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Comments 1 to 50:

  1. The consequences of climate change (in our lifetimes)

    "For me human behaviour is the most frightening aspect of climate change."

    Yes, but is it possible to change this?











  2. Of Averages and Anomalies - Part 1A. A Primer on how to measure surface temperature change

    Tristan, yes. If you have a measurement of the minimum and maximum temperature, they are simply averaged to get the daily mean. 

    In the time before minimum-maximum thermometers were invented other averaging schemes have been developed where temperature measuremens were made at 2, 3 or 4 fixed hours and then averaged to get the daily temperature. For example, in Germany it was costum to measure at 7, 14 und 21 hours. And then compute the average temperature from Tm = (T7+T14+2*T21)/4.

    Nowadays we have automatic weather stations that measure frequently and the average temperature is computed from 24 hourly measurements or even measurements every 10 minutes.

    Changes from one method of computing the mean temperature to another can produce biases. How large such biases are can be computed from high frequency measuremens, for example from automatic weather stations.


  3. 2014 SkS Weekly Digest #16

    michael sweet @1, the issue of feed in tarrifs is slightly vexed. With to high a feed in tariff, it pays the person installing solar panels to change their energy consumption habits so that they consume most electricity at night time. Indeed, when we were sold a solar panel at our house (in Qld, Australia), we were actively encouraged to do so by the salesman, in order to maximize our return from the solar panel. The effect, if we had followed his advise, would be to minimize the mitigation advantage of the solar panel. It also maximized the costs to the distribution network. On the other hand, any feed in tariff lower than the mean wholesale price of electricity to the power company represents an implicit subsidy of the power company (and indirectly of other consumers) by the person buying the solar panel. Indeed, any price less than the wholesale price of renewable power, where that is marketed at a premium, represents such a subsidy.

    It follows that ideally the feed in tariff should fall between the wholesale and retail prices of electricity. That does represent a subsidy of the person with the solar panel installed - but that is a good thing. We want to subsidize renewable power to mitigate climate change. Treating all subsidies as bad is equivalent to saying that the market should determine all prices - and the unrestrained market has a good chance of turning the Earth into a place that cannot sustain advanced economies, or a global population in excess of 2 billion. Therefore pointing out that a pricing structure represents a subsidy is not, by itself, an argument to remove that pricing structure.

    Having said that, if there is large scale take up of solar panels, distribution costs will represent an ever larger proportion of electricity company costs. The suggestion that bills should be broken into two components - a connection fee plus a rate on electricity consumed is reasonable, provided it is done to all customers, not just those installing solar power. If done, however, it should be legislated that profits from the connection fee not exceed those from the electricity tariff; and that companies not providing a discount on the connection fee to households using solar panels also not be permitted to count the solar power generated by that household towards renewable energy targets. Lacking the first, companies will have a perverse incentive to inflate the connection fee so as to deflate the impact of the tariff on their total earnings. Absent the later, or some equivalent measure, the effective subsidy for domestic solar power will deflate as it is taken up by more and more people.

  4. Breathing contributes to CO2 buildup

    hlpump @26, Vitousek et al (1986) calculated that with a population of 5 billion, and assumed global average caloric intake of 2500 kcal per person, per day, that humans directly consume 0.76 Pg of organic material (0.35 PgC) annually.  The global populatin has since expanded to 7.2 billion, and and global average caloric intake is now estimated as 2940 kcal per person per day (2015 estimate).  Scaling accordingly, humans now directly consume 1.29 Pg of organic material (0.59 PgC) per annum.

    That represents just 0.5% of terrestial (not global) net primary activity, and 10.6% of emissions from fossil fuel use and cement manufacture.  Of course, all of that Carbon is drawn from the atmosphere originally, as noted in the OP.  You argue that the increase (< 0.025% of net terrestial productivity, and < 0.53% of antropogenic industrial emissions) represents a true increase in emissions.  However, the CO2 emitted in human respiration is still drawn from the atmosphere first by photosynthesis.  Therefore, the direct effect of the increase in human population is only to sequester an amount of carbon equal to the amount of carbon in the bodies of the additional population.

    TD (inline to your comment) notes that the impact of increased human population is to increase substantially anthropogenic emissions both through industrial (fossil fuel and cement manufacture) and non-industrial (Land Use Change) emissions.  That is correct.  Indeed, the increased sequestration in human bodies is almost certainly exceeded by reduced sequestration in forests.  However, all of those changes are already included in the accounting of anthropogenic emissions.  They are not additional, unaccounted for changes.  And they are not changes from human respiration.  

  5. michael sweet at 06:57 AM on 21 April 2014
    2014 SkS Weekly Digest #16

    Today (April 20) the Los Angeles Times ran an article about conservatives, including the Koch brothers, trying to get net metering chnaged to make rooftop solar less economical.  The utilities have figured out that rooftop solar challenges their business model and are trying to charge people exorbitant amounts of money to be connected to the grid.  These arguments will undoubtedly continue for a long time.  Progressive countries, like Germany, will lead the implementation of disbursed generation.

  6. Breathing contributes to CO2 buildup

    Your argument is not wrong.  It does, however, fail to account for the population explosion from 1800 thru today (from approximately 1B persons to now over 7B persons).  While the CO2 is in a different form when exhaled from the human body (roughly 5-6% of total exhaled volume), it requires time for each molecule of CO2 to be absorbed and returned to plants, oceans, etc.  How much time is actually a variable based on numerous factors.  That is one of the primary changes that has taken place over the last 200 years.  Now with that said, should we all (including China and India) be responsible with how we manage our common resources?  Of course!  Let's just not take the approach that some have taken for the sake of publicity, wealth and fame (we all know who I'm talking about).  Rather, let's work together to ensure our home can be enjoyed for all the years to come.

    The other huge factor that I don't have time to go into depth about today are solar cycles.  It's a very big deal and it should be included in all our equations when we responsibly discuss global climate conditions.  Here's the bottom line - we need to learn as much as we can about the things that affect our environment.  But none of us have a handle on the enormity of components that make up the final equation.  Responsibly pursuing knowledge (not reacting to actors and politicians) is where we will find our long term solutions.  Let's start there and see how we do.

    Moderator Response:

    [TD] The counterargument to the myth does indeed account for the increased population's CO2 exhalation, because the increased population's food grown also has increased to feed those people.  But you are correct that increased population increases net greenhouse gas emissions, because of large fossil fuel use to produce, process, transport, and cook/prepare the food for consumption, and in some cases replacement of carbon-sequestering plants (e.g., old forests) with cropland. 

    Regarding the Sun:  The Sun's "cycles" indeed are included in all our equations.  As a start, read the counterargument to the myth "It's the Sun."  After you read the Basic tabbed pane there, read the Intermediate and then the Advanced tabbed panes.  If you want to comment on that topic, do so over there, please.

  7. Global warming can't be blamed on CFCs – another one bites the dust

    Unusually, I chose to read Mr Lu's paper to see what it was all about. I must commend the Skeptical Science authors on their restraint in assessing the paper and commenting on it. I have never trusted papers that resort to emotive hyperboles in describing the state of knowledge and their findings. They always smack of ego exceeding intellectual capacity and rigour and almost always indicate serious amounts of confirmational bias. Snide negative commentary about others (yes Albatross his paper is much like his rebuttals) just reinforce my lack of trust.

    Mr Lu clearly has a favourite topic which is CFCs and he seems to think they rule the world and much of what goes on in it. His purpose appears to be more one of proving just how important they are - and by inference how important he is because he knows more about them than others do. A clear case of FIGJAM.

    I found his comments about CFC processes related to ozone reasonably well argued and supported. I haven't taken the time to check out all the references though, but this appears to be his area of speciality and possibly expertise.

    The leap from these analyses to climate impacts is less than impressive. He makes the most basic, amateurish mistake of implying causality from statistical correlation. I am quite surprised that any journal with aspirations of professionalism could allow this type of reasoning to be presented as scientific - especially one that purports to be about physics.

    Lu's proposition is entirely dependent on his bald statement that the warming effect from CO2 is saturated. The statement looked suspicious and the arguments and analyses presented to support the statement are so clearly and obviously flawed that all following inferences must be rejected. So I was pleased to hear that the proposition was debunked long ago.

    Mr Lu may well know lots about CFCs, but he needs to improve his methods of analysis and inference.

  8. WebHubTelescope at 15:33 PM on 20 April 2014
    Global warming can't be blamed on CFCs – another one bites the dust

    I side with HughBat.  The figure you show does suggest that the fluorocarbons contribute around 0.15C of warming, leveling off since 2000. How much extra warming would these have caused if their concentration had continued to rise since 2000?   

    There are grains of truth in all research. The tricky part is scaling back the exaggeration. This one required a scaling back to perhaps 1/5 of the claim?

  9. Global warming can't be blamed on CFCs – another one bites the dust
    All that not withstanding, flurocarbons are potent, and quite long lasting, green house gasses, and "ABC" issues should not prevent us from working mightily to reduce their use. They tend to be 'invisible' in discussions, but with the escalating growth of air-conditioning ("it's a human right to have A/C" !!) - we will see increase in the release of these refrigerants - sure they are not major GHG's - but their contribution is significant, and growing. Attempts to get non-flurocarbon refrigerants into common use (primarily iso-propane and its relatives - which have miniscule GHG forcing ability (2??) - are making headway - against the strenuous lobbying efforts of duPont and other fluro manufacturers. But there are enormous amounts already in systems - often in abandoned facilities - which will eventually leak out unless recovered and destroyed. (and we must not forget automobiles and transport systems!) Because of lobbying, here in Australia (and I suspect elsewhere) the destruction process (plasma arc) has slowed - and with the poor administration of the carbon tax, the incentive to recover flurocarbon refrigerants is not very high - even though collection is mandated by the Fed Gov't. We forget - once refrigerant is put into a system, it eventually enters the atmosphere - unless active steps are made to recover and destroy them.. (and if we are not paid to do that... why bother.. psssssssst.. )So we mustn't let our reactions to Lu and his ilk, blind us to the fact that flurocarbons are a serious contributing factor.
  10. Global warming can't be blamed on CFCs – another one bites the dust

    Magma @3,
    Agreed.  It is unfortunate that the journal permitted Lu's vitriolic remarks to stand-- allowing such strong language in a journal is unusual.

    I shudder to think what his papers read like. IMO, Lu's snarky and angry replies are consistent with the fake skeptics' tendency to try and obfuscate criticisms of their work with bluster and Gish gallops and to never, under any circumstances, admit fault or wrong doing. Lu had a potentially novel idea, it was wrong, and he now needs to accept that and move on (difficult as that may be).

  11. Dumb Scientist at 09:17 AM on 19 April 2014
    The anthropogenic global warming rate: Is it steady for the last 100 years? Part 2.
    We start with the HadCRUT4 surface temperature data. We fit it with a 6th order polynomial over the entire period of 1850-2011, instead of just over the period 1979-2011 as DS did. This produces the observed 0.17 C per decade of warming after 1979, the same as in DS. But in contrast, the warming here exists over the entire period, not just after 1979. The polynomial is smoothed by a cubic spline so that the trend is monotonic before 1979. This anthropogenic component will be called human. It is denoted by the red curve in Figure a. To create the AMO the-above-obtained human is subtracted from HadRUT4 data. The difference is smoothed with a 50-90 year wavelet band pass filter. This is the AMO (note: not the AMO Index). This is called nature (denoted by the purple curve in Figure b) and is the counterpart to DS's 70-year sinusoid. [KK Tung]

    I'm sorry for the long delay; my day job has consumed my life. I like your new simulation, and tried to reproduce it in R, though I used a Fourier transform band pass filter instead of wavelets. Regardless, the human and natural influences look similar to those in Dr. Tung's plots (which are sadly no longer visible in his comment).

    New human influence
    New natural influence

    My first tests had 10,000 Monte Carlo simulations each:

    1. 0.132±0.012°C/decade, 19% contain the true trend.
    2. 0.156±0.012°C/decade, 100% contain the true trend.
    3. 0.137±0.012°C/decade, 70% contain the true trend.
    4. 0.159±0.012°C/decade, 100% contain the true trend.
    5. 0.168±0.012°C/decade, 100% contain the true trend.
    6. 0.125±0.013°C/decade, 2% contain the true trend.
    7. 0.140±0.012°C/decade, 86% contain the true trend.

    They varied so much that I ran a few tests with 10,000,000 simulations each:

    1. 0.129±0.012°C/decade, 42% contain the true trend.
    2. 0.121±0.012°C/decade, 2% contain the true trend.

    I also tried matching ARMA(p,q) noise parameters to those of the real residuals.

    I still don't know why the mean trends vary so much when using 10,000 Monte Carlo simulations. I agree with Dr. Tung that millions of runs shouldn't be necessary, but for some reason "merely" 10,000 runs yield wildly varying results. More disturbingly, none of the trends in either of the 10,000,000 runs overlap with the mean trend in some of the 10,000 run cases. Maybe I'm not using the random number generator correctly?

    Without seeing how Dr. Tung's code differs from mine, I don't know how he was able to specify the percentage of 10,000 simulations that contained the true trend to two significant digits ("91%") when my estimates vary from 2% to 100%, and most of those 20,070,000 white noise simulations don't include the true trend.

    First, attribution is not necessarily a thermodynamics problem. The method adopted by IPCC AR4, the "optimal fingerprint detection and attribution method". "is based on a regression of the observation onto model simulated patterns and relies on the spatio-temporal response patterns from different forcings being clearly distinct... The global energy budget is not necessarily conserved and observed changes in the energy budget are not considered". This quote came from Huber and Knutti, 2012. [KK Tung]

    That's a fair point; I should've qualified those statements as my opinion to avoid implying that everyone agrees. Personally, I read Huber and Knutti's statement as a criticism of the optimal fingerprint method because it doesn't consider or conserve the energy budget. This is an unusual situation where I've criticized fingerprints used by the IPCC and many researchers while agreeing with Dr. Pielke Sr. that ocean heat content is a better diagnostic than surface temperatures or stratospheric cooling fingerprints, etc. In my opinion, diagnostics more closely related to conservation of energy are more compelling. But you're right, this is just my opinion.

    Towards the end of the paper, the authors compared the 50-year linear trends derived from unforced control runs in the CMIP3 models with the observed 50-year trends. These models do have internal ocean variability. ( DS, please note, this part is not based on a thermodynamic argument, but the result was what you referred to as from a thermodynamic argument.) [KK Tung]

    Why isn't this part based on a thermodynamic argument? Since CMIP3 models have internal ocean variability, aren't they're simulating heat transfer between the deep ocean and surface (i.e. thermodynamics)?

    The authors concluded "For global surface temperature it is extremely unlikely (<5% probability) that internal variability contributed more than 26+/-12% and 18+/-9% to the observed trends over the last 50 and 100 years, respectively". So the "upper bound" is 38% for the last 50 years and 27% for the past 100 years, respectively. [KK Tung]

    Attribution over the last 50 years is based on Fig. 3(c) from Huber and Knutti 2012:

    Huber and Knutti 2012 Fig. 3(c)

    Given mean radiative forcings (etc.), the upper bound on the post-1950 surface trend due to internal variability is 26%. The lower bound is -26%, implying that internal variability actually offset surface warming. Regarding the "+/-12%" Huber and Knutti state "The probabilistic ranges presented here account for uncertainties in the observations, radiative forcing, internal variability and model inadequacy (see Methods)."

    Since the upper bound in Huber and Knutti is itself given as a probabilistic range, I don't see why Dr. Tung's singular estimate of "40%" should be compared to the upper bound of the upper bound rather than the best estimate of the upper bound.

    Given the uncertainty in the model's oceans, I do not think these upper bounds rule out our ~40% and ~0% contribution of internal variability to the 50-year and 100-year trends, respectively. [KK Tung]

    Even if we compare your estimate to the upper bound on the upper bound of Huber and Knutti 2012, the probabilistic range on that upper bound at least attempts to account for "model inadequacy." And 38% here is the upper bound on the upper bound of all modes of natural variability summed together. Even if this upper bound on the upper bound is appropriate and needs to be expanded because it didn't fully account for model inadequacy... doesn't this leave very little room for the PDO (for instance) to affect surface temperatures (at the same phase)?

    On Isaac Held's blog#16 that DS refers to as providing an upper bound of 25% for the contribution of internal variability to the surface warming for the past 50 years: We need to recognize that Held is using a very simple two-box ocean model to illustrate the process of energy balance that can be used to constrain the contribution from internal variability. The exact figure of 25% as the upper bound should not be taken too seriously, and it could easily be 40%, given the fact that there is at least a factor of two variation in climate sensitivity in the IPCC models and he picked one particular value of climate sensitivity from one of the GFDL models for illustrative purpose. There were many other simplifying assumptions so that an analytic result could be obtained. [KK Tung]

    Yes, all thermodynamic estimates involve simplifications but in my opinion simplifications are preferable to not mentioning energy or heat altogether. And 40% here is the upper bound of all modes of natural variability summed together. Even if this upper bound needs to be expanded... doesn't this leave very little room for the PDO (for instance) to affect surface temperatures (at the same phase)?

  12. Global warming can't be blamed on CFCs – another one bites the dust

    "The journal also allowed Lu to respond to that critique."

    Allowing authors to reply to comments is standard practice, of course. What is unusual is the angry and personal nature of Lu's replies, at least judging from the abstracts. This is particularly the case in the reply to Müller and Grooß.

  13. Global warming can't be blamed on CFCs – another one bites the dust

    Fantastic job to all involved!  Well done.

    Lu has been pushing this pet hypothesis of his for a while now, so it is good to see it soundly refuted in the peer-reviewed scientific literature.  Another fake skeptic myth busted, and another influential SkS journal paper too :)

  14. Global warming can't be blamed on CFCs – another one bites the dust

    I would have thought Lu's paper unpublishable, but I suppose it falls into category #2: flawed paper in off-topic journal.

    A selection from one (of many) lists of impact factors for 2012 journals (physics)

    • Nature 38.6
    • Science 31.0
    • Physical Review B 34.3
    • Physical Review Letters 7.94
    • Applied Physics Letters 3.79
    • International Journal of Modern Physics B 0.32
  15. Rob Honeycutt at 02:08 AM on 19 April 2014
    The consequences of climate change (in our lifetimes)

    Tom @10 is, as always, correct. We're talking about large mammals which could not survive at the tropics.

    Sherwood and Huber 2010 is a good read on the human aspect of this topic. They state:

    We conclude that a global-mean warming of roughly 7°C would create small zones where metabolic heat dissipation would for the first time become impossible, calling into question their suitability for human habitation. A warming of 11–12 °C would expand these zones to encompass most of today’s human population.

    So, the broader point is that, the fact that "the earth has seen such conditions" in the past, doesn't preclude the catastrophic nature of such conditions on humans. Going back to PETM conditions would reduce the carrying capacity of the earth down to a small fraction of today's human population.

  16. michael sweet at 21:50 PM on 18 April 2014
    The consequences of climate change (in our lifetimes)

    To me the issue with it beng "too hot" is can agriculture continue.  If it is too hot for cattle they cannot  be raised.  It is impossible to provide shelter to large scale agriculture animals.  Can agriculture continue with goats?  Will enough plants grow for the plants to live all year as food?  Can food crops continue to be raised?  If only weeds will grow few humans will be able to live there

    Humans could devise shelters so that they can continue to live in areas that are too hot for them without shelter.  Humans cannot live where they cannot raise food.  It takes a lot of locally grown food to support a city.  We see the interior of Australia does not support any cities because it is too hot to grow enough food.  Even in the wet north they cannot support cities because the climate is hostile to cities.

  17. The consequences of climate change (in our lifetimes)

    Another great potholer video, and the caveat at the end is a classic! (Make sure you hang around for it.) I'll just add that I would have liked to see more attention to Ocean Acidification...

  18. The consequences of climate change (in our lifetimes)

    For me human behaviour is the most frightening aspect of climate change. Not only the denial that it is happening but the breakdown of civilized society when food and water become inadequate to sustain a population growing at a rate of 200,000 a day. At what point you call it a catastrophe much depends on how well fed you are.

  19. The consequences of climate change (in our lifetimes)

    Therefore the use of CAGW, implying as it does a belief in a certain, or almost certain catastrophe from AGW, is a strawman. I have only ever seen it used for rhetorical effect by AGW deniers.


    Tom, @7, I agree totally, that's why I like (C)ostly, because I could just refuse to play their game by acting obtuse and use costly instead.

  20. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    WRT Marco's comments - interaction was essential to the development of conspiratorial ideation, the very thing being studied. This includes variations on "spammed responses", the two day "IP blocking" theory, the self-sealing extentions to UVA and some kind of world order, all the various reactions to additional information. 

    If you are studying the development of recursive conspiracy theories, you are studying them in the context of reactions to additional information, to corrections of previous conspiracy theories. 

    So yes, it's entirely consistent and in fact required to include interaction responses in this study. Complaints to the contrary seem to add up to (as somebody put it on one of the various blog discussions) a contrarian claim that "...Lew made me do it!".

  21. The consequences of climate change (in our lifetimes)

    Siberian gas venting and the end-Permian environmental crisis

    Are you not comfortable with 10% chance of catastrophe?

    Even 1 ppm (i.e. 0.0001% ) of chance of triggering the greatest massacre in human history (and possibly in all the planet history) would me be very very anxious if I were a policymaker.

    To give one idea of what I am talking about, see this paper [insert link here] (moderator, please put my link inside the [])

    It is about the most likely cause of the so-called Great Dying (officially Permian-Triassic extinction): a massive flood basalt eruption inside a oil and coal field in Siberia, the Tunguska Basin.

    Basically the magma ignited the oil and coal releasing 100 000 Gt of CO2 (and some methane). Sounds familiar?

  22. Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.

    I'm realy amused by that report. To confirm my amusement, I just wated to make sure: is it the same type of annual conference by Heartland that we used to see in previous years? Those bygone conferences I recon have been held in exquisite venues, like Hilton hotels and attreacted hundreds of people together with mainstream medias and I've seen them reported on i.e. my ABC news the same day.

    If so, the Heartland collapse is finally imminent (although long overdue).

  23. Climate contrarian backlash - a difficult lesson for scientific journals to learn


    Thanks for this important clarification. After that, I still maintain that Marco@4 intentionaly misleads readers like myself by avoiding to provide a clear context of his claim, therefore he tries to muddy the issue rather than to explain it. So I still maintain that he tells us demostrably false information in his comment@4.

    By the same token, the climate science deniers, claim e.g. that "CO2 lifetime [of individual molecule] in the atmosphere in merely 5 years". Which is "right" at the molecular level according to the Henry's law and dynamic equilibrium with the ocean but which has nothing or very little to do with the actual issue at hand of the excess CO2 persistance in the atmosphere. With such worldview, you can produce "right" claims that deny the reality ad infinitum.

    Another argument raised by Marco has not been addressed in this discussion yet:

    While the conclusions and analysis may be sound, in my opinion it was improper for several of the authors to interact with their study objects. I don't buy the "psychopathological characterization", but I also don't buy the paper to be an objective analysis. Lewandowsky should have known better and asked a third party to do the analysis.

    I find it at adds with Dana's assertion that "Frontiers [and UWA] had found no academic or ethical problems with the paper". Surely, they should have found claimed a bias of "interraction" or acquiantance, if there was one. Should the study been "double blindfolded" to be unbiased?

  24. The consequences of climate change (in our lifetimes)

    Rob @9, I think the claim that the tropics were uninhabitable by complex organisms is overstated.  What is true is that the tropics were seasonally uninhabitable by large mammals, where large means anything larger than a labrador.  It would also have been extremely restrictive for some large cold blooded creatures, and for some small warm blooded creatures.  Further, all warm blooded creatures would have been at a competitive disadvantage relative to cold blooded competitors, and relative to todays conditions.  On top of that, small animals would have been at a competitive advantage relative to large animals, and relative to todays conditions.

    That set of restrictions applies once you get sustained wet bulb temperatures of 35 C or more.  In contrast, to truly limit complex organisms in general, you need sustained dry buld temperatures above 50-60 C.

  25. Rob Honeycutt at 13:20 PM on 18 April 2014
    The consequences of climate change (in our lifetimes)

    Tom... What also often gets missed in the statement that the earth has seen similar conditions is the fact that those conditions were such that the tropics we uninhabitable by complex organisms. 

    Going back to those conditions would, indeed, be catastrophic... And very expensive along the way.

  26. michael sweet at 11:13 AM on 18 April 2014
    The consequences of climate change (in our lifetimes)


    What an extraordinarily depressing graph!  If positive feedbacks are bad (say a bunch of Arctic Methane) what will it look like?  Hopefully renewable energy will continue to go down in price and replace fossil fuels more rapidly.

  27. The consequences of climate change (in our lifetimes)

    BojanD @1, my preffered acronym is AGW, but I am happy to go with PCAGW, ie, Potentially Catastrophic Anthropogenic Global Warming.  The point, however, is that catastrophic effects from global warming are not certain.  Depending on what you consider to be catastrophic, they are even unlikely (0-33% chance) or very unlikely (0-10%).  Therefore the use of CAGW, implying as it does a belief in a certain, or almost certain catastrophe from AGW, is a strawman.  I have only ever seen it used for rhetorical effect by AGW deniers.  Having said that, I, and I hope global policy makers, am not comfortable with even a 10% chance of a global catastrophe, and think we should do something about it.

  28. The consequences of climate change (in our lifetimes)

    Harry Twinotter @3, Rob Honneycutt @5, for some impacts of climate change (eg, extinction rates), rate of change in temperature is the most important factor.  For others (eg, melting sea ice), it is absolute temperature that is the most important factor.  For the potential of a runaway greenhouse effect it is the later.  Of course, neither you nor I think the later is at all likely, and on current best evidence is not even possible in the coming millenia.

    Having said that, it is possible that the Earth will soon face absolute temperatures conditions never faced before while complex life has existed on Earth.  Below is a modified graph showing the radiative forcing due to CO2 concentration and insolation over the history of the phanerozoic (last 550 million years).  The original is from Royer (2006).  I have drawn in lines representing the radiative forcing in 2011 (2.23 W/m^2), and the expected radiative forcing for RCP 8.5 for 2100 (8.3 W/m^2) and 2300 (12 W/m^2).

    As you can see, even in 2100, radiative forcing is expected to exceed any in the past 550 million years due to changes in insolation and CO2 concentrations.  Those are not the only factors effecting radiative forcing, and the resolution of the graph is low.  It is likely, therefore, that for shorter intervals than shown radiative forcing has exceeded that expected fro 2100, and possible that it has exceeded that expected for 2300.  It is, however, by no means certain that worst cast BAU scenarios have ever been matched in the Earth's past.  

  29. Rob Honeycutt at 08:51 AM on 18 April 2014
    The consequences of climate change (in our lifetimes)

    Harry Twinotter... I don't want to give any credence to the boiling oceans idea, but I don't believe the earth has had similar conditions as today. This is specifically because the rate at which we're introducing CO2 into the atmosphere is greater than even the Siberian Traps could have achieved.

    I would also add that, eventually the oceans on earth will boil away. It's just not likely to be because of human carbon emissions. 

  30. The consequences of climate change (in our lifetimes)

    Harry Twinotter - If you listen just a few seconds past that point Peter points out that boiling oceans aren't going to happen. That statement by Hansen is often taken out of context; the context that Hansen notes that while physically _possible_, it's not going to happen on Earth as the result of our emissions.

    Context context context...

  31. citizenschallenge at 07:33 AM on 18 April 2014
    Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.


    Nicely written!

    As another who could find himself described as a "grumpy-looking old white guy" I still liked your article. :- )  I thought it was well written and it painted a vivid image.

    Also thanks to SkS REPOSTing policy I'm able to reproduce it at my blog.  

    Thanks for a job well done.

  32. Harry Twinotter at 06:05 AM on 18 April 2014
    The consequences of climate change (in our lifetimes)

    I discount the possibility of the oceans evaporating based on the fact that it did not happen before when conditions on the earth were similiar.

  33. johnthepainter at 02:59 AM on 18 April 2014
    The consequences of climate change (in our lifetimes)

    Hansen's 2012 statement, shows in the video, that we could get to a condition where the oceans would begin to boil was unfortunate and opened him to ridicule by the deniers. It shows the danger of simplifying complex matters for the public. In his most recent paper he was more careful in assessing the possibility of such an occurrence:

    "In principle, an extreme moist greenhouse might cause an instability with water vapour preventing radiation to space of all absorbed solar energy, resulting in very high surface temperature and evaporation of the ocean [105]. However, the availability of non-radiative means for vertical transport of energy, including small-scale convection and large-scale atmospheric motions, must be accounted for, as is done in our atmospheric general circulation model. Our simulations indicate that no plausible human-made GHG forcing can cause an instability and runaway greenhouse effect as defined by Ingersoll [105], in agreement with the theoretical analyses of Goldblatt & Watson [128]."

  34. Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.

    As I grumpy-looking old white guy I protest your denigrating grumpy-looking old white guys! I know you are being tonge-in-cheek, but deniers will use anything they can agianst this site. Might be better to leave out the racial humor.  

  35. The consequences of climate change (in our lifetimes)

    When I heard about EAGW, I thought why not just rename CAGW to Costly AGW?

  36. One Planet Only Forever at 14:03 PM on 17 April 2014
    Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.


    It is important to be as aware and informed as possible. The key point was the Fox TV camera. These same frauds will be the guests on many of the staged Fox News propoganda sessions. And those orchatrated song and dance numbers have a large audience of grumpy-looking old white guys with money who are easily impressed into contributing to the "Good Work being done against the Threat posed by the likes of the IPCC".

    Money and the "image it can create" still matters more than true substance in America and many of its Mini-Me type followers. It is important to be aware of the real challenge, actually succeeding at disappointing unethical powerful rich people and all those who want to be like them. That can only happen when everyone who actually wants to be a caring and considerate person genuinely interested in developing a sustainable better future for all, better understands who and what should impress them.

  37. To frack or not to frack?

    The Purdue study listed above (Caulton et al.) has now been published:

    Toward a better understanding and quantification of methane emissions from shale gas development, Dana Caulton et al, PNAS, April 14, 2014, doi: 10.1073/pnas.1316546111

  38. 2014 SkS Weekly News Roundup #15B

    The real main problem with nuclear energy is we are still way too ignorant in how to convert it directly (or at least more directly) into electrcicity. All we do is create heat and boil water with it which wastes 99% of the energy pontential. Fukushma for example, all that heat generated they were desperately trying to cool down is wasted energy ... Nuclear waste is still radioactive is generating Energy, energy that is completely wasted 

    BTW does anone know the 'Carbon Budget" for 10,000 years of babysitting nuke waste? I'm pretty sure it's going to be well about zero ......

  39. Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.

    Curious...  any idea whom the "5 grumpy-looking old white guys" or the "2 bored looking middle-aged guys playing with electronic devices" were?

    Would be nice if Heartland was discouraged by spooning with Fox will keep em excited (around) I am sure (unfortunately).

  40. Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.

    Simon,   Because this thinking is STILL controlling the Republican party almost completely as well as oil and coal democrats. The blogsphere is filled with all stripes of deniers effectively confusing the accurate science even in palces like Scientific American. So, while it may be a nutty fringe in Washington, it still has vast sway in parts of the country and prevents any legislative action on a national level. And inaction by the US gives cover for the entire rest of the world to not increase efforts to curb CO2.

    I am pleased that no legislators turned up fo this. I hope it makes Heartland rather discrouraged

  41. Simon Peatman at 01:24 AM on 17 April 2014
    Heartland logic: More people have heard of Fidel Castro than Michael Mann, therefore global warming is false.

    The tiny turnout showed that most people give this nutty fringe the attention it deserves.

    Good, but why are you then giving it publicity by writing this article?  If people aren't listening to this group of people anyway, why not just ignore them?

  42. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    A further clarrification needs to follow from my post @12.  The original retraction notice for "Recursive Fury" was approved by Axel Cleeremans, Field Chief Editor for "Frontiers in Psychology".  In contrast, the blog that attempted to alter the story was from the Editorial Office of Frontiers, the organization.  It was not a statement by the Editorial Board of "Frontiers in Psychology".  Consequently, concern about the lack of integrity shown by that statement should result in concern about the integrity of the organization as a whole, rather than one particular Journal.

    Further, neither of the authors of the blog, Costanza Zucca and Fred Fenter, are members of the Editorial Board of "Frontiers in Psychology".  Indeed, they should not have beeen.  Zucca is a physicist specializing in magnetized plasmas.  Fenter is an evironmental scientist.  That is ironic given Marco's argument above that journalists would not have a proper handle on ethical issues in Psychology as ethical requirements differ between disciplines.  If that were true, then Zucca and Fenter would themselves be in no position to judge the ethical issues involved in publishing "Recursive Fury".  Indeed, as no specialists in psychology, they appear to have put themselves at odds with the specialists from the editorial board of "Frontiers in Psychology".  

  43. If growth of CO2 concentration causes only logarithmic temperature increase - why worry?

    I would argue that the calculations in this article are not convincing, because Figure 3 represents the dynamic response rather than hypothetical equilibrium T, assuming constant remaining atmospheric CO2 fraction. These are two different entities and the entity calculated in the article is unrealistic. It's only by coincidence, that equilibrium T curve as calculated above closely matches the IPCC dynamic temp curve in response to their scenarios.

    The recent relevant literature for example Allen et al 2009, (on which the Figure 3 is based) conclude that the peak dT response to CO2 emissions (rather than equilibrium dT this article calculates) depends on the cumulative emissions but does not depend on the rate of emissions. In other words, if we burn our fossil fuels fast (e.g. RCP8.5 and stop burning abruptly due to FF limit/civilisation collapse), we reach the same maximum temperature as if we blissfuly burned FF slower (say RCP6) buf longer. The only difference is that Tmax comes earlier.

    In climate change mitigaion, peak dT response is a better measure than equilibrium dT: e.g. in icesheet stability considerations.

    As Allen et al have shown in their sumulations, within the range of possible antropogenic CO2 slug (1-5exagram C), the dT response is indeed linear. The reason of such response is the fact that dT signal lags the dCO2 signal due to ocean thermal inertia (resulting in delayed warming), while the remaining fraction of the original dCO2 in the atmosphere at the later time drops over time (due to ocean CO2 uptake). It turns out those two dynamic processes about cancel each other, resulting in almost linear dependence of peak dT and the emission slug. And that explanation is the key outcome, alowing a simplified measure of cumulative CO2 emissions as the only restriction is climate change mitigations.

  44. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    Dana, WheelsOC, Chriskoz, in this dispute, the title of the journal "Frontiers in Psychology" has often been abbreviated as "Frontiers", thereby leading to confusion.  Frontiers, according to their blurb, is "... a community-oriented open-access academic publisher and research network".  Frontiers publishes nearly fifty journals, all of them called "Frontiers in XXX", where XXX is the name of some particular academic specialization.  The three editors that resigned are all editors for Frontiers.  One is an editor for two of their journals, but none of them are editors for "Frontiers in Psychology", ie, the journal that published and then withdrew "Recursive Fury".  The OP does get that wrong, and should have an update noting the error.

    Marco @4, OK, you got the above right but so what?  The editors in resigning have shown that they feel the retraction of "Recursive Fury", with subsequent comments so calls into question the integrity of the entire organization that they have resigned from any participation in that organization.  How is this better than merely calling into question the integrity of just one journal published by Frontiers?  To my mind it is a much greater indictment.

  45. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    John Vonderlin@8,

    You assert that you occupy "different part of AGW spectrum" but you said nothing substantial.

    For example I'm interested in your argument in response to "Wheels OC" (sic!): 'A number of other blogs, mainly Contrarian, have dissected this issue "ad nauseum."' Please give me an example together with your short comment as to what that example shows. Note that a short comment is required per this site's policy - "naked links" are not accepted.

    Your responses to One Planet Only Forever and dana1981 appear to be not in good faith, but rather ad hominem trolls so I'm not interested in them.

    But I note hewever, that in case of your response to dana1981, you're engaging in the nitpicking spell/grammar checks, while on the other hand you mispelled WheelsOC's name. While I don't engage in spelling nitpicks, people names are an exception to me. IMO, the care of name spelling is a sign of respect towards others on the internet. So I understand Lewandowsky who suggests the same with his "Say whatever you want about me, but be sure to spell my name right." You seem to denigrate/not understand the issue of person's name respect. No surprise, because you've denigrated WheelsOC's name in the same message.

    Moderator Response:

    [JH] Vonderlin's post was nothing more than concern trolling and therefore was deleted.  

  46. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    Marco@4, your prologue statement

    First, "the journal" when referring to Frontiers is wrong. None of the people who resigned are from the journal that published the Lewandowsky paper


    This is a rather bold statement. However, you pronounced that statement "as is" without any supporting evidence. By contrast, dana has provided the link to the blog by one of the resigned editors Björn Brembs (that I repost here) entitled Recursive fury: Resigning from Frontiers, where Björn writes:

    In the coming days I will send resignation letters to the Frontiers journals to which I have donated my free time for a range of editorial duties.

    Given this evidence, I conclude that your statement is demostrably false. Unless you can show some link that supports your statement and contradicts the evidence herein, I stop reading all of your comments. I generally stop reading comments by people who are not debating in good faith or by paople who tell demostrably false information.

  47. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    WheelsOC, care to tell me what relevant expertise McKewon has to allow her to make a qualified judgment about the ethical guidelines in the field of *psychology*? Journalists have different rules than psychology.

    One can even find differences in rules *within* scientific fields, depending on the region. There are known examples of medical studies being performed in certain places because the rules there are less strict, and resulting discussions of whether someone from country A should be allowed to perform the studies in country B to deliberately circumvent the rules in country A. Some say yes, some say no.

    Note that there also is the very real possibility she was not involved in the discussions about the other complaints (several came quite a bit later, I have understood).

    In the meantime, Kenyon can easily take the "no ethical concerns" while also supporting the same concerns as raised later by several Frontiers staff higher up the food chain. I disagree with the idea that the other concerns are "legal" in nature, but I can also see how they can be constructed as such (rather than ethical). Plenty of things are illegal but ethically defensible, and vice versa.

  48. The Debunking Handbook: now freely available for download

    Fantastic information but I would also like to request either a Kindle version or at least abandon the two column format. It's pretty hard to read this pdf on a Kindle or tablet.

  49. IPCC says adapt and mitigate to tackle climate risks

    Just an observation: pretty much every problem under the "environmental" rubric is an unintended consequence of a solution to some other problem. Civilization itself is a consequence of the invention of agriculture as the solution to some mesolithic clan's food security problem.  One doubts the first farmers foresaw, much less intended, all that's happened since then.

    However global society reacts (or doesn't) to AGW, we can be sure there will be winners and losers, and that even what's intended "for the benefit of all mankind" will be to the detriment of countless other species. 'Twas ever thus!

  50. Climate contrarian backlash - a difficult lesson for scientific journals to learn

    It seems to me that your objections are basically just raising points that A) have none of the evidence necessary to support them, and B) are already contradicted (not just spoken around) by the evidence we do have. You have to assume that there's more going on than we have any evidence for (which is not implausible by itself), and you have to assume that the evidence we already have from multiple sources has been falsified or is inadmissable for some reason (which has some credulity-stretching to do).
    If McKewon's version of events does not discuss the "other complaints," then we can either assume that those other complaints were not at stake at all or that they were not something on which the journal felt she could give any valuable input. I don't find the latter to be very convincing. Why wouldn't she have the relevant knowledge about issues of potentially unethical revelation of sources being quoted for publication? Doesn't she have a background in journalism?

    Kenyon's statements seem to go beyond lawyerly bafflegab and misdirection; he flatly states that Frontiers' investigation found no academic or ethical problems with the paper. He plainly describes the paper as "ethically sound." This is entirely consistent with the version of events relayed independently by both Lewandowsky and by McKewon, and perhaps unsuprisingly with the original retraction statement. It's not consistent with the version of events later given by Frontiers (it might be reconciled with their second statement if we give THEM the benefit of circumspection in their choice of words, but doesn't work with the third). I've considered his words from several angles and can't reconcile it with the idea that mere "lawyerspeak" explains the discrepancy. It's not as though he's avoiding the question of ethics to shift the focus onto something else, he directly deals with it. So either he lied about there being ethical issues and convinced everybody to sign a statement to that effect, or there didn't turn out to be any ethical issues. A pinch of salt tastes insufficient here. Maybe that's just lack of imagination on my part; I'd love to hear some proposed explanations that don't boil down to either of "Kenyon's lying" or "the editors are lying."

    I'm not settled on the answer yet, but so far the arguments marshalled to support the journal's side of the story are unconvincing and weak. We can't expect one of the reviewers to know this stuff, and we can dismiss unambiguous statements just because they came from a lawyer? It still seems simpler and more consistent to conclude that the editors are in damage-control mode, and that it's they who are engaging in some kind of misdirection to deflect criticisms in the wake of first legal, and then academic backlash, rather than the other sources being ignorant (McKewon) or dishonest (Kenyon, Lewandowsky[?]) about the issues leading up to the retraction.

    The apparent shift in the journal's stange in going from "This investigation did not identify any issues with the academic and ethical aspects of the study. It did, however, determine that the legal context is insufficiently clear," to this later version implicating ethics rather than "legal context" seems to have caught everybody flat-footed, which we wouldn't expect if they were all privy to the conversation. If the discussion really did revolve around this ethics angle from the start, why didn't anybody else involved in it take that message from it? I also find it compelling that the University of Western Australia has decided that the paper as published is defensible enough to host on their servers, even though Lewandowsky has moved on to Bristol in the UK. And so far, the journal is the only side in this to have seemingly changed their tune in the wake of outside reactions.

    It could come out that this is all wrong, but we'd need e a lot of very convincing evidence to the contrary coming to light. The contrarian position simply doesn't have a lot of wiggle room right now.

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