a 20 year overlap between ice cores CO2 measurements and direct measurements at the South Pole.
As I have repeatedly explained – and you have repeatedly ignored –
It is not because you don’t like what I said that I have ignored your explanation: temperature is the main driver for the seasonal uptake/release of CO2. Pressure is the main driver for the uptake of extra CO2 out of the atmosphere. The first is cyclical the second is one-way until a new equilibrium is reached. Different processes, different capacities, different speeds.
And sorry, your explanation of why the increase may be non-human doesn’t hold water: any of the alternative explanations I have heard of violates one or more observations…