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Unforced Variations: Jan 2019

Filed under: — group @ 1 January 2019

This year’s first open thread on climate science topics. Usual rules apply – and let’s make a particular effort to stay substantive and not devolve into empty bickering (you still have Facebook for that).

Any expectations or predictions for climate science in 2019?

248 Responses to “Unforced Variations: Jan 2019”

  1. 1
    nigelj says:

    Kevin McKinney @168 (last months UV) thanks for that, very interesting indeed. I like the historical perspective. The following article has some nice graphics and analogies related to some of your points. But I wish someone like BPL would confirm if I’m on the right track in my question near the end of the previous UV thread.

  2. 2
    mike says:

    ok, carryover from Dec thread:

    Nigel: at 113 you said: “I also asked the question of anyone who knows how much would we have to decrease emissions for it to register above the noise in atmospheric levels, and what would the time delay be?”

    So, Al appears to confirm my sense that a reduction in emissions is reflected in MLO numbers in less than one month.

    It takes 2-3 years for emissions to become thoroughly mixed in the atmosphere, but a thoroughly mixed number is not what is measured at MLO. Can we consider the question of time frame between emissions and MLO data points to be settled?

    As to the question of how big a reduction is needed to rise above the noise level in the MLO numbers, that is a complicated question. If you think it has happened, post the month/year that you think you see the reduction peak out from behind the noise level and we can have a discussion about that.

    I am not a pessimist generally, I am wildly grateful for being alive and conscious. I am quite optimistic about the planet’s ability to support life and to restore life after a great extinction event.

    I think there is a story about harry truman that goes like this: Harry was walking to the stage when a man yelled at him: Give’m Hell, Harry! and Harry stopped and responded: You know, I never did give them Hell, I just told them the truth and they thought it was Hell. Perspectives, huh?

    MAR came up with his idea that the background increase rate might be 2.1 ppm after smoothing out ENSO type noise. I think the background rate is 2.4 ppm using a much less rigorous set of mathematical operations. Either way, 2.1 or 2.4 ppm annual increase is an increase and we need to be driving the number down soon, like yesterday. So, we need an annual increase number of zero, then we need to start driving a slow removal of CO2 from the atmosphere to restore a more stable and accommodating climate. Let’s do that. We can do that, right?

    Let’s do it soon! Optimistic start to the New Year for me!



  3. 3
    Russell says:

    Before the year is out, CFACT, Breitbart, and The Daily Telegraph will feature Who Needs Climate Policy ? articles pointing to the lack of global warming on Ultima Thule

  4. 4
    nigelj says:

    Mike @2, please refer to my previous comment at number 165 on last months UV. You should be able to see my methodology (crude that its is). The end result is the average yearly growth of atmospheric levels for the last 5 years appeared to be slightly down on the previous 10 years and this sure seems to corrlelate well with the flat period in emissions after 2014.

    Sorry I didn’t keep the numbers, and I’m not going to work it all out again right now, but you could perhaps work through it if interested, its just arithmetic. Like I said MAR seems to have reached the same conclusion using a far more robust method, so its resolved enough for me.

    It’s all fairly nit picky stuff anyway, that merely suggests the drop in emissions after 2010 and particularly 2014 looks like it might be showing up in the mlo data. You would only expect a slight difference anyway. For me the main point is it suggests the emissions data is at least not totally unreliable.

    I think you have hit the nail in the head in your final paragraph. This is the main issue. I feel the same way!

  5. 5

    nigel, I’m sorry, I lost track. What was the question?

  6. 6
    MA Rodger says:

    UAH have posted its December TLT anomaly at +0.23ºC, a small drop from November’s +0.25ºC. The UAH anomalies for 2018 sit in the range +0.32C to +0.18ºC.
    It is the =6th warmest December in UAH TLT behind previous Decembers 1st 2015 (+0.47ºC), 2nd 2017 (+0.42ºC), 3rd 2003 (+0.38ºC), 4th 1987 (+0.37ºC) & 5th 2016 (+0.27ºC) and equalling 1997 & 1998.
    December 2018 is the =68th warmest monthly anomaly on the full all-month RSS TLT record.
    With the year complete, the UAH TLT average 2018 anomaly comes in at +0.23ºC, making it as expected the 6th warmest year in the UAH record after warmest year 2016 (+0.52ºC), 2nd 1998 (+0.48ºC), 3rd 2017 (+0.38ºC), 4th 2010 (+0.34ºC) & 5th 2015 (+0.27ºC). (RSS is almost certainly also placing 2018 in 6th). The surface records will show 2018 as 4th as the El Nino years (1998 & 2010) are boosted less than in TLT data.

    In another ranking, 2018 comes in as the second least icy year up in the Arctic Ocean. The JAXA SIE for the calendar year averaged 9.91M sq km, above the record annual average set in 2016 of 9.84M sq km and below 2017 (10.00M), 2012 (10.01M), 2011 (10.06M), 2007 (10.09M), 2015 (10.11M). A graph of JAXA SIE anomaly (usually 2 clicks to ‘download your attachment’) does seem to show periods of big variation in recent years which suggests there may be some surprises in store with the Arctic sea ice waiting to show themselves. It is perhaps worth a look to see how exceptional the big wobbles shown in the anomaly actually are.

  7. 7

    #3, Russell–Actually, if I had to guess, I’d opine that the usual suspects are more likely to claim the opposite–that Ultima Thule *is* in fact warming, and that since there are no SUVs there–not even New Horizons, anymore–therefore:


    After all, didn’t New Horizons monitor a steady increase in radiance brightness?

  8. 8
    nigelj says:

    BPL @5, my question as below. I know you are probably super busy, so even just a simple indication if I’m on the right track of not would be helpful. You or any expert.

    “I would love some expert feedback on this. I want to get an understanding of how we get from the energy absorption spectra of the CO2 molecule to predicting increases in global temperature, and I don’t know enough advanced maths / physics or have the time to plough through research papers. But accounts I have read for laypersons are too general and simplistic.

    My understanding is it works as follows: I know you cannot simply go from the energy absorbing properties of CO2 to global warming by some simple equation. I understand experiments have been done with CO2 in a canister at high concentrations with a light source applied, and warming measured, but I believe the couple of parts per million of CO2 we have in the atmosphere is too small to register in a tube and on measuring devices like this, and a tube does not capture the physical properties of the atmosphere.

    So we have to approach the issue differently like this. My understanding is the Stefan Boltzman laws allow us to know how much the planet would heat without any atmosphere, and we know how much the earth heats with an atmosphere, so this forms the basis to work out how much heating additional CO2 will cause. Knowing the spectral differences between CO2 and water vapour etc allows you to calculate the more precise effect of CO2 alone, and Arrhenius calculated this. Other feedbacks are also integrated into the calculations.

    Is this ball park right or wrong or what? People are busy, so even a simple answer would be great.

  9. 9
    mike says:

    I wonder if it would help to compare our CO2 accumulation problem with that of an overweight human being who keeps gaining weight?

    In that scenario, we could look at our weight on January 1, 2018, like 407 pounds and say, wow, we really need to get back to our weight of 350 pounds. At 350 pounds, we could hope to be an NFL line person. At 409, we are too slow to get any playing time. Some days, we even have trouble getting up and out of our bed or chair.

    Then January 1, 2019 rolls around and we step on the scale. Uh oh, we gained 2.1 pounds and now weigh 409 pounds. Well, it could have been worse, right? We were afraid we might gain more than 3 pounds in 2019, but then we went on a diet and cut our weight gain to only 2.1 pounds last year. Ok, 409, now, need to get back to 350 pounds. Gained a little weight last year, but we know what we have to do. It was a pretty good year. We made some progress. Our rate of gain didn’t balloon up to over 3 pounds again. That’s good news.

    It’s worrisome weighing 409 pounds, though. We have never weighed that much before. One problem that arises with even a small weight gain when we weigh 409 pounds is that we can’t be sure when our knees will break down under the weight and our exercise routine to lose weight gets harder and less productive when our knees fail. And we are starting to experience some pretty painful episodes with the knees already. Plus our back has been hurting. But maybe if we can toe the line in 2019 and gain no more 2 additional pounds, we will be alright.

    All discussion about the rate of increase is somewhat problematic because we really need to start losing weight. We don’t want to become discouraged and pessimistic, but at 409 pounds, the idea of gaining two pounds or 1 1/2 pounds this year could be catastrophic.

    No, let’s not go there. Let’s celebrate that we are not gaining 3 pounds, we need to keep our spirits up to do the hard work of weight loss. We are at 409.45 today, that’s not too awful. Could be worse. Keep up the good work.



  10. 10
    Pieter Zijlstra says:

    mixing of CO2 can be deducted from the Pumphandle 2017 animation on Youtube.
    Differences between NH and SH are cleary visible.
    The steps on Anarctica are showing the effective mixing within one year.

  11. 11
    Victor says:

    re nigelj #8: A handy “Tutorial on the Basic Physics of Climate Change” can be found online here:

    If you read through it carefully, you’ll see how very simple the whole matter really is.

    My favorite bit:

    “There are also feedbacks, but IPCC has observed that feedbacks are more positive than negative, meaning they will further increase warming. It is our belief that ‘theory leads experiment’ on climate change because all well-accepted atmospheric models predict a temperature rise.”

  12. 12
    nigelj says:

    Victor @12, well thank’s and I had a read, but I specifically said I didn’t have the knowledge to sift through a tutorial full of equations, half of which I don’t recognise. I asked a simple question of any expert here, is my understanding as I outlined broadly right or wrong? And in what way if you have the time?

    “It is our belief that ‘theory leads experiment’ on climate change because all well-accepted atmospheric models predict a temperature rise.”

    You obviously think you have made a discovery of something nefarious, but you have fired a blank again. This is because you cannot put the entire planet inside a labortatory and do an experiment. Had you not thought about that before jumping to conclusions? Anyway its why we are reliant on modelling. Think about it!

  13. 13
    MA Rodger says:

    Pieter Zijlstra @10,
    You say “The steps on Anarctica are showing the effective mixing within one year.” I think you need more consideration than identifying the existence of SH “steps.”

    Even with the size of the NH annual CO2 cycle varying massively with latitude, I would argue that the NH mixes rapidly, in a matter of weeks. The SH likely also mixes in a matter of weeks. I would suggest it is the mixing between the NH & SH which provides the substantial delay in global mixing.
    The NH annual cycle (here MLO) waggles 7ppm peak-to-peak with the maximum peak in May and the minimum in Sept/Oct. The NH average is perhaps 3ppm+ above the SH average (here South Pole). Thus we could perhaps expect the NH CO2 transport across the equator to hit a maximum in May and shrink to zero in Sept/Oct.
    The growing season in the SH is presumably 6 months out-of-sync from the NH. So if the high-latitude lands in the SH were able to create an annual CO2 cycle, it would peak in October and drop into May.
    The SH annual CO2 cycle waggles (South Pole) 1ppm peak-to-peak. The SH maximum (relative to a rolling 12-month average) is in July and the minimum February, which doesn’t look like it is driven by the SH growing season.
    The “rise” in the “step” of the SH CO2 cycle is greatest in May and the “tread” of the “step” runs from October to February. This suggests the SH cycle is indeed driven by the NH CO2 cycle, perhaps with a little bit of growing season extending the “step” through to February.
    Yet, the rise in NH CO2 due to human emissions is giving the NH an average of 3ppm+ more CO2 than the SH. And that 3ppm+ represents a one-&-a-half year lag during the NH rise in CO2 and so not “effective mixing within one year.”

  14. 14
    Killian says:

    Re #2 mike said Nigel: at 113 you said: “I also asked the question of anyone who knows how much would we have to decrease emissions for it to register above the noise in atmospheric levels, and what would the time delay be?”

    So, Al appears to confirm my sense that a reduction in emissions is reflected in MLO numbers in less than one month.

    It takes 2-3 years for emissions to become thoroughly mixed in the atmosphere, but a thoroughly mixed number is not what is measured at MLO.

    I’m going to disagree here. Hawaii is in the MIDDLE OF THE PACIFIC. If anything is well-mixed, or as close as we can get, isn’t it ML, HI?

  15. 15

    nigel 8,

    The warming effect follows from the fact that CO2 absorbs IR but lets visible light–like sunlight–(mostly) pass. Thus the surface gets warmed, but since it’s only at 200-300 K and not 6000 K like the sun, radiates in IR rather than visible light. The CO2 absorbs the IR and it also radiates, some of the radiation going back down to the surface. Thus the ground has both sunshine and “airshine”–atmospheric back-radiation–raising its temperature.

  16. 16
    nigelj says:

    BPL @8 thanks yoda kemu sabe, but I know that. I was wondering more about how its quantified, so if my understanding as outlined above @8 was ball park right or wrong.

  17. 17
    mike says:

    To Killian per 16:

    This question of CO2 mixing in atmosphere is a sideshow to me that only arises because Nigel appeared to be working to see decreased emissions in the MLO data, so I don’t know a huge amount about the mixing, but the placement of MLO in the middle of the pacific at about 14,000 feet is not a guarantee that MLO is measuring well-mixed concentrations. MLO just measures what MLO reads at specific geo-location.

    MAR has provided a lot of technical info about the mixing that sounds right to me. You can review MAR’s stuff here at 14 and at last month’s UV at 159. You can also watch CO2 mixing in a video like this one and see that Hawaii is regularly on receiving end of CO2 plume from SO CA. You will also see that CO2 arises primarily in the Northern Hemsisphere and mixes to Southern Hemisphere somewhat slowly.

    you asked: “Hawaii is in the MIDDLE OF THE PACIFIC. If anything is well-mixed, or as close as we can get, isn’t it ML, HI?” I think the answer is sometimes it is, but MLO’s function is to pull data at a certain geolocation. Deriving the “well-mixed number” is something that would be done through different processes, like the ones that MAR is doing and presenting, I think.

    Is that helpful to you?

    How are we doing on CO2? So far, the elevator only goes up.

    Weekly averages, noisy numbers:

    December 23 – 29, 2018 409.13 ppm
    December 23 – 29, 2017 407.22 ppm 1.88 ppm one year increase (very noisy number)
    December 23 – 29, 2008 385.98 ppm 23.15 ppm increase in ten years, yielding annualized average of 2.31 ppm increase for that decade, (less noisy number

    Could be worse. I think we should celebrate for a moment, then get back to the serious work of driving the atmospheric accumulation of CO2e down and keep our eyes on the prize. The prize is an actual drop in the accumulation number. Slowing increase is good, but the prize is an actual drop in the accumulation number.



  18. 18
    nigelj says:

    The following article has some strikingly good photos and videos of housing being damaged by a combination of storms and sea level rise: “One summer left: On Haumoana’s beachfront, the climate-change hourglass is ticking”

    Sea level rise in New Zealand: “Historically, the gradual rise in sea level has accumulated to be around 20 cm over the 20th century through to present. This can be enough, in combination with a severe storm-tide event, to cause seawater inundation of low-lying coastal margins, as occurred in parts of Auckland in 2011 and 2014. Further rises in sea level will further exacerbate such situations with more frequent coastal inundation and erosion of vulnerable coastal areas (Parliamentary Commissioner for the Environment 2015 report).”

  19. 19
    nigelj says:

    NASA animated visualisation of plumes of CO2 over a one year period. This seems to suggest it’s the northern and southern hemisphere that are slowest to mix given circulation patterns.

    Hawaii is near the middle of the pacific. Its going to get emissions from the northern hemisphere quite quickly and that is where much of the industry is, and it would get emissions from the southern pacific sooner than many areas further to the north.

  20. 20
    sidd says:

    Re: the mixing between the NH & SH which provides the substantial delay in global mixing.

    I think this in right. But I am noot certain. The models have difficulty with a double ITCZ too, but i dont know if models get the mixing time right either.

    Any modellers care to comment ?


  21. 21
    mike says:

    Please take the capitalism discussion to the Force Variations thread. UV is about climate science.

    [Response: Yes. Comments have been moved. – gavin]

  22. 22
    Omega Centauri says:

    I think the problem is that the only “correct” way to understand it, is to model it mathematically.
    Now is astrophysics for stellar interiors they had a thing called Rosalind(sp?) opacity, which was a way to average frequency dependent absorption. But that only works for optically thick regions, and our atmosphere even in thermal IR doesn’t fit that. But in any case the total radiative flux is the temperature gradient divided by the suitable averaged opacity time the derivative of the Stefan Boltzmann law with temperature. Greater opacity means less thermal flux is carried by radiation.
    But our planet’s atmosphere is messier. A lot of the vertical thermal flux is carried by convection. Except near the peaks of the absorption lines the atmosphere isn’t optically thick in the IR either. So even if we never had any clouds its messy, because the height of the tropopause will vary depending upon the surface temperature, which is affected by the very CO2 we are dealing with. Then of course water vapor is an important greenhouse gas, and it depends upon temperature, and is mixed by convection and removed by precipitation. So one ends up needing a fairly detailed model to have any hope of capturing all these effects. Then we add cloudiness…..

  23. 23
    Mr. Know It All says:

    2 – mike
    “I am quite optimistic….”

    Here’s another reason to be optimistic – it’s freezing azz cold up north:

    I’m not sure how those numbers compare to long-term avearages, but they must be adding some ice up there and that’s a good thing.

    And Barrow has some cool weather finally:

    11 – nigelj
    Do you think “equality” is normal or desirable? If so, why? What would it look like? We all have different talents, work ethics, motivations, opportunities, etc. I guess the old USSR had equality to some degree for the peasants; they were mostly broke-ass po, right? Is that a good thing? I don’t think so – they had to build walls to keep them from escaping. The US started out socialist but it quickly failed – story starts from 9:30 to 17:20 here:

    22 – nigelj
    “Sea level rise in New Zealand: “Historically, the gradual rise in sea level has accumulated to be around 20 cm over the 20th century through to present. This can be enough……”

    I have a hard time finding sympathy for anyone dumb enough to build such that an 8″ change in the ocean level makes a difference. ;)

  24. 24
    David B. Benson says:

    nigelj — Not certain what you are looking for but the standard simple formula for the carbon dioxide concentration forcing effect is

    dt = k*log(c/b)

    where dt is the increase in temperature compared to when the carbon dioxide concentration was b and the current concentration is c. The constant k includes the so-called climate sensitivity factor, often taken as 3 °C for a doubling of the carbon dioxide concentration. Then the logarithm is taken base 2.

    Probably Skeptical Science has a page explaining more thoroughly.

  25. 25

    nigel 18,

    Well, unless you have some kind of semigray approximation, you can only work it out with a climate model, e.g. a radiative-convective column model. There isn’t an easy quantitative answer that you can get from an equation. It’s like an equation that can’t be solved analytically but has to be integrated numerically.

  26. 26

    KIA 27 is still posting classic denier memes: Here’s another reason to be optimistic – it’s freezing azz cold up north:

    BPL: Yes, folks, he still doesn’t get the difference between weather and climate. Or he gets it damn well but wants to troll us.

    KIA: I have a hard time finding sympathy for anyone dumb enough to build such that an 8″ change in the ocean level makes a difference. ;)

    BPL: I have a hard time finding sympathy for anyone evil enough to pretend that this doesn’t make a difference when the 8″ rise comes in the form of storm surges distributed unequally around the world, or that an 8″ vertical rise doesn’t correspond to several meters inland.

  27. 27

    #27, KIA-

    Just to clarify: no, those aren’t really reasons for climate (or sea ice) optimism. First, Arctic sea ice extent is once again at near-record low levels for the time of year, having just edged a bit above the record lows for the date clocked in 2016:

    And, no, those temperatures forecast aren’t particularly cold for Resolute in January–the normal mean temp is -26 F, and most of the forecasted time you linked is/was above that.

    Barrow, on the other hand, actually is a bit on the cool side, compared with its monthly mean of -13 F:

    In the big picture, the Arctic as a whole is currently quite warm, at 3.3 C above climatology, though there are a couple of transient cold blobs, one in the eastern Canadian Arctic (including, I think, Iqaluit, as well as much of coastal Quebec and Labrador) and in eastern Siberia.

    Not a whole lot of cool areas globally, as things go, though much of central Europe is a bit on the cool side, and there’s one really big cool streak in central Asia. For the world as a whole, the mean’s currently a pretty humdrum 0.7 C above climatology.

    But weather isn’t climate. (I may possibly have said that before.)

    Weather over time is climate.

  28. 28
    nigelj says:

    MR KIA @23, I will respond on FR thread. Plus once again you didn’t actually read what I said.

  29. 29
    nigelj says:

    Thanks for the helpful feedback on the warming issue people.

  30. 30
    Adam Lea says:

    23: “I have a hard time finding sympathy for anyone dumb enough to build such that an 8″ change in the ocean level makes a difference. ;)”

    Firstly, sea level rise is not uniform. Eight inches might be the global average, but some areas could be significantly higher than that.

    Secondly, it certainly makes a difference for those living along coastlines vulnerable to tropical cyclone storm surges. An eight inch or more rise in sea level means it won’t take as powerful a hurricane/typhoon/cyclone to cause catastrophic flooding, even without accounting for the possibility that warming sea surface temperatures will boost the peak intensity of intense tropical cyclones. It is often not a case of being dumb. In many developing countries, in order to support your family you have to make a living from the sea, and are forced to live in these high hazard zones vulnerable to storm surges from tropical cyclones. Those of us living in the priviliged affluent West have no idea what it is like to have to live like that.

  31. 31
    nigelj says:

    For Mr KIA, who loves to quote any cold weather event: “Extreme cold wave over East Asia in January 2016: A possible response to the larger internal atmospheric variability induced by Arctic warming”

  32. 32
    Hank Roberts says:

    another reason to be optimistic – it’s freezing azz cold up north

    Clueless, and determined to remain so.

  33. 33
    Killian says:

    Mauna Loa CO2 at 410ppm for Jan 3rd. The concentration typically rises between 4 and 5ppm from early Jan to the peak in May.


  34. 34
    Omega Centauri says:

    Know it all @23.
    For one who is accustomed to a sea shore with large waves, it looks nontrivial to even be able to tell what sea level is to 8inch accuracy. But what about those on a protected bay, or lagoon, where waves aren’t very high. Then every inch may mean many meters of change in the position of the shoreline. And sea have been rising for a very long time, so old infrastructure that was comfortable above sea level when it was built no longer is, think of a place like Venice, or even New Orleans. Lots of valuable stuff that dates back hundreds of years that is increasingly at risk. Then realize that rivers that flow into the sea may go tens of miles before they reach an elevation of a meter. Stockton California is nearly a hundred miles inland from San Francisco, yet is barely above sea level. And rising sea levels can move the place where salt water intrudes upon fresh river water by many tens of miles, potentially overwhelming fresh water intakes. Also a sea wall that is designed to fend off say a five meter storm surge, will handle a 4.95 meter surge without difficulty, but a 5.02 meter surge would be catastrophic. Little changes can make the difference between a close call and disaster.

  35. 35

    Reflecting once again on this:

    “I have a hard time finding sympathy for anyone dumb enough to build such that an 8″ change in the ocean level makes a difference. ;)”

    There have been many quite sensible comments on why this is, shall we say, a bit simplistic. Particularly notable (IMO, natch) is Omega’s #34, which gets to the issue that’s striking me this morning, which is the underlying assumption that nothing matters but individual property.

    It’s an understandable one, in a way, in that it is a fairly prevalent framing, and particularly among folks strongly influenced by classical and neoclassical economic thought. As Herman Daly (among others) has shown, that thought often provides quite an unrealistic picture of the world, courtesy of what he terms the “fallacy of misplaced concreteness”. (In essence, that’s the multistep intellectual faux pas of treating one’s abstractions as if they were concrete realities.) But the individualistic framing breaks down, or at least becomes unrealistically cumbersome, when dealing with widespread environmental issues. The harms are just too ubiquitous, and just too diffuse.

    Who owns San Marco in Venice, for example? The Catholic Church, I suppose, so if San Marco is destroyed eventually, the Church could sue–somebody. Fossil fuel companies who knew that their product would eventually prove dangerous, and hid that knowledge from the public? Well, attempts are underway, but at least one prominent one has failed to clear a significant hurdle.

    But even say the Church wins a settlement from Exxon. What about all the peripheral businesses? The food vendors, the mom-and-pop bed-and-breakfasts, the vendors of souvenirs? And what about the city of Venice itself? As their infrastructure crumbles into the rising waters, so does their revenue base. In the limit, the city must be partially abandoned and we have another migration issue on our hands.

    (It’s worth mentioning in this connection that Venice has been in the process of building hard flood defenses on an heroic scale since a prototyping phase in 1988, at a (2015) projected cost of 5.5 billion Euro with expected completion in 2022. Needless to say, Exxon isn’t paying.)

    Or take those estuaries and freshwater intakes become saline. Again, who can collect? Farmers driven out of business, perhaps? Tourism-driven small businesses? Yet clearly the harms don’t stop there. (Least of all the ecological one, which are notoriously difficult to translate into economic one in the first place–presumably why some are reluctant to believe in their reality.) And again, who will pay?

    I know, I know–it’s all the tragedy of the commons. Again.

    I’m also struck by the temporal assumptions wrapped up in KIA’s gibe. (He did provide a ‘smile’ emoji, remember.) As I’ve mentioned a few times, I live in South Carolina, so when I think about SLR, I have to think about Charleston. It’s been there since 1670, and the historic area near the Battery is a national treasure. Should we blame the folks who built it for failing to foresee that fossil fuel consumption would put their work at risk for flooding? (A risk increasingly being realized, by the way–and like Venice, Charleston is spending some real coin on flood defenses.)

    So, given that the historic district is highly valuable (for now), and that nobody’s been building there (much) in recent decades–who are we supposed to feel sorry for, if anyone? Especially given that the destruction of that district would affect the entire region?

    (All of which said, we thought very seriously about flooding when we considered our present address. Sadly, this year’s flooding suggests that we should have thought about it in relation to our dock, not just our house. ;-) )

  36. 36
    mike says:

    I read this:

    “the IPCC Special Report on Global Warming of 1.5C – calculates that a 1.5C warming trajectory would require the global economy to cut greenhouse gas emissions by around 45 per cent between 2010 and 2030, before then delivering a net zero emissions economy by 2050.

    Even meeting the Paris Agreement’s upper target of limiting temperature increases to 2C above pre-industrial levels would require emissions to fall around 20 per cent by 2030, before achieving net zero emission status by around 2075.”

    and wondered, has anyone charted/modeled what the annual or monthly co2ppm numbers should look like to achieve either of these paths? I realize there are a lot of variables that impact how/when CO2 emissions fall during the two time frames, but it seems like the kind of task that modeling and mathematics can address.

    When folks post up graphs that track emissions/accumulations, it might be helpful to always have the anticipated numbers that lead to the 1.5 and 2.0 degree outcome that are discussed in policy. It might be more informative than just saying over and over that we are failing to make the changes that limit warming to 1.5 or 2.0 degrees.



  37. 37
    Hank Roberts says:

    Surface air temperatures in the Arctic continued to warm at twice the rate relative to the rest of the globe. Arctic air temperatures for the past five years (2014-18) have exceeded all previous records since 1900.

    In 2018 Arctic sea ice remained younger, thinner, and covered less area than in the past. The 12 lowest extents in the satellite record have occurred in the last 12 years.

    Sea ice over 4 years old, now makes up only 1 % of Arctic ice! This sets the stage for the remaining ice to disappear suddenly in the next few decades.

    Clues are available, for those in need.

  38. 38
    nigelj says:

    This is a must read: “A Terrifying Sea-Level Prediction Now Looks Far Less Likely. But experts warn that our overall picture of sea-level rise looks far scarier today than it did even five years ago.”

    “Two years ago, the glaciologists Robert DeConto and David Pollard rocked their field with a paper arguing that several massive glaciers in Antarctica were much more unstable than previously thought. Those key glaciers—which include Thwaites Glacier and Pine Island Glacier, both in the frigid continent’s west—could increase global sea levels by more than three feet by 2100, the paper warned. Such a rise could destroy the homes of more than 150 million people worldwide.

    They are now revisiting those results. In new work, conducted with three other prominent glaciologists, DeConto and Pollard have lowered some of their worst-case projections for the 21st century. Antarctica may only contribute about a foot of sea-level rise by 2100, they now say. This finding, reached after the team improved their own ice model, is much closer to projections made by other glaciologists.


    Yet their work—and the work of other sea-level-rise scientists—still warns of potential catastrophe for our children and grandchildren… In their new research, DeConto and his colleagues say that there’s a tipping point, somewhere between 2 and 3 degrees Celsius of temperature rise, after which the West Antarctic Ice Sheet will slip into rapid and shattering collapse.

    Their short-term revisions also barely change their long-term forecast of West Antarctic disintegration. If emissions keep rising, they warn that global sea level could rise by more than 26 feet by 2300.”

    To me that is still very bad news and not so far into our future. However I will stick with my own prediction of the worst case scenario of sea level rise. Meltwater pulse 1a 14,000 years ago was associated with 2 metres of sea level rise per century, spread over about 5 centuries, and attributed to the Antarctic destabilising. This actually happened and doesn’t require modelling so we should pay particular attention to it.

  39. 39
    Mal Adapted says:

    Fascinating stuff: Tropical uplift may set Earth’s thermostat, in the current Science. In the past half-billion years, glaciations are correlated with episodes of mountain-building due to continental collision in the wet tropics.

  40. 40
    steve says:

    There seems to be someway to go before this is validated by the ‘community’, but for me there is enough to be ‘scary’. Though not in my lifetime.

    Has any research been undertaken in regard to the timescale for sea level rise to spread across the oceans? ie where will be hit first and how hard?

    Additional water will be deposited in just a few known specific places. Will there be some kind of ‘slow-motion’ tsunami effect? How quickly and by what routes will the water be swept around the oceans? Will there be a surge in nearby places before it eventually begins to settle to a new equilibrium?

  41. 41
    Omega Centauri says:

    Steve @40.
    The timescale for geographic sea level redistribution is only a day or two. Essentially the time for a tsunami to reach the other side of the world (it still reaches that far even if the amplitude is too small to detect).

    Now we have another effect that not too many are aware of, land ice attracts seawater because of gravity, and that is important in redistributing where the water goes if it melts. Within roughly 2000KM of where the ice was removed, the sea level will actually drop. The max rise will be at the antipode (the other side of the world). So for instance if we melt the Greenland Ice sheet, it won’t flood eastern Canada but will be worse in the southern hemisphere than the northern.

  42. 42
  43. 43
    jgnfld says:

    “I have a hard time finding sympathy for anyone dumb enough to build such that an 8″ change in the ocean level makes a difference.”

    A kia argument from personal incredulity!!! I’m incredulous!

  44. 44
    Lara Rios says:

    I thought about SLR, I had to think about Charleston. It’s have been there since 1670, and the historic area near the Battery is a national treasure.

  45. 45
    Mr. Know It All says:

    1 – Dennis
    “No wonder man resorts to war. You can’t change minds once they’re made up.”

    As Patriot Nurse says on Youtube, it’s hard to come to agreement when the 2 sides can’t even agree on the basics such as the fact that a man and a woman are not the same. Speaking of war, I think both sides can relate to this but in different ways:

    This story reminds me of the Mueller investigation where all the investigators are virulently anti-Trump, had a legal obligation to recuse themselves but did not; except for PERHAPS his one supporter Jeff Sessions who DID recuse himself! You can’t make this stuff up!

    [Response: It should go w/o saying that neither discussions of gender nor Mueller are climate science related. No more on this, thanks. – gavin]

  46. 46
    MA Rodger says:

    It was refreshing to hear an AGW item on the BBC Radio 4 Today programme this morning (although aired at 6:45am, so buried as deep as it could be in the programme). It contained an interesting analogy of climate change denial which I thought to share.
    Veteran foreign correspondent John Simpson reported that in his travels AGW had become obvious across the world. (He was reporting from Thailand, recently struck by the unseasonal Tropical Storm Pabuk.) He continued with the analogy, pointing to the crazy BBC policy of not-long-ago allowing swivel-eyed contrarians into any AGW coverage, the equivalent of allowing folk (presumably Reading FC fans) to dispute the Manchester United 2:0 win yesterday. “The referee has ruled,” Simpson said. And of course, Reading FC are out of the FA Cup.
    But while the BBC no-longer has a policy allowing such air-time to the Gentlemen Who Prefer Fantasy, we do now have Bolsonaro and wee Donald who, Simpson points out, would rather believe in a fantasy Chinese conspiracy that accept the truth.

  47. 47
    MA Rodger says:

    Have Adams & Dessler (2018) (there is a full pre-print version available here) gone and shot Nick Lewis’s fox? Mind, Gebbie & Hybers (2019) may have also put the mangy old thing out if its misery – “The implied heat loss in the deep ocean since 1750 CE offsets one-fourth of the global heat gain in the upper ocean.”

  48. 48

    KIA: it’s hard to come to agreement when the 2 sides can’t even agree on the basics such as the fact that a man and a woman are not the same.

    BPL: This is something the climate deniers are bringing up again and again lately. Some people disagree about the number of “genders,” so all the righties are saying, “See? You accuse us of not agreeing about basic facts, but the libtards(TM) don’t even agree that men are men and women are women!” Men, of course, being defined as those who know automotive mechanics and buy season tickets, while women cook and care for the children.

    KIA: This story reminds me of the Mueller investigation where all the investigators are virulently anti-Trump, had a legal obligation to recuse themselves but did not; except for PERHAPS his one supporter Jeff Sessions who DID recuse himself! You can’t make this stuff up!

    BPL: And another right-wing irrelevancy, including the dead lie that “all the investigators are virulently anti-Trump,” overlooking the fact that most of them are, in fact, Republicans (like Mr. Mueller). The Gish Gallop is a basic denier tactic. You can’t make this stuff up!

  49. 49
    Chris says:

    Selected talks from the 50th Anniversary Meeting of the Club of Rome (October 2018).

    Robert Constanza, Wellbeing Economy needs to be Primary Goal

    Johan Rockström: Potential irreversible Planet thresholds for a disastrous Future

    Actual Expert tells audience, We won’t have an Ice Age again!

    Ugo Bardi: Societal Collapse, the Seneca Effect

  50. 50
    Ray Ladbury says:

    Mr. KIA,
    I’ll go you one better: no man is the same as any other man. People are individuals first, classes second. Who am I to question their experience of themselves?

    Climate, on the other hand, is not a complex social construct (see what I did there? ;-) ). There are mountains of self-consistent data that all point toward the scientific consensus–which of course is why it is the consensus.

    Social issues…not so much.