sethoflagos

No. Just our way of telling you to...

Not sure @zapatos has yet posted to this thread. That's you referring to those who have not read the papers... ... and this is also you referring to people who have and don't buy into the science (otherwise "obtuse" would be the wrong word) Different "thems". Why are you attempting to conflate two mutually exclusive contexts? Obviously. The phrasing had a distinct odour of LLM. The paper discusses the challenges of real world measurement NOT the validity of estimates generated by mathematical modelling. Two entirely different classes of data and therefore utterly irrelevant to the discussion. It doesn't support your argument in the slightest. Clearly a bit of dead catting. Howl it to the moon. No one else is agreeing with you. My assertion is withheld as it would contravene site rules in so many ways.

The other way round, isn't it? Australia sent them Rupert Murdoch.

Back when "them" referred to people who hadn't read any of the science rather than those who had but were simply being "obtuse"? Nevertheless,, comment withdrawn with apologies.

But it didn't, did it. It is even further away from the <-50o C limit currently accepted for an ice dominated earth. So your assertion is, as you would not hesitate to say, "factually inaccurate". The heart of this thread is about how to establish credibilty. Your postings are fine examples of how to achieve the opposite. You didn't use those words either. Not even close. Haven't you been pulled up for misquoting in other threads? Illuminating. Chrome has a neat little "Find" function that allows one to check if a purported quote is truly contained within a document. This one isn't from your referenced paper. Not even close. Under the circumstances, I don't feel inclined to take this assertion at face value.

Yet your 'precise' -18o C turns out to be a worse estimate than my 'nearest round number' -20o C. Isn't that strange. Where exactly did you say this? Can't seem to find it.

In the absence clearly stated tolerances, the more the number of significant digits, the greater the lie (a generalisation but pretty well grounded) Do you have a shred of evidence that more than one person in a hundred habitually reads academic papers?

The lunar diurnal variation has been gnawing away at me. I approximated the lunar surface temperature to be 251 +/- D Kelvin for daytime/nighttime average temperature values and calculated for D. Turns out that a D value as low as 60 K was enough to account for the temperature discrepancy of 20 K I'd run into in the opening post.

If the message is to be taken on board by the target audience then it most definitely does have to be intentionally simplified - to a choice of where we want to be in a narrow Goldilocks zone in the spectrum between Moon (really bad) and Venus (even worse). The moment you get into tipping points and feedback mechanisms etc., you've lost your target audience and the other side win. That is the nature of the game whether you wish it or not. Arguing over eg. exact figures for hypothetical scenarios is just playing into the enemy's hands. It shows us to be weak and divided when it is imperative we appear strong and united.

Think this through. If as you say, this hypothetical earth were at or around -20oC then what state are the oceans in? As things stand, earth has a significantly higher albedo than the moon, and an ice covering will increase that difference considerably. This will drive the equilibrium temperature of the earth down to the <-50oC estimates for 'Snowball Earth' scenarios of the late Proterozoic. (Ref: Hoffman, P. F., Kaufman, A. J., Halverson, G. P., & Schrag, D. P. (1998). "A new model for Neoproterozoic glaciation." Earth and Planetary Science Letters, 286(1-2), 295-310.; Abbot, D. S., & Tziperman, E. (2009). "Glacial–interglacial cycles and Snowball Earth." Nature, 457(7227), 179-183.) For the specific purposes of this topic, I did not need to introduce this complication in order to establish the principle that having some greenhouse gases in the atmosphere is beneficial. I chose this wording carefully: it is in agreement with expert concensus. Something of an understatement actually.

Perhaps you should read through the threads before you post to them and gain some small understanding of what's actually being discussed.

On what planet is "-18°C to -19°C" "much colder" than "-23°C"? "much colder (than)" is a subset of "no higher than" Why the italics and quotation marks around "like the Moon"? Not my words, even inferentially. "because the greenhouse effect is absent" is a subset of "Without CO2" Can't actually find any significant rebuttal in your post - more of an incoherent paraphrasing of my own argument. You say that as if it were (in context) a bad thing.

Is that big business where you come from - exporting roadkill to the international sashimi market?

IMHO the best priest is the pointy end of a spring-handled welding hammer. Definitely the bees knees if you're sharing the deck of a small boat with a lively 20 kg barracuda or similar. I've tried most options...

Is that pertinent? The OP seems to present an arguable reason.

... which was?

Priest Simple, time-proven method that's least likely to cause injury to yourself.

Surface seawater CO2 concentration is typically <10 ppm or <10 g/m3 Average sea level air concentration is 428 ppm or ~0.5 g/m3 So I make it 20:1 max However, the acidification process will protonate some of the ~1,500 ppm of bicarbonate releasing more CO2 so I assume that's where the extra boost is coming from. The thinking appears to be that CO2 extraction from a source with 150 × the volumetric concentration will save ~ RTln(150) J/mol on the entropy reversal cost. A major consideration for carbon capture from low concentration sources.

Mrs Tilly likes Lennon but not McCartney Mrs Tilly likes Jagger but not Richards Mrs Tilly likes Sonny but not Cher Mrs Tilly dislikes Rodgers but not Hammerstein

A bit late to the topic, but for what it's worth, I think it is a mistake to be drawn into detail. When I'm called to summarise the climate situation to non-scientists, which happens quite often, I tend to limit the discussion to a few simple, easily defended points: Without CO2 Earth's average temperature would be no higher than the average temperature of the moon. About -20oC and life as we know it would not be possible. Until very recently, the planet had 6,000 years of an unusually stable CO2 level of a little below 300 ppm warming the planet to a comfortable average of 15oC and life as we know it flourished. The earliest historical civilisations began 6,000 years ago and have continued, developed, and flourished ever since. This is no coincidence. We are currently well on the way towards doubling that CO2 level at a rate far faster than either human civilisation or the natural world can adapt to the rapidly increasing temperature. Repeat as necessary. It's worked for me though I appreciate that those living in other environments may have a different experience. Comments welcome.

Sometimes one forgets that for large, established swathes of physics, the empirical matches the theoretical with extraordinary precision. A message easily lost amongst the blizzard of disingenuous clickbait media.

Thanks, yes. Very slight differences in the numbers, but same formulae

Just spent a couple of hours trying to derive 'natural' temperature of the planet in the absence of greenhouse gas effects from basic Stefan-Boltzmann equation and inverse square law. My first engineering approximation : a small rotating sphere of something approximating to graphite gave me a temperature of 278.5 K which is not bad perhaps, but considerably higher than the figure 255 K I've seen commonly quoted. Correcting the solar influx for albedo figures of no particularly strong provenance hit the nail pretty well on the head for earth, but not so well for the moon - 270.3 K is still 20 too high. Can anyone point me towards a bona fide source reference or maybe just yea or nay the attached back of envelope calcs. Best regards, and thanks in advance for your kind attention. 'Planetary Natural Black Body Temperature.pdf

+ This for the development of appropriate beam sections etc. Plain aluminium is strongish, light, and easily machined. Ideal starting point. Maybe not so good for joints and bushings. Nylon block is your friend here. Once you're happy with the structural design, if there's a weight problem, you can start looking at alternative substitute materials (Al alloys, composites etc) to replace some of the larger components.

It's a water column. Think I'd look at a seabed pressure gauge first. They seem to work well enough on whale monitors etc.