Dung "but I am interested in the truth far more than I am interested in influencing others", so you're prepared to wait as long as it takes for the truth to come out (no matter what it is) and you don't care how much is wasted in the name of CAGW in the interim?

Carbon dioxide GHG warming is well known, even if it is still just a hypothesis. The spiral of warming - more evaporation - more GHG water vapour - more warming - more evaporation - more water vapour, etc is the real killer that was the source of the alarmist tipping point and put the C in CAGW.

The catastrophic warming is not mentioned today. It didn't happen and clearly will not happen, but although it never gets mentioned, its existence and discussion about its disappearance never gets mentioned either. What is wrong with water vapour positive feedback? It is still there as part of the threat, the fear factor, but it has gone as a tipping point. Why does it not appear on alarmist agendas any more?

It still figures in the climate models in a big way. It is the global warming demon whose name we must not mention. It is the cause of the hot spot that has never been found. It is the middle troposphere increase in humidity that has never been found either. It is still the temperature multiplier in climate models that drives policymaking by government.

http://www.ncdc.noaa.gov/paleo/abrupt/images/data2-dome-fuji-lg.gif

When you look at the ice cores, what makes you think the CO2 effect has reached a maximum? It’s not obvious why an interglacial happens at some points where the insolation spikes but not others or why the CO2 levels rise higher sometimes than others. It certainly seems like CO2 levels delay a sharp fall but it might be something else. What else is going on? What turns a small insolation nudge into a meteoric temperature rise?

Yes, climate is clearly very complicated, so why do you think you can see what those who make it their life’s work can’t? I certainly can’t work it out but I can find flaws with procedure, solutions and the politics of CAGW. I don’t have to discover the truth about climate to start demanding changes to policy. I don’t need to explain the science in detail to others to persuade them they should be sceptical too. One of the key failure for warmists is their inability to nail the science. They fall back on consensus. We don’t need to supply an alternative ‘truth’ to point out the flaws in theirs.

May 12, 2014 at 9:50 PM | Dung
That's what happens on the Interweb, things take a life of their own.

The recent deviation of this discussion has raised an interesting point for me, as Martin A says the catastrophe theory requires a water +ve feed back; as you say increasing CO2 content has always followed increasing temperature.. As far as I'm aware the properties of both H2O and CO2 haven't changed recently (in the last 10,000 years) and the atmospheric mix of gases is roughly the same as it has been for the recent past. That leads to the conclusion that whatever the process is in terms of feedback, +ve.-ve or none, it doesn't fit with the CAGW theory. It is also true that this warm period is no different to previous ones in this inter-glacial, its no warmer, various parts of the globe have warmed at different rates some have even cooled (can't remember where I read that), a fact which is used to "prove" that the MWP wasn't global. So this discussion has added to the logical arguments against the CAGW supporters.

Thanks for kicking it off, it's been interesting.

Dung, you want the freedom to influence the debate by expressing your theories but object to others doing the same by removing some of your comments when they interfere with what they are trying to say?

You may think CO2 is not having an effect but you don't KNOW it's not. I won't try to tell you that your theory is wrong but I will say you've not offered any evidence to back it up. If there's one thing I have little time for any more it's theories, and yes, I'm guilty too ;-) It's not lying to keep theories to yourself, it's only lying if you withold facts. That's what irks us about warmists, it's all wild theories and edited facts.

"Suspicious old me wonders whether the researchers really want to go there."

You are not alone rhoda. I've had this paper quoted to me by Simon Singh and Richard Betts as the go-to definitive paper proving CO2 causes global warming, but it is 13 years old now, and the research probably a lot older. Why hasn't someone else driven the nail in the coffin? Why hasn't Harries followed up himself? Their could be a lot more citations for him in it.

Dung the truth is sacrosanct, but it isn't possible to tell it all the time. People who do tend to be lacking a feedback loop, if you want to get into an argument about CO2 not being a GHG fine, but you're wasting your time. That's why the politically experienced and astute, Nigel Lawson, starts out by explicitly stating he doesn't reject the science, it is more important to fight the political actions because that's where the damage is done.

What do you say when your wife asks if her "bum looks too big in these jeans"?

Dung, to give you an idea about the size of the problem here's a quote from Don Easterbrook, sceptical scientist, at WUWT:

"That’s not the question—it’s not if CO2 is a greenhouse gas, it’s how much is there in the atmosphere (Fig. 3) and how much can it affect climate?"

Just stand back for a minute and think about it. Do you really want to be arguing with people who support your view that there is little danger, or "risk" ( mot du jour) arising from the increase in CO2 in the atmosphere?

OK Martin, as others will not play I will try to answer your question "what would happen if all of the CO2 in the atmosphere was teleported to a star far, far away" with a wildass guess:

If I am correct that the temperatures of the arid deserts (relatively unaffected by water vapour and clouds) over the diurnal cycle have not altered during the instrumental record, while atmospheric CO2 has supposedly increased by 40%, we can deduce that either the radiative effect of CO2 has saturated, or that conduction and convection dominate, or possibly both, so.....

I would expect diurnal surface temperatures across the planet to be virtually unaffected apart from deserts, which would become marginally hotter by day and colder by night. The effect on the average surface temperature of the planet would be negligible.

But I admit, a wildass guess....

Martin, as I understand it CO2 absorbs OLR in the 4 and 15micron radiation frequencies, and mostly in the 15 micron, while water vapour absorbs, more extensively in the 20 to 70 micron radiation frequencies. I don't have a clue what that means in terms of w/m^2 I can't say what that means in terms of temperatrue, except that absorbing OLR in a range 50 times that of CO2 looks like CO2 represents a small proportion of the GHG effect.

Of course I haven't the knowledge, or abilities of the cli scis, but if they were applying to me for funding (where I have some experience) to prove that CO2 was a major driver of global warming, I'd kick them into touch until they'd some testable empirical evidence.

"...would the Sun's radiation eventually restore the earth's surface conditions to more or less what they are now?"

Yes, if insolation was constant the system must return to steady state, or diurnal thermodynamic equilibrium (energy in = energy out). The gas laws (PV = nRT) would apply, and the Earth system must return to minimum entropy production.

But the problem with these hypothetical considerations is that they are physically impossible in the first place, therefore, returning to the original question I would ask:

If I am correct that the temperatures of the arid deserts (largely unaffected by water vapour and clouds) over the diurnal cycle have not altered during the instrumental record, while atmospheric CO2 has supposedly increased by 40%, can we deduce that either the radiative effect of CO2 has saturated, or that conduction and convection dominate? And that either one, or a combination of both effects show that the CAGW hypothesis is flawed?

Roger Longstaff

You may be mistaken in thinking that no desert warming has taken place.

http://www.researchgate.net/publication/230734867_Recent_trends_of_temperature_change_under_hot_and_cold_desert_climatesComparing_the_Sahara_(Libya)_and_Central_Asia_(Xinjiang_China)

The data is paywalled, but this is the abstract.

sets are now available from continental Africa through which past variations in temperature can be assessed. This paper, co-authored by members of the PAGES Africa2k Working Group, synthesises published material to produce a record of temperature variability for Africa as a whole spanning the last 2000 years. The paper focuses on temperature variability during the ‘Medieval Climate Anomaly’ (MCA), ‘Little Ice Age’ (LIA) and late 19th–early 21st centuries. Warmer conditions during the MCA are evident in records from Lake Tanganyika in central Africa, the Ethiopian Highlands in northeastern Africa, and Cango Cave, the Kuiseb River and Wonderkrater in southern Africa. Other records covering the MCA give ambiguous signals. Warming appears to have been greater during the early MCA (c. AD 1000) in parts of southern Africa and during the later MCA (from AD 1100) in Namibia, Ethiopia and at Lake Tanganyika. LIA cooling is evident in Ethiopian and southern African pollen records and in organic biomarker data from Lake Malawi in southeastern tropical Africa, while at Lake Tanganyika the temperature depression appears to have been less consistent. A warming trend in mean annual temperatures is clearly evident from historical and instrumental data covering the late 19th to early 21st centuries. General warming has occurred over Africa since the 1880s punctuated only by a period of cooling in the mid 20th century. The rate of temperature increase appears to have accelerated towards the end of the 20th century. The few long high-resolution proxy records that extend into the late 20th century indicate that average annual temperatures were 1–2°C higher in the last few decades than during the MCA.

Note particularly the last three sentences discussing the modern temperatures.