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Unforced Variations: Feb 2013

Filed under: — group @ 4 February 2013

This month’s open thread on climate science…

421 Responses to “Unforced Variations: Feb 2013”

  1. 1
    Vineet says:

    I had a question regarding this. Got redirected from Neven’s blog.

    Can anyone confirm this and whether this is serious ? I am a regular visitor here but a noob.


    [Response: It’s interesting, but the near one-to-one correspondence between methane and the ice outline and coasts sends a bit of warning message related to the satellite retrieval. I think these images come from spectral analysis of the reflected Near-IR, and that means the strength of the signal will be different over ice and water and land. Additionally, if this was related to warm water and methane hydrates, you wouldn’t see it in January, you’d see it in August. It is plausible that this is an impact of gas/oil extraction and transport (which increases in winter), but this would need some checking. – gavin]

  2. 2
    grypo says:

    In a response to Gavin at DotEarth, Andy Revkin says “In policy circles, including popular calculations of emissions trajectories necessary to avoid a high chance of exceeding 2 degrees C. of warming, the hot tail has not been trimmed (unless I’m missing something?).”

    Is it true that the “fat tail” exists on all projections to stop 2C warming?

    [Response: No. Meinshausen et al (2009) and Allen et al (2009) are two key papers here, and they used a ‘likely’ range of 2-4.5 C, and 5-95% range of 2 to 4.8 C respectively. Since the % of scenarios that go above 2 deg warming are linear in CS, equal reductions in the tails (ie making 2-4.5 a more and more strict criterion) doesn’t impact the likelihood of exceeding the limit. – gavin]

  3. 3
    Toby says:

    Any comments on the sensitivity discussions from James Annan’s and William Connolley’s blogs?

    [Response: The ‘state of the science’ on climate sensitivity was discussed here recently – and there are a few things to add related to specific claims being bandied about (soon). But as for the notion that there is some huge movement away from an imagined consensus on the ‘high tail’ let alone a movement to a negligible value, I don’t see any evidence for that. – gavin]

  4. 4
    john byatt says:

    Eric Steig 2007 Real Climate critique of Mark Lynas Six Degrees of Global Warming

    “If a reading of the published scientific literature paints such a frightening picture of the future asSix Degrees suggests – even while it honestly represents that literature – then are we being too provocative in the way we write our scientific papers? Or are we being too cautious in the way we talk about the implications of the results?”

    suggests the later

  5. 5
    pete best says:

    re #1 – yes maybe some comment on methane and its potential relatively fast feedbakc effect on the arctic sea ice if any would be welcome

  6. 6
    Russell says:

    I’d like to second #3 Toby. What is the story about this?

  7. 7
  8. 8
    SteveF says:

    This may be of interest:

    “Spectral biases in tree-ring climate proxies”

  9. 9
    Carl says:

    From Annan:”The list of pollees in the Zickfeld paper are largely the self-same people responsible for the largely bogus analyses that I’ve criticised over recent years, and which even if they were valid then, are certainly outdated now. Interestingly, one of them stated quite openly in a meeting I attended a few years ago that he deliberately lied in these sort of elicitation exercises (i.e. exaggerating the probability of high sensitivity) in order to help motivate political action. ”

    Exaggerating to promote political action, says a lot about climate “science”..

    [Response: No – it says nothing about the science. It says something about the person who allegedly did this. Neither this nor Lindzen doing the opposite in an earlier paper by these authors (Morgan and Keith, 1995) is sensible or ethical, but actually both attempts are pretty pointless. – gavin]

  10. 10
    Carl says:

    But Gavin, when we know guys like this are choosing cloud feedback parameters for GCMs or is choosing proxies to use for temperature reconstructions etc, we know the science is in trouble.

    [Response: You know absolutely nothing about it. It is easy to game questionnaires, but it is almost impossible to game a GCM that needs to be tested against real world observations, and I know of no way to do it. – gavin]

  11. 11
    Carl says:

    Gavin, surely 90%-95% or so of GCM runs are shooting above target here? There are some feedback parameter in them that are not first principle and are put in by hand. Only in recent times we have seen what the hand(s) has done:

    Exaggerated positive feedbacks to produce results that will cause alarm.

    [Response: Your imagination is running away from you. As has been discussed in many places (most recently Mauritzen et al (2012)), model tuning is done against climatology (spatial and seasonal patterns of clouds, humidity, temperature, OLR etc.) not for trends or sensitivity. Short term trends are highly influenced by effectively stochastic nature of ENSO variability and imputing a significance of that to the long term trends is a mistake. If you were correct, why does the GISS CMIP5 model have a sensitivity ~2.5 deg C? (Short answer in case it isn’t clear – you are not correct). – gavin]

  12. 12

    #10–“…guys like this…”

    One guy allegedly ‘like that.’ And we don’t know what work he(?) does, or did.

    Generalize much?

  13. 13
    Chris Colose says:

    This new paper by Daniel Schrag et al. could have large implications for long-term carbon cycle work and deep-time paleoclimate. It would be interesting to have an RC post on this (David?); this is a topic that I know little about (and I suspect many others would be interested in too).

  14. 14
    Carl says:

    “For the atmosphere, cloud processes, including convection and its interaction with boundary layer and larger scale circulation, remain major sources of uncertainty. This is evident for the vertical distribution of water vapour and the distribution of clouds, particularly over subtropical and arctic regions. These in turn cause errors or uncertainties in radiation which propagate into the coupled atmosphere-ocean system.”

    “There is very high confidence that the primary factor contributing to the spread in equilibrium climate sensitivity continues to be the cloud feedback. This applies to both the modern climate and
    the last glacial maximum.”

    Stuff from leaked AR5 chapter 9.

    [Response: Why do you need to read draft reports for this? This has been true and well acknowledged for ages. See here for instance. – gavin]

    So cloud feedback seems to be not in conformance with reality.

    [Response: Now you are making stuff up. Just because something is uncertain, doesn’t mean that everything is wrong. – gavin]

    Now, since there are large uncertainties in how to model clouds (lack of good observations) it is of course tempting to use parametrisations that will produce desired outcomes. Parametrisations that would result in negative feedbacks (would still be consistent with the poor observations we have) is of course to be avoided.

    [Response: More imagination. – gavin]

    Of course, as time go on, co2 goes up and real world warming is lacking,the negative feedback will eventually be put into these models. Only way they can be saved.

    [Response: Feel free to propose any particular feedback you feel is missing and that we have some physical evidence for. Modellers are actually very keen to add in new processes (as long as there is some justification for them) and that explains the bulk of the physics differences between CMIP3 and CMIP5. – gavin]

  15. 15
    Brett Davidson says:

    The Guardian recently reported that:

    “Carbon dioxide emissions [in the U.S.] fell by 13% in the past five years, because of new energy-saving technologies and a doubling in the take-up of renewable energy”.

    I’m having a hard time figuring out how optimistic to be from this news. Without a national policy, it seems that this reduction is largely by chance. How optimistic do you feel from this news? How far can we trust the free market to solve our problems?


  16. 16
    Bianca says:

    Does methane escape from fracking wells have its own isotopic fingerprint that can be separated from that of decaying matter, melting tundra and/or clathrate methane? And does the (estimated) amount of escaping methane cause the balance to shift out of favor of natural gas as a transition energy source, or is it still better than coal in terms of warming potential?

  17. 17
    steve from brisbane says:

    Having watched the widespread flooding around me in Queensland (and Australia more generally) over the last 2 years, I have become curious as to whether the increase in the hydrological cycle due to increased temperatures has really been adequately factored into estimates of the likely cost of climate change. It’s one thing to talk of flood proofing one town or city, for example, but the damage to infrastructure in Queensland seems to have covered an enormous geographical area over the last couple of years, and the cost of dealing with that in future would (I presume) involve a fair bit of guesswork.

    I see that a recent Australian paper also appears to have confirmed an increase in intensity of rainfall over the long term:

    “there is a statistically significant association with globally averaged near-surface temperature, with the median intensity of extreme precipitation changing in proportion with changes in global mean temperature at a rate of between 5.9% and 7.7% per degree, depending on the method of analysis.”

    While such percentages don’t sound all that large, it seems that it may be having a big practical effect already.

    Any comment on the issue is welcome.

  18. 18

    “Without a national policy, it seems that this reduction is largely by chance.”

    I don’t think that fair; the increase in renewables coincides with a 4-year push to encourage same. Here’s the renewable sector’s take on it, immediately after the election:

    Natgas replacing coal, on the other hand…

  19. 19
    dhogaza says:


    Now, since there are large uncertainties in how to model clouds (lack of good observations) it is of course tempting to use parametrisations that will produce desired outcomes. Parametrisations that would result in negative feedbacks (would still be consistent with the poor observations we have) is of course to be avoided.

    [Response: More imagination. – gavin]

    Not really, Gavin. Though he doesn’t mean to, he’s speaking for all those who insist that uncertainties in cloud feedbacks totally counter the water vapor positive feedback, and perhaps CO2 forcing at all.

    He essentially is arguing that uncertainty means that there’s no warming when CO2 increases, i.e.:

    “Of course, as time go on, co2 goes up and real world warming is lacking,the negative feedback will eventually be put into these models.”

    I’m sure you’ve understood this … it would be nice if Carl would just openly state “I don’t think that CO2 affects climate at all” and be done with it.

  20. 20
    Hank Roberts says:

    for Bianca:

    “… there are more distinct methane source types than isotopic tracers …”

  21. 21
    nuclear_is_good says:

    Since we had so many points regarding the long tail for climate sensitivity – what is the status of that regarding ice-related feedbacks – is it correct to say that arctic melting was (vastly) underestimated by the vast majority of the models, and that measurable feedbacks related to that would be seen much, much faster and are poorly taken into account in current models?

  22. 22
    Carl says:

    dhogaza, no I think CO2 affects the climate pretty much as modeled, but I’m quite sure that negative cloud feedback are missing in GCMs, thus they tend to shoot over target.

    There could also be some strange solar influence that some people argue about but, I’m not convinced (yet).

  23. 23
    Perwis says:

    Grypo & Gavin at #2 (and Revkin)

    I can really recommend this new paper in GEC by Guivarch and Hallegatte: “2C or not 2C”

    They make a good job elucidating uncertainties and assumptions in mitigation alternatives using a very simple model.

    Interestingly, they find that if climate sensitivity is greater than 3.5C then the 2C target is impossible under a wide range of assumptions on peak emissions, annual decrease after peak and limited negative emissions.

  24. 24
    Salamano says:

    “@Revkin somewhat overstates impacts of changes in CS. It is not too small to be negligible, nor so large to be a nightmare”

    …Does this mean that if Carbon Sensitivity was actually largely lower than previously thought, it would be “a nightmare”?

    [Response: no, ‘it’ refers to the CS itself. Sorry that a tweet did not come with footnotes for people. – gavin]

  25. 25
    Andy Lee Robinson says:

    I recently updated the Arctic sea ice volume animated graph with the latest PIOMAS data, with appropriate music – Arctic Requiem.

    PIOMAS Arctic Sea Ice Volume 1979-2012

    Neven featured it on his excellent Arctic Sea Ice Blog last week, as did Peter Sinclair on ClimateCrocks

    I note from the data that this year begins with 1,058km³ less ice (one trillion tonnes!) than the same time last year.
    This missing amount is about a third of the amount of sea ice remaining at 2012’s record minimum!
    This is headline stuff.

    If this year follows last year’s pattern, then we are heading for a new record this year.

    Maybe Arctic methane is already escaping and contributing to the acceleration of ice melt. The Arctic Tundra methane and clathrate bombs suddenly seem less remote.

  26. 26

    #1 Gavin and Vineet, was actually waiting for this event to show, highly likely something to do with the advent of stronger winter lower tropospheric inversions. Winter is finally spreading everywhere (very late), this means that there is a more stable lower troposphere, actually reducing surface air mixing higher up, by summer like, adiabatic processes. Using methane as a tracer gas makes is ideal to understand meteorological dynamics. For instance, the high pressure hanging about -90E>180E>90W longitude over the Arctic ocean, has been weird, with strong lower isotherms , not inversion rich as anticyclones should be, this very stable high pressure was/is heavily influenced by open water from thousands of leads. The methane results confirm that. While the open water over Barents is finally loosing energy, signalling the onset of stable air even over there, although not to last since the sun is back. If I am right the higher methane levels will vanish as soon as summer like lower tropospheric profiles take hold (April onwards). Greenland not showing strong methane levels is another tracer about where its surface air is going, towards the Canadian Archipelago because of steady low pressures over Baffin bay. I do think the data given (to date) reflects events in the lower troposphere.

  27. 27
    John Carter says:

    Re Steves comment about rainfall intensity in Australia,
    Increasing rainfall intensity is a problem in regards soil erosion

    A simple empirical aproach to estimating 15 minute rainfall rate based on pluviograph data is described in paper at this link.

  28. 28
    wili says:

    Wayne, thanks for the insight about atmospheric dynamics in the Arctic. The other reason that much of the increase in methane concentrations will likely go away in the spring months is that the sunshine allows for the reaction of methane with OH, iirc.

    As gavin points out, though, it would be interesting to see what kinds of mining and transport are going on there right now. I’m also wondering about methanogenic bacteria that may be taking advantage of these ice-free regions.

  29. 29
    Ray Ladbury says:

    What Carl seems to want to ignore is that there are multiple constraints on overall climate sensitivity. If confidence limits on sensitivity tighten, it is most likely to rein in the positive tail a wee bit below 4.5 degrees per doubling and perhaps raise the lower limit above 2 degrees per doubling. It’s very unlikely to move the midrange very much.

    Carl says he’s sure climate models are ignoring negative cloud feedbacks, but being sure in the absence of evidence is not a good thing.

  30. 30

    Nickel Nanoparticles Catalyze Carbon Dioxide Fixation by Mineralization.


  31. 31

    I just looked up the activation energy of Methane Clathrate and it is like 323 kJ/mole or 3.35 eV

    That means that reaction rates are highly temperature sensitive, and it helps explain why the stuff needs to stay buried in very cold water, encased in a good heat sink.
    With that high an activation energy, even a 1C change in the a m b i e n t temperature will increase the reaction rate kinetics by 50%. A change of 20C will increase the rate by a factor of 10,000. If there are volcanic vents near the ocean floor, that would vaporize the local clathrate deposits quickly.

    Wolfram Alpha activation energy rate calculator

    By comparison solubility of CO2 in water has an activation energy of only 0.2 to 0.3 eV.

  32. 32
    Chris Dudley says:

    Brett (#15),

    The 13% reduction does not mean we met our Kyoto target in 2012, the end of the compliance period, so a day late and a dollar short. But you are mistaken about not having a national policy. We have standards to improve fuel efficiency in transportation, regulation on new sources of greenhouse gas emissions, efforts to promote better energy efficiency in appliances and buildings and efforts to build a domestic renewable energy industry such as punitive tariffs on dumping of solar panels and tax incentives for investment in renewable energy along with federally backed loans.

    There is also reason to expect regulation on existing sources of greenhouse gas emissions within the next few years. We do rely on market forces to respond to such policies or even just the rumor of policies.

    While much is made of a glut of natural gas owing to fracking, a shift from coal would have been happening in any case owing to the Supreme Court order to the EPA to obey the Clean Air Act. Fracking has displaced planned liquified natural gas import terminals and deep gas exploration in the Gulf, but natural gas would have displaced coal without fracking owing to low investment in improved coal burning technology compared to improved gas generation efficiency along with decreased quality in the remaining coal resource. Coal can’t get cheaper while natural gas can which steers investment. But investment that might have made coal cheaper such as carbon fuel cells or application of combined cycle generation to coal was already reduced even by the beginning of the law suit that resulted in the Supreme Court order. Only scoundrels and conservatives remained in coal; innovators, sensing which way the wind blew, moved on.

    We’ve had a national air pollution policy since 1963 and a renewable energy policy since the oil embargo. We are lacking a coherent international position that would allow us access to emissions markets, but that is not the same a not having national policies.

  33. 33
    Jim Galasyn says:

    50 doomiest graphs of 2012

    The important observation to take away from these graphs is the appearance of an entirely new class of extreme weather event that occurs beyond 3 sigma. These mega-events essentially did not occur before the 21st century – they are the fingerprints of abrupt climate change.

  34. 34
    Dan H. says:

    Not too surprising. Past records have always seemed to suppress the extremes. Growth is a combination of many factors, and an extreme in a factor may be tempered by others, such that the growth is not as great as envisioned.

  35. 35
    dhogaza says:


    dhogaza, no I think CO2 affects the climate pretty much as modeled, but I’m quite sure that negative cloud feedback are missing in GCMs, thus they tend to shoot over target.

    “quite sure” as in “Carl has read the relevant parts of GISS Model E”, or at least its documentation which includes references to the relevant papers?

    Or “quite sure” as in “Carl hasn’t examined the models but they must be overshooting because my gut tells me so”?

    I’m “quite sure” it’s the latter …

  36. 36

    Dan, it would be great if you could actually say something of an even minimally substantive nature when you occasionally post here, or failing that, give a link to a substantive discussion. Thanks in advance.

  37. 37
    vukcevic says:

    If sunspot cycles affect global climate than the prediction would be of a fundamental importance, if not and the effect is only + – 0.1C , then it’s importance is limited to the space science and astrophysics.
    Since most of interested readers know about differential rotation of the solar outer layers, which is often linked to the generation of the solar cycles, both sunspot and magnetic (Hale), but there are fewer who know that the Earth (this time liquid outer core) displays differential rotation too.

    “Non-steady differential rotation is one of the main characteristics of the-buoyancy-driven flow within the Earth’s liquid core that generates the main geomagnetic field by magnetohydrodynamic (MHD) dynamo action.”

    The above mentioned ‘geomagnetic field’- GMF is easily measured and since about 1880 there are relatively good records. From so measured GMF, scientists both at NASA and elsewhere have calculated changes going on in the Earth’s core rotation.
    I had look at their data and found that about 1/6th or ~17% of these long term changes of ~105 years long period, is made of oscillations with a period equal and synchronised to the solar magnetic cycle.

    Does this matter to the global climate?
    Circumstantial evidence shows not only that it matters but could be of the essential importance:

  38. 38

    It gets complicated wili, true enough, under the inversion peak all kinds of photosensitive reactions will occur, namely the said OH- will affect surface ozone, this is another way to detect the presence of methane (full circle!). But I expect more methane to gradually increase along with winter stratification of the lower atmosphere only to disappear thanks to photochemistry and convection.

  39. 39
    Windchaser says:

    Adding to #32, the lower US emissions of CO2 is not really due to luck.
    1) Fracking and EPA regulations make coal more expensive than natural gas.
    2) Higher gasoline prices lead to reduced gasoline usage and higher average MPG.

    On the other hand..
    Re: 1, More natural gas means less CO2 emissions, but not necessarily less GHG emissions. There’s debate over how much methane is leaking out during fracking or natgas transport, and methane is a much stronger GHG than CO2.
    Re: 2, The higher gas prices are largely a result of recent industrialization in Brazil, India, and China. That industrialization comes with higher coal and gasoline use in those countries.

    As a sidenote, fuel efficiency mandates are generally a pretty bad way of reducing gasoline use. Much better is higher gas prices, for reasons explained here:

  40. 40
    Mark Shapiro says:

    A huge ice flow recently broke off Antarctica, visible on MODIS:

    Any size estimates? Is this unusual at all?

  41. 41
    David B. Benson says:

    Mark Shapiro @40 — Modis states 1 km. I assume that is 1 km per cm. Once you know you can determine the size of the iceberg.

  42. 42
    Brett Davidson says:

    Kevin (#18) and Chris (#32),

    Thanks for your responses. I was incorrect in saying we have no national policy. Thanks for those examples, I did not realize we were doing all of those.

    It appears that U.S. policies currently focus on specific enhancements we can make (e.g. car mpg standards) but do not have an overall emissions ceiling that you would get from a cap-and-trade or similar system. So I’m having trouble determining if the current U.S. path is sufficient enough for the 2C target (some say 85% reduction in GHG emissions by 2050). The media can be confusing with a wide range of optimism and pessimism.

    How sure can we be that we’re on the right path? Or perhaps there’s no good way of knowing? Perhaps the IPCC projections are our best guess?


  43. 43
    David B. Benson says:

    Water Leaking Into Stratosphere Could Harm Ozone
    but how much is yet to be determined.

  44. 44
    Chris Dudley says:

    Brett (#42),

    We’re a day late and a dollar short at this point but there is movement on off-shore wind on the East Coast, big solar in the desert, and the US emphasis on thin film solar has seen First Solar get manufacturing costs below $0.70 per watt so that a new solar farm on the East Coast can sell at about $0.13 per kwh.

    Electric car sales seem to be picking up with Ford now entering the market. With a reasonable fraction of new cars being mostly electric in 7 years or so, we can anticipate a good source of stationary electric storage in 17 years or so as the battery packs cycle out of transportation owing to a degradation in capacity of 20% or so. That amount of storage coming on line allows pretty much 100% renewable power by 2040 or so. Aviation, trucking, and tractors may still use some fossil fuels in 2050, but the likelihood is that there will be such a glut of solar power that we’ll synthesis liquid fuels from water and charcoal rather than take them out of the ground.

    We are capable of reaching very substantial cuts in emissions by 2050. But, 2 C is not up to us, it is up to China and India. Our lack of a coherent international policy may harm us when trying to get concessions from them.

    Walking softly and carrying a big stick has been a useful US approach to foreign policy at times. I’d urge rather gentle punitive tariffs on Chinese imports to cover crop insurance and flood insurance losses from dangerous climate change that is caused by growing emissions. Those small penalties (compared with the volume of trade)would be walking softly. The big stick would be the potential for much larger tariffs should damage grow.

  45. 45
    Paraquat says:

    “Carbon dioxide emissions [in the U.S.] fell by 13% in the past five years, because of new energy-saving technologies and a doubling in the take-up of renewable energy”.

    I’m having a hard time figuring out how optimistic to be from this news. Without a national policy, it seems that this reduction is largely by chance. How optimistic do you feel from this news? How far can we trust the free market to solve our problems?


    I think the Guardian article is hogwash. Yes, I can believe that U.S. emissions have fallen in the past five years because of 1) recession, and 2) moving what remains of U.S. manufacturing to China (where emissions have been rising steadily).

    The USA has done almost nothing with renewable energy. Well, except for many electric power companies now putting photos of windmills on the envelopes when they mail a bill to you.

    The free market will always go with the cheapest short-term solution available. That means burning more coal while conducting public relations exercises like the above-mentioned windmill photos and slogans like “clean coal.”

  46. 46
    Hank Roberts says:

    > water leaking into the stratosphere

    Took a while to figure that out:
    here’s Paul Crutzen on the questions raised by supersonic transport aircraft:
    Ambio Vol. 1, No. 2, Apr., 1972

  47. 47
    Vineet says:

    You may be right, but how do we confirm this phenomenon ?

  48. 48
    Dave Peters says:

    Re: #’s 2, 3, 11 & 14

    Emerging from a deep attempt at marrying ENSO variations to the great puzzle of the spurt, stutter, spurt 20th Cen. heating pattern nearly a decade and a half ago, Drs. Mann and Park paused for some intriguing speculation: Anticipating another shift, they suggest a scenario whereby the “atmosphere and oceans reequilibrate after the post-1975 interval of secular atmospheric warming, global temperatures might level off for a few decades, similar to the 1940 – 1975 interval. Any such respite would likely be followed , however, by another interval of rapid warming. One can imagine that such a pause in the warming trend would complicate the incontrovertable detection of anthropogenic climate forcing, and, moreover any international governmental efforts to reduce greenhouse gas emissions.”

  49. 49
    Dan H. says:

    Thank you Dave,
    Excellent analysis of ENSO oscillatory patterns.

  50. 50
    Russell says:

    The Interstellar Boundary Explorer ( IBEX ) team reports in The Astrophysivsl Journal that the outer heliosphere may trap energetic ions from the interstellar medium.

    I doubt the ten order of magnitude difference in particle flux will prevent the usual suspects in the climate crankosphere from soon turning this into an alternative non-anthropogenic theory of climate change