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PhilippeChantreau at 16:02 PM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
What I found relative to the zonal index and Rossby waves "amplitude" (the size of the meanders):
"When temperature contrasts are very strong, the meanders are shallow in amplitude and strong weather systems (depressions) rapidly cross the Atlantic bringing wet and windy conditions to Europe. This is described as a "high" zonal index, where the contrasts between the temperate and polar zones are strong with little mixing north or south. In contrast, the meanders sometimes develop very large amplitude waves which eventually break down (rather like an ox bow lake forming from an overdeveloped river meander). When this happens the "zonal index" is said to be low, and strong north-south transfers of heat take place. This results in extremes of heat waves and cold snaps depending on whether the waves are bringing your locality deep tropical or deep polar air."
Source:https://moodle.thelangton.org.uk/gip/HTMLpages/w_depres.htm
This is consistent with the OP's description. However, I note that the authors of the OP discuss the Atlantic Oscillation more than the the gradient and zonal index.
This presentation from University of Oregon shows a similar relationship between the zonal index and amplitude, or wave number, and concurs with the OP that high zonal index leads to quickly passing and generally non extreme weather systems.
homework.uoregon.edu/pub/class/atm/rossbyprimer.pdf
Blocks and extreme weather events are associated with high amplitude waves and low zonal index in all the sources I have found so far. A low zonal index is associated with lower temperature gradients.
I can say that the information I have gathered on my own so far does not corroborate this statement from Chuck Wiese above: "It is a fcat that blocking patterns as discussed here are the result of larger, not lesser temperature gradients."
I also read in the OP that indeed Arctic amplification is expected to reduce the temperature gradient and be associated with a lower zonal index. However, the behavior of the AO is also quite important.
Given the short time so far spent looking into this interesting issue, I have obviously not be able to obtain the 1957 text cited by Chuck Wiese in support of his view. However, there is considerable work and research that is much more recent than that, including meteorology textbooks, and they should certainly be considered as more up to date. The theory of Rossby waves is a bit of a challenge to confirm by observation. I found some publications by a team at University Iowa that had sevreal observations in disagreement with the theory's predictions. They did, however, qualify their results and stopped short of drawing any conclusions on the theory itself.
This statement by Chuck Wiese: "static global temperature for over 18 years and counting" needs to be substantiated. Examination with statistical methods shows otherwise. It probably should be discussed on another thread.
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TonyW at 15:56 PM on 28 October 2015Interview with Gavin Schmidt
Is there a reason for cutting off these reposts, so that we have to go to another site to read the rest? Often it's only a paragraph or so more though, this time, it was a little more substantial.
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Chuck Wiese at 14:14 PM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Glenn: How do you know this? He is not the head of Deutscher Bank. He is a part of their "cliamte division". It is believable I have the right person. Just look at the references and content of discussion.
If he is not this person, he reveals a shallow understanding of atmospheric science or meteorology and perhaps he would like to tell us who he is.
(snip)
Chuck Wiese
Meteorologist
Moderator Response:(RH) Who any person is or isn't is not important here. Address the issues.
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Glenn Tamblyn at 14:01 PM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Small problem Chuck.
Thats not the Tom Curtis you are having a conversation with!
Hard to be head of Deutscher Bank of America or any other division of Deutscher Bank when you live in Australia. -
Chuck Wiese at 13:27 PM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Of course not, bozzza. Your point makes the point that as the ocean temperatures rise, so does atmospheric CO2 concentration. But without a positive feedback from water vapor, the expectations from climate models fail, which they have done. We have had a static global temperature for over 18 years and counting, contrary to failed modeling in spite of rising CO2. This implies as the data does that the feedbacks are negative, which the data shows with a dryer upper troposphere.
Chuck Wiese
Meteorologist
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bozzza at 13:13 PM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
The facts are that CO2 is less soluble at higher temperatures. Does Chuck disagree with this?
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Chuck Wiese at 10:51 AM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Mr. Curtis: Your comments reflect an individual who knows little or next to nothing about meteorology or atmospheric science. As such, the only thing in your background that you seem capable of is to launch personal attacks against those who don't agree with you. (snip)
The physics of Rossby waves are well established in the published scientific literature. Those who don't get that like the comment from scaddenp and you assume I need to publish a paper to prove my assertion. That is incorrect. The opposite is actually true. It is up to the author of this article and Jennifer Francis to show where the prior established and peer reviewed literature is wrong. References of this include "Dynamic Meteorology and Weather Forecasting", authors Godske,Bergeron, Bjerknes and Bundgaard. American Meteorological Society Volume 605, 1957, Chapter 11, Hydrodynamics of the Atmosphere. With your background, you wouldn't recognize the names but the authors are famous for their work in atmospheric science. Another reference, " Dynamical and Physical Meteorology" Haltiner and Martin Chapter 12, Horizontal Frictionless Flow, 1957 ISBN 57-8005.
The physics of planetary Rossby waves are quite clear in all of this literature and point at the fact that if latitudinal tempertaure gradients decrease from arctic amplification, the amplitude of the waves and mean inflection points migrate to higher latitude and decrease. This is the opposite of what this article and Francis claim. As I said, she has offered no physics to demonstrate where the founding literature is wrong. But that is how the scientific method works. You need to prove where the established literature is in error and that has not been done.
I want to thank you for pointing out my lecture to the Oregon Chapter of the American Meteorological Society and would encourage the readers to watch it. There were also two other presenters who share my views, physicist Gordon Fulks and Climatologist George Taylor.
Your point 1 has been debunked. The ice core records prove temperature actually leads increasing CO2, not follows it. There is no demonstrated cause of CO2 affecting temperature as claimed by politicians like Al Gore. (snip)
Your point 2 is wrong. My lecture used MODTRAN and water vapor IR radiation calculations derived by Dr. Ferenc Miskolczi, a principle research scientist from NASA who specialized in IR radiative transfer. The point in doing the calculations were to show the warming of the last century far exceeded what basic IR radiation calculations would demonstrate and that there are no positive feedbacks from water vapor as claimed by warmers.
It is interesting that those like youself with no apparent science background are quick to name call those like me as "deniers" and all of the other nasty things you do, but it is also interesting to look at your background, This is from Bloomberg Business: "Mr. Thomas Curtis is the Managing Director and Global Co-Head of DB Climate Change Advisors. He has been the Global Head of Strategic Planning and Communications, Head of Business Development, and Member of Global Operating Committee at Deutsche Asset Management Inc. As Global Head of Business Development from 2004 to 2009, and prior to that, as the Head of Corporate Strategy for Deutsche Bank Americas from 2000, Mr. Curtis has been responsible for initiating and executing ...the full bio is here:
http://www.bloomberg.com/research/stocks/private/person.asp?personId=13010869&privcapId=84655488 (snip)
It would appear that you are a heavily invested special interest banker and finace person of sorts who stands to lose a lot of profit and potential income if the desired regulations and taxes imposed from carbon upon individuals fails to get traction from politicians. It also appears from your comments that you not only don't understand the fallacy of claimed "consensus" opinion on AGW, but fail to realize the concept is a ruse and a lie. There si no "consensus" on AGW like you and many other special interests claim:
http://www.climate-resistance.org/2013/07/tom-curtis-doesnt-understand-the-97-paper.html
BTW, I have more experience in opertaional meteorology than you claim. I am President of Weatherwise, Inc, and have developed a first generation brand of weather instrumentation of its kind that has predictive value:
http://www.google.com.gh/patents/US5372039
(snip)
Chuck Wiese
Meteorologist
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Tom Curtis at 09:38 AM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
Given that Chuck Wiese provides no data, or citations in support of his claims, instead relying entirely on his authority as "Chuck Wiese, Meteorologist", it is appropriate to find out what that means. It turns out it means he has a BS in Atmospheric Science from Oregon State University, and (by his claim) 25 years experience "in operational weather forecasting". According to David Appel, that experience comes down to his being a former TV weatherman.
What ever his prior experience, it is clear he is no scientist. His Jan 2012 presentation at the Oregon Chapter of the American Meteorological Association, for example, is a play book of refuted denier arguments. (As an aside, he is presented their as a "Meteorologist, Oregon State University" which would normally, and in this case falsely, suggest he had a staff position at OSU. He seems addicted to inflating his credentials by ambiguity.) My favourite section is where he 2002 - 2010 correlation of CO2 with two global temperature measures showing he is not afraid to blatantly cherry pick. This is a particularly egregious case given that:
1) We have more than a centuries worth of data on temperature and (using icecores) CO2 concentration so that there can be no need and no excuse to use a shorter period than (at minimum 1959 - present) for purposes of correlation; and
2) He knows the maths of radiative physics so that he knows annual variations in CO2 are predicted to have almost no temperature effect, even ignoring thermal inertia, so that by presenting less than a decade of temperatures for the correlation, he knowingly chose a time span over which the tempeature variation is dominated by other factors than CO2 rise (primarilly ENSO).
This episode shows that not only does he dispute the consensus position on global warming, but that he is prepared to go into full denier mode, using all the cunning and dishonest tricks that implies to defend his position.
Consequently, my view is that the opinions of Chuck Wiese, Meteorologist should be treated with a very large grain of salt, unless he backs them up in detail with cited works from the peer reviewed literature.
Speaking of which, here is a more recent review of the Francis & Vavrus hypothesis. It is amazing how none of the eleven authors thought of Wiese's objections. That may be because, as I have understood the hypothesis, Francis and Vavrus propose an increased local thermodynamic gradient due to some of the Arctic Ocean being ice covered, and some not. From that it follows that Wiese is arguing a strawman.
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scaddenp at 06:27 AM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
That is an interesting observation. The obvious response would be to submit a comment on the paper to the journal. Have you thought of doing so?
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Chuck Wiese at 03:22 AM on 28 October 2015A Rough Guide to the Jet Stream: what it is, how it works and how it is responding to enhanced Arctic warming
This article's conclusions consist of frivolous nonsense and and clearly wrong.
The amplitude of atmospheric Rossby waves is proportional to the speed of the jet and the speed is directly proportional to the gradient of tempertaure across the latitudes.
It is a fcat that blocking patterns as discussed here are the result of larger, not lesser temperature gradients. If the arctic was warming as cliamed, the amplitude of the waves MUST decrease and the mean inflection point of trough to ridge must do the same thing. It is impossible for the conclusions here to be correct if it is warming rapidly in the arctic. If that were true, the oppososite would occur, that is, a decrease in amplitude of the waves and a northward migration. Increased severe weather can only bec a consequence of addtional stored potential energy, not less, which tranlates to INCRESING temperature gradient, not decreasing.
I have written to Jennifer Francis about this and challenged her claims. She has never responded with any proofs of her assertions to demonstrate where the physics of Rossby waves in the published literature are wrong, which they would have to be for this article or her assertions to be correct.
Chuck Wiese
Meteorologist
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One Planet Only Forever at 00:05 AM on 28 October 2015Interview with Gavin Schmidt
Regarding the minimum Arctic Sea Ice extent, reviewing the minimimums presented by NSIDC it appears that minimum ice extent values that are noticably lower than adjacent years occur within a few years after an El Nino (The straight line trend on the NSIDC chart is a bit misleading for this evaluation. A curved line through the data points would more obviously highlight what I am referring to).
Values significantly lower than adjacent years in the minimum extent occured in the following years (with El Nino event years in brackets based on the NOAA ONI history):
- 2012 (2009/10)
- 2007 and 2005 (extended mild El Nino 2002 through 2007)
- 1999 (1997/98)
- 1995 (1991/92)
- 1990 (1986/87/88)
- 1985 (1982/83)
If this is a significant correlation between El Nino and Arctic minimum extents then a minimum below 2012 levels would be expected in 2017 or 2018.
Time will tell, but the ability of people to maintain a 'disbelief of the contantly improved understand that rapid global climate system changes are occurring with the only viable explanation for the changes being human impacts that can be reduced (contrary to developed popularity and profit interests)' appears to be diminishing at an increasing rate.
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Digby Scorgie at 17:04 PM on 27 October 2015The Brave New World of Ecomodernism
#66 KR
My question was partly rhetorical (!), but you're right, it comes down to money and infrastructure. Something like a carbon tax has to make fossil fuel expensive enough to result in its phase-out. However, I can't help thinking this is like dividing by zero: for fossil-fuel production to tend to zero, the tax has to tend to infinity. A sure-fire way of achieving decarbonization is to require fossil-fuel producers to cut their production by a mandated amount every year for a mandated period. But I can't see that happening.
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Glenn Tamblyn at 14:00 PM on 27 October 2015Climate sensitivity is low
psagar
Some points to remember. Climate response (and thus climate sensitivity) isn't just about radiative balance, heat capacity etc. Another key factor is Albedo - how reflective the Earth is.If the earth reflects the same percentage of sunlight then climate change is about radiation, heat capacity etc.
However if the Albedo is changed by climate change this in turn changes the energy balance and adds other climate change. There may be changes in cloud cover. Far more certainly there will be changes in surface reflectivity; changes in snow and ice cover, open water area, regions of desert, vegetation patterns etc. All these impact reflectivity. Warming certainly reduces snow & ice cover for example.
Importantly, many of these changes take long time periods to occur. Ice sheet changes particularly take centuries to unfold.
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Tom Curtis at 12:18 PM on 27 October 2015Climate sensitivity is low
psagar @367, first, Forcing (or Radiative Forcing) is given the following definition by the IPCC:
"Radiative forcing Radiative forcing is the change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun."
(My emphasis)
I have quoted the full entry in the glossary below, as it contains relevant technical information plus some comments on idiosyncracies of usage.
The important point for this discussion is that radiative forcings are only those changes in TOA energy flux due to external drivers, ie, those not effected by climate variables such as (particularly) temperture and (also) precipitation, wind velocity etc; at least not on the time scale of interest. So, while a change in CO2 concentration will cause a change in radiative forcing, and changes in temperature will cause changes in TOA energy flux, changes in temperature do not cause changes in radiative forcing (by definition of radiative forcing). While this is a just a matter of definition, in my experience those who ignore the clarity given by distinguishing between radiative forcings and changes in TOA energy flux in response to feedbacks always end up making mistakes when thinking about issues of climate change.
Looking at this in more detail, we have:
ΔQ = ΔF - α ΔT (1)
where ΔQ is the change in net downward TOA energy flux, ΔF is the change in forcing, ie, the change in net downward TOA energy flux that is independent of climate states, ΔT is the change in global means surface temperature, and α is the climate feedback parameter. The climate feedback parameter is also defined in the IPCC glossary, and equation (1) is just an algebraic transformation of the mathematical definition of the climate sensitivity parameter given there. (Note, however, that the IPCC uses ΔQ for forcing, and ΔF for energy flux. I use the opposite values as it is more intuitive, and also the common practise among some climate scientists.) The units for α is in Watts m-2 oC-1, and it is the converstion factor between GMST and change in net upward TOA energy flux.
From (1), simple algebra tells us that when the GMST is at equilibrium, ie, ΔQ = 0, then
ΔF = α ΔT (2)
Equation (2) just tells us that ΔF and α ΔT have opposite intrinsic directions, ie, while ΔF reffers to net downward flux, α ΔT refers to net upward flux (as emphasized above).
Now, by definition, if ΔT equals the Transient Response to a given forcing, ΔF, then ΔF - α ΔTCR does not equal zero. If it did, the TCR would be the also be the Equilibrium Climate Response. Nor can it be greater than the ECS, for (with a positive forcing) if it were ΔF - α ΔTCR would be negative. It would follow that at some lower temperature the TOA heat flux (ΔQ) would have been equal to zero, at which point the GMST would have stopped changing, thereby preventing the temperature rising to the greater value. It follows that TCR < ECS, more or less of necessity.
So, while it is possible to construct unrealistic scenarios where TCR is approximately equal to ECS, it is literally not possible to construct one where TCR > ECS. At least, not without a fantasy physics.
Glossary Entry
"Radiative forcing Radiative forcing is the change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun. Sometimes internal drivers are still treated as forcings even though they result from the alteration in climate, for example aerosol or greenhouse gas changes in paleoclimates. The traditional radiative forcing is computed with all tropospheric properties held fixed at their unperturbed values, and after allowing for stratospheric temperatures, if perturbed, to readjust to radiative-dynamical equilibrium. Radiative forcing is called instantaneous if no change in stratospheric temperature is accounted for. The radiative forcing once rapid adjustments are accounted for is termed the effective radiative forcing. For the purposes of this report, radiative forcing is further defined as the change relative to the year 1750 and, unless otherwise noted, refers to a global and annual average value. Radiative forcing is not to be confused with cloud radiative forcing, which describes an unrelated measure of the impact of clouds on the radiative flux at the top of the atmosphere."
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michael sweet at 12:07 PM on 27 October 2015Corals are resilient to bleaching
It strikes me as ulikely that sunscreen is harming corals in remote Hawaiian islands with no tourists, the Great Barrior reef where tourists do not go and in many other remote locations. Even if it were poisoness enough to affect corals in the ocean, which I doubt, it would only affect the most visited locations.
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Daniel Bailey at 08:58 AM on 27 October 2015Corals are resilient to bleaching
"It may not be ‘ocean acidification’ killing coral after all..."
And
"A greater threat to corals than warming and acidity may be..."
The operative phrase is "may be". Further study is required to quell the pell-mell rush down the steep path to Hyperbole land.
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Argus at 07:45 AM on 27 October 2015Corals are resilient to bleaching
"Oops! It may not be ‘ocean acidification’ killing coral after all – common chemical found in sunscreen is poisonous to coral reefs"
A greater threat to corals than warming and acidity may be suntan lotion that contains oxybenzone or any of three other ingredients. See:
Sunscreen contributing to decline of coral reefs, study shows
Moderator Response:(Rob P) There no evidence, as far as I am aware, of ocean acidification killing reef coral in the modern ocean. The decline in saturation state and the increase in hydrogen ions (falling pH) are likely making calcification, the building of coral's calcium carbonate skeleton, more difficult though.
This is because coral build their skeletons in internal chambers semi-sealed off from the ambient seawater and need to pump hydrogen ions out of the chamber in order to raise the saturation state. It permits aragonite crystals formation in this highly supersaturated environment. Lower ocean pH, as ocean acidification is currently doing, and you increase the concentration of hydrogen ions dissolved in seawater. Coral therefore have to expend more energy in pumping these ions out of the calcification chamber.It's problematic because, like many organisms, the energy budget is very tight and they can't afford to use up energy allocated to reproductive purposes. Skimp on calcification and the coral skeleton will become weaker. And there is evidence that it is indeed occurring at some locations.
But this rebuttal is about coral bleaching and subsequent mortality because the world's oceans are becoming too warm. That's the more immediate concern
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The Brave New World of Ecomodernism
Digby Scorgie - Short answer(s): money and infrastructure. Right now fossil fuels are cheaper and there is a supply and distribution network for them. Change won't happen on a large scale until there are economic reasons for it.
Case in point: Swift Fuels has developed alternative aviation gas, not to mention jet fuels, that are derived from either plant or fossil fuel feedstocks. The reason this is actually going to market is that general aviation fuel consists of 100LL, that is 'low-lead', as the 50-60 year old piston engine designs on use by GA require leaded fuel. That's an ecological nasty, and there's considerable pressure to phase the really small 100LL market out entirely - but the GA fleet will need _something_ to fly with, so Swift Fuels has an economic opportunity.
I suspect that carbon taxes and to some extent regulations that increase the cost of fossil fuels commensurate with their actual costs to the environment and health would rapidly drive a change-over to renewable synfuels for all aviation and for much of the transportation market. But until it's economically advantageous to do so, it's going to be difficult to reduce transportation use of fossil fuels.
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psagar at 02:08 AM on 27 October 2015Climate sensitivity is low
Tom Curtis @366, Thank you. "The smaller the effective heat capacity, the more rapidly will the model reach equilibrium, and the closer TCR will be to ECS." I agree that the the samller the effective heat capacity, the more rapidly will the model reach equilibrium, but I do not understand how that lead to conclude "and the closer TCR will be to ECS".
I like the definition of climate sensitivity as 'change in surface temperature per unit change in radiative forcing'. But the change in surface temperature would also cause a change in radiative forcing. So, we cannot say with certainty that ECS is higher or lower than TCS.
I clearly see that the change in surface temperature and TOA radiative forcing simulated by the model depends upon the model complexity, for example, how the ocean circulations are represented. Assuming a constant external forcing, different models would show different surface temperature change and so the climate sensitivity of different models would also be different. So I still have a thinking that ECS could be higher or lower than the TCS depending upon the complexity of the model.
Talking about real world or observations, we cannot still be certain that the TCS would be lower than ECS. For example, say we measured temperature change and radiative forcing for a decade and get a transient climate sensitivity. Now lets calculate the same for 100 years (assuming that we have the data). How can we say with certainty that one would be higher than another?
Moderator Response:[JH] Please see the SkS Glossary for the comonly accepted scientific definitions of TCS and ECS.
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michael sweet at 20:19 PM on 26 October 20152015 SkS Weekly Digest #43
I teach High School in Tampa, Florida. Every year at this time I assign a writing assignment where students read the NSIDC summary of the Arctic Sea Ice melt season (located here, scroll past the Antarctic summary). I just finished reading the reports.
I received about 53 reports from my AP Chemistry students. They are 11th and 12th graders. They are the best students in the school. This year 2 students said that they were aware of the melting sea ice situation before they wrote their report, one of those students had written the same report for me two years ago. One student who had written the report two years ago said they had never heard of the sea ice melting. (about 5 students had me two years ago).
This year only one student suggested that the melting ice is not a problem. Students may slant their reports since they know I feel strongly about the subject. 6 or 7 years ago it was much more common for students to say AGW was no problem or a hoax, at least 10% of students (unfortunately never counted). For the past three years few students say AGW is a hoax and only one or two per class strongly question AGW.
Selected comments (they are required to say something they learned):
"I learned that Global Warming is, in fact, not a myth, and that there is numerical data to support that."
"Before this I didn't really think Global Warmiing existed but now, from the data, I can see that it really does exist".
"I had no idea of the problem"
"I was very shocked to find out just how much [sea ice] had been lost over the years".
"I knew [Global Warming] was a problem, but I was unaware that it was that big of a problem ...I learned that Global Warming is not a myth, but that it is a reality affecting us now, and will continue to be a problem in the future".
"I had no prior knowledge regarding Arctic Sea Ice ... this is the first evidence of [global warmng] that I have ever really seen, and it is quite shocking".
[From this report] "I learned that decreasing ice levels can have bad effects on the Earth's environment"
"Is this normal, I am a vegan and I did not know this."
[The decrease] "suprised me, I did not think it was so drastic."
"I learned the Arctic Sea ice was melting more than most people, including me, were aware of."
Students frequently call for more research to determine if this is normal and what is the cause. They say we should do something if it turns out to be caused by humans. They are concerned this might be a problem for future generations and worry about their grandchildren. Many students this year acknowledged AGW and suggested action should be taken immediately.
I have my students do another report in January about the NOAA temperature data. That should be interesting this year. Sorry for the long post.
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Tom Curtis at 12:41 PM on 26 October 2015Climate sensitivity is low
psagar @365, the IR flux from the top of the atmosphere is a function of Global Mean Surface Temperature (GMST), not of how much heat is stored at the Earth's surface. Therefore, as a forcing is an imbalance in the Top Of Atmosphere (TOA) energy flux, to restore equilibrium with a change of forcing requires a change of GMST. No amount of change in Ocean Heat Content (OHC) by itself will have any effect on that.
Of course, change in heat content is related to change in temperature by the heat capacity. Therefore, increasing the OHC will also increase GMST. That increase, however, will continue until the TOA imbalance is eliminated, which is to say, until the change in GMST causes a change in OLR sufficient to compensate for the original forcing and any consequent changes as a result of feedback. The difference the effective heat capacity of the system makes is that the larger the capacity, the more heat must be pumped into the ocean for the same rise in GMST.
So, turning to the relationship between Transient Climate Response (TCR) and Equilibrium Climate Sensitivity (ECS). Technically the TCR is the temperature after 70 years of increasing CO2 concentration by 1% per annum (ie, at the time the CO2 concentration reaches twice the initial value). The ECS is the temperature after the CO2 is doubled and the temperature stops changing (ignoring slow feedbacks). Typically that is about 200 years after the CO2 reaches 2 times its initial concentration, although it varies from model to model depending on the effective heat capacity of the Earth's surface in the model. The smaller the effective heat capacity, the more rapidly will the model reach equilibrium, and the closer TCR will be to ECS.
In the real world, the TCR is a close approximation to the immediate temperature response to a slow forcing change. Thus we can treat the TCR is the current mean decadal temperaure divided by the current forcing and multiplied by 3.7 W/m^2 (ie, the forcing for doubled CO2). However, as the TOA energy imbalance currently is about 0.8 W/m^2, we clearly are not yet at equilibrium even though we are, by the approximation above, at the TCR for the current forcing. As closing that imbalance requires increasing GMST, it follows that ECS > TCR in real life, and not just in the models. As an aside, ECS cannot be less than TCR by virtue of the definitions of the terms, and will only equal TCR if the effective heat capacity of the Earth's surface closely approximates to zero.
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psagar at 08:55 AM on 26 October 2015Climate sensitivity is low
The wikipedia article on Climate Sensitivity states that the transient climate sensitivity is lower than equilibrium climate sensitivity which I do not quite understand. By definition, climate sensitivity is the change in surface temperature per unit change in radiative forcing. As I understand, climate sensitivity can be obtained both from models and observations. Lets talk about models' climate sensitivity. In models, the ocean heat uptake is not quite well represented in transient simulations while in long term simulations (assuming that model reaches equilibrium), ocean heat uptake may be well represented. So in long term model simulations, one would expect that the surface temperature change per unit change in radiative forcing would be lower because the heat would be well mixed in the ocean as compared to transient simulations. Am I missing something? Could anyone comment on this?
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nigelj at 07:43 AM on 26 October 2015Tracking the 2C Limit - September 2015
"until we're far enough past the El Nino that they can restart the "it hasn't warmed since 2016..." schtick."
That particular sceptical argument has been used to saturation, and wont work any more.
It will be on to "CO2 is plantfood".
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NORCALGUY101 at 06:48 AM on 26 October 2015It's the sun
I find this article intresting since it pre-dates post NASA's prediction in May of 2006 that the sun was about to go into a state of lower solar sunspot activity.
Now just in July at the National Astronomy Meeting in Llandudno, Wales, Professor Valentina Zharkova presented an argument that due to the sinusodal period of the dynomo effects within two layers of the sun thgat have been quited accurately observed and predicted, will essentially cancel oneanother out by 2030 placing the sun in a lower state of inactivity than present and could very well spell another "mini ice age" Maunder Minimum event. We shall soon see.
Moderator Response:[TD] There are many things wrong with that news story about Zharkova you are relying on. Read the relevant SkS post and comment there, please.
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Rob Honeycutt at 23:50 PM on 25 October 2015Tracking the 2C Limit - September 2015
TonyW... The 1880-1909 baseline is the closest to preindustrial that I can get just using the GISS data. Part of my reasoning for posting this on SkS every month is to get people thinking about where we actually are relative to preindustrial. I hope climate researchers eventually come up with a better estimation of a preindustrial baseline that could be used across all the data sets.
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TonyW at 16:40 PM on 25 October 2015Tracking the 2C Limit - September 2015
By the way, Rob, I was confused by the term "baseline", in the article. First you talked about a pre-industrial baseline but the graph gives the baseline as the period 1880-1909. That wouldn't be pre-industrial. Is there a further adjustment to be made for true pre-industrial (which would presumably be a 30 year period centred on 1750)?
James Hansen (and others) regard 1C as the dangerous warming level. It seems we're already past the dangerous level, if the extra adjustment doesn't amend 1.062C downwards. It's getting interesting.
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TonyW at 16:34 PM on 25 October 2015Tracking the 2C Limit - September 2015
Tamino examined various datasets, including RSS, in this post. It certainly looks as though "something happened" around 2000, to send the RSS data off, relative to actual surface temperature measurements. It would be great to get some serious research into the satellite data sets to see why they diverge from that time. Maybe there is something we don't yet know about the lower troposphere (though Tamino's post also shows radiosonde data doesn't appear to go off track at 2000. My guess (worth nothing, of course) is that the calculations were thrown off in 2000, and this hasn't yet been picked up.
Longjohn, two warmest years in a row would not be unprecedented. I think it's often forgotten that 1997 was the warmest year on record, at the time. Then 1998 eclipsed it, by some margin. Looks like a similar thing is going to happen this time, though 2016 will be very interesting. -
kymhorsell at 15:20 PM on 25 October 2015Accumulated Cyclone Energy Questions and Answers
OK, I've come to this quite late.
I've just started looking at ACE values.
My background is in data science and not "real" science, so I've found a trend in global ACE over time using some simple methods. Perhaps too simple.
I was wondering what is the EXPECTED change to global ACE for a gradual change in surface temps of say 1C.
I can see via various means an estimate of a very transient change can be obtained using seasonal variations in ACE/surf temps. But that — of course — gets an expected change in ACE per deg C that is quite large.
I'm looking for a "fudge factor" more than anything else, that might account for buffering effects that might give a ballpark equilibrium change in ACE for a 1C change in surf temps.
Any ideas?
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Bob Loblaw at 07:27 AM on 25 October 2015Tracking the 2C Limit - September 2015
...until we're far enough past the El Nino that they can restart the "it hasn't warmed since 2016..." schtick.
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Rob Honeycutt at 01:44 AM on 25 October 2015Tracking the 2C Limit - September 2015
I'm expecting the "no warming since..." to turn into "it's just el nino."
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longjohn119 at 00:45 AM on 25 October 2015Tracking the 2C Limit - September 2015
As Cooper13 noted the atmospheric heat came on the downside of the '97-'98 el Nino
We are already on track to set an unprecendented global temperature record two years in a row and I submit that 2016 could very well make it 3 straight years or at least the top 3 years all in a row but not necessarily in order
That should quell the "It stopped warming in blah, blah, blah" Myth but likely it won't .... Denial is seldom overcome by facts and Reality
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Tom Curtis at 21:17 PM on 24 October 2015Other planets are warming
Bi5h0p argument turns out on examination to be an appeal to changes in cosmic ray frequencies as a driver of climate. Consequently, I have responded on a more appropriate thread. On the unsubstantive diatribe with which he begins, Phillipe Chantreau @37 raises the relevant question.
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Tom Curtis at 21:12 PM on 24 October 2015It's cosmic rays
Elsewhere Bi5h0p presents an argument that is off topic there, and on topic here. Specifically they say:
"So, if the Sun has such a major impact on the Earth's weather, how much more does our own galactic weather have on our Sun and it's solar system? It's reasonable to hypothesize that galactic weather could have a much greater effect on the solar system, as a whole, during certain galactic weather events. Our solar system is travelling through an interstellar medium, the density and energy of which may vary greatly - and for extended periods of time. This could also explain any other planetary changes which have been, or may have been observed as every object in our solar system could be impacted by such events."
In support of this, they link to a conservative "news" site that is stong on pseudoscience, and in particular to a 2012 article that claims that:
1) Two professors have discovered new particles reaching Earth from galactic center; and
2) That some unknown particle from the Sun causes variations in the rate of nuclear decay.
With regard to (1) it is hard to comment. At the time of publication of the article, the professor's work has been "submitted to the peer-reviewed American Physical Society journal Physical Review" as of 2012, but of which I can find no sign three years later. Because I cannot find a source paper, all I an say is that nothing in the report from "beforeitsnews" implies either new particles, or new energy intensities. Indeed, at most it seems to imply that the professors have better localized the source of already observed cosmic rays.
With regard to (2), the report is of actual peer reviewed papers that have not been consistently confirmed by later observations. That is, it is still possible that there is no such effect. Further, it is presently conjectured that if the effect is real, it is caused by neutrinos rather than as yet unobserved (and untheorized) mystery particles.
With regard to climate, if real, the effect only applies to beta particle decay (ie, the conversion of protons to neutrons by the emission of a neutrino and an electron, or of neutrons to protons by the emission of a neutrino and a positron). As such, it has minimal imact, if any, on geophysical heat, which is primarilly based on alpha particle decay. Further, even if it did, any such impact would be long delayed and difuse due to the time it takes for heat to rise through the mantle and crust. Finally, and most importantly, newly discovered does not mean recently started. If the ambiguous support for this phenomenon turns out to be accurate, that only means that an effect that has been in existence for the enirety of the Earth's existence will have been newly discovered. Ergo, it implies no change in heatflow, and hence no change in climate.
You will notice that neither (1) nor (2) have any bearing on "galactic weather". Nevertheless I did find websites discussing the above phenomenon which also drew attention to a NASA press release drawing attention to a newly discovered interstellar magnetic field. The magnetic field is associated with the local interstellar cloud, and when the Sun exits the local interstellar cloud, this could result in a different strength of the interstellar magnetic field, and hence a change in the number of galactic cosmic rays reaching the Earth. As the news release says:
"The fact that the Fluff is strongly magnetized means that other clouds in the galactic neighborhood could be, too. Eventually, the solar system will run into some of them, and their strong magnetic fields could compress the heliosphere even more than it is compressed now. Additional compression could allow more cosmic rays to reach the inner solar system, possibly affecting terrestrial climate and the ability of astronauts to travel safely through space. On the other hand, astronauts wouldn't have to travel so far because interstellar space would be closer than ever. These events would play out on time scales of tens to hundreds of thousands of years, which is how long it takes for the solar system to move from one cloud to the next."
(My emphasis)
Completely ignoring the highlighted statement, the pseudoscientific sites trying to sell this phenomenon as a cause of recent climate change suggest the Sun has only just recently entered the local cloud, perhaps encouraged by the illustration below.
They have paid not attention, however, to the relative distances involved. A recent mapping of the structure and velocities of the local cloud shows that the most recent time in which the Sun could have entered the local cloud (based on relative velocity and the lower bound estimate of the closest cloud surface) was ten thousand years ago. Even if we allow that cosmic rays effect climate (and it is very dubious that they have a major effect, as detailed in the OP above), this change occured 10 or more thousand years ago, and is certainly not the cause of the rise in temperature in the 20th century.
In sum, the evidence Bi5h0p relies upon is (at best) a beat up of far more mundane facts, presented breathlessly, inaccurately, and treated as certainties despite the highly qualified nature of the actual reports. This tissue of distortion, misrepresentations on uncertain basis is then presented as better than the very well established facts of climate science.
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MA Rodger at 20:22 PM on 24 October 2015Other planets are warming
5i5h0p @36.
Your link dates from 2012 and is wrtten in particularly sensational language, usually a bit of a give-away with such publication. It quotes only three scientists (It is not always the wisest thing to rely on very small numbers of scientists. Remember the phrase “There's always one” and with scientists that is certainly the case.) and your link is actually mashing four different phenomenon and three separate issues rolled into the one account.
The first is gamma-ray emissions from the centre of our galaxy. The news is that that Profs Abazajian & Kapling have “patiently sifted through reams of data accumulated from 2008 to 2012 by NASA’s orbiting Fermi Gamma-ray Space Telescope” and now (in 2012) propose that the gamma-rays streaming from the stellar conflagration can be used to infer the presence of dark matter.
On this first issue, with no change in this phenomenon there can be no change resulting on planet Earth. There is no new situation being discussed, just the measuring of something in more detail than before. It is also very new science (as written it had yet to pass peer review and I see no sign of publication today) so should not be accepted from what is just one 'paper in submission'.
The second issue is down to a lunatic called Dr. Alexey N. Dmitriev who has been preaching for some time (This reference date 1998) of a coming armagedon resulting from “highly charged material and energetic non-uniformities in anisotropic interstellar space which have broken into the interplanetary area of our Solar System.” If Dmitriev hasn't managed to convince his fellow scientists in (2015-1998=) 18 years, it likely isn't worth examining the details of his assertions and rather put it down to “There's always one!”
The third issue is very poorly described and presented most sensationally. It is referenced only by use of a NASA quote “once in a lifetime super solar storm event” that apparently dates to March 2006 (the NASA archive links to this are not providing any text at present) and is about the 11-year solar cycle which (No 24) was soon to begin in 2006. With a lot more satellite use since the height of the previous solar cycle, NASA was warning of potential problems from the coming cycle. This does not stop the nutters deciding the warning is about something completely different. Indeed, the only uses of that quote on-line actually discusses, not 11-year solar cycles but instead the rotation of our bit of the Milky Way around the centre of the galaxy. The quote is thus exclusively used by a bunch of real nutters who predict the end of the world. Whether the result will be ”thousands of rocks and asteriods … raining out of the sky” or a “rampage” of “powerful x-class solar storms and coronal mass ejections”, we are apparently in danger of “great earthquakes, super volcanic eruptions, pole shifts, planet crossers and so forth” and that is despite acknowledging that the peak storms of 2012-13 are now passed. All this has zero credibility.
So I conclude that on all three issues mentioned by your link, there is nothing that requires fresh investigations.
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PhilippeChantreau at 16:00 PM on 24 October 2015Other planets are warming
Bi5h0p,
I am straining how you can give the appearance of being rational and acknowledge your superficial understanding of a scientific subject matter while at the same throwing out an opinion that dismisses an entire body of knowledge as, also, mere opinion. A body of knowledge with which you have confessed lack of familiarity. How does that make any sense?
As far as the rest of your questions, there is a start here button on the site that you should use to start exploring.
I'll add that not everything is a matter of point of view. There is a right answer. Uninformed opinions carry no validity whatsoever against those formed by the understanding of the scientific issues involved. It really is that simple. If you want to form a opinion worth its salt, you have to do the work. If you don't, you'll just say whatever suits your already existing system of belief and values, or parrot other sources that you recognoze as sharing that same system. That's worth somewhere between a rabitt's fart and a mouse turd on the scale of reality based understanding. The internet contains the best and the worst. Why do you trust the source you cited?
I tried your link, it didn't load for me; I couldnt' evaluate whether they cited any scientific work and how faithful to the original content it was. It appears to be about galactic cosmic rays (GCRs). That's old news and there is a number of threads exploring the question on this site. Use the search engine. CERN has experimented on the subject and they do have info available online. Do your work. Don't expect people to spoon feed you the info. Select serious sources. Examine published science papers. If a blurb mentions a science article, read it, as many cite a paper and draw from it conclusions that are often nowhere near what the authors conclude or even say. That's how it works.
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Bi5h0p at 13:55 PM on 24 October 2015Other planets are warming
(This is my first post ever in this forum so please, bear with me if I break some cardinal rule. But, please point it out to me.)
First off, I'm not formally educated about any of these topics - cosmology is more of a point of interest or a hobby for me. I approach all of this in fairly broad strokes.
"Climate Warming," now re-fashioned into, "Climate Change," seems to be very little based on science and much more related to your political philosophy nowdays. It is a good excuse to raise taxes and place further controls on the entire planet, for those in power. I honestly don't really have an opinion on all of that, one way or the other, except for my own brief lifetime.
Personally, I do think that the planet is becoming more turbulent, and I don't think mankind has done anything to help the situation. There is no doubt that human industry, war, nuclear testing, pollution, deforestation, etc. have damaged our ecosystems - just a debate over the degree to which we have damaged things. I agree with what I think was the OP's original assertion that the Sun's weather is, by far, the greatest determinant of weather on the Earth. That being said, the Earth's environment, it's "goldielocks" position in the universe being just right, I don't think it takes much to knock things way out of balance - say, a .02% change in the amount of CO2 in the atmosphere. Things could be more delicate than most of us realize.
So, if the Sun has such a major impact on the Earth's weather, how much more does our own galactic weather have on our Sun and it's solar system? It's reasonable to hypothesize that galactic weather could have a much greater effect on the solar system, as a whole, during certain galactic weather events. Our solar system is travelling through an interstellar medium, the density and energy of which may vary greatly - and for extended periods of time. This could also explain any other planetary changes which have been, or may have been observed as every object in our solar system could be impacted by such events.
So, here is a link to a site which explains the phenomenon in greater detail than I ever could:
http://beforeitsnews.com/space/2012/09/strange-energy-from-galactic-center-bombarding-earth-2446172.html
I hope this adds something to the discussion - another point of view which may not have been investigated yet. -
Digby Scorgie at 13:49 PM on 24 October 2015The Brave New World of Ecomodernism
#61 KR
The essential message is that, whether it's ammonia or some other synthetic fuel, it is possible to manufacture and burn a fuel for aircraft that does not entail any carbon emissions. So why aren't we?
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Rolf Jander at 11:46 AM on 24 October 2015They changed the name from 'global warming' to 'climate change'
I like to use the phrase "global warming induced climate change" in my rebutles.
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WRyan at 09:04 AM on 24 October 2015Tracking the 2C Limit - September 2015
The satellite temperature measurements for El Ninos tend to be strongly biased toward the southern hemisphere summer months. So they spike during the first 6 months of the calendar year, which is normally the second half of an El Nino event.
I don't know why this is the case. It might have something to do with greater amounts of latent heat being released from clouds forming over the southern tropical Pacific during those months. This would occur at an altitude close to the 2-4 km range where the satellite TLT measurements are centred.
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Cooper13 at 07:09 AM on 24 October 2015Tracking the 2C Limit - September 2015
Worth pointing out the observation that we are currently in the same stage of the '97-'98 El Nino per the Fall of 1997 (if I have my dates correct). On the UAH plot, 1997 still shows rather cool overall temperatures, with the El Nino spike delayed by 6-9 months, overall.
That we are already seeing a very significant jump in temperatures already in 2015, a full year ahead of when that spike showed up in the previous 'major' El Nino event, implies that we may destroy the all-time high temperature records, again, in 2016. That is, of course, assuming that we will see the same delayed response with this El Nino (but pretty sure that delay in global temperature response is typical).
Moderator Response:[RH] Changed all caps "very" to italics, per commenting policy.
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Paul Pukite at 06:33 AM on 24 October 2015Tracking the 2C Limit - September 2015
The mechanisms behind ENSO are still not completely understood, but the closely related Quasi-Biennial Oscillation (QBO) of atmospheric winds is showing promise in being solved.
http://ContextEarth.com/2015/10/22/pukites-model-of-the-quasi-biennial-oscillation/
You may think this model is too straightforward to be believable, but you have to remember is that it is replacing the traditional QBO model of the AGW skeptic Richard Lindzen, who has also left a trail of debunked theories (the Iris Cloud hypothesis) and trail of retracted papers. That is not the scientist that you want to lend credence to.
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Dcrickett at 03:31 AM on 24 October 2015The Brave New World of Ecomodernism
#63 Eli — Thanks, again. An excellent case can be made for a future in which only one person in a nuclear family need travel away from home premises for work. (In my nuclear family, that worker has been the wife & mother, as well as yours truly, husband & father… altho this had more to do with vagaries of the economy and employment market than any idealism on our part.) More specifically, “There is no one way for all of us. Stability is in diversity.” Right on target.
One can readily picture multi-generational families in one “Dwelling Unit” and even situations in which “Dwelling Unit” needs serious redefinition.
My wife & I have lived in Latin America, where it is common practice for single young adults to live with their parents until marriage. (Engagements tend to be unconsionably long.) And the Old Testament dictum, “Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.” Genesis 2:24 suggests it might have been difficult, back when that verse was written, for a man to be up to cleaving unto his wife with his (or her) parents in oh-so-close proximity. But it is quite practicable, if the Dwelling Unit is appropriate. For a number of years, we had not only my wife’s widowed mother living with us, but also the widowed mother of her first husband (who once said, “Poor David! Only one wife but two mothers-in-law!”).
People are amazingly inventive and adaptable, especially when it comes to getting thru adversity and taking advantage of opportunity.
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ELIofVA at 00:20 AM on 24 October 2015The Brave New World of Ecomodernism
scaddenp wrote at 05:55 AM on 23 October, 2015
Eli, most household need 2 workplaces within working distance and schools as well. This is far easier with dense cities. I agree with idea of carbon tax. I think the result would be more compact cities, with multiple hubs to reduce transportation costs.I will question the need to have two working spouses for every household. Yes, in our current urban environment where we provide for almost all our needs with money and we are sold to desire so much, 2 full time working spouses has become common. However, imagine support for reducing your need for resources where our desire for stuff is tempered, such that our work for money is reduced. If we had sufficient support for public transportation, urban and rural such that we could let go of our car would be an example of reducing income needs. Also, owning simple net zero house or condominiums that are comfortable and durable is another reduction of need. With a stable population, we can build durable shelters that could be used for multiple generations. We must challenge the myth that we must continually grow the economy where all our needs are delivered by other paid people. With less demand for money, we can have more time self directing our energy into ways of reducing our need for resources. Sewing, gardening, carpentry are examples of things we can do for ourselves to reduce our need for money. We need a contracting economy. Theoretically, if we all worked half time for half the income, we would have more time to spend of activities that reduce our need for money. This may not be less work. However, it would allow a reduction of half the size of the economy and still achieve full employment. As I said earlier. There is no one way for all of us. Stability is in diversity. Some can work full time or even overtime for limited periods with extended periods of self directed work to achieve your needs directly and bonding with your family and community. This reduced need for money translates to reduced time use for commuting and the need to burn fossil fuels for transportation. We need to see this model to find a path for transitioning from our current high carbon lifestyle.
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PhilippeChantreau at 23:29 PM on 23 October 2015The Brave New World of Ecomodernism
"IMO long term aircraft will depend on synfuels simply due to the required energy density"
I tend to agree with that. Especially as the trend is toward larger aircrafts carrying more people, i.e. tighter weight constraints in the engineering and design. Furthermore, synfuels similar to kerosene/diesel are easier to obtain than those similar to gasoline.
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The Brave New World of Ecomodernism
Ammonia is just one potential synthetic fuel. Pretty much any synfuel generated from renewable energy can be carbon neutral, whether ammonia, kerosene, methanol, etc. As long as the carbon (if any) in the synfuel comes from atmospheric, plant, or (much easier from an energy/availability standpoint) ocean water sources, it's just cycling around and not adding additional carbon to the biosphere.
There is ongoing US Navy research on generating synthetic jet fuel from seawater - they estimate costs of $3 to $6 per gallon, powered by carrier nuclear plants. This would greatly extend possible time at sea, as jjet fuel represents a limiting consumable for long carrier missions.
There are multiple possibilities for cars - improved batteries, fuel cells, etc. - but IMO long term aircraft will depend on synfuels simply due to the required energy density.
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Digby Scorgie at 19:44 PM on 23 October 2015The Brave New World of Ecomodernism
Well, it's a case of using ammonia and paying a high price to keep flying or using fossil fuel and paying a low price in the short term and a far higher price in the long term!
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scaddenp at 13:28 PM on 23 October 2015The Brave New World of Ecomodernism
The Belgium bus ammonia was FF derived however. While it can be done from carbon-free power sources, you have the expensive process of splitting water for the hydrogen. Possibly a way to keep us flying but not as efficient as electric for vehicles. I believe NH3 is more efficient in a jet engine than in an IC engine but I struggled to find good numbers on that. I could only find one example of commercial ammonia plant (Vermork) using FF-free process and it ceased in 1971.
It looks it could keep you flying but at a high price.
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Digby Scorgie at 12:51 PM on 23 October 2015The Brave New World of Ecomodernism
scaddenp
I only put "analysis" in quotes because it was a link. I'm not qualified to comment on your calculations!
Regarding ammonia, you should explore further. It was used by a Belgian bus company for their buses during the Second World War when the Germans confiscated their petrol. It was tested by the US as a fuel for a helicopter and a small transport aircraft. Its protagonists reckon it can be used in jet airliners. It is not as efficient as fossil fuel; aircraft range and payload are reduced, but at least it works. The most important point is that, if you have a renewable source of electricity (hydro, solar, wind), you can manufacture ammonia without carbon emissions. What I don't know is how feasible this is on a large scale.
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Tom Curtis at 07:20 AM on 23 October 2015CO2 was higher in the late Ordovician
CO2 at eight times preindustrial levels represents a forcing with respect to the preindustrial era of 11.1 W/m^2. A 4% reduction in solar activity represents a forcing of 9.52 W/m^2. The difference of 1.58 W/m^2 represents the net positive forcing relative to the preindustrial. For comparison, we currently have a radiative forcing more than 2.3 W/m^2 relative to the preindustrial.
Here is Scotese's map of continental configurations in the Ordivician:
Contrary to the main article, it does not show a continent over the South Pole.
What is important about the continental configuration is the lack of north/south oriented shorlines, particularly in the NH. That means ocean currents would have been diverted to polar regions far less than is currently the case. As a result, polar regions would have been warmer, and tropical regions hotter, all else being equal. That greater variation in temperature, however, means all else is not equal. Specifically, the greater the variation in temperature, the greater the intensity of outgoing radiation for the same mean temperature means in turn that the Earth will be cooler for the same radiative forcing, given greater variations in surface temperature. All in all, in modern terms that means the mean Ordivician conditions were effectively on the cusp of a new glaciation.
Against that is the high sea levels throughout the Ordivician (see also here):
The 120 meter plus Ordivician sea levels indicate that, all else being equal, typical conditions in the Ordivician were almost ice free. That should be taken with a grain of salt, however, as the change may be in part due to changes in the volume of the ocean basin.
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scaddenp at 06:32 AM on 23 October 2015The Brave New World of Ecomodernism
Tom, fortunately this seems to be a trend, even in China. Not hard to find some interesting examples. Friends who lived in Helsinki for a few years commented on how well their living arrangements worked - 3-4 storey apartment blocks surrounded by garden/wood arranged around retail/school hub.
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