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Eclectic at 08:56 AM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert, I am happy to be of help. The so-called Greenhouse Effect is rather counter-intuitive for many people (including me), and I find a deficiency of sites where it is explained completely all in one chapter. In particular, the stratospheric cooling effect is interesting, partly because it demonstrates the falsity of some of the claims of the climate science denialists [the faux-skeptics].
As you are aware, the large majority of 15-micron IR is lost from Earth at the altitude of the upper troposphere, yet a tiny amount is lost from the stratosphere itself, too.
My apologies for my typographical error ["typo"] in my third paragraph of #147, where I wrote "and a smaller mount will escape" ~ the correct word would be amount. This sort of typo must be troublesome and annoying for a reader who is not 100% fluent in English.
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Josbert Lonnee at 01:11 AM on 26 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Eclectic @ 147
What you say is very clear and shows my theory is false.
MA Rodger just kept mentioning the same point and that I do not understand that. My English was to blame.
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michael sweet at 00:06 AM on 26 November 2018Did bombing during second world war cool global temperatures?
Libertador,
The other nuclear explosions that you mention were all performed in remote locations, often underground. That means little smoke from was generated. Since the effect on climate of burning cities mentioned in the OP was small, the effect of other nuclear explosions on climate would be expected to be very small.
We all hope that the effect of nuclear war on climate will never be measured.
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Eclectic at 21:56 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert @145 ,
in your [post #128] scenario, the essential point is that the rate of CO2 molecules emitting IR photons is extremely low in comparison to the rate of collisions, in both the Stratosphere and the Troposphere. In other words, the chance of a photon-emitting relaxation is (very roughly) around 0.01% compared with the chance of an intervening collision (the collision being likely to de-energize the CO2 molecule from its newly-gained photonic packet of energy).
If, owing to different temperatures and densities, that percentage should vary between (very roughly) 0.03% and 0.003% [one order of magnitude] in the two layers of atmosphere . . . then you see that the absolute difference from the [almost 100%] collision chance, remains approximately equal for "S" and "T".
Thus your #128 proposal is barking up the wrong tree. You should focus on the absolute distances ~ the mean travel distance from one "emitting-CO2" to the next "absorbing-CO2". This distance is very short, and (greatly enhanced by the relaxation "delay" period) is the reason why the appropriate IR takes a long time to rise from planetary surface up to the top of the troposphere and eventually make its escape (upwards) from there [and a smaller mount will escape upwards from the stratosphere ~ which is why increased solar irradiation of the stratosphere has a stratosphere-warming effect compared with the stratosphere-cooling effect of increased CO2 concentration [regardless of whether it's a human-caused or natural-caused CO2 increase]).
Josbert, stay on MA Rodger's good side, and he may well provide a much more rigorous explanation than I can !
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MA Rodger at 21:48 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @145,
While you appear to be struggling with the English language, I feel we have reached the end of this interplay. After five attempts to communicate with you regarding a blindingly simple concept, you complain that I understand you "all wrong all the time." If that were true, it is up to you to explain yourself properly. However, I do not consider it true. Your 'theory' set out @128 is nonsense and if you cannot grasp the blindingly simple idea that if CO2 takes longer to travel between collisions then there must be less collisions; if you cannot grasp that obvious truth then there is no point in my responding to you. [Mind, I will likely respond to your comments but not to you.]
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libertador at 21:33 PM on 25 November 2018Did bombing during second world war cool global temperatures?
I have a little question. There have been more bombs dropped, than the ones on Hiroshima and Nagasaki. There has been atomic testing. The number I found in the Bulletin of the Atomic Scientists Mai 1996 is, that 16,000 times the power of the Hiroshima bomb was used in testing in just a 16-month period in 1961/62.
Have these testings be studied? Might these testings give further objects of study?
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Josbert Lonnee at 17:29 PM on 25 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 144
It was already clear to me that you understand me all wrong all the time. With "the theory" I of course mean my theory from @128.
There is no need to repeat your point.
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Synapsid at 08:07 AM on 25 November 2018New research, November 12-18, 2018
Ari,
Thank you again for these summaries, I find them very useful each week.
I am particularly grateful for your posts in palaeoclimatology as that is my primary focus.
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nigelj at 05:07 AM on 25 November 2018The Scientific Consensus on Climate Change
BaerbelW @20, yes I realise the Cook study interpreted abstracts, I was just using a bit of short hand or paraphrasing. Don't have all day to write an essay!
Thank's for the guidlines. This clarifies things, and makes it clear the consensus finding is limited to papers that explicitly or implictly state humans are the main cause of the recent climate change. Your categories on how you categorised papers on this look convincing. The 97% result is a huge, powerful consensus, especially given the nature of the contrarian papers.
It just seemed to me the wording that humans 'contributed' was not specific enough. Maybe I'm nit picking.
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BaerbelW at 20:49 PM on 24 November 2018The Scientific Consensus on Climate Change
nigelj @18 - regarding: "It was really asking people whether they think the greenhouse effect is real and that we are adding to it. I mean its a valid and useful study but rather too general for me"
For one in Cook et al. we didn't ask people what they think but instead interpreted the abstracts of peer-reviewed studies according to defined guidelines for rating abstracts. And, a careful reading of esp. the definitions for the rejection criteria should make it clear that any minimising (< 50%) of human-causation, wouldn't have been counted towards the consensus. Which, to me, makes it quite clear that our paper did in fact restrict the consensus to "mostly human-caused". But then, I'm obviously biased!
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Daniel Bailey at 08:55 AM on 24 November 2018The Scientific Consensus on Climate Change
Interestingly, the 4h National Climate Assessment, Volume 2, was released today. Among many interesting findings, this was prominent:
"Scientists have understood the fundamental physics of climate change for almost 200 years. In the 1850s, researchers demonstrated that carbon dioxide and other naturally occurring greenhouse gases in the atmosphere prevent some of the heat radiating from Earth’s surface from escaping to space: this is known as the greenhouse effect.
This natural greenhouse effect warms the planet’s surface about 60°F above what it would be otherwise, creating a habitat suitable for life. Since the late 19th century, however, humans have released an increasing amount of greenhouse gases into the atmosphere through burning fossil fuels and, to a lesser extent, deforestation and land-use change. As a result, the atmospheric concentration of carbon dioxide, the largest contributor to human-caused warming, has increased by about 40% over the industrial era.
This change has intensified the natural greenhouse effect, driving an increase in global surface temperatures and other widespread changes in Earth’s climate that are unprecedented in the history of modern civilization.
Global climate is also influenced by natural factors that determine how much of the sun’s energy enters and leaves Earth’s atmosphere and by natural climate cycles that affect temperatures and weather patterns in the short term, especially regionally.
However, the unambiguous long-term warming trend in global average temperature over the last century cannot be explained by natural factors alone.
Greenhouse gas emissions from human activities are the only factors that can account for the observed warming over the last century; there are no credible alternative human or natural explanations supported by the observational evidence.
Without human activities, the influence of natural factors alone would actually have had a slight cooling effect on global climate over the last 50 years."
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nigelj at 06:22 AM on 24 November 2018The Scientific Consensus on Climate Change
I may not be be too popular for this, but I like getting to the bottom of things. The John Cook study found that "97.1% endorsed the consensus position that humans are contributing to global warming" which could be interpreted to mean humans are causing all or just some of the recent warming. It was really asking people whether they think the greenhouse effect is real and that we are adding to it. I mean its a valid and useful study but rather too general for me.
Powell 2013, Orekses 2014, and Doran et al 2009 and Stats 2009 asked much the same question about whether humans were a contributory factor, and found a similar result to Cook. Farnsworth and Lichter found a lesser result with 84% believing humans contributed to climate change. So overall all studies do find theres a good consensus that humans at least cause global warming. Anything over 80% seems powerful to me and most studies are well over 90%.
But I think the more important question is whether humans are causing the 'majority' of recent climate change. The study by Verheggen, 2014 finds that 90% of climate scientists agree that greenhouse gases are the main cause of warming. Anderegg et al 2011 also found well over 90% of climate scientists endoresed the IPCC position (which finds humans are the main cause of the recent warming period)
Lefsfrud and Meyer 2012 found no consensus that humans are the main cause of warming, but their study comprised "petroleum geologists" so they have a vested interest in fossil fuel producers.
I think the Verheggen study asked the key question. For me 90% of climate researches concluding humans are the main cause of the recent warming period is a strong finding. Given the fossil fuel industry funds some research and some scientists are just contrarians by nature, or have subconscious biases in a small number of cases, its of no surprise to me that 10% would question how much humans are contributing and could think its largely natural ( a position I personally disagree with). I would have guessed it would be around this number and I recall seeing a list of recent research papers taking contrarian position like climate change is mostly caused by adiabatic processes etc (all very dubious material)
I think what really matters is to get the message across to the public that 1)several studies find over 90% of climate scientists thinks we are the dominant cause of climate change and 2) the contrarian studies are fringe science with a similar range of methodological flaws. The problem is the public believe theres more of a 50 / 50 split. They need correcting on this, but probably won't care so much whether its 90% 0r 92.256% or 97%. If it was less than 80% I think the consensus would be classified as weak.
The bottom line is numerous published and peer reviewed studies do show a strong consensus regarding climate change.
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One Planet Only Forever at 01:35 AM on 24 November 2018The Scientific Consensus on Climate Change
There appears to be confusion due to incorrect conflating of:
- Scientific consensus of understanding (development of an emergent truth that is open to correction if substantive new evidence is contrary to the developing understanding).
- An individual's helpfulness in efforts to improve awareness and understanding: in the field of understanding, among leaders in society, among the general population.
Individuals are not 'part of the 97% or 3%'. The consensus measure is regarding how much of the 'literature that is a legitimate part of the effort to improve the understanding of an area/field of understanding' is aligned with a developing understanding. As the degree of alignment increases it can be understood that an emergent truth is being established (an understanding that is unlikely to be significantly altered by new investigation in that field of learning).
An evaluation of all of an individual's actions is the basis for determining how helpful they are to the improvement of the understanding and to the increased 'correct' awareness and understanding among leaders and the general population.
While the likes of Judith Curry, Roy Spencer and Richard Lindzen may have their names on a specific piece of literature that is included in the 97% side of the climate science consensus evaluation regarding the understanding that human activity is significantly impacting the global climate, that does not make them 'a part of the 97% side'.
Individual merit would be determined by their collective actions regarding the understanding. That evaluation would undeniably indicate that the likes of Judith Curry, Roy Spencer and Richard Lindzen are very unhelpful (harmful) to the improvement of awareness and understanding the understanding that human activity is significantly (and negatively) impacting the global climate that future generations will suffer the consequences of and the challenge of trying to maintain perceptions of prosperity that are the result of a portion of humanity getting away with benefiting from the damaging unsustainable burning of fossil fuels (benefiting in ways that do not develop sustainable improvements for the future of humanity - like perceptions of reduction of poverty that cannot be sustained if the damaging impact creation of fossil fuels is significantly and rapidly curtailed like it has to be in order to minimize the damage done to the future generations of humanity).
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MA Rodger at 00:37 AM on 24 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @142/143,
Correct me if I am wrong. When you talk of "the theory" you are meaning that set out @128 where you describe "my theory." In it you describe a mechanism for a cooling stratosphere and a warming troposphere. You suggest this may be a re-statement of the situation described in the post at the top of this thread [although it is not]. You base your "theory" on the probability of a CO2 molecule emitting a photon following a molecular collision in which it is excited and thus able to emit a photon of IR, a probability which will be greater if this CO2 molecule has longer before it is in another collision. If more photons are emitted by a gas (per molecule), more cooling will occur.
That is what you appear to be saying.
Your suggestion is wrong in a number of ways. The most straightforward error is to consider a higher probability of a CO2 molecule emitting a photon after a collision without considering the lower probability of CO2 molecules being in an appropriate collision. Simplisitically, the two probabilities cancel out. So it is not the case that more photons are emitted from lower pressure air.
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michael sweet at 00:28 AM on 24 November 2018The Scientific Consensus on Climate Change
Art Vandelay,
Richaed Lindzen cannot be considered part of the 97%. He has widely criticized the IPCC. The IPCC report is the basis of the 97% claim. He probably also claims to be part of the consensus to muddy the waters when he speaks.
Many deniers now claim to be part of the 97% to muddy the waters. The mainstream press allows themn to get away with it.
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michael sweet at 00:19 AM on 24 November 2018The Scientific Consensus on Climate Change
Spencer's papers put him in the 3% that do not agree with the consensus. Regarding Spencer:
"This statement is wrong because it misses the nuance in our study. The "skeptic" papers included those that rejected human-caused global warming and those that minimized the human influence. Since we made all of our data available to the public, you can see our ratings of Spencer's abstracts here. Five of his papers were captured in our literature search; we categorized four as 'no opinion' on the cause of global warming, and one as implicitly minimizing the human influence.
Thus, contrary to his testimony, Spencer was not included in the 97 percent consensus. In fact his research was included in the fewer than 3 percent of papers that either rejected or minimized the human contribution to global warming." source my emphasis
Spencer claims to be part of the 97% since no-one would listen to him is he admitted that he is not part of the consensus. Spencer is not part of the consensus.
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Josbert Lonnee at 22:42 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 140
The point of the theory is to eplain why T warms up while S cools down. So I do not understand why you come up with these facts.
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Josbert Lonnee at 22:39 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 140
What you tell here is not new to me and the theory is based on assuming that what you say here is true.
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Josbert Lonnee at 22:35 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Eclectic @ 139
Interesting!
Do you also mean that the stratosphere intercepts most infrared (as intercepted by the CO2 in it) and the troposphere intercepts it all?
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MA Rodger at 22:11 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @138,
I am unclear about your reason for presenting your "picture."
There is no need to set up hypothetical situations. The temperature of the lower stratosphere is no different to the temperature of the top of troposphere. All that changes is the reduction of pressure with altitude.
And the CO2 levels don't vary to any significant degree through these altitudes, as these coloured traces of CO2 for altitudes 8km to 18km demonstrate.
As for photons escaping to space, that occurs mainly in the upper troposphere where the IR warming runs along side (and thus is in balance with) warming from atmospheric circulations.
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Eclectic at 20:20 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert, the relaxation time for a gasseous CO2 molecule is about 10 microseconds. But during that timespan, a CO2 molecule (even in the cold lower statosphere) has roughly 10,000 collisions with neighbouring N2 (or O2) molecules.
If a CO2 molecule does "relax" to emit an IR photon, the photon can travel only a very short distance until it is absorbed by another CO2 molecule. So it is highly likely that the second CO2 molecule will lose this added energy, by collision with a neighbouring N2 (i.e. by warming the nearby air molecules).
As air density decreases, a few IR photons will be able to "miss" CO2 molecules and escape to outer space — in other words, the CO2 in the stratosphere will cool the stratosphere (while the stratosphere is being warmed by the lower atmosphere, which is being warmed from the planet surface by radiation & convection & H2O condensation).
I am unclear on how your ideas fit in with this picture.
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Josbert Lonnee at 14:50 PM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 137
What if one would isolate a (huge) amount of air from S and make it the same temperature and put it under the same (low) pressure as there.
The theory is not that the time between collisions is (initially) longer between all O2, N2 and CO2 molecules etc. The time is just longer in S than in T because of the lower pressure. Hereby the CO2 concentration is irrelevant.
After a while, after the gas (like in S) cooled down (slightly), there will be (slightly) less molecule collisions. That makes a difference, but for this it needs to cool down first. The theory is just that the CO2 molecules took the kinetic / heat energy out by readiating it out of the isolation.
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Eclectic at 14:30 PM on 23 November 2018The Scientific Consensus on Climate Change
Philippe, you make a good point about the "disconnect" of Spencer, and his ilk, in respect of their public opinions and their actual scientific work.
If Dr Spencer contributes to the scientific body of knowledge . . . yet he also sacrifices newborn babies to the god Aeolus [god of climate?] . . . then do we classify him as a mainstream [consensus] scientist, or classify him as an anti-scientist [=denialist] ?
IMO, one needs to have both feet in the scientific camp, to qualify as a 97-percenter.
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Philippe Chantreau at 13:15 PM on 23 November 2018The Scientific Consensus on Climate Change
As I recall, there has been a longstanding disconnect between what Roy Spencer's reseach results show and the opinions he communicates to mass media. One can say that his own research does not really support his opinions. Perhaps that's why he figures as part of the consensus. The consensus is one of results more than opinions. AFAIK, Spencer's peer- reviewed papers do not show anything that deviates significantly from the all the rest of the science.
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Art Vandelay at 13:12 PM on 23 November 2018The Scientific Consensus on Climate Change
Eclectic @10, "it would be interesting to hear your reasons for wishing to see a more detailed analysis of climate scientist opinion."
Just curiosity really, because (in my view) the 97% consensus isn't necessarily meaningful if it includes persons with all levels of concern, including almost no concern at all - as is the case with Lindzen & Spencer.
What would be nice to see is a breakdown on level of concern, so that it's immediately apparent what percentage of scientists are: very concerned, reasonably concerned, slightly concerned, etc..
Understanding of course that such a breakdown would probably require some sort of formal survey to be undertaken.
Also of interest would be similar analysis of the opinion of scientists from related disciplines, which could include some earth sciences, physics and mathematics.
Lastly, there does appear to be a correlation with age, with older persons tending to be less concerned about the impacts of climate change, and this appears to hold within the science community too. The implication of this should be an increasing level of consensus over time, even without considering other factors. This of course assumes that a person's level of concern is unlikely to fall with increasing age if it's been established during formative years.
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Eclectic at 11:45 AM on 23 November 2018The Scientific Consensus on Climate Change
Art Vandelay @10 , it would be interesting to hear your reasons for wishing to see a more detailed analysis of climate scientist opinion.
Yes, that is a rather separate matter from the perceptions (of the AGW issue) held by politicians and the man in the street.
But we already know the high-90's consensus opinion of mainsteam scientists. The Cook-et-al 97% figure is already more than a decade behind the times [the study published 2013 but based on cumulative figures from early 1990's onwards]. And we know from human nature, that however thoroughly conclusive the scientific evidence is, there will always be a small percentage of scientists & scientifically-literate people who will continue to "deny" the physical realities (for their own reasons of psychological perversity and/or political extremism). So why analyse the last few percent of these? They won't change. Personally, I think Spencer, Curry, Lindzen & similar, do not qualify to be counted in the so-called 97% majority, because their position(s) are not scientifically logical.
What matters is A/ the science itself, which is revealed in the scientific papers published (and you will have noted how "contrarian" papers are becoming rarer and rarer ~ getting close to zero% ~ and far more importantly, the contrarian papers are entirely lacking in valid counterpoints against the mainstream scientific assessment)
. . . and B/ the education of and opinions held by politicians & the general voters.
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Art Vandelay at 09:57 AM on 23 November 2018The Scientific Consensus on Climate Change
One Planet Only Forever @ 9. I take your points but I'm not convinced that any of those forementioned scientists have too much impact on the public's perception of climate change. Very few people I speak to have heard of Roy Spencer, even if they're aware of satellite based temperature measurements, so I would be suprised if his blog is widely read and influential to any significant extent. Most people's attitudes to climate change are derived from their media channels of choice, which to a large extent is determined by their political leanings.
But still, it's anomalous that Spencer is probably included in the 97% along with several other scientists with profiles in the faculties of climate research, which is why I would personally like to see a more detailed analysis of climate scientist opinion.
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MA Rodger at 03:21 AM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @136,
Another point? Let us stick with this one. It is surely the most straightforward.
You say the number of collisions stays the same, this presumably collisions per molecule. Your thesis is that a lower pressure in the stratosphere (relative to the troposphere) provides a longer time between collisions, more time for a photon to be emitted and so there will be more photons emitted, the gas will cool more.
But if a molecule takes more time between collisions, how can there be the same number of collisions? Simply, there cannot be!!
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One Planet Only Forever at 01:59 AM on 23 November 2018The Scientific Consensus on Climate Change
Art Vandelay@8,
A more important measure than 'grudging acceptance of climate science to a limited degree' is how helpful a person is to improving the more correct awareness and understanding of climate science in the general population and among leadership.
By that measure Judith Curry, Roy Spencer, Richard Lindzen are dismal damaging failures.
As a case in point, I frequently visit Roy Spencer's site (just for the amusement, but in case he actually presents a meaningfully insightful point).
Roy Spencer spends almost all of his time making up stories to refute the need for the burning of fossil fuels to be curtailed. The lack of validity of his story-telling is consistent. He also spends a significant amount of time creating creative ways to intrerpret satellite data in an attempt to refute that unacceptable warming and climate change is happening (he has been forced to partially correct his misinterpretations of the satellite data many times).
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Josbert Lonnee at 01:37 AM on 23 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
MA Rodger @ 135
The number of collisions between molecules stays the same, independent of the concentration of CO2. Only the CO2 molecules are less likely to pass all kinetic energy from collision to collision. So, the mode CO2 is in S, the more energy is radiated away as photons.
I still do not get this point. Do you have another? You suggest you have more points.
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Art Vandelay at 17:27 PM on 22 November 2018The Scientific Consensus on Climate Change
It should be noted too that Judith Curry, Roy Spencer, Richard Lindzen et al, are all painted as skeptics or "deniers", but are in fact members of the 97% consensus.
Perhaps a more valuable statistic would be one that indicated a percentage of (climate) scientists who hold the view that it's a serious threat requiring urgent, universal remedial action.
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Art Vandelay at 08:05 AM on 22 November 2018The many ways climate change worsens California wildfires
nijelj @ 20, "Obviously we do both, but management of forest fires is off topic. We are supposed to be talking about climate change."
I see and hear quite a bit of media commentary - to the effect that "forest fires" is why we should act on climate change.
As if there aren't enough reasons already.
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MA Rodger at 06:53 AM on 22 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
Josbert Lonnee @131,lecules
Mu point is that you are wrong. Your stated hypothesis contains a number of fundamental flaws. I set out just one (and it only requires one).
You say the probability of an excited molecule emitting a photon following a collision is increased by an increased average path-length between collisions (thus your A:B ratio increases). You suggest this increase would increase cooling in S relative to T but you ignore the lower number of collisions that the molecules endure in S relative to T, a consideration which will cancel out your A:B increase.
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nigelj at 04:34 AM on 22 November 2018The many ways climate change worsens California wildfires
Art Vandelay @18, fair enough you are not being incoinsistent, some places are having success reducing ignitions. I was being a bit overly suspicious of your comments.
"The question is, do we accept that challenge or do we simply ignore it and focus solely on reducing CO2 emisions?"
Obviously we do both, but management of forest fires is off topic. We are supposed to be talking about climate change.
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John Hartz at 02:45 AM on 22 November 2018The many ways climate change worsens California wildfires
Recommended supplemental reading:
California’s wildfires are hardly “natural” — humans made them worse at every step by Umair Irfan, Energy & Environment, Vox, Nov 19, 2018
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Josbert Lonnee at 01:32 AM on 22 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
scaddenp @ 133
Im am not doing any of both. Please, can you, based on the RTEs, tell me why my theory is wrong?
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michael sweet at 23:49 PM on 21 November 2018The Scientific Consensus on Climate Change
Rickg,
What could possibly be more detailed than the IPCC report? The 97% consensus is that scientists agree with the IPCC report.
The IPCC report was set up to be very conservative. The consensus position is always reported as the consensus of the minimum risk, not the consensus of the maximum risk. That means sea level rise is reported as several feet when the high end of estimates is several meters.
All the nations of the world, including the Trump administration, have accepted the IPCC reports. What more detail do you think is necessary?
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RickG at 22:46 PM on 21 November 2018The Scientific Consensus on Climate Change
I my view I think the public needs a more specific persentation of just what the 97% consensus is. It is not an opinion or poll of what scientists think about climate change, it is what 97% of the published professional scientific research addressing climate change shows. Note that I said "professional" rather than "peer reviewed". I think that is important because the public doesn't have any idea what the peer review process is and the denial side is quite happy misrepresenting it as a buddy system.
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Art Vandelay at 22:41 PM on 21 November 2018The many ways climate change worsens California wildfires
nigelj @ 15: "You say in comment @2 "the actual incidence of ignitions is also increasing," and now you say "but ignitions have actually reduced over the past 20 years thanks to government education programs"
"Which is it? You are not very consistent or convincing".
If you read my posts again you'll find that there's no "inconsistency" at all.
And I would be surprised if there aren't other regions or localities that are also bucking the global trend for similar reasons.
Eclectic @ 14 says, "a small nitpick : California's wildfire risks are influenced by the ongoing rising global CO2 emissions ~ regardless of whether (or not) the USA's emissions have fallen in recent years.
(Of course, reducing local wildfire incidence & severity, is a difficult and expensive task.)"
OK, I confess, your small nitpick was anticipated, and i agree with you of course, on both points.
Reducing the incidence and severity of forest fires will definitely be challenging in many cases, and probably also expensive. The question is, do we accept that challenge or do we simply ignore it and focus solely on reducing CO2 emisions?
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ancient_nerd at 19:05 PM on 21 November 2018The many ways climate change worsens California wildfires
Southern California has had Santa Ana winds for a long time. However, the conditions seem to be getting more common in northern California over the past few years. We definitely had that weather pattern as the recent Camp fire was getting started. If I recall correctly, last years wine country fires got started under similar conditions. We did not get these every year in the past in northern California.
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ancient_nerd at 16:22 PM on 21 November 2018The many ways climate change worsens California wildfires
Many of southern California's brush fires get started during the Santa Ana windstorms. The ones that grow past a few acres are almost impossible to stop until the winds die down. A big factor in the severity of these fires is the frequency, duration, and intensity of these windstorms. As a long time resident of California, it seems like we may be seeing an increase in all three parameters. But, I have to wonder if there is any data. It seems difficult to quantify.
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nigelj at 14:55 PM on 21 November 2018The many ways climate change worsens California wildfires
Art Vandelay @13
Partial clearing is not going to solve the problem, according to this scientific expert.
You say in comment @2 "the actual incidence of ignitions is also increasing," and now you say "but ignitions have actually reduced over the past 20 years thanks to government education programs"
Which is it? You are not very consistent or convincing.
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One Planet Only Forever at 13:37 PM on 21 November 2018The Scientific Consensus on Climate Change
This article sparked a clarification of understanding for me.
A logical extension of the Dentist, House, and Airline examples is to consider what the future would be for an Association or Society of Dentists, Home Builders, or Airlines that allows harmful misunderstanding to remain uncorrected. It is obvious that they would be replaced by groups that base their actions on more correct understanding.
And the logical extension of that understanding is that any socioeconomic-political system that fails to curtail the marketing of misunderstanding has no future, is destined to fail.
Tragically, a lot of harm can be done before that failure is undeniably realized. And tragically, the failing system may be damaged beyond correction.
Humanity has successfully developed the understanding of the need to achieve the Sustainable Development Goals which include the key Goal of Climate Action (key because achieving it to a higher degree and achieving it more rapidly makes it easier to achieve and improve on the other SDGs)
Any perceptions of success that are not consistent with achieving and improving on the SDGs are destined to be corrected.In order to survive and thrive an institution/society/system/game must be able to effectively identify and correct misunderstandings that could lead to unsustainable or harmful developments, regardless of the temporary regional popularity or profitability of a misunderstanding that is harmful to others (especially to the future of humanity). The quicker an institution/society/system/game identifies and corrects those misunderstandings, the more rapidly it will improve its chances for a better future. And any institution/society/system/game that struggles to correct misunderstandings can easily be understood to be headed towards failure, no matter what perceptions of prosperity or superiority relative to others it has developed.
The case of climate science has exposed that free-market democratic capitalism is headed for failure. Free-market democratic capitalist competition that is restricted to truly sustainable activities would be a brilliant system/game to help advance humanity. It would be a tragedy if free-market democratic capitalism continues to progress so far down the incorrect path of marketing misunderstanding that the thought of it is crippled beyond easy repair and recovery.
Anyone who sees value in free-market democratic capitalism should be extremely concerned about the damage being done to the reputation of free-market democratic capitalism by the popularity and profitability of marketing misunderstanding related to climate science (and similar damaging actions related to all of the other SDGs).
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Eclectic at 13:31 PM on 21 November 2018The many ways climate change worsens California wildfires
Art Vandelay @13 ,
a small nitpick : California's wildfire risks are influenced by the ongoing rising global CO2 emissions ~ regardless of whether (or not) the USA's emissions have fallen in recent years.
(Of course, reducing local wildfire incidence & severity, is a difficult and expensive task.)
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Art Vandelay at 12:21 PM on 21 November 2018The many ways climate change worsens California wildfires
nigelj@12: "If we want to reduce the forest fire problem our best bet might actually be reducing emissions".
Unfortunately, reducing emissions won't help in the short or medium terms, and a case in point is the USA, where emissions have fallen against a rising incidence and severity of forest fires. That's not a reason not to reduce emissions of course, but rather an acknowledgement of reality.
The solution(s) to reduce severity and incidence will differ for different areas of the globe, but will obviously involve better monitoring and management methods. In some cases it may even involve partial clearing. If 90% have a human cause it does at least provide reasonable scope to reduce ignitions. For instance, in my part of the world, scientists estimate a 10% increase in risk due to climate change, but ignitions have actually reduced over the past 20 years thanks to government education programs to make people more aware and diligent, and better forest management, which includes hazard reductions during winter.
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Daniel Bailey at 10:59 AM on 21 November 2018Solar cycles cause global warming
NASA tracks the solar forcing and compares it to global temperatures over time, here.
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dalesmith at 10:52 AM on 21 November 2018The Scientific Consensus on Climate Change
@BeezelyBillyBub, the US could easily cut 50% from its military budget, but only when other countries start paying their fair share for their own defense.
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scaddenp at 08:43 AM on 21 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
I do understand that, but I have massive mistrust of hand-wavy models compared to precisely stated mathematical models which reproduce multiple types of observations. It isnt clear to me whether you are challenging the RTEs or trying to do a plain English explanation of the net effect.
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michael sweet at 08:33 AM on 21 November 2018Solar cycles cause global warming
Ed,
Googling "Solar Cycle Activity" gives a number of hits that describe solar cycle 24 as the weakest in a century. That means that you would expect the solar forcing would be smaller than usual, probably around 0.1C (my estimate). The peak was in 2014.
We observe that 2014 was the hottest year recorded at that time and was the hottest year without an El Nino (now 2017 holds that record). The effect of the sun is often delayed for a year or two. 2015 and 2016 also set heat records.
It seems to me that it was fortunate the solar cycle was so low or we would have roasted even more than we did 2014-2016. Hopefully politicians will do something before it is too late.
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Josbert Lonnee at 07:22 AM on 21 November 2018Stratospheric Cooling and Tropospheric Warming - Revised
scaddenp @ 129
Do you understand that I am not challenging the observations that the troposphere is warming and the stratosphere is cooling?
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