Dudes, it is not as if all this stuff has not been worked out previously by people who actually understand the subject matter.
1) Technically, CO2 does not emit blackbody radiation at all. It can only radiate at energies corresponding to its absorption energies. The intensity of radiation in that band will be at the level one would expect from a blackbody source, more or less. Blackbody radiation requires a jumble of materials–or ideally a black cavity in which radiation can come to equilibrium.
2) Backradiation IS important for warming the surface, but it is not the only source. Remember that the CO2 excited vibrational band is long-lived, so collisional relaxation is common. This heats gasses in the atmosphere other than CO2.
3) Also remember that the “temperature” of the radiation we see from CO2 in the inky darkness of space is the TOA temperature–lower than the temperature at lower altitudes.
4) The time required to establish a “norm” for the climate depends on the timescale of perturbations to that norm. The climate change “signal” is persistent on long timescales. The “noise” includes things like ENSO and other oscillations (timescales of up to several years), solar irradiance (including 11-year solar cycle), etc. The WMO has concluded that the time it takes for a persistent temperature rise to be detected as significant, given those noise sources is ~30 years. This depends on a) the noise sources and b) the definition of “significant”. Other signals will have other temporal thresholds.
Remember the old researcher’s saying: 6 months in the lab will save you an hour in the library.
Al Bundysays
Killian: a few thoughts on moderation:
1. First recognize boards go through sequences of calm, chaos, assholery by the core group. That latter is very much a constant. So, does any given period of civility/non-civility matter?
(Ask the core questions first.)
AB: OK, so you’ve defined a problem (as opposed to the inevitable). So we disagree.
Killian: 2. The worst thing for any board (on-line forum) is when the moderator and a core group become “institutionalized,” i.e., they dominate the board and are hostile to outliers/outside-the-boxers (relative to the core group.)
AB; Agreed. Fortunately, this is a science site, and as such a propensity to caveat (aka admit non-infallibility) is accessible.
Killian: 3. This board was an example of #2 very, very much over the last three years, and still is. It doesn’t seem so bc I, Thomas, and other outliers are posting very little. When I do, I am largely ignored – even when I simply post links to important science. Literally, over the las three years, my science-only posts get virtually no comments while people complaining about my “style” or non-scientific thinking – according to them – get threads that can go on for months.
AB: Dude, you have been posting without being attacked for at least a month. What’s changed? Not that you haven’t posted, but that you’ve improved your attitude.
Killian: That, AB, is when you know a board is calcified.
AB: OK, but note how you have some serious control over the calcification of this board. KIA, Victor, and you are prime drivers of the flavor of discourse. We’re all lemmings. We all can throw grenades. Combine.
Killian: 4. 1 – 3 are not complaints, they are observations setting up my suggestions:
A. Boards go through phases. So be it.
AB: NO! I build systems. Kindergarten issues are ever so not difficult to solve.
Killian: B. Because of personal differences, moderators must be of an eclectic mindset, or a very narrow mindset, and nothing in between. Choose to be institutionalized (very, very easy, and very 1994) or open (very, very difficult and more democratic.)
C. If A, just get your core group (aka the Peanut Gallery in this case) to be moderators and drive any interesting dissention away. A calm, focused, less-than-creative board will result,
D. If B, then select an eclectic group to be moderators. A more quarrelsome, more creative board will result.
E. With good moderators, either C or D can succeed. What is good moderation?
E.1. Have clear rules as to what gets moderated.
E.2. Have moderators collaborate on any moderation that is due to style, language, rudeness, etc. Clear, direct insults should always be moderated. Denial, too.
E.3. Decide what gets snipped, what gets deleted, what gets Boreholed.
E.4. Do not set moderators up as gods that cannot be questioned. Totalitarianism breeds distrust.
AB: Some good points. I’ll let your thoughts marinate…
Killian: F. Modration slows a board down and screws with continuity. If you have a group with time on their hands, then set up a site where you copy and past problematic posts, the moderators suggestion, and discuss. Ideally, a 1-day max acceptance time is the result.
F.1. It could be set up as a passive system: Here’s the original, here’s my moderation.
F.2. Any comments, suggestions or objections must be made within X hours.
G. if you don’t do F, then you have to deal with moderators having to moderate themselves as a group, which can work, but is slow and messy.
AB: I think a MWFSundayMorning publishing scheme can solve all your issues.
Killian: All that said, this would be the “Least Change for Maximum Effect” (permaculture principle)
AB: Physical systems more or less depend on existing logic and absolutely depend on physics. Computer code depends on zip-zero-nada. The possibility of your analogy being informative, as opposed to distracting, is way low.
We should pick the best free comment code currently available, then decide on customization (though customizationability is a feedback and everything is fractal, so don’t quote me)
So, who has a suggestion? What site or package most impresses you?
Mal, what in ther name of all things bipartisan could possibly go wrong with 250 science journals & newspapers of record, including Nature, Science, The Indy and The Graun lining up behind the lead climate gurus of Vanity Fair and the Nation Institute?
Heh. Yes, the Guardian article discussed Mr. Hertsgaard’s role in the initiative. Sounds like he’s one of the relatively good guys.
Speaking of bipartisanship: Forbes, apparently not a participant in Covering Climate Now, nonetheless carries an (IMHO) incisive piece by “Green Tech” contributor Jeff McMahon, No One Seemed To Notice Greta Thunberg’s Critique Of The Green New Deal. The author, another relatively good guy, highlights Greta’s impatience with partisan posturing to make what I think is a necessary point, despite the tu quoque “blame the Democrats” slant one expects from the venue:
The Achilles’ Heel of the Green New Deal is that it deploys the climate crisis as a liberal cause, which ensures conservative opposition.
The climate crisis is a universal cause.
Conservatives need a way to get on board. It’s difficult for them to support a policy that evokes the New Deal. And conservative opposition will relegate the Green New Deal to the realm of fantasy at least until a cataclysm arrives like the one that inspired the original New Deal.
We need a climate policy sooner than that.
To explain Greta’s sudden, global impact, people have begun speaking of her superpowers. One might be that at 16 she understands political reality better than some who have spent their lives in politics.
Discuss?
Al Bundysays
” Physical systems more or less depend on existing logic and absolutely depend on physics.”
Hmmm, “existing logic” refers to genetics, epigenetics, and various species’ social constructs. Kinda going top-level there…
If we inoculate humans should we not inoculate the world – – shut down all fossil fuel sites? By force if necessary. One present US Presidential candidate has asserted he will declare the environmental threat to constitute a “national emergency”. Scientists and Engineers tend to reluctantly and reticently enter political debate. Have we reached the point where that is appropriate, maybe essential? Perhaps one or more of you should volunteer your expert services to every major political candidate.
I haven’t any expert services to offer, but keeping in mind that effective force requires financial underwriting, whom do you trust to deliver it? Wouldn’t climate realists prefer to reserve the use of force for later stages in the struggle to decarbonize the global economy? Even if we had the wherewithal to do so, does shutting down fossil fuel sites by force really seem more likely to succeed at this juncture than duly enacted carbon pricing? I could be wrong, but even something as radical as a unilateral, revenue-neutral US Carbon Fee and Dividend with Border Adjustment Tariff, for example, presumably has a better chance in the US Congress than a declaration of war on fossil fuel producers. We don’t have time for a revolution!
Alastair B. McDonaldsays
Alistair B. McDonald @273
Greenhouse gas molecules do not emit black-body radiation back to the surface. If they did then they would be unable to emit it to space and balance the energy flow at the TOA.
What? This is utter nonsense. Greenhouse gas molecules radiate heat in all directions equally. They have no idea of up down right or left. Thermal equilibrium occurs when the energy radiated into the earth system equals the energy radiated out. Per the Stefan-Boltzmann law knowing the solar constant and surface area giving the energy into the earth system this equilibrium occurs with the radiation generated from a temperature of 255 degrees Kelvin. Since greenhouse gases inhibit the radiation from escaping freely to space from the surface that temperature must move from the planet surface to somewhere up in the atmosphere where the density of greenhouse gases is such that the portion of the radiation emitted upward can then escape freely to space without reabsorption. This in turn results in a warmer surface from the portion of the radiation emitted downward.
…
BPL knows what he is talking about. You do not.
Surprisingly, it is both you and BPL who do not know what you are talking about. You are just repeating the conventional wisdom which is wrong!
The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.
Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the earth’s surface is re-emitted upwards. Only very little radiation is reemitted spontaneously back to the surface of the Earth.
Mr. Know It Allsays
Several comments last month on what period of time constitutes “climate”. Some say 30 years, but that really isn’t true, since we know of other cycles that are longer than 30 years which resulted in the various warming periods of the past, ice ages, etc. Recent weather seems to suggest an ~80 year cycle from the 30s to today. Evidence:
Strange weather events happening in 2019. Big Cat 5 hurricane Dorian. Big snowstorm in the northern Rockies.
Stranger still, both events were matched almost exactly in 1935 and 1934, respectively. Why is that? Appears to be cyclic.
“Over 9 inches of snowfall was recorded by the National Weather Service in Great Falls, Montana, on Saturday alone, an all-time record daily snowfall in September there. Its total of 18.8 inches since Saturday was an all-time autumn two-day snowstorm record,….. It was already the snowiest September in Great Falls, topping September 1934’s 13.2 inches of snowfall.”
What forcing is making the weather today exactly the same as it was in the 1930s when CO2 was ~100 ppm lower than today? What are some of the other climate cycles we know about and what are their forcings?
O.says
@J_Menadue, #4: See this playlist, there is a lot of material:
#5 I fully agree with McMahon’s piece on Greta Thunberg. What makes her unique is her insistence on accepting and urging everyone else to accept the full challenge of the climate crisis she so unquestioningly accepts as gospel truth — which is, as she never hesitates to stress: extreme.
From my book: “. . . many will find it easy to dismiss her. After all she is “merely,” as she admits, a child. And the sacrifices she is demanding do seem excessive. However, unless you want to be labeled a “denier,” and if you really believe the projections of the IPCC (“the science”) that we have only 12 years to take sufficient action to save the planet, you have no choice but to take her seriously, because unlike many who profess to “believe in” climate change, she is, indeed, willing to “tell it like it is.” And there is no getting around it. As she says, “there is no middle ground.” If you accept the basic premise that climate change is truly an existential threat, then half measures such as the Paris accords will not be enough to stem the inevitable tide.”
I’m not a scientist, but I’m interested. I’ve seen similar claims made before and some relevant information, so here’s just a very quick take on this issue:
1) US heatwaves. The page in the link has a graph labelled actual data which show an increase in the heatwave season from the 1960s to this decade, which looks correct. The denialists say this is nothing special and their alleged underlying data (source unknown) shows a peak in heatwaves in the 1930’s. This is not controversial. Its well known that the 1930s dust bowl period experienced some huge heatwaves related to the warming period early last century, combined with some extreme weather at the time (in America). Heatwave activity fell after WW2 as temperatures fell then the heatwave season lengthened after the 1960’s as the climate warmed, so nothing surprising there. I would say the trend after the 1960s should be the focus of attention given that is a)the modern warming period and b) is a longer so more significant period and so natural factors can be ruled out.
2)US Wildfires. The page has another graph labelled actual data which shows the trend since the 1980’s and an increase in area burned since the 1980’s and is correct , and the denialists so called underlying data shows a big peak in the area burned around the 1930’s as if to suggest the more recent increase is nothing special, perhaps just natural. However much of this 1930’s burning is due to land clearing, and perhaps some influence of the high temperatures during this period. However this early pre 1950’s deforestation data is more or less a guess and should not be relied on, as in this carbon brief article:
The increase in area burned since the 1950s parallels the modern warming period and has been related in large part to the warming period as opposed to deforestation.
3) Arctic sea ice extent. The actual data show a steep decline in summer sea ice since the 1970’s as we all know. The denialists so called underlying data shows what appears to be a big dip over the period 1970’s -1980, a peak around 1980 then a shallow decline until 1990 creating the impression that the recent decline is nothing special. The denialists shout cherry picking! However the reason the slopes look different is simply because the NOAA graph quoted by the denialists uses a compressed vertical scale, the data is the same. And it’s the denialists graph that is doing the cherry picking because its a short period. Simply refer to either of the graphs below which are very long term, (you will have to search down the page in the second link).
As is clear the arctic sea ice was roughly constant from 1870 – 1950 and has been falling quite steeply since about then until now. So as is often the case once we see the really long term trend all the lights come on (or should, obviously not with some people) .
4) Sea level rise. The actual data shows sea level increasing from 1920 to this decade. The denialists data shows a long term graph of sea level rise since the last ice age, showing sea level rise from 18,000 – 8000 years ago of about 120 m as if to say current sea level rise is insignificant. Well of course, there were a lot of ice sheets back then and it took ages for them to melt. We have started a similar process, and it could proceed much more quickly! The denialists also point to ‘zero’ on this graph as if to say “look no sea level rise” but zero is just a start point on the scale, and the trend line only points generally at zero, the graph is too large scale to pick up the sea level rise we have seen since 1900 to this decade (roughly 300mm). Predictions are that this rate will accelerate and it does appear to be doing this.
5) Number of hot days at Waverly Ohio. The denialist cries cherry picking of time periods, while blissfully cherry picking one single city in the USA, which obviously has little use and gives no guide as to what is happening in America as a whole. So its a pointless example.
Maybe that helps a little.
James Charlessays
18.8 and 13.2 are “exactly the same”. Really?
Jan Sunnersays
J Menadue @4
A debunking of the Tony Heller video that you refer to, by one Mallen Baker, can be found on YouTube. It took him only a few days to respond! (I have not had time to critically evaluate either of them). https://www.youtube.com/watch?v=XjPkclkZh6o
I regularly spend a bit of time with climate change sceptics on the web. I know, it is horrible and mostly a waste of time, but I am worried that the dominance of social medial will allow a “detachment” of widely held beliefs from science, data and facts. This is a phenomenon that also has made Real Climate less enjoyable to read. (There is simply too much junk in the comment sections).
We need to think creatively about how to deal with this problem. One suggestion is to introduce some sort of quality label that would allow a reader to choose whether he/she would like to read a comment that has by some acceptable mechanism been found not to fulfill minimal requirements of (scientific) accuracy or relevance.
On a side note, I find that the recent(?) conclusions that the Little Ice Age and the Medieval Warm Period were regional phenomena make many skeptics very uncomfortable.
zebrasays
#2 Ray Ladbury, also AB, Mal and others on the 30-year thing,
Ray, excellent comment but I have to nitpick #4 because it illustrates the point I was going to make to the others before I read it.
“The time required to establish a “norm” for the climate…”
“The climate change “signal” is persistent…”
“the time it takes for a persistent temperature rise”
” Other signals will have other temporal thresholds.”
This isn’t just me being a noodge about communicating clearly to visitors trying to learn stuff; it speaks to the substance (the physics).
AB, you were very clear in communicating on the parallel-Earth storm example with respect to the climate being a chaotic system. But here the discussion seems to be heading towards KIA-level superficiality and incoherence.
What question are you guys trying to answer? Let’s, to begin, limit it to GMST (not “climate change” or “climate” or “other signals”.)
I have no idea what you are trying to determine or what your premises are, much less what relevance [it] might have.
Are you talking about delta_GMST/delta_time? If so, how are you treating other variables and/or parameters? And, what new physical information does increasing the resolution give us??
ABM: Only very little radiation is reemitted spontaneously back to the surface of the Earth.
BPL: This is measurably wrong, and I write “measurably” because back-radiation has been measured for a long time. It is about 324 watts per square meter of sky. You use a device called a pyrgeometer, available at least since the 1950s, to measure it. You can also just point a camera with IR-sensitive film at the night sky.
Arguing against back-radiation is like arguing against sunshine. There it is, in the sky.
KIA 10: Some say 30 years, but that really isn’t true, since we know of other cycles that are longer than 30 years
BPL: You need AT LEAST 30 years to measure a climate TREND. That’s not exactly === 30 years.
Rex Tashasays
Al Bundy great ideas, please get your own website so that you can implement them and we more easily ignore you.
Al Bundysays
KIA: Recent weather seems to suggest an ~80 year cycle from the 30s to today.
AB: Ah, yes. It’s nice to be able to count on things, such as the Denialist Definition of the Biggest Baddest Natural Cycle, which is defined as peaking (on the hot side) “Right Now”. I remember the warm and fuzzy feeling I got when I learned about the Big 60 year cycle in the late 1990s and I’m looking forward to the late 2030s and denialists’ pontifications about the Huge 100 year cycle.
I’ve only got one question: why hasn’t anybody detected this Gargantuan Cycle’s effects on temperatures prior to the industrial age? Given its immense size, shouldn’t it show up in proxies and whatnot as clearly as the waves in the Keeling curve?
Oh well, at least there’s solace in knowing that There Will Be Anecdotal Weather Events somewhere that will fit the Cycle Duration of the day.
“The Gargantuan Cycle is dead. Long live the Gargantuan Cycle!”
Russellsays
2
Killian: That, AB, is when you know a board is calcified.
Al Bundy: OK, but note how you have some serious control over the calcification of this board. KIA, Victor, and you are prime drivers of the flavor of discourse. We’re all lemmings.
It’s easier to let d the lemmings run the hampster wheel than build an off rsmp to the bore hole.
5
As Mal has invited bipartisan discussion, here is some
“He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate.”
Could you clarify how your are applying “the ratio” to this situation?
To have stimulated emission, you must have incident radiation to do the stimulating. If you had zero incident radiation, you would have only spontaneous emission, correct?
jbsays
Re: Knumbskull in America at 10:
It asks: What forcing is making the weather today exactly the same as it was in the 1930s when CO2 was ~100 ppm lower than today?
Clearly, it is the same forcing that allows you to say that a document that implicates a person in 11 felony counts of obstruction of justice is a complete exoneration. It is the same forcing that allows you to say that your mortal fear of wearing your MAGA hat in public is because some Antifa hoodlum is going to rape you.
It is the forcing of lies into fact, at least in the ringed-off knumb area between your ears.
So, let’s look at this issue. If I look at the 1880-2018 GISS annual land-sea temperature anomaly data:
The trailing 30 year moving average for 1930 is -0.289. For 2018, it is 0.559. In your knumb skull, these are “exactly the same.” In the real world, they are not. That is the forcing.
If I do a simple linear regression on the data, the 1930 fitted value (i.e., the temporal local mean) is -0.106 and the 2018 fitted value is 0.535. Once again, the only place that these are “exactly the same” is in your knumb skull. That is the forcing.
No matter what method I use to try to extract the local values for 1930 and 2018, they are only the same if I lie. Which is what your entire world view requires you to do. So, carry on with your “forcing.”
barrysays
Alastair @ 9:
I’m sorry –
“Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the earth’s surface is re-emitted upwards. Only very little radiation is reemitted spontaneously back to the surface of the Earth.”
I didn’t get the logical sequence that leads to very little of the IR radiation being emitted downwards to the surface of the Earth.
Do the molecules somehow know that they are generally supposed to emit upwards? Can you explain the mechanism for this? I’m inclined to think that this assertion is pure BS. But I’m not an expert, and look forward to a clear, clinical explanation.
Recent weather seems to suggest an ~80 year cycle from the 30s to today. Evidence:
I do not think that word means what Mr. IAT thinks it means. Pareidolia doesn’t add up to actual evidence. Codifying and maintaining standards for climatological evidence is one of the World Meteorological Organization’s principle raisons d’être.
Science is a way of trying not to fool yourself. For it to help, you have to be trying! The primary obstacle to Mr. IAT’s understanding of climate science isn’t just that he’s not trying not to, but that he’s manifestly determined to fool himself.
J_Menadue @4,
The 12 minute YouTube video by Goddard/Heller is the usual denialist claptrap. You ask if folk “here can readily show the falsity of these attempts.” As the video is so wide-ranging in its bold assertions, demonstrating its nonsensical nature is not something that can be achieved without some effort digging it out of the rabbit hole Goddard/Heller tossed it into.
One of the many grand assertions made in this latest video by Steve Goddard (aka Tony Heller) concerns Arctic Sea Ice Extent and tries to make out that Fig 7.20a of IPCC FAR 1991 can be considered as being an entirely accurate record of Arctic SIE. Note that the denialists rather ignore the Antarctic version Fig 7.20b which doesn’t suit their purpose. (Fig 7.20 is available on-line here via Wattsupia.)
The pre-1979 satellite data was far from accurate yet survived into the mid-1990s (it is still there in IPCC SAR fig 3.8a) before the extent of the data problems were fully appreciated. Unfortunately the record of this does not appear strongly within the scientific literature and the duff data was simply set aside.
And beyond the accuracy of the data, there are other fundamental problems with the data in that it is not pan-Arctic which is quite evident when the 1972-79 data is plotted against today’s post-1979 data.
I have a spreadsheet with a graphic of the different data plotted out but it is so-far not available on-line.
As with Arctic SIE, the other grand assertions of Goddard/Heller fall away when properly examined. But that is not immediately a trivial task and does take some effort.
CCHolleysays
ABM @9
The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.
Neither Saussure or Fourier even knew what a greenhouse gas was. These were not determined until Tyndall’s work after both were dead. Do you always just make things up?
The downwelling radiation from greenhouse gasses can and has been measured at the surface.
Brian Dodgesays
After reading Dr Steig’s Antarctic ice post, I got to thinking about the giant cavity that appeared under the Thwaites Glacier, and the physical processes that have driven such a rapid evolution of the system. Comments were closed before I got a chance to ask there, so I’m asking here.Laminar flow through circular pipe varies with the 4th power of the diameter, so it seems to me that thermohaline circulation on a retrograde bed under a glacier would have a high order feedback that would accelerate mass loss. Though flow channels would start with high aspect ratio of width to height, physics would drive the shape towards a circular, or including gravity, since it is a gravitational flow, a Jabba-the-Hutt cross section. I grew up in Florida; looking at the radar scan, it reminded me of the development of sink holes. Is it reasonable that the cavity under the ice would thin the top to such an extent the it could collapse like a sink hole? Mechanical support from the sides might hold the surface volume of ice above sea level higher than the flotation of the submerged volume below sea level, so it would not require the formation of an air pocket. If there were a hundred meters of ice above sea level, and a water filled cavity that had eroded the ice from below to within a hundred meters below sea level, the buoyancy of the mass below sea level would not be sufficient to float the mass above sea level. Mechanical force from the solid ice mass around the cavity, either floating with enough draft, or grounded could supply enough force to support the cavity roof, up to a point. Would the cover collapse abruptly, or would the ice more likely deform in plastic flow, so a depression would form, sink to sea level, and form a filled moulin?
Alastair B. McDonaldsays
@2 Ray Ladbury says:
2 Oct 2019 at 4:46 AM
Dudes, it is not as if all this stuff has not been worked out previously by people who actually understand the subject matter.
We are talking about quantum mechanics here. And as Richard Feynman said “If you think you understand quantum mechanics, then you don’t.”
1) Technically, CO2 does not emit blackbody radiation at all. It can only radiate at energies corresponding to its absorption energies. The intensity of radiation in that band will be at the level one would expect from a blackbody source, more or less. Blackbody radiation requires a jumble of materials–or ideally a black cavity in which radiation can come to equilibrium.
The intensity of the radiation does depend on the temperature of the gas because that determines the percentage of excited molecules but it is not related to Planck’s function.
2) Backradiation IS important for warming the surface, but it is not the only source. Remember that the CO2 excited vibrational band is long-lived, so collisional relaxation is common. This heats gasses in the atmosphere other than CO2.
The source which heats the surface is solar energy. When that is not present, nighttime, the surface cools.
3) Also remember that the “temperature” of the radiation we see from CO2 in the inky darkness of space is the TOA temperature–lower than the temperature at lower altitudes.
But the temperature in the thermosphere at the top of the atmosphere is much higher thatn that at the surface.
4) The time required to establish a “norm” for the climate depends on the timescale of perturbations to that norm. The climate change “signal” is persistent on long timescales. The “noise” includes things like ENSO and other oscillations (timescales of up to several years), solar irradiance (including 11-year solar cycle), etc. The WMO has concluded that the time it takes for a persistent temperature rise to be detected as significant, given those noise sources is ~30 years. This depends on a) the noise sources and b) the definition of “significant”. Other signals will have other temporal thresholds.
True! So what?
Remember the old researcher’s saying: 6 months in the lab will save you an hour in the library.
It takes more than an hour in the library to read Chapter 2 of Goody and Yung, and much longer to see where they are going wrong.
Thomas and Stamnes almost get it right when they propose that their Microscopic Radiative Transfer Equation, in Chapter 4, contains the correct source function, but they then argue it is equivalent to the Schwarzschild equation, which is wrong. Their source function has two terms, whereas the Schwarzschild equation has only one.
Victor @13, the entire world knows the Paris Accord doesn’t go nearly far enough. Your book is only stating the obvious. But there’s nothing to suggest we have to adopt a primitive lifestyle if we get organised and get on top of this problem properly. You are making getting organised difficult with your negative blather.
nigeljsays
Alistair B. McDonald,just to let you know you might be flirting dangerously with the Crank Shaft. New place for crazy pseudo science in case you don’t know, below the Bore Hole.
And RSS has posted for September with a TLT anomaly of +0.89ºC, as per UAH, the highest RSS TLT anomaly of 2019 so far and by some margin. (They previously spanned from +0.67ºC to +0.81ºC.)
It is the warmest September on the UAH TLT record, just ahead of 2017 (+0.88ºC), followed by 2016 (+0.80ºC), 2010 (+0.66ºC), 2015 (+0.64ºC), 2009 (+0.61ºC) and 2012 (+0.59ºC).
It is the 6th highest anomaly on the all-month RSS TLT record (8th in UAH), sitting behind four 2016 months and one 1998 month (all El Nino boosted). A spike in the anomalies occurred in 2017 and I wonder if this will turn out to be a repeat. The 2017 TLT spike was not evident within the surface records which had had a spike of their own earlier in the year.
Now with three-quarters of the year complete, 2019 sits firmly in 2nd place for the year-to-date. To drop to 3rd place by end-of-year behind 2017 would require Oct-Dec to average less than +0.47ºC while to gain 1st place would require Oct-Dec to average above +0.96ºC.
Mr. KIA: ” Recent weather seems to suggest an ~80 year cycle from the 30s to today.”
What is the periodicity of the 2nd variable in the ordered pair wrt the 1xt (y on x)
1,2
2,7
3,1
4,8
5,2
6,8
7,1
8,8
9,2
10,8
Based on your answer to the periodicity, what is the 11th y value, a
11,a
If you said 4, you are correct, since the y numbers are simply the digits of e, the Napierian base of natural logarithms. If you said 1 or 2, you are an idiot who looks for periodic behavior where there is none.
Series that seem to exhibit periodic or quasi-periodic behavior are quite common, because data tends to return to its mean after a fluctuation. For this reason, I would suggest being very careful in attributing periodicity to a data series unless you have a forcing of comparable periodicity that is driving it.
But then you listen to Faux News, so you are probably ineducable.
Alastair B. McDonaldsays
Re CCHolley @29 who wrote:
“Neither Saussure or Fourier even knew what a greenhouse gas was. These were not determined until Tyndall’s work after both were dead. Do you always just make things up?”
& Re BPL @ 19
ABM: Only very little radiation is reemitted spontaneously back to the surface of the Earth.
BPL: This is measurably wrong, and I write “measurably” because back-radiation has been measured for a long time. It is about 324 watts per square meter of sky. You use a device called a pyrgeometer, available at least since the 1950s, to measure it. You can also just point a camera with IR-sensitive film at the night sky.
Arguing against back-radiation is like arguing against sunshine. There it is, in the sky.
ABM Of course downwelling radiation exists but it is mainly blackbody radiation from the underside of clouds.
Your 324 watts per meter includes the blackbody radiation from clouds. That greatly exceeds the back radiation from carbon dioxide as can be seen on a cloudless night when the temperature is much lower than that on cloudy nights.
Re @24
Zebra wrote “To have stimulated emission, you must have incident radiation to do the stimulating. If you had zero-incident radiation, you would have only spontaneous emission, correct?”
Yes, that is correct, but the incident radiation is coming from the surface of the earth, i.e. terrestrial black-body radiation. Note that the CO2 molecules are also excited by collisions with other molecules.
Re @26 Barry wrote:
“I didn’t get the logical sequence that leads to very little of the IR radiation being emitted downwards to the surface of the Earth.
Do the molecules somehow know that they are generally supposed to emit upwards? Can you explain the mechanism for this? I’m inclined to think that this assertion is pure BS. But I’m not an expert, and look forward to a clear, clinical explanation.”
The Earth’s surface emits blackbody radiation upwards, and when a photon of the correct frequency collides with an excited molecule a second photon is emitted in the same direction as the first. In other words, both travel upwards.
Hope this helps!
John Pollacksays
Seems to me that both ABM @9 and MKIA @10 could be satisfied if the greenhouse gases were only stimulated to radiate downward in an 80-year cycle. I could go further and speculate that it’s really an 84-year cycle created by the orbital cycle of Uranus – knocking invisible dark matter down on Earth and stimulating those greenhouse gases.
Seriously, I think that the 1930s have been somewhat neglected. At least in the North American sector, there were some really huge blocking patterns and meridional flows. Many of the worst summer heat records in the U.S. still date back to the 1930s, and there were many other large anomalies. It would be nice to know more about what was going on. The pattern is likely to repeat eventually, since there were even worse megadroughts in the pre-industrial period. When it does, the extra 100+ ppm of CO2 will result in even more intense heat and drought, and we certainly aren’t ready for it.
zebrasays
#37 Alastair B McDonald,
My question was about your use of the term “the ratio”.
I read your responses to other people and I still don’t understand what you are trying to say. Let’s consider a simplified atmosphere with no water vapor or other GHG.
You agree that if we start with no radiation from the surface, we have only spontaneous radiation from CO2 molecules, which would be equally “up” and “down”. (For simplicity, ignoring all the other directions.)
Now, we increase the surface radiation in increments. What is the formula by which we calculate “the ratio” of stimulated to spontaneous emissions?
Alastair B. McDonaldsays
Just a quick repost of @9 which John Pollack can’t differentiate from KIA’s denialism.
ABM wrote last month @273
“Greenhouse gas molecules do not emit black-body radiation back to the surface. If they did then they would be unable to emit it to space and balance the energy flow at the TOA.”
CCHolley wrote last month @278
“What? This is utter nonsense. Greenhouse gas molecules radiate heat in all directions equally. They have no idea of up down right or left. Thermal equilibrium occurs when the energy radiated into the earth system equals the energy radiated out. Per the Stefan-Boltzmann law knowing the solar constant and surface area giving the energy into the earth system, this equilibrium occurs with the radiation generated from a temperature of 255 degrees Kelvin. Since greenhouse gases inhibit the radiation from escaping freely to space from the surface that temperature must move from the planet surface to somewhere up in the atmosphere where the density of greenhouse gases is such that the portion of the radiation emitted upward can then escape freely to space without reabsorption. This in turn results in a warmer surface from the portion of the radiation emitted downward.
BTW, 16 per cent of solar radiation is absorbed by water vapor, dust, and O3 in the atmosphere. 3 per cent is absorbed by clouds. [ABM This discussion is about the emission of downwelling longwave radiation, not the absorption of short or longwave radiation.] BPL knows what he is talking about. You do not.”
ABM wrote @
Surprisingly, it is both you and BPL who do not know what you are talking about. You are just repeating the conventional wisdom which is wrong!
The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.
Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation. For the relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the Earth’s surface is re-emitted upwards. Only very little radiation is re-emitted spontaneously back to the surface of the Earth.
More,
There is downward radiation, as pointed out by BPL later, but that is mostly black-body radiation from clouds and aerosols.
Ray Ladburysays
Alastair,
We’ve been through this before. You don’t have the foggiest idea what you are talking about. If the only source of surface warming were TSI, then the night time temperature of the planet would be a whole helluvalot colder than any temperature ever recorded on Earth.
Backradiation can be measured at the surface. Your argument is not with me, but with reality.
barry @26,
There are two ways for a GHG molecule to emit a photon.
Spontaneous emissions result from an excited waggling molecule generating a photon using the waggle energy. As the waggle is almost always caused by collision with another air molecule (indeed it is lucky to get off a photon given the frequency of collisions), the direction the photon shoots-off-in is any-which-way.
Stimiulated emissions result from a suitably excited GHG molecule being disturbed by a passing photon of the correct wave number resultng in the GHG moecule emitting a photon on the coat-tails of the passing photon and in the same direction.
The comment @9 asserts that “… as described by Einstein is his 1917 paper … the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate.” It is true that the lower the frequency, the greater the proportion of spontaneous emission but my understanding (which I see is also the understanding of others) is that “there’s always much more spontaneous than stimulated emission.” As a result the photons emitted by GHG are predominantly any-which-way.
ABM 37: Your 324 watts per meter includes the blackbody radiation from clouds. That greatly exceeds the back radiation from carbon dioxide as can be seen on a cloudless night when the temperature is much lower than that on cloudy nights.
BPL: No. Cloudless nights are colder because more radiation is being lost from the surface.
Rex Tashasays
Is the Pillsbury Dough Mann moderating these comments? Is he in the State Penn or Penn State?
zebrasays
#38 John Pollack,
“the pattern is likely to repeat eventually”
Why? The climate system is very different now. Why would you predict this specific local extreme to occur in our current or a future regime?
Have you run a model that shows it is likely to occur?
I would think the opposite is true; it’s like predicting that hurricane Dorian would occur exactly the same on a planet with a much lower climate system energy level.
Seriously, I think that the 1930s have been somewhat neglected. At least in the North American sector, there were some really huge blocking patterns and meridional flows. Many of the worst summer heat records in the U.S. still date back to the 1930s, and there were many other large anomalies. It would be nice to know more about what was going on. The pattern is likely to repeat eventually, since there were even worse megadroughts in the pre-industrial period. When it does, the extra 100+ ppm of CO2 will result in even more intense heat and drought, and we certainly aren’t ready for it.
The relationship between global warming and individual weather events is complex.
Regarding this drought, “the only thing that can be conclusively said to be related to climate change is the high temperatures, just because temperatures were warmer by about 1 or 2 degrees already, compared to what they were the last century,” Dr. Nielsen-Gammon said. “With the rainfall levels, there are competing influences.”
One assumes weather in the 1930s was also the result of competing influences. There may not be enough data from that time, before satellites and solid-state electronics, to puzzle them out. Comparison with recent record-setting events is interesting, nonetheless.
Al Bundysays
John Pollack: I could go further and speculate that it’s really an 84-year cycle created by the orbital cycle of Uranus –
AB: So denialists are actually on to something when they pull stuff out of their ass
CCHolleysays
ABM @37
Once again, you made it up when you stated: “The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.”
Neither Saussure nor Fourier had any concept of a greenhouse gas.
Saussure made a device which was essentially a miniature greenhouse. He showed that it trapped solar heat from the sun; however, he had no explanation for why it did so. “Physicists are not unanimous as to the nature of sunlight. Some regard it as the same element as fire, but in the state of its greatest purity. Others envisage it as an entity with a nature completely different from fire, and which, incapable of itself heating, has only the power to give an igneous fluid the movement which produces heat.” Saussure lived at a time when scientists were just starting to study the nature of heat. He had no clue as to the difference between infrared and short wave radiation. He most certainly did not show “that is how the air warms.”
Fourier’s contribution was mostly mathematical. He showed that the surface of the earth should be much colder than it actually is. He proposed that this may be do to interstellar radiation or that perhaps the atmosphere somehow inhibited the transmission of long wave radiation which is what he suspected Saussure’s device did. But he also understood that it prevented convection of the heat away which was the correct interpretation. Fourier never hypothesized that there were greenhouse gases in the atmosphere, he simply thought that somehow perhaps the atmosphere might block some of the radiation by which he did not speculate on the mechanism other than: “because the heat finds fewer obstacles in penetrating the air, when it is SW, than in repassing when converted into IR.”
Why do you think Tyndall tried to measure the greenhouse effect if he did not know that the air absorbed radiation? Tyndall cites both Saussure and Fourier in his paper
Tyndall didn’t try to measure the greenhouse effect. He merely measured the radiative properties of the components of the atmosphere, which in turn showed that “greenhouse” gases did, in fact, exist. Why did he do this? Because the nature of heat was better understood by his time and the fact that different materials had different radiative properties had become known. From Fourier’s work, he understood that the earth should be cooler and that the mechanism was likely due to components in the atmosphere with absorptive properties in the IR. That is why he did his experiments, to determine what they were and that they actually existed.
The Earth’s surface emits blackbody radiation upwards, and when a photon of the correct frequency collides with an excited molecule a second photon is emitted in the same direction as the first. In other words, both travel upwards.
This is comical. Photons are emitted randomly due to the increased energy state. Photons don’t know the direction the photon came from that increased the energy. Nor does the molecule know if the increased energy state came from absorption of radiation or a collision with another molecule. In either case, it just randomly emits photons in any random direction.
Brian Dodgesays
@ Alastair B. McDonald 4 Oct 2019 at 3:41 PM
There is the small matter of relaxation time between when the molecule absorbs a photon and becomes excited, and the time it emits a photon. How does the molecule remember which way the photon was going when it was absorbed? If it is rotating as well as vibrating, how does it detect its new orientation when it decides to relax, so that it can emit the new photon in the old direction. The direction of the incoming photons has a 3 dimensional distribution,(Lambertian?); does the excited molecule remember both the angle with respect to gravity, or with respect to magnetic or true polar North as well?
John Pollacksays
#45 Zebra The climate system is not so different now that it won’t generate periodic droughts over North America. California had an intense one earlier this decade, which included an extension across the Great Plains into the Midwest in 2012. These are more than “local extemes” because they involve a persistent anomaly in atmospheric waves on a hemispheric scale https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0664.1
If you are suggesting that because the climate system is accumulating energy, there won’t be an exact repeat of the 1930’s Dust Bowl or hurricane Dorian down to the last precise local detail, then I agree with you. You can stop repeating the point, or take it to a philosophy blog where you can endlessly discuss the meaning of “things are different because they aren’t exactly the same.”
What I expect is that under similar synoptic conditions, droughts, heat waves, and hurricanes will become more extreme. I’m interested in figuring out how much and how fast, which also involves understanding historical weather to the extent possible. Telling me repeatedly that the next weather system or climate regime won’t be exactly the same as the last is a completely unhelpful truism.
SROCC is out. It has many interesting things to say.
https://www.ipcc.ch/srocc/download-report/
sidd
Dudes, it is not as if all this stuff has not been worked out previously by people who actually understand the subject matter.
1) Technically, CO2 does not emit blackbody radiation at all. It can only radiate at energies corresponding to its absorption energies. The intensity of radiation in that band will be at the level one would expect from a blackbody source, more or less. Blackbody radiation requires a jumble of materials–or ideally a black cavity in which radiation can come to equilibrium.
2) Backradiation IS important for warming the surface, but it is not the only source. Remember that the CO2 excited vibrational band is long-lived, so collisional relaxation is common. This heats gasses in the atmosphere other than CO2.
3) Also remember that the “temperature” of the radiation we see from CO2 in the inky darkness of space is the TOA temperature–lower than the temperature at lower altitudes.
4) The time required to establish a “norm” for the climate depends on the timescale of perturbations to that norm. The climate change “signal” is persistent on long timescales. The “noise” includes things like ENSO and other oscillations (timescales of up to several years), solar irradiance (including 11-year solar cycle), etc. The WMO has concluded that the time it takes for a persistent temperature rise to be detected as significant, given those noise sources is ~30 years. This depends on a) the noise sources and b) the definition of “significant”. Other signals will have other temporal thresholds.
Remember the old researcher’s saying: 6 months in the lab will save you an hour in the library.
Killian: a few thoughts on moderation:
1. First recognize boards go through sequences of calm, chaos, assholery by the core group. That latter is very much a constant. So, does any given period of civility/non-civility matter?
(Ask the core questions first.)
AB: OK, so you’ve defined a problem (as opposed to the inevitable). So we disagree.
Killian: 2. The worst thing for any board (on-line forum) is when the moderator and a core group become “institutionalized,” i.e., they dominate the board and are hostile to outliers/outside-the-boxers (relative to the core group.)
AB; Agreed. Fortunately, this is a science site, and as such a propensity to caveat (aka admit non-infallibility) is accessible.
Killian: 3. This board was an example of #2 very, very much over the last three years, and still is. It doesn’t seem so bc I, Thomas, and other outliers are posting very little. When I do, I am largely ignored – even when I simply post links to important science. Literally, over the las three years, my science-only posts get virtually no comments while people complaining about my “style” or non-scientific thinking – according to them – get threads that can go on for months.
AB: Dude, you have been posting without being attacked for at least a month. What’s changed? Not that you haven’t posted, but that you’ve improved your attitude.
Killian: That, AB, is when you know a board is calcified.
AB: OK, but note how you have some serious control over the calcification of this board. KIA, Victor, and you are prime drivers of the flavor of discourse. We’re all lemmings. We all can throw grenades. Combine.
Killian: 4. 1 – 3 are not complaints, they are observations setting up my suggestions:
A. Boards go through phases. So be it.
AB: NO! I build systems. Kindergarten issues are ever so not difficult to solve.
Killian: B. Because of personal differences, moderators must be of an eclectic mindset, or a very narrow mindset, and nothing in between. Choose to be institutionalized (very, very easy, and very 1994) or open (very, very difficult and more democratic.)
C. If A, just get your core group (aka the Peanut Gallery in this case) to be moderators and drive any interesting dissention away. A calm, focused, less-than-creative board will result,
D. If B, then select an eclectic group to be moderators. A more quarrelsome, more creative board will result.
E. With good moderators, either C or D can succeed. What is good moderation?
E.1. Have clear rules as to what gets moderated.
E.2. Have moderators collaborate on any moderation that is due to style, language, rudeness, etc. Clear, direct insults should always be moderated. Denial, too.
E.3. Decide what gets snipped, what gets deleted, what gets Boreholed.
E.4. Do not set moderators up as gods that cannot be questioned. Totalitarianism breeds distrust.
AB: Some good points. I’ll let your thoughts marinate…
Killian: F. Modration slows a board down and screws with continuity. If you have a group with time on their hands, then set up a site where you copy and past problematic posts, the moderators suggestion, and discuss. Ideally, a 1-day max acceptance time is the result.
F.1. It could be set up as a passive system: Here’s the original, here’s my moderation.
F.2. Any comments, suggestions or objections must be made within X hours.
G. if you don’t do F, then you have to deal with moderators having to moderate themselves as a group, which can work, but is slow and messy.
AB: I think a MWFSundayMorning publishing scheme can solve all your issues.
Killian: All that said, this would be the “Least Change for Maximum Effect” (permaculture principle)
AB: Physical systems more or less depend on existing logic and absolutely depend on physics. Computer code depends on zip-zero-nada. The possibility of your analogy being informative, as opposed to distracting, is way low.
We should pick the best free comment code currently available, then decide on customization (though customizationability is a feedback and everything is fractal, so don’t quote me)
So, who has a suggestion? What site or package most impresses you?
I am concerned about new attempts to deny climate science:
https://youtu.be/8455KEDitpU
and from a normally respectable site here: https://revolution-green.com/global-warming-fraud-exposed-pictures/
I hope the scientists and commentators here can readily show the falsity of these attempts.
Russell, last month:
Heh. Yes, the Guardian article discussed Mr. Hertsgaard’s role in the initiative. Sounds like he’s one of the relatively good guys.
Speaking of bipartisanship: Forbes, apparently not a participant in Covering Climate Now, nonetheless carries an (IMHO) incisive piece by “Green Tech” contributor Jeff McMahon, No One Seemed To Notice Greta Thunberg’s Critique Of The Green New Deal. The author, another relatively good guy, highlights Greta’s impatience with partisan posturing to make what I think is a necessary point, despite the tu quoque “blame the Democrats” slant one expects from the venue:
Discuss?
” Physical systems more or less depend on existing logic and absolutely depend on physics.”
Hmmm, “existing logic” refers to genetics, epigenetics, and various species’ social constructs. Kinda going top-level there…
BTW, Russell: not that it matters to your implied warrant, but AFAICT Science isn’t on the list.
Lee Hustead:
I haven’t any expert services to offer, but keeping in mind that effective force requires financial underwriting, whom do you trust to deliver it? Wouldn’t climate realists prefer to reserve the use of force for later stages in the struggle to decarbonize the global economy? Even if we had the wherewithal to do so, does shutting down fossil fuel sites by force really seem more likely to succeed at this juncture than duly enacted carbon pricing? I could be wrong, but even something as radical as a unilateral, revenue-neutral US Carbon Fee and Dividend with Border Adjustment Tariff, for example, presumably has a better chance in the US Congress than a declaration of war on fossil fuel producers. We don’t have time for a revolution!
Alistair B. McDonald @273
What? This is utter nonsense. Greenhouse gas molecules radiate heat in all directions equally. They have no idea of up down right or left. Thermal equilibrium occurs when the energy radiated into the earth system equals the energy radiated out. Per the Stefan-Boltzmann law knowing the solar constant and surface area giving the energy into the earth system this equilibrium occurs with the radiation generated from a temperature of 255 degrees Kelvin. Since greenhouse gases inhibit the radiation from escaping freely to space from the surface that temperature must move from the planet surface to somewhere up in the atmosphere where the density of greenhouse gases is such that the portion of the radiation emitted upward can then escape freely to space without reabsorption. This in turn results in a warmer surface from the portion of the radiation emitted downward.
…
BPL knows what he is talking about. You do not.
Surprisingly, it is both you and BPL who do not know what you are talking about. You are just repeating the conventional wisdom which is wrong!
The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.
Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the earth’s surface is re-emitted upwards. Only very little radiation is reemitted spontaneously back to the surface of the Earth.
Several comments last month on what period of time constitutes “climate”. Some say 30 years, but that really isn’t true, since we know of other cycles that are longer than 30 years which resulted in the various warming periods of the past, ice ages, etc. Recent weather seems to suggest an ~80 year cycle from the 30s to today. Evidence:
Strange weather events happening in 2019. Big Cat 5 hurricane Dorian. Big snowstorm in the northern Rockies.
Stranger still, both events were matched almost exactly in 1935 and 1934, respectively. Why is that? Appears to be cyclic.
https://weather.com/forecast/regional/news/2019-09-25-september-blizzard-montana-northern-rockies-snow
“Over 9 inches of snowfall was recorded by the National Weather Service in Great Falls, Montana, on Saturday alone, an all-time record daily snowfall in September there. Its total of 18.8 inches since Saturday was an all-time autumn two-day snowstorm record,….. It was already the snowiest September in Great Falls, topping September 1934’s 13.2 inches of snowfall.”
What forcing is making the weather today exactly the same as it was in the 1930s when CO2 was ~100 ppm lower than today? What are some of the other climate cycles we know about and what are their forcings?
@J_Menadue, #4: See this playlist, there is a lot of material:
Climate change explained, and the myths debunked
https://www.youtube.com/watch?v=52KLGqDSAjo&list=PL82yk73N8eoX-Xobr_TfHsWPfAIyI7VAP
And this one:
The story of the Earth in 33 minutes
https://www.youtube.com/watch?v=MQWJbLTyDlc
Coldest Winter on Record in USA
Watch it if you dare!
#5 I fully agree with McMahon’s piece on Greta Thunberg. What makes her unique is her insistence on accepting and urging everyone else to accept the full challenge of the climate crisis she so unquestioningly accepts as gospel truth — which is, as she never hesitates to stress: extreme.
From my book: “. . . many will find it easy to dismiss her. After all she is “merely,” as she admits, a child. And the sacrifices she is demanding do seem excessive. However, unless you want to be labeled a “denier,” and if you really believe the projections of the IPCC (“the science”) that we have only 12 years to take sufficient action to save the planet, you have no choice but to take her seriously, because unlike many who profess to “believe in” climate change, she is, indeed, willing to “tell it like it is.” And there is no getting around it. As she says, “there is no middle ground.” If you accept the basic premise that climate change is truly an existential threat, then half measures such as the Paris accords will not be enough to stem the inevitable tide.”
Younger Dryas Impact Hypothesis evidence in South Africa:
Did a large meteorite hit the earth 12,800 years ago? Here’s new evidence
Francis Thackeray
2019 Oct 02
Phys.org
https://www.google.com/amp/s/phys.org/news/2019-10-large-meteorite-earth-years-evidence.amp
See also
https://www.google.com/amp/s/phys.org/news/2019-10-hypothesis-asteroid-contributed-mass-extinction.amp
J_Menadue @4 says “I am concerned about new attempts to deny climate science….and from a normally respectable site here: https://revolution-green.com/global-warming-fraud-exposed-pictures/”
I’m not a scientist, but I’m interested. I’ve seen similar claims made before and some relevant information, so here’s just a very quick take on this issue:
1) US heatwaves. The page in the link has a graph labelled actual data which show an increase in the heatwave season from the 1960s to this decade, which looks correct. The denialists say this is nothing special and their alleged underlying data (source unknown) shows a peak in heatwaves in the 1930’s. This is not controversial. Its well known that the 1930s dust bowl period experienced some huge heatwaves related to the warming period early last century, combined with some extreme weather at the time (in America). Heatwave activity fell after WW2 as temperatures fell then the heatwave season lengthened after the 1960’s as the climate warmed, so nothing surprising there. I would say the trend after the 1960s should be the focus of attention given that is a)the modern warming period and b) is a longer so more significant period and so natural factors can be ruled out.
2)US Wildfires. The page has another graph labelled actual data which shows the trend since the 1980’s and an increase in area burned since the 1980’s and is correct , and the denialists so called underlying data shows a big peak in the area burned around the 1930’s as if to suggest the more recent increase is nothing special, perhaps just natural. However much of this 1930’s burning is due to land clearing, and perhaps some influence of the high temperatures during this period. However this early pre 1950’s deforestation data is more or less a guess and should not be relied on, as in this carbon brief article:
https://www.carbonbrief.org/factcheck-how-global-warming-has-increased-us-wildfires
The increase in area burned since the 1950s parallels the modern warming period and has been related in large part to the warming period as opposed to deforestation.
3) Arctic sea ice extent. The actual data show a steep decline in summer sea ice since the 1970’s as we all know. The denialists so called underlying data shows what appears to be a big dip over the period 1970’s -1980, a peak around 1980 then a shallow decline until 1990 creating the impression that the recent decline is nothing special. The denialists shout cherry picking! However the reason the slopes look different is simply because the NOAA graph quoted by the denialists uses a compressed vertical scale, the data is the same. And it’s the denialists graph that is doing the cherry picking because its a short period. Simply refer to either of the graphs below which are very long term, (you will have to search down the page in the second link).
https://skepticalscience.com/arctic-sea-ice-recovers-to-6th-lowest-extent-in-millennia.html
https://sites.google.com/site/arcticseaicegraphs/longterm
As is clear the arctic sea ice was roughly constant from 1870 – 1950 and has been falling quite steeply since about then until now. So as is often the case once we see the really long term trend all the lights come on (or should, obviously not with some people) .
4) Sea level rise. The actual data shows sea level increasing from 1920 to this decade. The denialists data shows a long term graph of sea level rise since the last ice age, showing sea level rise from 18,000 – 8000 years ago of about 120 m as if to say current sea level rise is insignificant. Well of course, there were a lot of ice sheets back then and it took ages for them to melt. We have started a similar process, and it could proceed much more quickly! The denialists also point to ‘zero’ on this graph as if to say “look no sea level rise” but zero is just a start point on the scale, and the trend line only points generally at zero, the graph is too large scale to pick up the sea level rise we have seen since 1900 to this decade (roughly 300mm). Predictions are that this rate will accelerate and it does appear to be doing this.
5) Number of hot days at Waverly Ohio. The denialist cries cherry picking of time periods, while blissfully cherry picking one single city in the USA, which obviously has little use and gives no guide as to what is happening in America as a whole. So its a pointless example.
Maybe that helps a little.
18.8 and 13.2 are “exactly the same”. Really?
J Menadue @4
A debunking of the Tony Heller video that you refer to, by one Mallen Baker, can be found on YouTube. It took him only a few days to respond! (I have not had time to critically evaluate either of them).
https://www.youtube.com/watch?v=XjPkclkZh6o
I regularly spend a bit of time with climate change sceptics on the web. I know, it is horrible and mostly a waste of time, but I am worried that the dominance of social medial will allow a “detachment” of widely held beliefs from science, data and facts. This is a phenomenon that also has made Real Climate less enjoyable to read. (There is simply too much junk in the comment sections).
We need to think creatively about how to deal with this problem. One suggestion is to introduce some sort of quality label that would allow a reader to choose whether he/she would like to read a comment that has by some acceptable mechanism been found not to fulfill minimal requirements of (scientific) accuracy or relevance.
On a side note, I find that the recent(?) conclusions that the Little Ice Age and the Medieval Warm Period were regional phenomena make many skeptics very uncomfortable.
#2 Ray Ladbury, also AB, Mal and others on the 30-year thing,
Ray, excellent comment but I have to nitpick #4 because it illustrates the point I was going to make to the others before I read it.
“The time required to establish a “norm” for the climate…”
“The climate change “signal” is persistent…”
“the time it takes for a persistent temperature rise”
” Other signals will have other temporal thresholds.”
This isn’t just me being a noodge about communicating clearly to visitors trying to learn stuff; it speaks to the substance (the physics).
AB, you were very clear in communicating on the parallel-Earth storm example with respect to the climate being a chaotic system. But here the discussion seems to be heading towards KIA-level superficiality and incoherence.
What question are you guys trying to answer? Let’s, to begin, limit it to GMST (not “climate change” or “climate” or “other signals”.)
I have no idea what you are trying to determine or what your premises are, much less what relevance [it] might have.
Are you talking about delta_GMST/delta_time? If so, how are you treating other variables and/or parameters? And, what new physical information does increasing the resolution give us??
Anyone?
ABM: Only very little radiation is reemitted spontaneously back to the surface of the Earth.
BPL: This is measurably wrong, and I write “measurably” because back-radiation has been measured for a long time. It is about 324 watts per square meter of sky. You use a device called a pyrgeometer, available at least since the 1950s, to measure it. You can also just point a camera with IR-sensitive film at the night sky.
Arguing against back-radiation is like arguing against sunshine. There it is, in the sky.
KIA 10: Some say 30 years, but that really isn’t true, since we know of other cycles that are longer than 30 years
BPL: You need AT LEAST 30 years to measure a climate TREND. That’s not exactly === 30 years.
Al Bundy great ideas, please get your own website so that you can implement them and we more easily ignore you.
KIA: Recent weather seems to suggest an ~80 year cycle from the 30s to today.
AB: Ah, yes. It’s nice to be able to count on things, such as the Denialist Definition of the Biggest Baddest Natural Cycle, which is defined as peaking (on the hot side) “Right Now”. I remember the warm and fuzzy feeling I got when I learned about the Big 60 year cycle in the late 1990s and I’m looking forward to the late 2030s and denialists’ pontifications about the Huge 100 year cycle.
I’ve only got one question: why hasn’t anybody detected this Gargantuan Cycle’s effects on temperatures prior to the industrial age? Given its immense size, shouldn’t it show up in proxies and whatnot as clearly as the waves in the Keeling curve?
Oh well, at least there’s solace in knowing that There Will Be Anecdotal Weather Events somewhere that will fit the Cycle Duration of the day.
“The Gargantuan Cycle is dead. Long live the Gargantuan Cycle!”
2
Killian: That, AB, is when you know a board is calcified.
Al Bundy: OK, but note how you have some serious control over the calcification of this board. KIA, Victor, and you are prime drivers of the flavor of discourse. We’re all lemmings.
It’s easier to let d the lemmings run the hampster wheel than build an off rsmp to the bore hole.
5
As Mal has invited bipartisan discussion, here is some
https://vvattsupwiththat.blogspot.com/2019/10/the-republican-scores-on-science.html
#9 Alistair B. McDonald,
“He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate.”
Could you clarify how your are applying “the ratio” to this situation?
To have stimulated emission, you must have incident radiation to do the stimulating. If you had zero incident radiation, you would have only spontaneous emission, correct?
Re: Knumbskull in America at 10:
It asks: What forcing is making the weather today exactly the same as it was in the 1930s when CO2 was ~100 ppm lower than today?
Clearly, it is the same forcing that allows you to say that a document that implicates a person in 11 felony counts of obstruction of justice is a complete exoneration. It is the same forcing that allows you to say that your mortal fear of wearing your MAGA hat in public is because some Antifa hoodlum is going to rape you.
It is the forcing of lies into fact, at least in the ringed-off knumb area between your ears.
So, let’s look at this issue. If I look at the 1880-2018 GISS annual land-sea temperature anomaly data:
The trailing 30 year moving average for 1930 is -0.289. For 2018, it is 0.559. In your knumb skull, these are “exactly the same.” In the real world, they are not. That is the forcing.
If I do a simple linear regression on the data, the 1930 fitted value (i.e., the temporal local mean) is -0.106 and the 2018 fitted value is 0.535. Once again, the only place that these are “exactly the same” is in your knumb skull. That is the forcing.
No matter what method I use to try to extract the local values for 1930 and 2018, they are only the same if I lie. Which is what your entire world view requires you to do. So, carry on with your “forcing.”
Alastair @ 9:
I’m sorry –
“Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the earth’s surface is re-emitted upwards. Only very little radiation is reemitted spontaneously back to the surface of the Earth.”
I didn’t get the logical sequence that leads to very little of the IR radiation being emitted downwards to the surface of the Earth.
Do the molecules somehow know that they are generally supposed to emit upwards? Can you explain the mechanism for this? I’m inclined to think that this assertion is pure BS. But I’m not an expert, and look forward to a clear, clinical explanation.
Mr. Ironically Anosognosic Typist (emphasis mine):
I do not think that word means what Mr. IAT thinks it means. Pareidolia doesn’t add up to actual evidence. Codifying and maintaining standards for climatological evidence is one of the World Meteorological Organization’s principle raisons d’être.
Science is a way of trying not to fool yourself. For it to help, you have to be trying! The primary obstacle to Mr. IAT’s understanding of climate science isn’t just that he’s not trying not to, but that he’s manifestly determined to fool himself.
J_Menadue @4,
The 12 minute YouTube video by Goddard/Heller is the usual denialist claptrap. You ask if folk “here can readily show the falsity of these attempts.” As the video is so wide-ranging in its bold assertions, demonstrating its nonsensical nature is not something that can be achieved without some effort digging it out of the rabbit hole Goddard/Heller tossed it into.
One of the many grand assertions made in this latest video by Steve Goddard (aka Tony Heller) concerns Arctic Sea Ice Extent and tries to make out that Fig 7.20a of IPCC FAR 1991 can be considered as being an entirely accurate record of Arctic SIE. Note that the denialists rather ignore the Antarctic version Fig 7.20b which doesn’t suit their purpose. (Fig 7.20 is available on-line here via Wattsupia.)
The pre-1979 satellite data was far from accurate yet survived into the mid-1990s (it is still there in IPCC SAR fig 3.8a) before the extent of the data problems were fully appreciated. Unfortunately the record of this does not appear strongly within the scientific literature and the duff data was simply set aside.
And beyond the accuracy of the data, there are other fundamental problems with the data in that it is not pan-Arctic which is quite evident when the 1972-79 data is plotted against today’s post-1979 data.
I have a spreadsheet with a graphic of the different data plotted out but it is so-far not available on-line.
As with Arctic SIE, the other grand assertions of Goddard/Heller fall away when properly examined. But that is not immediately a trivial task and does take some effort.
ABM @9
Neither Saussure or Fourier even knew what a greenhouse gas was. These were not determined until Tyndall’s work after both were dead. Do you always just make things up?
The downwelling radiation from greenhouse gasses can and has been measured at the surface.
After reading Dr Steig’s Antarctic ice post, I got to thinking about the giant cavity that appeared under the Thwaites Glacier, and the physical processes that have driven such a rapid evolution of the system. Comments were closed before I got a chance to ask there, so I’m asking here.Laminar flow through circular pipe varies with the 4th power of the diameter, so it seems to me that thermohaline circulation on a retrograde bed under a glacier would have a high order feedback that would accelerate mass loss. Though flow channels would start with high aspect ratio of width to height, physics would drive the shape towards a circular, or including gravity, since it is a gravitational flow, a Jabba-the-Hutt cross section. I grew up in Florida; looking at the radar scan, it reminded me of the development of sink holes. Is it reasonable that the cavity under the ice would thin the top to such an extent the it could collapse like a sink hole? Mechanical support from the sides might hold the surface volume of ice above sea level higher than the flotation of the submerged volume below sea level, so it would not require the formation of an air pocket. If there were a hundred meters of ice above sea level, and a water filled cavity that had eroded the ice from below to within a hundred meters below sea level, the buoyancy of the mass below sea level would not be sufficient to float the mass above sea level. Mechanical force from the solid ice mass around the cavity, either floating with enough draft, or grounded could supply enough force to support the cavity roof, up to a point. Would the cover collapse abruptly, or would the ice more likely deform in plastic flow, so a depression would form, sink to sea level, and form a filled moulin?
We are talking about quantum mechanics here. And as Richard Feynman said “If you think you understand quantum mechanics, then you don’t.”
The intensity of the radiation does depend on the temperature of the gas because that determines the percentage of excited molecules but it is not related to Planck’s function.
The source which heats the surface is solar energy. When that is not present, nighttime, the surface cools.
But the temperature in the thermosphere at the top of the atmosphere is much higher thatn that at the surface.
True! So what?
It takes more than an hour in the library to read Chapter 2 of Goody and Yung, and much longer to see where they are going wrong.
Thomas and Stamnes almost get it right when they propose that their Microscopic Radiative Transfer Equation, in Chapter 4, contains the correct source function, but they then argue it is equivalent to the Schwarzschild equation, which is wrong. Their source function has two terms, whereas the Schwarzschild equation has only one.
Back to the future:
http://bravenewclimate.proboards.com/thread/561/back-future?page=1#post-5965
Goodbye to the low lands.
Victor @13, the entire world knows the Paris Accord doesn’t go nearly far enough. Your book is only stating the obvious. But there’s nothing to suggest we have to adopt a primitive lifestyle if we get organised and get on top of this problem properly. You are making getting organised difficult with your negative blather.
Alistair B. McDonald,just to let you know you might be flirting dangerously with the Crank Shaft. New place for crazy pseudo science in case you don’t know, below the Bore Hole.
And RSS has posted for September with a TLT anomaly of +0.89ºC, as per UAH, the highest RSS TLT anomaly of 2019 so far and by some margin. (They previously spanned from +0.67ºC to +0.81ºC.)
It is the warmest September on the UAH TLT record, just ahead of 2017 (+0.88ºC), followed by 2016 (+0.80ºC), 2010 (+0.66ºC), 2015 (+0.64ºC), 2009 (+0.61ºC) and 2012 (+0.59ºC).
It is the 6th highest anomaly on the all-month RSS TLT record (8th in UAH), sitting behind four 2016 months and one 1998 month (all El Nino boosted). A spike in the anomalies occurred in 2017 and I wonder if this will turn out to be a repeat. The 2017 TLT spike was not evident within the surface records which had had a spike of their own earlier in the year.
Now with three-quarters of the year complete, 2019 sits firmly in 2nd place for the year-to-date. To drop to 3rd place by end-of-year behind 2017 would require Oct-Dec to average less than +0.47ºC while to gain 1st place would require Oct-Dec to average above +0.96ºC.
…….. Jan-Sept Ave … Annual Ave ..Annual ranking
2016 .. +0.86ºC … … … +0.79ºC … … … 1st
2019 .. +0.73ºC
2010 .. +0.68ºC … … … +0.62ºC … … … 3rd
2017 .. +0.66ºC … … … +0.66ºC … … … 2nd
1998 .. +0.66ºC … … … +0.58ºC … … … 5th
2015 .. +0.54ºC … … … +0.59ºC … … … 4th
2018 .. +0.52ºC … … … +0.52ºC … … … 6th
2005 .. +0.47ºC … … … +0.46ºC … … … 8th
2014 .. +0.46ºC … … … +0.47ºC … … … 7th
2007 .. +0.45ºC … … … +0.41ºC … … … 10th
2013 .. +0.42ºC … … … +0.42ºC … … … 9th
Mr. KIA: ” Recent weather seems to suggest an ~80 year cycle from the 30s to today.”
What is the periodicity of the 2nd variable in the ordered pair wrt the 1xt (y on x)
1,2
2,7
3,1
4,8
5,2
6,8
7,1
8,8
9,2
10,8
Based on your answer to the periodicity, what is the 11th y value, a
11,a
If you said 4, you are correct, since the y numbers are simply the digits of e, the Napierian base of natural logarithms. If you said 1 or 2, you are an idiot who looks for periodic behavior where there is none.
Series that seem to exhibit periodic or quasi-periodic behavior are quite common, because data tends to return to its mean after a fluctuation. For this reason, I would suggest being very careful in attributing periodicity to a data series unless you have a forcing of comparable periodicity that is driving it.
But then you listen to Faux News, so you are probably ineducable.
Re CCHolley @29 who wrote:
“Neither Saussure or Fourier even knew what a greenhouse gas was. These were not determined until Tyndall’s work after both were dead. Do you always just make things up?”
Why do you think Tyndall tried to measure the greenhouse effect if he did not know that the air absorbed radiation? Tyndall cites both Saussure and Fourier in his paper:
https://www.jstor.org/stable/108724?seq=1#metadata_info_tab_contents
& Re BPL @ 19
ABM: Only very little radiation is reemitted spontaneously back to the surface of the Earth.
BPL: This is measurably wrong, and I write “measurably” because back-radiation has been measured for a long time. It is about 324 watts per square meter of sky. You use a device called a pyrgeometer, available at least since the 1950s, to measure it. You can also just point a camera with IR-sensitive film at the night sky.
Arguing against back-radiation is like arguing against sunshine. There it is, in the sky.
ABM Of course downwelling radiation exists but it is mainly blackbody radiation from the underside of clouds.
Your 324 watts per meter includes the blackbody radiation from clouds. That greatly exceeds the back radiation from carbon dioxide as can be seen on a cloudless night when the temperature is much lower than that on cloudy nights.
Re @24
Zebra wrote “To have stimulated emission, you must have incident radiation to do the stimulating. If you had zero-incident radiation, you would have only spontaneous emission, correct?”
Yes, that is correct, but the incident radiation is coming from the surface of the earth, i.e. terrestrial black-body radiation. Note that the CO2 molecules are also excited by collisions with other molecules.
Re @26 Barry wrote:
“I didn’t get the logical sequence that leads to very little of the IR radiation being emitted downwards to the surface of the Earth.
Do the molecules somehow know that they are generally supposed to emit upwards? Can you explain the mechanism for this? I’m inclined to think that this assertion is pure BS. But I’m not an expert, and look forward to a clear, clinical explanation.”
The Earth’s surface emits blackbody radiation upwards, and when a photon of the correct frequency collides with an excited molecule a second photon is emitted in the same direction as the first. In other words, both travel upwards.
Hope this helps!
Seems to me that both ABM @9 and MKIA @10 could be satisfied if the greenhouse gases were only stimulated to radiate downward in an 80-year cycle. I could go further and speculate that it’s really an 84-year cycle created by the orbital cycle of Uranus – knocking invisible dark matter down on Earth and stimulating those greenhouse gases.
Seriously, I think that the 1930s have been somewhat neglected. At least in the North American sector, there were some really huge blocking patterns and meridional flows. Many of the worst summer heat records in the U.S. still date back to the 1930s, and there were many other large anomalies. It would be nice to know more about what was going on. The pattern is likely to repeat eventually, since there were even worse megadroughts in the pre-industrial period. When it does, the extra 100+ ppm of CO2 will result in even more intense heat and drought, and we certainly aren’t ready for it.
#37 Alastair B McDonald,
My question was about your use of the term “the ratio”.
I read your responses to other people and I still don’t understand what you are trying to say. Let’s consider a simplified atmosphere with no water vapor or other GHG.
You agree that if we start with no radiation from the surface, we have only spontaneous radiation from CO2 molecules, which would be equally “up” and “down”. (For simplicity, ignoring all the other directions.)
Now, we increase the surface radiation in increments. What is the formula by which we calculate “the ratio” of stimulated to spontaneous emissions?
Just a quick repost of @9 which John Pollack can’t differentiate from KIA’s denialism.
ABM wrote last month @273
“Greenhouse gas molecules do not emit black-body radiation back to the surface. If they did then they would be unable to emit it to space and balance the energy flow at the TOA.”
CCHolley wrote last month @278
“What? This is utter nonsense. Greenhouse gas molecules radiate heat in all directions equally. They have no idea of up down right or left. Thermal equilibrium occurs when the energy radiated into the earth system equals the energy radiated out. Per the Stefan-Boltzmann law knowing the solar constant and surface area giving the energy into the earth system, this equilibrium occurs with the radiation generated from a temperature of 255 degrees Kelvin. Since greenhouse gases inhibit the radiation from escaping freely to space from the surface that temperature must move from the planet surface to somewhere up in the atmosphere where the density of greenhouse gases is such that the portion of the radiation emitted upward can then escape freely to space without reabsorption. This in turn results in a warmer surface from the portion of the radiation emitted downward.
BTW, 16 per cent of solar radiation is absorbed by water vapor, dust, and O3 in the atmosphere. 3 per cent is absorbed by clouds. [ABM This discussion is about the emission of downwelling longwave radiation, not the absorption of short or longwave radiation.] BPL knows what he is talking about. You do not.”
ABM wrote @
Surprisingly, it is both you and BPL who do not know what you are talking about. You are just repeating the conventional wisdom which is wrong!
The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.
Greenhouse gas molecules do not emit blackbody radiation as it is widely believed. But they do emit stimulated and spontaneous radiation, as described by Einstein is his 1917 paper. He showed that the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation. For the relatively low-frequency IR emissions stimulated emissions dominate. Thus the IR radiation from the Earth’s surface is re-emitted upwards. Only very little radiation is re-emitted spontaneously back to the surface of the Earth.
More,
There is downward radiation, as pointed out by BPL later, but that is mostly black-body radiation from clouds and aerosols.
Alastair,
We’ve been through this before. You don’t have the foggiest idea what you are talking about. If the only source of surface warming were TSI, then the night time temperature of the planet would be a whole helluvalot colder than any temperature ever recorded on Earth.
Backradiation can be measured at the surface. Your argument is not with me, but with reality.
barry @26,
There are two ways for a GHG molecule to emit a photon.
Spontaneous emissions result from an excited waggling molecule generating a photon using the waggle energy. As the waggle is almost always caused by collision with another air molecule (indeed it is lucky to get off a photon given the frequency of collisions), the direction the photon shoots-off-in is any-which-way.
Stimiulated emissions result from a suitably excited GHG molecule being disturbed by a passing photon of the correct wave number resultng in the GHG moecule emitting a photon on the coat-tails of the passing photon and in the same direction.
The comment @9 asserts that “… as described by Einstein is his 1917 paper … the ratio of stimulated emission to spontaneous emission depended on the frequency of the radiation and that for relatively low-frequency IR emissions stimulated emissions dominate.” It is true that the lower the frequency, the greater the proportion of spontaneous emission but my understanding (which I see is also the understanding of others) is that “there’s always much more spontaneous than stimulated emission.” As a result the photons emitted by GHG are predominantly any-which-way.
ABM 37: Your 324 watts per meter includes the blackbody radiation from clouds. That greatly exceeds the back radiation from carbon dioxide as can be seen on a cloudless night when the temperature is much lower than that on cloudy nights.
BPL: No. Cloudless nights are colder because more radiation is being lost from the surface.
Is the Pillsbury Dough Mann moderating these comments? Is he in the State Penn or Penn State?
#38 John Pollack,
“the pattern is likely to repeat eventually”
Why? The climate system is very different now. Why would you predict this specific local extreme to occur in our current or a future regime?
Have you run a model that shows it is likely to occur?
I would think the opposite is true; it’s like predicting that hurricane Dorian would occur exactly the same on a planet with a much lower climate system energy level.
John Pollack:
Thanks for your comment, Mr. Pollack. Headline in today’s NYTimes: Flash Drought in the South Brings Record Heat Without Rain. Texas state climatologist John Nielsen-Gammon is quoted:
One assumes weather in the 1930s was also the result of competing influences. There may not be enough data from that time, before satellites and solid-state electronics, to puzzle them out. Comparison with recent record-setting events is interesting, nonetheless.
John Pollack: I could go further and speculate that it’s really an 84-year cycle created by the orbital cycle of Uranus –
AB: So denialists are actually on to something when they pull stuff out of their ass
ABM @37
Once again, you made it up when you stated: “The main function of greenhouse gas molecules is to absorb IR radiation, not to emit it. That is how the air warms. That is what Saussure showed, and Fourier misinterpreted.”
Neither Saussure nor Fourier had any concept of a greenhouse gas.
Saussure made a device which was essentially a miniature greenhouse. He showed that it trapped solar heat from the sun; however, he had no explanation for why it did so. “Physicists are not unanimous as to the nature of sunlight. Some regard it as the same element as fire, but in the state of its greatest purity. Others envisage it as an entity with a nature completely different from fire, and which, incapable of itself heating, has only the power to give an igneous fluid the movement which produces heat.” Saussure lived at a time when scientists were just starting to study the nature of heat. He had no clue as to the difference between infrared and short wave radiation. He most certainly did not show “that is how the air warms.”
Fourier’s contribution was mostly mathematical. He showed that the surface of the earth should be much colder than it actually is. He proposed that this may be do to interstellar radiation or that perhaps the atmosphere somehow inhibited the transmission of long wave radiation which is what he suspected Saussure’s device did. But he also understood that it prevented convection of the heat away which was the correct interpretation. Fourier never hypothesized that there were greenhouse gases in the atmosphere, he simply thought that somehow perhaps the atmosphere might block some of the radiation by which he did not speculate on the mechanism other than: “because the heat finds fewer obstacles in penetrating the air, when it is SW, than in repassing when converted into IR.”
Tyndall didn’t try to measure the greenhouse effect. He merely measured the radiative properties of the components of the atmosphere, which in turn showed that “greenhouse” gases did, in fact, exist. Why did he do this? Because the nature of heat was better understood by his time and the fact that different materials had different radiative properties had become known. From Fourier’s work, he understood that the earth should be cooler and that the mechanism was likely due to components in the atmosphere with absorptive properties in the IR. That is why he did his experiments, to determine what they were and that they actually existed.
This is comical. Photons are emitted randomly due to the increased energy state. Photons don’t know the direction the photon came from that increased the energy. Nor does the molecule know if the increased energy state came from absorption of radiation or a collision with another molecule. In either case, it just randomly emits photons in any random direction.
@ Alastair B. McDonald 4 Oct 2019 at 3:41 PM
There is the small matter of relaxation time between when the molecule absorbs a photon and becomes excited, and the time it emits a photon. How does the molecule remember which way the photon was going when it was absorbed? If it is rotating as well as vibrating, how does it detect its new orientation when it decides to relax, so that it can emit the new photon in the old direction. The direction of the incoming photons has a 3 dimensional distribution,(Lambertian?); does the excited molecule remember both the angle with respect to gravity, or with respect to magnetic or true polar North as well?
#45 Zebra The climate system is not so different now that it won’t generate periodic droughts over North America. California had an intense one earlier this decade, which included an extension across the Great Plains into the Midwest in 2012. These are more than “local extemes” because they involve a persistent anomaly in atmospheric waves on a hemispheric scale
https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0664.1
Climate models show plenty of droughts of varying time scales and intensity. https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-18-0010.1
If you are suggesting that because the climate system is accumulating energy, there won’t be an exact repeat of the 1930’s Dust Bowl or hurricane Dorian down to the last precise local detail, then I agree with you. You can stop repeating the point, or take it to a philosophy blog where you can endlessly discuss the meaning of “things are different because they aren’t exactly the same.”
What I expect is that under similar synoptic conditions, droughts, heat waves, and hurricanes will become more extreme. I’m interested in figuring out how much and how fast, which also involves understanding historical weather to the extent possible. Telling me repeatedly that the next weather system or climate regime won’t be exactly the same as the last is a completely unhelpful truism.