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bozzza at 12:08 PM on 16 May 20162016 SkS Weekly Digest #20
The concept of Hysteresis means long felt multi-year ice melt remains the reality. The kids will read about it in the akashic record called NSIDC as if it were reality tv!
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villabolo at 09:51 AM on 16 May 20162016 SkS Weekly Digest #20
From NOAA:
La Niña is favored to develop during the Northern Hemisphere summer 2016, with about a 75% chance of La Nina during the fall and winter 2016-17.
Is this likely to have an impact on the Arctic icecap's Minima?
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michael sweet at 23:48 PM on 15 May 2016CO2 effect is saturated
Concerned Citizen,
The temperature lapse rate is the amount the temperature changes as you increase altitude. It is about 6C per kilometer. That means that if you increase in altitude by one kilometer the air is 6C cooler.
Essentially all the energy emitted by the Earth is at the 6.0 km altitude. This amount of energy equals the amount of energy that arrives each day from the sun. If you increase the amount of CO2 in the atmosphere than the CO2 absorbs more of the energy coming up from the surface. The emission height raises to 6.1 km. This we have agreed on.
Heat is emitted from all materials in amounts proportional to the temperature. When the emission height increases to 6.1 km, less energy is emitted because the air is colder. This is because of the temperature change, not the change in pressure. There is an imbalance between what is arriving from the sun and what is emitted. This imbalance causes the Earth to heat up.
In order to reach a new equilibrium where the heat emitted from the atmosphere is the same as the heat arriving from the sun the temperature at 6.1 km has to increase. Because the lapse rate remains the same, the temperatue of the entire air column under 6.1 km increases the same amount as it increases at 6.1 km. Since the lapse rate is 6C per km the temperature has to increase about 0.6 C if the emission altitude increases from 6.0 to 6.1 km. When the rest of the air column increases in temperature the surface is 0.6C warmer. This is the global warming caused by the increase in CO2.
Do you understand the way that the increase in the emitting altitude (caused by the increase in CO2) results in an increase in the surface temperature?
The atmospheric pressure does not increase measurably from the increase in CO2. This is well known and no-one has suggested that atmospheric pressure changes the temperature. This is an example of a basic misunderstanding that needs to be corrected.
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ConcernedCitizen at 19:19 PM on 15 May 2016CO2 effect is saturated
michael sweet @418 Yes, I know about the temperature lapse rate, didnt 'Air at 6,1 km is thinner, I now that, I already said its colder' make that self evident?
So far not one of you has been able to describe the physics, the mechanical process, whereby putting an additional CO2 mollecule at 6.1 km raisies temperature by interaction wioth the lapse rate.
The lapse rate is based on atmospheric pressure, so if you added enough CO2, yes, you would increase the atmorpheric pressure, but this isnt the suggestion here and certainly isnt hapening because atmopspheric pressure isnt increasing.
So again, in the absence of any logical and clear explanaiton the explanation given here holds no water.
Moderator Response:[JH] If you cannot be civil, you will forfeit your privilege of posting comments on this site.
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denisaf at 16:48 PM on 15 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
I have seen a list somewhere of the cities that are likely to be hard hit by sean level rise and storm surges. London, New York and the Netherlands have massive works in progress to cope with this predicament.
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Tom Curtis at 10:40 AM on 15 May 2016CO2 is not the only driver of climate
Ken Kimura @22, I discuss the trend from 1940-1970 because you asked a question about the trend from 1940-1970, and for no other reason. For you to then turn around and ask "you know that the industrialization started long before 1940" looks like a calculated, and hypocritical insult.
With regard to your former question, stratospheric aerosols are almost exclusively from volcanic erruptions. Tropospheric aerosols are from a combination of wind born sea salt, refractory compounds from forest, desert sand and anthropogenic factors. Forcings, however, represent the change in a factor over time, and the vast majority of the change in tropospheric aerosol load is from anthropogenic factors - primarily from sulfur in coal and oil. As can be seen from this graph from the IPCC AR5, the combined anthropogenic effect (red line) from 1940-1970 results in a positive slope in forcing:
The combined anthropogenic plus natural forcing is flat or negative due to the lack of volcanic erruptions from about 1915 and the onset of a large eruption (Agung, 1963-4) along with a number of smaller eruptions.
Note that the above graph sets the zero point for forcings at 1750 rather than the 1880 used in the GISS forcing graph you pointed to, and the Meinhausen 2011 forcings displayed in the model to which I linked.
With regard to the relation between anthropogenic GHG forcings and anthropogenic aerosol forcings, initially the aerosol forcing from oil and (particularly) coal dominate in the short term, but with steady state use the GHG forcing comes to dominate very quickly. That is because the initially dominant aerosol load is quickly washed out of the atmosphere by rain, while the GHG concentration (particularly CO2) accumulates. With accelerating coal combustion, these factors can approximately balance for a while, as can be seen from 1750-1860 above, but in the 20th century the GHG forcing has been stronger both because of the accumulation of CO2 in the atmosphere and a gradual switch to cleaner (ie, less sulphur content) fuels.
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Eclectic at 22:47 PM on 14 May 2016There's no correlation between CO2 and temperature
Ken @53 , there is something in what you say ~ yet you misunderstand the basic Modus Operandi of this SkepticalScience website.
When you ask a question or dispute a point, then your post will show in the Recent Comments page . . . where everyone will see it, and those who wish to reply will have the opportunity to go to your chosen thread. As a matter of course, the replies will also be funnelled through the Recent Comments page too. This way everyone can see them conveniently, and those who wish to add to / correct / or dispute those replies, will be able to do so.
So you see, that way you will get the best range of views / opinions / controversy / facts / useful links ~ all in the shortest time. And most conveniently all round.
It is a sensible & efficient arrangement ~ which is why I recommended that you keep your particular cluster of questions in one thread only. If you develop entirely unrelated questions as the discussion progresses . . . then it's best to get the first question(s) sorted out, before going on to another topic / another thread. It is best to progress step-by-step, reather than throwing up a large number of questions.
( Simultaneous multiple-pellet "shotgun" questioning is viewed poorly . . . since it's usually a sign of lack of sincerity in the poster ).
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Ken Kimura at 15:22 PM on 14 May 2016There's no correlation between CO2 and temperature
Eclectic @52,
This thread and the other thread(and many others) are closely related.
And many members post their opinions into these threads.
So it is inevitable their opinions overlap.
Hence, it is also inevitable that questions to them overlap.
I don't see why asking similar questions to different members is discouraged.
People have different opinions so that their answers may differ. Knowing different answers(some may be right, some may be wrong) is usually useful for most people. -
Eclectic at 13:33 PM on 14 May 2016There's no correlation between CO2 and temperature
Ken Kimura @51 , it would be best if your questions about aerosols & other drivers of climate, were kept on the one thread i.e. "CO2 is not the only driver of climate". That seems the most approriate thread; and it has the most approriate discussions in its comments column e.g. @20 and @21.
Running the same/similar questions in parallel (in different threads) is not good policy on your part. It gives the impression [ wrongly, I'm sure! ] that you may be more interested in "sloganeering" (as the moderators call it) . . . rather than in showing your genuine interest in finding information.
Similarly, your comment in the above-mentioned thread, that [your quote:] "you know that the industrialization started long before 1940" . . . does suggest [ wrongly, I'm sure! ] that you think in binary terms of industrialization being entirely absent and then on a particular date, being suddenly present at a high level of activity. Such comments by you, give the impression [ wrongly, I'm sure! ] that you prefer word games rather than science.
Good luck with your search for information & wisdom. There are some very knowledgeable people on this forum, who can help you.
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Ken Kimura at 11:12 AM on 14 May 2016CO2 is not the only driver of climate
Tom Curtis@21,
According to the figure 5 of the following page, stratospheric and reflective tropospheric aerosols were major negative forces during the period.
What do you think the main cause of those aerosols was?
If it was due to the industrialization, you know that the industrialization started long before 1940.
http://www.skepticalscience.com/co2-temperature-correlation-intermediate.htm -
Ken Kimura at 09:45 AM on 14 May 2016There's no correlation between CO2 and temperature
Eclectic @50,
I have at least two questions.
1) How did they measure the aerosol density?
2) If the aerosols were created by the industrialization and they counterbalanced the CO2 effect,
how do you explain that the global temerature had been increasing from 1910 to 1940?
See figure 1 of the following thread.
http://www.skepticalscience.com/ivar-giaever-nobel-physicist-climate-pseudoscientist.html -
Tom Curtis at 09:06 AM on 14 May 2016CO2 effect is saturated
braintic @419, thankyou for your clear, and accurate exposition of the band saturation effect. That is a genuine effect that is described very clearly by David Archer in Chapter 4 of his book, Climate Change: Understanding the Forecast (available online here); and also by Riccardo in the advanced version of the rebutal to the myth. The reason band saturation is presented as the advanced rebutal, while increased effective altitude of radiation is presented as the rebutal of the "CO2 is saturated" myth is that band saturation is a subtle consequence of the fundamental effect of the increasing altitude of radiation in an atmosphere in which the stratosphere warms with altitude (something I will explain in more detail below). In an atmosphere with a cooling stratosphere with altitude, there would be no band saturation - and the greenhouse effect would be stronger as a result.
You are clear that increasing CO2 causes increasing warming, but you appear to miss the fact that the myth is not about band saturation, but rather the myth is a claim that CO2 is saturated across all bands, and that this means increasing CO2 concentration will cause no warming. Given that Skeptical Science targets its basic explanations to those who have studied no science since their 10th year of education, you will understand that a basic rebutal saying that "CO2 is band saturated, but not saturated" is likely to generate confusion. Hence, the basic rebutal concentrates on the fundamental mechanism, while more advanced rebutals deal with the more subtle effects and refer those who are interested to more detailed explanations.
In any event, the theory of the greenhouse effect is fundamentally a theory about the energy balance between the Earth and space (including radiation from the Sun). It follows that the relevant altitude at which to determine "saturation" is not from the surface, but from space (effectively 70 km altitude). At 70 km, the mean free path for the resonant frequency of CO2 is not just over 30 cm, but effectively infinite in a tangent to the Earth, or approximately 35 Km vertically towards the Earth's surface. Adding more CO2 to the atmosphere decreases that downward, vertical mean free path, and hence the distance IR radiation from the Sun can penetrate the atmosphere from space. In more standard terms for climate science, adding CO2 reduces the optical depth of the atmosphere. (Note that I am not saying "mean free path" and "optical depth" are the same thing. They are not. But they are related concepts, and the later is most commonly used in discussing the issue in climate science.)
Because the mean free path downward from space has decreased at the resonant frequency, by Kirchoff's Law the mean altitude of radiation to space increases. That is because, altitude determined by mean free path downward is also the mean altitude of radiation to space, but while the former is measured from the notional boundary to space, the later is measured from the surface. Further, the same effect will be experienced at all frequencies in which CO2 absorbs IR radiation, and therefore also over the average of all thermal IR frequencies. Thus, when speaking of the effect of adding CO2, a simpler way of saying what happens is to say:
"So if we add more greenhouse gases the air needs to be thinner before heat radiation is able to escape to space. So this can only happen higher in the atmosphere. Where it is colder. So the amount of heat escaping is reduced."
Of course, while it is generally true that as we get higher in Earth's atmosphere, it gets cooler, it is not true in either the tropopause or the stratosphere:
That means that for those frequencies of CO2 absorption where the mean free path from the nominal edge of space places the mean level of radiation to space in the tropopause, increasing CO2 will not change the temperature of the gas radiating to space, and therefore not change the energy radiated to space at that frequency. At the resonant frequency of CO2, the mean altitude of radiation to space is in the stratosphere, so that increasing CO2, all else being equal, would result in more radiation to space. As it happens, not all else is equal and that excess CO2 cools the stratosphere on a very short time scale (hours) so in practise the effect is minimal change in the radiation to space. At the wings of the CO2 absorption band, however, the mean altitude of radiation to space is in the troposphere. Consequently raising the mean altitude of radiation to space decreases IR energy transmitted to space at that frequency until the mean altitude of radiation to space reaches the tropopause.
It follows from this that the band saturation effect represents a saturation of the energy radiated to space as the mean altitude of radiation to space enters the tropopause for given frequencies. It does not represent optical saturation (as it would need to be relevant to the myth). Rather, it represents a stable level of radiation to space due to the mean altitude of radiation to space at a given frequency being in the tropopause.
It should be noted that H2O (due to precipitating out rapidly with increased altitude) and other greenhouse gases (due to relatively low concentration) do not have this effect. Their mean altitude of radiation is firmly in the troposphere and increasing concentrations do not lead to band saturation for that reason. The one exception is stratospheric ozone, and stratospheric H2O (introduced by jet fuel). Because both are in the stratosphere, increased altitude increases thermal radiation to space.
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bjchip at 08:15 AM on 14 May 2016The things people ask about the scientific consensus on climate change
This also relates well to the fact of the consilience of the science, as discussed by Michael Shermer - here...
http://www.scientificamerican.com/article/why-climate-skeptics-are-wrong/
I hope that guy/gal is on good terms with their boss. I would be steering clear of such discussions unless I got a clear idea that it was possible to discuss them.
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villabolo at 04:48 AM on 14 May 2016Volcanoes emit more CO2 than humans
Hi John C, you might want to use this quote from the United States Geological Survey as regards the amount of CO2 released by volcanoes compared to human emmissions:
Gas studies at volcanoes worldwide have helped volcanologists tally up a global volcanic CO2 budget in the same way that nations around the globe have cooperated to determine how much CO2 is released by human activity through the burning of fossil fuels. Our studies show that globally, volcanoes on land and under the sea release a total of about 200 million tonnes of CO2 annually.
This seems like a huge amount of CO2, but a visit to the U.S. Department of Energy's Carbon Dioxide Information Analysis Center (CDIAC) website (http://cdiac.ornl.gov/) helps anyone armed with a handheld calculator and a high school chemistry text put the volcanic CO2 tally into perspective. Because while 200 million tonnes of CO2 is large, the global fossil fuel CO2 emissions for 2003 tipped the scales at 26.8 billion tonnes. Thus, not only does volcanic CO2 not dwarf that of human activity, it actually comprises less than 1 percent of that value.
This might be a more digestible reference for a basic level audience compared to a quote from two scientific papers.
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citizenschallenge at 23:51 PM on 13 May 2016Medieval project gone wrong
Hoskibui, thank you for a valuable article, you do a nice of explaining. It's come in very handy for a recent blog post regarding the misdeeds of CO2Science.org - and I've copied long sections to share.
"Is CO2Science.org 'criminally negligent'? Why not consider it?"
http://whatsupwiththatwatts.blogspot.com/2016/05/co2scienceorg-criminally-negligent.html
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jgnfld at 23:50 PM on 13 May 2016Coal made its best case against climate change, and lost
A number of people here are misunderstanding the nature of the proceedings. An adminstrative court hears evidence, takes submissions, takes testimony and cross examination, etc. but is not a "case" in the TV sense. In this case, the hearing is prescribed by legislation to write a legal opinion on evidence provided about a specific point (the social cost of coal) for the consideration of a higher body which will make the final decision.
It is an important step. But in no way was coal found "guilty". The finding is that on the preponderance of evidence (a criterion much lower than beyond a reasonable doubt) the evidence provided by the high social cost side is correct and that the evidence provided by the deniers was not correct. It's a beginning, but there is a very, very long way to go on the legal front.
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William Leslie at 23:25 PM on 13 May 2016The things people ask about the scientific consensus on climate change
I especially like the first point. Newton didn't need to replicate Kepler's observations before formulating his famous laws. He also readily acknowledged that he "stood on the shoulders of giants."
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braintic at 21:37 PM on 13 May 2016CO2 effect is saturated
This is NOT the correct explanation of the saturation of CO2 absorption of IR radiation. The fact is that the effect IS saturated at the resonant frequency of bending of a CO2 molecule (wave number 667).
However molecules CAN absorb radiation at frequencies that don't match the resonant frequency, albeit with a lower probability of absorption.
IR radiation at the resonant frequency has a mean free path of just over 30 cm with the current CO2 concentration. So almost all of that radiation makes it back to the ground. In fact that frequency becomes saturated at only a couple of parts per million.
A rough rule of thumb is that the probability of absorption reduces to about 10% for every 5% change in IR frequency. So the mean free path is multiplied by 10. So IR radiation which differs in frequency from the resonant frequency by 20% has a mean free path of about 3 km. At these altitudes the calculation is complicated by the thinning atmosphere, so the mean free path would actually be somewhat longer than that.
The effect of adding more CO2 is to reduce the mean free path of IR radiation at ALL frequencies. This has the effect of widening the band of frequencies that attain absorption saturation.
This is called BAND SATURATION. It is the widening of the band of frequencies that achieve saturation that causes the greenhouse effect to increase as more CO2 is added. And mathematically, it explains why the temperature effect increases logarithmically with CO2 concentration (ie. a constant temperature increase for every doubling of CO2 concentration).
I strongly suggest you change your article to reflect this science.
Moderator Response:[RH] All caps is against policy. Please take the time to read our commenting policies before you continue.
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michael sweet at 20:19 PM on 13 May 2016CO2 effect is saturated
Concerned Citizen,
It is too bad that you have alienated Tom Curtis. He generally is patient with learners and provides lots of data to support the consensus.
You need to step back and address one of your misconceptions at a time. When you list 5 or 6 misconceptions in a single post it is difficult to respond without a major post. You need to read the OP again and see what you misunderstand.
The increase in the radiation altitude causes the Earth to warm because of the temperature lapse rate. As you go higher in the atmosphere it gets colder. When the emission altitude is increased, less energy is emitted because it is colder. In order to reach equilibrium, the temperature must increase at 6.1 km so that the emitted energy equals the energy incoming from the Sun. Because the temperature lapse rate in the atmosphere stays the same, in order for the temperature to increase at 6.1 km, the surface has to warm also.
If you still do not understand why increasing emission altitude causes the surface to warm post again here. Do not add additional questions until we establish this description of the increase in temperature.
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ubrew12 at 19:55 PM on 13 May 2016The things people ask about the scientific consensus on climate change
I tell people that Scientific consensus is important less for Scientists, and more for Policymakers. And in lay discussions, the Policy is actually what is being discussed. The 'Do Nothing' alternative is promoted on the basis that the Science isn't 'proven' or 'complete' (which is an odd thing to promote, since logically an 'incomplete Science' should call us to 'Do twice as much of Something' if we were true conservatives). But if Policymakers admit that they aren't Scientists, then Scientific Consensus is the justification for action. On this topic, Policymakers of the last 30 years have taken the 'Do Nothing' alternative based on a 'whopping' 3-10% consensus of expert opinion. It's hard not to conclude they simply ignored the Scientists and made policy on the basis of intuition. We shall see how that goes.
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ConcernedCitizen at 19:33 PM on 13 May 2016CO2 effect is saturated
@Moderator: Right, so when I point out that I accept that CO2s GH effect isnt saturated but question the proposed explanation I am going to be blocked am I?
Tom Curtis@416
Air at 6,1 km is thinner, I now that, I already said its colder. How does putting an additional CO2 mollecule there cause warming? By changing kinetic into radiative energy and radiating it downwards.
The suggestion that there is a kind of 'CO2 lapse rate' just doesnt fit.
Moderator Response:[JH] Moderation complaint snipped.
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ubrew12 at 19:29 PM on 13 May 2016Coal made its best case against climate change, and lost
For 30 years, Richard Lindzen has been criticizing the Climate Models under apparently no pressure to offer a prediction alternative. Imagine Opthalmologist Lindzen ordering a patch on your one good eye because it wasn't seeing 20/20: "Trust me! You're better off blind!"
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DrivingBy at 12:35 PM on 13 May 2016Coal made its best case against climate change, and lost
@ OPOF
We can easily agree here: "There is an even less popular point regarding population."
I think you'll find that the rest is not a new idea, and is a hard sell. I was a bit off topic in my post, so I'll not pull the it further OT.
Moderator Response:[PS] Thank you. This thread is indeed drifting offtopic.
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One Planet Only Forever at 11:31 AM on 13 May 2016Coal made its best case against climate change, and lost
DrivingBy@4,
There is an even less popular point regarding population.
The highest consuming and highest impacting portion of the population is what needs to be reduced.
My preference would be for the most fortunate among humanity to be expected and required to be leaders of the advancement of humanity to a lasting better future for all. Anyone uninterested in being that kind of person, preferring to live life as a partying spectator, would choose to give up the opportunity for the life of a leader (and find the wealthier life opportunity unavailable to them no matter how tricky or secretive they tried to be).
The current system that excuses (and encourages) known to be unacceptable behaviour if it can be gotten away with, especially if it can be popular and profitable, clearly fails the needs of the future of humanity (as it focuses on meeting the desires of the most callous among us).
Total global wealth and food production has grown more rapidly than the population yet a significant portion of the global population still live short horrible existences. That clearly needs to change.
The elimination of the ability of the already most fortunate to continue to enjoy their undeserved perceptions of prosperity is a step in the right direction. It is a step that will need to be taken affirmatively by humanity in spite of the potential reactions from those who would try to fight against losing their ability to win rewards by behaving unacceptably.
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Digby Scorgie at 10:50 AM on 13 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
mancan18 @9
For deniers to say that "correlation does not imply causality" dodges the fact that high levels of carbon dioxide are "associated" with high temperatures, and vice versa. Since CO2 levels are now high, the deniers have to admit that high temperatures are therefore to be expected — in other words, global warming has to be real.
To put it another way, the deniers can't have their cake and eat it. To use the correlation-causation argument they have to admit the reality of global warming. (This treats as a separate issue the adding of more CO2 to the atmosphere from burning fossil fuel.)
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DrivingBy at 23:04 PM on 12 May 2016Coal made its best case against climate change, and lost
Coal was a great step forward, 200 years ago, it brought us out of the era of wiping out forests for fuel, 12 hour workdays and travel by horse for the wealthy or by foot for the rest. Today's problems are mosqito bites compared to the harshness of life then, and fossil fuel provided the physical energy undelying that change.
Coal's time has now passed, we need to move away from carbon fuels (unless some clever soul figures out how to economically capture C02 emissions). We also need to reduce the world population unless we are willing to live with conflicts and poorer lives, but that is not a popular thought and probably never will be.
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CBDunkerson at 23:02 PM on 12 May 2016Coal made its best case against climate change, and lost
I'm surprised the contrarians were even allowed to testify given the rules of evidence. Possibly Minnesota is less strict than the federal court system, but generally only well established science can be presented.
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Tom Curtis at 22:28 PM on 12 May 2016CO2 effect is saturated
Frankly ConcernedCitizen has amply demonstrated his refusal to think clearly about this topic. I am no longer going to waste my time on him. When he is so wrapped up in his own "wisdom" that he does not recognize the air at 6.1 km is thinner than that at 6.0 km, and that consequently his own counterexample proves the claim he is disputing, it is completly pointless to continue any discussion. (Romans 1:22 applies.)
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Eclectic at 22:18 PM on 12 May 2016There's no correlation between CO2 and temperature
Ken @49, your question is answered in the thread "CO2 is not the only driver of climate".
Quickest to go to the comments column there, and see Bozzza's (@20) laconic quote: "aerosols" ~ which is the short story . . . that could be expanded slightly to: "increasing industrialization produced reflective aerosols which counterbalanced the rising CO2, until the ever-higher CO2 levels overpowered the aerosol effect by around 1970 [combined with some clean-up of aerosol emissions].
You will note Tom Curtis's (@21) longer explanation of additional factors which contributed to a "flat" 1940-1970 record.
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ConcernedCitizen at 21:06 PM on 12 May 2016CO2 effect is saturated
Tom Curtis@414
Not wanting to create a long thread, and to keep it trelevant to the theory postulasted here, I focused on heat transfer space, not from the surface and not internally, so it wasnt a refutation of the GH effect at all.
" but you neglect that the lack of greenhouse gases also reduces the introduction of energy into the atmosphere by absorption of thermal radiation from the surface, with the absorbed IR radiation from the surface being much greater than the emitted radiation from the upper atmosphere"
At the top of the atmosphere, where the additional CO2 mollecules are now radiating at higher altitude, you have said that less than 1% of energy is direct radiation from the surface which contradicts this statement.
"if we add more greenhouse gases the air needs to be thinner before heat radiation is able to escape to space"
Why? If it isnt direct radiation from the surface (in which case the energy is maintained regardless of what altitude its radiated at, and is very rare (free path lenght and all that)) then its a kinetic-radiative change of energy.
So, if a colision happens with CO2 at 6km and is radiated to space the photon's energy represents the temperature at 6km.
Add more CO2 and now more of the collisions happen at 6.1km with the photon's energy representing the temperature at that altitude.
This doesnt mean there is more heat in the system.
Better to say that adding more CO2 turns kinetic energy at 6.1 km into photons which have an even chance of being emitted towards the surface. ie, more GH gas = more back radiaiton.
Taking the Feldmanpaper data from the paper above, and using 370 and 390 ppm for CO2 at 2000 and 2010 MODTRAN gives a 0.3 wm^-2 forcing change, which isnt far off fro the Feldman value, so I am not doubting CO2 as a GH gas or CO2 non-saturation just that the mechanism proposed here isnt feasible.
Add CO2 and now we have
Look, I am not saying CO2 is saturated, but the mechanism proposed here doesnt hold water when you pull it apart, and you certainly havent explained it, all you have done is explain the GH effect.
Moderator Response:[RH] Removed excess blank space. Concerned Citizen, the process has been explained to you in a very detailed and accurate manner. You're skating on this ice at the moment.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
Link to the commenting policy is just above the comment window.
[PS] The detailed process with the maths is in the Ramanathan and Coakley paper pointed to earlier. Do you dispute that paper?
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mancan18 at 19:50 PM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
Congratulations SkS, well deserved.
As for the greatest threat from AGW, it is quite likely to be, using Donald Rumsfeld terminology, an unknown unknown. Climate Scientists know what they know i.e. known knowns. They are also aware of the known unknowns but are not yet sure as to their likely impact. However, considering that the world is directly on a climate path that existed long before humans first evolved, then the global ecosystem that will exist long after fossil reserves have been burnt, if they are not left in the ground, is an unknown unknown. It may well be that the resulting global ecosystem may not be favourable to humans. Of course humans now have a limited ability to control their own evolution and create their own climate and ecosystems. Whether that will be enough to avert the more adverse impacts of AGW is also an unknown unknown.
Incidently, one of the best temperature graphics I have seen in recent times that shows the rise in global temperature since 1850, has been produced by Ed Hawkins, an academic from the University of Reading. It is worth a look. It might also be worthwhile for someone to create a similar graphic showing the rise in CO2, and run them side by side, even though the denialists will use the argument that correlation does not imply causality.
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Tom Curtis at 18:10 PM on 12 May 2016CO2 is not the only driver of climate
Ken Kimura @19, if you sum all forcings (ie, not just that from CO2) using the values estimated by Meinhausen et al (2011), the trend in the forcings from 1940 to 1970 is 0.0003 +/- 0.0007 W/m^2 per annum. That is, it is essentially zero, and may well have been negative. On top of that, there was a substantial El Nino early in the sequence and a La Nina following the volcanic eruption in 1965 which together with the very low trend in forcings may have tipped the temperature record negative.
Having said that, if you look at this model of the ENSO adjusted temperature responce to forcings, you will see to large temperature spikes around 1939 and 1945 that are not accounted for by the model and which also contribute to the negative slope. It is difficult to know that to attribute those spikes to. They may be due to unusually large forcing by Black Carbon during World War 2. They may also be due to an artifact in the temperature record due to the sudden, very large reductions in temperature coverage along with the simultaneious large changes in methods of measuring Sea Surface Temperature brought about by WW2.
What they are not due to is the Pacific Multidecadal Oscillation (which is captured by the ENSO signal) or the Atlantic Multidecadal Oscillation (which does not have a suitable pattern to explain the phenomenon). Nor are they due to a fundamental misunderstanding of the forcings, or the relative effects of natural and anthropogenic forcings. The model I linked to allows you to weight the various forcings, making natural forcings much stronger in effect than anthropogenic forcings if you desire. Any such attempt, however, greatly increases the number of temperature discrepancies. That fact shows conclusively that theories that attempt to explain the twentieth century temperature record without anthropogenic factors being the dominant factor post 1940 (and a significant factor prior to 1940) are doomed to failure.
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bozzza at 17:27 PM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
You are saying desertification could get a guernsey for biggest threat?
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bozzza at 17:25 PM on 12 May 2016Arctic Ice Volume is diminishing even more rapidly than Area
Figure 2 only has a downward trend of less than ten years.
How does the trend look now in 2016?
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Tom Curtis at 17:19 PM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
bozza @6, I don't think anybody knows what the biggest threat is, and certainly I do not. We know there are several very large threats but exactly which is largest depends on time scale and how much we push global warming; but in addition to that the error margins on how bad the threats are are such that a clear worst effect cannot be picked on a global basis. Even if we push global warming to the extreme, in which case the seasonal rendering of tropical regions of the Earth uninhabitable to humans due to heat stress may be pipped by the effect of deoxydisation of the oceans (the probable cause of the worst mass extinction todate). The later also has a less clear cut off so that it may occur at lower temperatures. These are likely the worst possible impacts from purely anthropogenic global warming. Ocean acidification and changes in the hydrological cycle (which involves both more intensive flooding, droughts and storms) are likely the worst impacts at more moderate levels by my inexpert estimate.
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bozzza at 17:16 PM on 12 May 2016CO2 is not the only driver of climate
..aerosols !
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brendan1 at 16:06 PM on 12 May 2016Coal made its best case against climate change, and lost
Thanks for the article and the graphics, I enjoyed the description of the law suit as well. We have been discussing the direct impacts of coal burning in my climate change course, which makes this article very relevant for me. Not only that, but we have also discussed the idea of social costs (by looking at K. William Kapp's writings on the subject), and I enjoyed the fact that you touched on that. It seems like if the true social costs inflicted by fossil fuel burning were made to be answered for by the companies who do it, no one would want to use this method for energy because of the massive costs. In a perfect world, the giant subsidies could go toward sustainable forms of energy instead. I don't know if this can ever happen in the United States in time.
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bozzza at 15:48 PM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
Thus, Tom, this begs the question of what Climate Change has as it's biggest threat if not sea level rise?
I presume desertification...
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Ken Kimura at 15:01 PM on 12 May 2016CO2 is not the only driver of climate
If the unremitting rise of CO2 from industriail activities is the dominant factor, why did the global temperature decrease from 1940 to 1970?
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Ken Kimura at 14:43 PM on 12 May 2016There's no correlation between CO2 and temperature
I had read the article and still I did not understand why the global temperature did not increase
from 1940 to 1970. Could you tell me what is the main cause of it?Moderator Response:[PS] From the article, "If CO2 causes warming, why isn't global temperature rising over this period? To answer this, one needs to recognise that CO2 is not the only driver of climate. There are a number of factors which affect the net energy flow into our climate. Stratospheric aerosols (eg - from volcanic eruptions) reflect sunlight back into space, causing cooling. When solar activity increases, the amount of energy flowing into our climate increases. Figure 5 shows a composite of the various radiative forcings that affect climate."
Figure 5 shows all the factors other than CO2 affecting climate of the period and Fig 6 sums all them, positive and negative, to show little net forcing till 1970. Please take some time to study actually study and understand the figures.
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Ken Kimura at 13:02 PM on 12 May 2016There's no correlation between CO2 and temperature
The global temperature did not increase from 1940 to 1970.
How do you explain this?Moderator Response:[PS] Read the article. (Net forcings, see figures 5 and 6 on the intermediate version of the article). Warning: Asking questions without any interest in the answers is simply sloganeering and forbidden by the comments policy.
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Ken Kimura at 10:06 AM on 12 May 2016Ivar Giaever - Nobel Winning Physicist and Climate Pseudoscientist
From 1940 to 1970, the world industrialized nations produced far larger amount of CO2 than before due to the rapid economic growth.
However, the global temperature did not increase during the period(Figure 1).
How do you explain this?Moderator Response:[PS] This is offtopic here. Please see co2 temperature correlation. Climate responds to net forcings not just CO2. See the graph of net forcings versus temperature at bottom of article and make any comment on that topic, not here.
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Tom Curtis at 09:55 AM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
John A. Broussard @4, the total land lost to date is to small to even show on the scale of a global map. Even a six meter sea level rise (not expected for several centuries) appears more as a highlighting of the coast rather than a significant land loss:
This does not mean sea level rise is insignificant. People living on river deltas (Bangladesh, much of the Egyptian population) or what are in effect extended sand bars (Florida) along with will lose almost all their territory from such a sea level rise. Further, 40% of the world's population lives in coastal areas and will experience some negative impact from sea level rise, either through increased storm damage and flood risk (due to slower drainage of rivers due to the elevated sea level); or through the necessity to move cities or major infrastructure several kilometers inland (or build massive sea walls to obviate that necessity, with the risk of a Katrina like catastrophe as a result).
Consequently, while the idea of an updated index of sea level rise impacts is a good one; using a global map to provide that index is unsuitable. On the other hand, in some areas local maps might be very useful.
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Tom Curtis at 09:44 AM on 12 May 2016CO2 effect is saturated
ConcernedCitizen @413:
"The quesiton isnt whether the GH effect exists, it is wether CO2 is saturated as GH gas."
You say that, but immediately mount an argument that, if valid, would mean there is no greenhouse effect, not that it was saturated.
"The suggesiton is this: A CO2 mollucule at 6 km radiates a photon upwards. This photon was either radiated out from the surface and stayed as a photon at 15 microns all the way up, and finally, this CO2 molecule was the last one in the chain, and the photon made it out to space."
In fact, both of these are true for very small parts (<1% at a guess) of the energy radiated to space by CO2 from the middle to upper troposphere. For most energy, it will have been radiated from the surface (68%), or transferred by latent heat or conduction (18%), or absorbed in the atmosphere from solar radiation (14%). From there, most energy transfers will have been by collisions with other molecules, with transfer to molecules travelling downwards as likely as those to molecules travelling upwards, and with lateral motion of molecules receiving energy as great as either upwards or downwards motion. Most upwards motion will be from emissions from molecules, but (firstly), radiation will be as likely to take energy downwards as up, equally likely to take it laterally as either; and the molecules radiating the energy are more likely to be H2O molecules in the lower troposphere than CO2 molecules (and hence have a different, but lower energy content per photon than that eventually radiated to space by CO2). Of course, some of the radiation will have been by radiated by other greenhouse gases (CH4, NO2, O3, etc) which typically have a higher energy content per photon than that radiated by CO2. Of course, energy radiated by a greenhouse gas other than CO2 will have to be absorbed by that same greenhouse gas (except for a small amount radiated by H2O) and then transferred to CO2 by collisions (probably mediated by collisions with N2 and O2). Even energy transferred by radition from CO2 and absorbed by CO2 will have different energies to that finally radiated to space because of doppler energy shifts, and pressure broadening (and a couple of other effects).
The net consequence of this is that:
1) Of the energy finally radiated to space by a single CO2 molecule, not all will have come by the same pathway except in very rare cases;
2) The energy finally radiated by CO2 to space will typical have followed a very convoluted pathway through the atmosphere, spending almost as much time travelling downwards as upwards, and twice as much time travelling laterally as either downwards or upwards (with different parts of the energy travelling different paths as per (1));
and (most importantly)
3) Because the lower layers of the atmosphere are warmer, and hence radiate more energy, and downward radiation is as probable as upward radiation at all levels of the atmosphere, the majority of energy entering the atmosphere (59%) will follow a convoluted path that returns it to the Earth's surface.
The upshot is that the convoluted pathway of energy from the surface introduced by the presence of greenhouse gases in the atmosphere serves as a filter limiting the escape of energy to space. There is a bias in that filter caused by the lower temperatures at higher altitudes which means that less than 50% of the energy escapes to space.
Unfortunately for your theory, none of this fits your simplistic analysis. In your analysis, either all radiation is upward only, in which case all energy emitted from the surface escapes to space without impediment. And indeed, if all radiation was upwards only, there could be no greenhouse effect - but such a situation is unphysical.
Alternatively, on your second scenario, energy is transfered upwards by collisions and IR radiation from the upper troposphere reduces the thermal energy relative to the case with no greenhouse gases: but you neglect that the lack of greenhouse gases also reduces the introduction of energy into the atmosphere by absorption of thermal radiation from the surface, with the absorbed IR radiation from the surface being much greater than the emitted radiation from the upper atmosphere. So, while the IR radiation to space cools the atmosphere, the IR absorption from the surface warms it at a much faster rate.
In both scenarios, you ignore essential features of the system in order to draw obtuse conclusions.Moderator Response:[PS] Thanks Tom. ConcernedCitizen, note that the effects of increased CO2 has been directly measured (see "Observational determination of surface radiative forcing by CO2 from 2000 to 2010") so it real despite your difficulties in understanding why.
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mitch at 01:50 AM on 12 May 2016Coal made its best case against climate change, and lost
Thanks for giving the background on the Minnesota lawsuit. I have been wondering why the case was in court. My expectation is that if other GHG lawsuits get to court they will have a similar outcome. The 'fossil fuel' scientists are too few and too old.
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John A. Broussard at 00:46 AM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
It's time for a world map, posted on this site, showing the daily, monthly, yearly loss of land to the rising seas (e.g. recent disappearance of several islands in the Solomons)
An up-to-date depiction of lost land and threatened losses would be very effective in demonstrating the actual and approaching effects of global warming.
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dana1981 at 00:29 AM on 12 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
Thanks!
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ConcernedCitizen at 22:59 PM on 11 May 2016CO2 effect is saturated
M A Roger @411
Tom Curtis @412
The quesiton isnt whether the GH effect exists, it is wether CO2 is saturated as GH gas.
The suggesiton is this: A CO2 mollucule at 6 km radiates a photon upwards. This photon was either radiated out from the surface and stayed as a photon at 15 microns all the way up, and finally, this CO2 molecule was the last one in the chain, and the photon made it out to space.
Or the CO2 mollecule was impacted by an O2, or N2 molecule and thus kinetic to radiative change happened, with the energy of the photon representing the energy at that altitude, ie, temperature.
The proposal here is that an additional CO2 mollucule at 6.1 km causes cooling. HOw so? Lets look at the wto cases. Either the photon was passed up from the surface, and this is the last CO2 mollecule in the chain, in which case it is pased out to space with exactly the same energy as before. Ie, no loss of energy, no warming.
Or, if the photon came from kinetic energy and was radiated out to space, then yes, the energy of the photon would be less, because it represents the temperature at 6.1 km, but if the CO2 mollecule werent there then this radiation wouldnt happen at all and the kinetic energy would have just stayed in the system.
So I dont see how the suggesiotn that 'A CO2 mollecule radiates from higer and colder' means additional energy in the system and hence warming.
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Rob Honeycutt at 21:57 PM on 11 May 2016Comparing models to the satellite datasets
Christy actually is comparing TMT with a similar comparison of the atmosphere from CIMP5 model. So, it's now what he's comparing that's misleading, it's how he's doing it.
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shoyemore at 17:55 PM on 11 May 2016Skeptical Science wins 2016 NCSE Friend of the Planet award
Congratulations!
Totally merited.
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