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Unforced variations: Nov 2014

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This month’s open thread. In honour of today’s New York Marathon, we are expecting the fastest of you to read and digest the final IPCC Synthesis report in sub-3 hours. For those who didn’t keep up with the IPCC training regime, the Summary for Policy Makers provides a more accessible target.

Also in the news, follow #ArcticCircle2014 for some great info on the Arctic Circle meeting in Iceland.

Reader Interactions

410 Responses to "Unforced variations: Nov 2014"

  2. Another feedback (magnitude yet to be determined, I gather):

    Perspective
    Effects of stratospheric ozone depletion, solar UV radiation, and climate change on biogeochemical cycling: interactions and feedbacks

    Photochem. Photobiol. Sci., 2015, Advance Article
    DOI: 10.1039/C4PP90036G
    First published online 07 Nov 2014

    Climate change modulates the effects of solar UV radiation on biogeochemical cycles in terrestrial and aquatic ecosystems, particularly for carbon cycling, resulting in UV-mediated positive or negative feedbacks on climate. Possible positive feedbacks discussed in this assessment include: (i) enhanced UV-induced mineralisation of above ground litter due to aridification; (ii) enhanced UV-induced mineralisation of photoreactive dissolved organic matter (DOM) in aquatic ecosystems due to changes in continental runoff and ice melting; (iii) reduced efficiency of the biological pump due to UV-induced bleaching of coloured dissolved organic matter (CDOM) in stratified aquatic ecosystems, where CDOM protects phytoplankton from the damaging solar UV-B radiation. Mineralisation of organic matter results in the production and release of CO2, whereas the biological pump is the main biological process for CO2 removal by aquatic ecosystems. This paper also assesses the interactive effects of solar UV radiation and climate change on the biogeochemical cycling of aerosols and trace gases other than CO2, as well as of chemical and biological contaminants. Interacting effects of solar UV radiation and climate change on biogeochemical cycles are particularly pronounced at terrestrial-aquatic interfaces.

  3. Recommended reading:

    Global Carbon Neutrality Should Be Reached By Mid-To-Late Century
    By Joshua S. Hill
    Cleantechnica.com
    November 20th, 2014

    Excerpt:

    Building on the findings published in the ‘Fifth Assessment Report’ by the International Panel on Climate Change (IPCC), the UN Environment Programme (UNEP) has released a report showing clearly that in order to limit global temperature rise to 2°C and the subsequent environmental impacts, global carbon neutrality must be attained by mid-to-late century.

    According to UNEP, global carbon neutrality “would also keep in check the maximum amount of carbon dioxide that can be emitted into the atmosphere while staying within safe temperature limits beyond 2020.”

  4. Jon, this is the discussion you might want to follow:
    http://www.geosociety.org/gsatoday/archive/22/7/article/i1052-5173-22-7-60.htm

    Stratigraphic boundaries commonly appear as abrupt in the rock record but are often imprecise in time. A boundary as broad as a few thousand years resolves most problems in deep-time stratigraphy but would be of little use to identify a boundary intended to separate events of recent centuries. Definition and delineation of a basal Anthropocene boundary would be sufficient to introduce the term ….

    Subcommission on Quaternary Stratigraphy
    WORKING GROUP ON THE ‘ANTHROPOCENE’
    http://quaternary.stratigraphy.org/workinggroups/anthropocene/

    The ‘Anthropocene’ is a term widely used since its coining by Paul Crutzen and Eugene Stoermer in 2000 to denote the present time interval, in which many geologically significant conditions and processes are profoundly altered by human activities. These include changes in: erosion and sediment transport associated with a variety of anthropogenic processes, including colonisation, agriculture, urbanisation and global warming, the chemical composition of the atmosphere, oceans and soils, with significant anthropogenic perturbations of the cycles of elements such as carbon, nitrogen, phosphorus and various metals. environmental conditions generated by these perturbations; these include global warming, ocean acidification and spreading oceanic ‘dead zones’. the biosphere both on land and in the sea, as a result of habitat loss, predation, species invasions and the physical and chemical changes noted above.

    [sic — periods in the middle of sentences look like typos/mangled text]

  6. http://www.eurekalert.org/pub_releases/2014-11/awih-psp111914.php
    Peter Köhler, Gregor Knorr und Edouard Bard (2014): Permafrost thawing as a possible source of abrupt carbon release at the onset of the Bølling/Allerød. Nature Communications 5:5520; DOI: 10.1038/ncomms6520; http://www.nature.com/naturecommunications

    The abrupt CO2 rise about 14,600 years ago examined by the scientists was one of three rapid fluctuations in the carbon cycle during the transition from the last ice age to the present interglacial. This was shown by American colleagues (Marcott et al.; doi:10.1038/nature13799) by means of new CO2 data from an ice core in West Antarctica that was published in the journal Nature at the end of October 2014.

    Since CO2 analyses on ice cores always contain only an averaged version of the atmospheric signal due to the inclusion process of the gases in the ice, the exact size of the CO2 pulse is still uncertain. Nevertheless, scientists can clearly determine that the rates of change in atmospheric CO2 during these abrupt CO2 rises were significantly lower than the corresponding rates caused by fossil fuels of approx. 2-3 ppm per year, which are occurring today.

  7. And NCDC is in for October: once again, the warmest on record. The highlights:

    –The combined average temperature over global land and ocean surfaces for October 2014 was the highest on record for October, at 0.74°C (1.33°F) above the 20th century average of 14.0°C (57.1°F).

    –The global land surface temperature was 1.05°C (1.89°F) above the 20th century average of 9.3°C (48.7°F)—the fifth highest for October on record.

    –For the ocean, the October global sea surface temperature was 0.62°C (1.12°F) above the 20th century average of 15.9°C (60.6°F) and the highest for October on record.

    –The combined global land and ocean average surface temperature for the January–October period (year-to-date) was 0.68°C (1.22°F) above the 20th century average of 14.1°C (57.4°F). The first ten months of 2014 were the warmest such period on record.

  9. Yet more scorchio!!
    Hottest global October anomally reported by NCDC increasing yet further the chance of 2014 taking the ‘hottest year on record’ accolade.
    And while the highest rolling 12-month average on record for NCDC is presently 8/2009-7/2010 associated with the El Nino, the present 12-month average is closing in even though an El Nino has not (yet) fully appeared. If the present high anomalies continue, 2014 would become the hottest 12 month period on record as well as the hottest year.
    GISStemp would require a hot January to pip the 2009/10 12-month period while HadCRUT, which still has 9/1997-8/1998 holding top spot, would require a hot February 2015 (mainly because February 2014 was so cold).

    I also have an eye on the venerable HadCET where the remaining year will soon require a negative anomaly (ie be below the 1961-90 average) to prevent 2014 becoming the hottest year since records began in 1772. But that is much less of a done deal. Cold Decembers are not disappeared on HadCET which can be very cold. 2010 was the second coldest on record.

  11. To appreciate the U.S.-China climate agreement, there’s only one number you need to pay attention to.

    The excess CO2 we put into the atmosphere by burning fossil fuels such as coal, oil, or natural gas is removed very slowly by ocean uptake and other geological processes. As a result, a significant portion of the CO2 we emit each year will still be in the atmosphere 10,000 years from now. As long as human activities are transferring long-buried carbon into the atmosphere in the form of CO2, the atmospheric CO2 levels will continue to rise, and they will drive ever-greater warming. CO2 accumulates in the atmosphere like mercury accumulates in the fat of a fish swimming in polluted waters. The impact of fossil-fuel burning (and deforestation) on climate depends not just on the current year’s emission but on the cumulative emissions of CO2 over all past times. The cumulative CO2 emissions are typically quoted in terms of the amount of carbon in the CO2 (which contains 27 percent carbon by weight), measured in gigatons, or billions of metric tons. (A metric ton is 1,000 kilograms, or just a bit more than an English ton.) In thinking about the human imprint on future climate, the cumulative carbon is the only number you really need to pay attention to.

    It turns out that 1,000 gigatons of carbon—1 trillion tons—is roughly what it takes to warm the globe by 2 C. If we release that much carbon into the atmosphere in the form of CO2, the warming will stick around for at least 1,000 years before the globe begins to recover, even if we go cold-turkey on fossil fuels when we release our first trillion. Since the beginning of the industrial revolution, we have gotten about halfway there. It took several hundred years to emit our first half-trillion tons, but worldwide CO2 emissions are growing exponentially at a compound rate of about 2.8 percent per year (since 1950) and so it will only take another 25 years at the current rate of growth to hit a trillion tons, at which point it’s game over for the 2-degree target (though of course not too late to try to keep warming under 3 degrees). We need to eventually get CO2 emissions down to zero, but in the meantime it’s the exponential growth that’s our main enemy, since that boxes us in and leaves little time for decarbonizing the economy. The first order of business is to get off the exponential curve, otherwise we are doomed to be on the Impossible Hamster track.

    –R. Pierrehumbert in “Slate,” 17 November, on the U.S.-China climate agreement.

    http://www.slate.com/articles/health_and_science/science/2014/11/obama_s_u_s_china_climate_agreement_carbon_budget_and_exponential_curves.html

  12. Comments about January through October being ranked the warmest in the record. How soon we forget. Last year January through November was the 2nd warmest in the record, and then the polar vortex became the hot news in Dcember, and January through December ended up around 4th warmest.

  13. Kevin (#292),

    Canada needs to be dealt with soon because they repudiated their ratified Kyoto commitment. However, the US probably can’t do much owing to NAFTA, which likely keeps us from using GATT Article XX tariffs. We can keep from permitting Keystone, of course, but we can’t put pressure on emissions using trade I think. China probably can. The other Annex I countries you mentioned did OK under Kyoto.

    I expect that Russia, along with Saudi Arabia and Iran can be bought off with a promise that their more valuable assets won’t be stranded. Canada, with junk assets, will probably have to be sacrificial in that deal.

  15. Geoengineering:

    http://www.seas.harvard.edu/news/2014/11/adjusting-earth-s-thermostat-with-caution

    1) The URL is misleading. We have already turned up the thermostat, by applying a huge weight of CO2. Now instead of lightening that weight (capturing CO2), or even reducing its rate of increase (non fossil carbon energy), i see Rube Goldberg mechanisms to attach hydrogen balloons. Gah.

    2) My nose is not fine enough to distinguish this from the odor of an attempt to keep us on RCP8.5 trajectory or worse.

    3)Once such engineering is in place, there will grow an industry devoted to it, which will have great power, and by its very nature, is empowered by the continued release of fossil carbon. An unholy alliance indeed. And like all such organisations, it will seek to perpetuate itself.

    4)Those most benefited by these schemes will be the ones funding it. Not, say, the destitute of the Ganges delta.

    sidd

  16. re: 307. What is quite amazing about these stats is that, unlike the previous global temperature peak in the 90s (that deniers always try to use to claim that there has not been warming since), there has not been the huge El Nino this year to add to the warming.

  17. 219, David B. Benson: Lightning expected to increase by 50 percent with global warming
    http://www.sciencedaily.com/releases/2014/11/141113142112.htm
    and so more wildfires.

    The original article was published in Science Magazine. Romps et al calculated a 12% (+/- 5%) increase in the lightning strike rate per 1C of global warming. In order to get that result, they calculate a 12% (+/- 5%) increase in the rate of non-radiative transfer of sensible and latent heat from the surface to the upper troposphere, a topic that I asked about here a few weeks ago. Their analysis is confined to the US, but it could possibly generalize.

  19. 219, David B. Benson: Lightning expected to increase by 50 percent with global warming http://www.sciencedaily.com/releases/2014/11/141113142112.htm
    and so more wildfires.

    The original is . Romps, D. M., J. T. Seeley, D. Vollaro and J. Molinari, 2014: Projected increase in lightning strikes in the United States due to global warming. Science, 346, 851-854.

    According to Romps et al, (1) an increase of 1C in global mean surface temperature is calculated to increase the rate of cloud-to-ground lightning discharges by 12%, +/- 5%. They say that this amount is directly proportional to the rate of energy transfer from the surface by evapotranspiration. They get the rate by multiplying the energy available times the rainfall rate. Essentially, their causal analysis, or narration, is that increased temperature produces faster evaporation and rainfall, and the increased rate of energy transfer in that speeded up process is what raises the lightning rate by 12%, +/- 5%.

    ” In mathematical form,
    F = h/E x P x CAPE
    where F is the lightning flash rate per area (m−2 s−1),
    P is the precipitation rate (kgm−2 s−1), and CAPE
    is in J kg−1.The constant of proportionality, h/E, contains the dimensionless conversion efficiency h and
    the energy discharge per flash E (in joules).” from Comps, et al.

    That was extremely interesting to me because I have been wondering/writing about the changes in non-radiative energy transfer with changes in temperature or CO2 concentration.

    I apologize if this is a repeat. My earlier comment seems to have disappeared.

  20. More on the new weird weather story from
    http://www.washingtonpost.com/blogs/wonkblog/wp/2014/11/20/theres-growing-evidence-that-global-warming-is-driving-crazy-winters/

    Francis … cites … five (1, 2, 3, 4, 5) scientific papers published in the last year or so that she considers supportive, and hints that more are coming. “We’ve got 5 papers that all look at that particular mechanism in different ways — different analysis, different data sets, observation and models — and they all come to the same conclusion and they all identify this mechanism independently,” she says.

  21. From Acqua Alta, Wikipedia (http://en.wikipedia.org/wiki/Acqua_alta)

    Exceptional high waters since 1923

    According to the records of the Tide Monitoring and Forecast Centre of Venice,[1] these are the maximal documented levels (in decreasing, not chronological, order):
    194 cm on November 4, 1966
    166 cm on December 22, 1979
    158 cm on February 1, 1986
    156 cm on December 1, 2008
    151 cm on November 12, 1951
    149 cm on November 11, 2012
    147 cm on April 16, 1936
    147 cm on November 16, 2002
    145 cm on December 25, 2009
    145 cm on October 15, 1960
    144 cm on December 23, 2009
    144 cm on November 3, 1968
    144 cm on November 6, 2000
    143 cm on February 12, 2013
    143 cm on November 1, 2012
    142 cm on December 8, 1992
    140 cm on February 17, 1979
    Maximum high tide level: 1.94 m recorded on November 4, 1966
    Minimum ebb tide level: -1.21 m, recorded on February 14, 1934
    Maximum difference between a high tide and the following ebb tide: 1.63 m, recorded on January 28, 1948 and on December 28, 1970
    Maximum difference between an ebb tide and the following high tide: 1.46 m, recorded on February 23 and 24, 1928, as well as on January 25, 1966

    Regards, from Victor the Troll ;-)

  22. Matthew (@319)

    As Romps et al. state, the convective available potential energy (CAPE) is defined such that “…the product of CAPE and P [the precipitation rate] is the theoretical maximum rate at which kinetic energy is imparted to ascending water condensates…”. This is not the same as “the rate of energy transfer from the surface by evapotranspiration”, which is controlled to a large degree by the radiative state of the atmosphere.

    You can get some idea of how non-radiative energy transfer responds to changing CO2, and why the the Romps et al. study is peripheral to this subject, from Held and Soden, and The Atmospheric Energy Constraint on Global-Mean Precipitation Change, by Pendergrass and Hartmann, available from Hartmann’s publications page.

  23. Thanks Tony and Kevin. CP does get a bit optimistic for me, sometimes. Then I turn to this guy:
    http://climateandcapitalism.com/2014/09/28/think-apocalyptic-turn-despair-action/

    Comment by wili

    I read that article and that’s pretty much my feeling about where things are headed. However, I can’t tease out from the various sources how close we are to “the party’s over” date or “sell by” if you prefer. I wouldn’t classify myself as a “doomer” because I think we still have time to head off some of the worst outcomes but that depends on our political situation which I don’t have much faith in. This new Republican controlled Congress and Senate are going to fight tooth and nail to keep fossil fuel money flowing into their pockets. I think a lot depends on who the next President is. Then there’s the “Rapture Bunch.” The level of ignorance out there is astounding.

  24. for VictorTT, who perhaps thinks he has picked a cherry:

    http://www.climateadaptation.eu/italy/coastal-floods/

    … Venice has particularities due to variations in local subsidence and therefore it is not usable in the context of long term sea level trends (2). Nevertheless it is worth noting that sea level proxy data indicate that the trend has remained unaltered in Venice since the early 18th century (3).
    …
    Two periods of sea level variability must be discussed further. Between 1960 and the beginning of the 1990s sea level in the Mediterranean Sea was either not changing or decreasing (5) due to atmospheric pressure changes during the winter period (6) as well as temperature reduction and salinity changes linked to the North Atlantic Oscillation (NAO) (7) or to the thermohaline Mediterranean circulation (8).

    Footnotes at the original page, q.v.

  25. Re- Comment by Victor — 22 Nov 2014 @ 1:46 PM, ~#321

    Victor, what is the significance of the Venice high water records to the concerns of this forum?

    Steve

  26. Thank you Victor the Troll @321. We now have lift off.
    However, I think you would do better finding a fellow troll that actually speaks Italian. The Wiki reference you provide gives us a link to this site, all about high tides in Venice, but in Italian. And given where Venice is, why not!!
    However, the list of stonkingly high tides listed on Wikithingybob is not immediately apparent, which suggests the list is probably a creation of one of your fellow trolls. I do note some deeply-linked and dense PDF lists that could provide the basis of that silly list, but this is getting seriously obscure. And far more prominently on that link is graphs like this one which, assuming my Italian isn’t entirely gone to pot, is titled “Variations of the mean sea level” and which sort of suggests a 40cm SLR over the last 140 years = 2.9mm pa.
    1966 may have been memorable for some because of the high 10 minute inundation at Venice. For me, it was far more memorable as the year of that England World Cup victory. “Some people are on the pitch. They think it’s all over. It is now.” And indeed this discussion is (bar trollish attempts to replay it from under the bridge).

  28. 323 Chuck Hughes says: 23 Nov 2014 at 10:54 AM

    Roger that and roger “The level of ignorance out there is astounding.” What do you do about it given that most people don’t want to learn science and would find science difficult if they did want to learn?

  29. What is this facebook nonsense? Why the change in recaptcha?

    Where did my comments go?

  30. Victor,

    this link may help you understand why looking at single records is not very helpful:
    http://www.comune.venezia.it/flex/cm/pages/ServeBLOB.php/L/IT/IDPagina/2967
    I am sure you understand that graph, even though the information is in Italian.

    Also quite helpful:
    http://www.comune.venezia.it/flex/cm/pages/ServeBLOB.php/L/IT/IDPagina/2969
    and
    http://www.comune.venezia.it/flex/cm/pages/ServeBLOB.php/L/IT/IDPagina/2972
    Looks to me like a significant increase in sea levels and more events with >+120 and fewer +120 cm is a cherry pick, try >+110 cm:
    http://www.comune.venezia.it/flex/cm/pages/ServeBLOB.php/L/IT/IDPagina/2970

  31. For those interested in a mitigation discussion:

    “We decided to combine our energy innovation study’s best-case scenario results with Hansen’s climate model to see whether a 55 percent emission cut by 2050 would bring the world back below that 350-ppm threshold. Our calculations revealed otherwise. Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO2 levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change, with all its dire consequences: shifting climatic zones, freshwater shortages, eroding coasts, and ocean acidification, among others. Our reckoning showed that reversing the trend would require both radical technological advances in cheap zero-carbon energy, as well as a method of extracting CO2 from the atmosphere and sequestering the carbon.”

    http://spectrum.ieee.org/energy/renewables/what-it-would-really-take-to-reverse-climate-change

  32. Belated addition to the thoughts about emissivity in the far infrared (“far-IR”), which used to be modeled using assumptions, as now detectors and observations give actual numbers that differ somewhat from the old assumptions.

    That was from the article that said in the abstract

    the calculated difference in far-IR emissivity between ocean and sea ice of between 0.1 and 0.2, suggests the potential for a far-IR positive feedback for polar climate change.

    http://www.pnas.org/cgi/doi/10.1073/pnas.1413640111

    The question arose whether the atmosphere was ever dry and clear enough for that band to efficiently radiate heat, rather than intercepting those photons (the article suggests a frozen Arctic ice cap was an efficient radiator to space)

    The same question about that band matters for infrared astronomy; I found a bit more info here:

    if you’re building a telescope on the ground to view the Universe, but the two biggest are high sky transparency (or how easy it is to see through the atmosphere; no wavelengths are 100% transparent to IR radiation) and low sky brightness (or how much light is emitted by the atmosphere itself). Unless you’re a professional observatory at incredibly high elevations, I’d really recommend, if you’re considering doing IR astronomy yourself, focusing on one of four very narrow windows between about 1.1-1.4, 1.5-1.8, 2.0-2.4, or 3.5-4.0 microns in wavelength.

    illustrated by this chart: http://scienceblogs.com/startswithabang/files/2014/11/IRwindow-600×233.png

    That’s from down in the comments at http://scienceblogs.com/startswithabang/2014/11/22/comments-of-the-week-36-the-nuclear-option/

    The question the article raised was whether there’s enough new information here to inform the models usefully.

  34. According to James Hansen, Antarctica has been permanently glaciated for the last 30 to 40 million years –

    http://images.sodahead.com/profiles/0/0/2/0/7/6/2/8/5/Cenozoic-39602951055.jpeg

    However we only have CO2 data from ice cores going back 800,000 years. Is there thought to be any older ice left, that we haven’t yet sampled?

    [Response: Perhaps back to 1.5 million years ago – there is a lot of discussion about where that might be found. The problem is that near bedrock, the ice gets messed up and turned over, and so it isn’t quite as easy as going to the deepest spot and drilling. – gavin]

  35. #333–“A geometaphysical phase arising from hermeneutic metamorphism of a factoidite melange during high-pressure deformation professional.”

    Indeed…

  36. Victor’s drive by troll encouraged me to review some of the sea level information I have gathered from Real Climate and came across- https://www.youtube.com/watch?v=RhdY-ZezK7w&feature=relmfu . This is an Arthur M. Sackler colloquia of the National Academy of Sciences by Jerry Mitrovica on sea level rise. It is an excellent and easy to understand explanation of why we cannot use a simple bathtub model when thinking about sea level and specifically addresses ignorant anti-science gotchas.

    Steve

  37. Corey (#331),

    Looks like Koningstein and Fork did not really explore how things can work together. http://www.engineering.com/ElectronicsDesign/ElectronicsDesignArticles/ArticleID/8272/Is-Storage-Necessary-for-Renewable-Energy.aspx

    There has also been a good deal of work on completely replacing fossil fuels even with single technologies. Wind power, for example has been studied on its own. http://news.stanford.edu/news/2012/september/wind-world-demand-091012.html

  38. Last month was the warmest October in the HADCRUT4 record at 0.613. If November and December average an anomaly of at least ~0.51, 2014 will end as the warmest year in the record.

    If that occurs, what do you think will become of the “GAT hasn’t risen since 1998” meme?

  39. Last month was the warmest October in the HADCRUT4 record at 0.613. If November and December average an anomaly of at least ~0.51, 2014 will end as the warmest year in the record.

    If that occurs, what do you think will become of the “GAT hasn’t risen since 1998” meme?

    P.S. If you’re having CAPTCHA problems, check your script blocker. The CAPTCHA addresses have changed.

    …

  40. OK, first of all. Contrary to public opinion, I am NOT a troll. My first appearance on this blog was a brief announcement that I was currently blogging on climate change and an invitation for interested parties to read my posts, and if anyone so desired, respond. I assumed interested readers would comment on my blog, but most of you chose to comment here instead. My subsequent posts were mostly in response to what you yourselves chose to present here, so it was only natural for me to respond here. That is not the behavior of a troll. I’d have preferred for you to respond on my blog, not this one. And you still have that option. If you’ve forgotten the URL, here it is again: http://amoleintheground.blogspot.com/ As you’ll see, there are now several additional posts on the same general topic.

  41. [Since my post seems to have disappeared, I’m giving it another try. Please forgive any duplication if both versions eventually appear.]
    Now as far as the Acqua Alta data is concerned, I posted that list partly out of curiosity, to see what sort of responses it would elicit. But mainly to stimulate thought on a fundamental epistemological question regarding the evaluation of data. And no, I didn’t post it to make some point about the reality of sea level rise. Sea levels do appear to be rising, yes. Climate science does seem to have established that. But epistemology is not the same as climate science, and epistemological questions cannot be decided by climate science, or any science. The evaluation of data is fundamentally a philosophical matter.

    What intrigues me about this data sample is that it can be interpreted in two contradictory ways. A defender of the “climate change” paradigm can point to the fact that 8 of the “exceptional high water” marks were recorded during the 21st century. However, a “denier” can respond by noting that the all time highest level since 1923 was recorded in 1966. This person can also point to the fact that the 5th and 7th highest levels were recorded in 1951 and 1936 respectively.

    Moreover, if we look at the historical record (http://en.wikipedia.org/wiki/Acqua_alta#Historical_records), we see evidence of extreme flooding in Venice going all the way back to the Middle Ages. Given the wide range of flooding events in Venice over the centuries, it’s awfully difficult to spot a trend in either direction. At the same time, the 8 instances of extreme flooding in the 21st century are hard to ignore.

    And of course, as we know, Venice is very slowly sinking, which adds yet another complication.

    What clinches it as far as I’m concerned are the numerous reports that flooding is become increasingly more frequent over the years. This apparently IS a real trend, strongly suggesting that the disappearance of this wonderful city into the sea is only a matter of time. But how much time? Judging from the dire warnings on this topic over many years, the city should be long gone by now. Yet it remains intact and continues to draw hordes of tourists each year — which in itself presents a huge problem.

    So. What is the moral of my little presentation? I guess it would be this: 1. unless there is a very clear and unmistakable trend, data like the Acqua Alta readings are difficult if not impossible to evaluate; and 2. it’s awfully easy to fall into the trap of confirmation bias, i.e., seeing in the data what you want to see, rather than what is actually there. And that goes for BOTH sides of the climate change coin.

  42. Hank (#332),

    If you examine your chart, the windows shown are near and mid-IR as well as the highest frequency submillimeter window. Far IR astronomy is usually done from space or the stratosphere (for examples Kuiper Airborne observatory or SOFIA) The paper is concerned with emissivity at about 50 microns, which is far infrared. So, the wavelength of interest is not even on the chart.

    The effect they are interested in will only occur if the atmosphere is as dry as the stratosphere. That will apparently only happen when the surface is dry (as in icy) since open water will evaporate and moisten the atmosphere. So, the only surface emissivity of importance is the ice emissivity. All others are invisible from space and thus have no effect.

  45. > the only surface emissivity of importance is the ice emissivity.
    > All others are invisible from space and thus have no effect.

    Yes, that’s how I read the paper — that during the ice season, heat departs the planet through dry air from the ice surface; the ice season (and ice surface area during the season) are less in extent now.

    So to that, er, extent, the planet loses heat less.
    They asked if that changed enough to matter to the modelers.

  46. > I did not cherry pick 1998. I chose graphs found on the Internet …

    — Victor, writing on his blog

    Some cherries you’ll find already picked and waiting for you.

  47. In #337, Meow asks

    If that occurs, what do you think will become of the “GAT hasn’t risen since 1998″ meme?

    Absolutely nothing. The deniers will continue to paint it as measurement error, conspiring scientists, and/or statistical noise.

    What SHOULD concern them – and the rest of us with a pulse – is that the 1998 record was seen with the largest el-nino in mankind’s history. If memory serves, that was a 3.7 sigma event.

    2014, however, is considered a neutral year. It got some help in the spring from what might have developed into a big el-nino, but it sputtered out. We may yet see the onset of a mild el-nino early next year, but that’s not sure yet either.

    The take-away is that neutral years now are as bad as record shattering el-nino’s were less than two decades ago.

  49. Hi all,

    To those who mentioned that I might be digging a little too far into the ice core methodologies, you were right. I don’t know enough about that sort of thing to be able to fully understand the information I was uncovering, and I would probably need to take a class to be able to understand it.

    I’ve done some reading on stratigraphy per some recommendations on this page. I think I now understand how scientists can say and be reasonably confident that CO2 events similar to today’s have not happened. From my understanding, as far as stratigraphic evidence goes, the precision of sample date estimates is irrelevant because markers of sudden climactic change would be observed regardless of whether their precise dates could be gleaned. Hence we would expect in the future to be able to look back and see that the fossil record for the “anthropocene” is entirely unique going back a million years (probably more). If there was a dramatic event in the past, we would similarly expect to see that reflected somewhere in the fossil record, but it is not.

    Please do correct me if I am wrong here.

    Special thanks to Hank Roberts for digging up some great links to related discussions since I was last on this page. And thanks to all who have taken part in this discussion.

    I’ve also learned that oxygen-18 and carbon-13 isotope records can provide relatively high resolutions going back millions of years? http://www.sciencemag.org/content/292/5517/686 I will definitely be doing some more digging down that particular avenue.

  50. Victor @338 I would describe as being the pot calling the shiny electric kettle black. His points as ever are very wide of reality.
    Had he the nous to read this comment thread rather than just popping off another missive of his own invention, he would see that indeed “there is a very clear and unmistakable trend” making his first “moral” entirely misplaced. And his second “moral” that confirmation bias can be present in all positions would only be relevant where theories are poorly defined. When the evidence confirms the veracity of a particular theory, as in this case, there must then be a prevelance of confirmation bias in those who do not accept that evidence and its conclusions.