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2014 SkS Weekly News Roundup #43B

Posted on 25 October 2014 by John Hartz

Recently discovered microbe is key player in climate change

As permafrost soils thaw under the influence of global warming, communities of soil microbes act as potent amplifiers of global climate change, an international study has shown.

Tiny  are among the world's biggest potential amplifiers of human-caused climate change, but whether microbial communities are mere slaves to their environment or influential actors in their own right is an open question. Now, research by an international team of scientists from the U.S., Sweden and Australia, led by University of Arizona scientists, shows that a single species of microbe, discovered only very recently, is an unexpected key player in climate change.

The findings, published in the journal Nature, should help scientists improve their simulations of future climate by replacing assumptions about the different  emitted from thawing permafrost with new understanding of how different communities of microbes control the release of these gases.

Recently discovered microbe is key player in climate change,, Oct 22, 2014

Researchers resolve the Karakoram glacier anomaly

Researchers from Princeton University and other institutions may have hit upon an answer to a climate-change puzzle that has eluded scientists for years, and that could help understand the future availability of water for hundreds of millions of people.

In a phenomenon known as the "Karakoram anomaly," glaciers in the Karakoram mountains, a range within the Himalayas, have remained stable and even increased in mass while many glaciers nearby—and worldwide—have receded during the past 150 years, particularly in recent decades. Himalayan glaciers provide freshwater to a densely populated area that includes China, Pakistan and India, and are the source of the Ganges and Indus rivers, two of the world's major waterways.

While there have been many attempts to explain the stability of the Karakoram glaciers, the researchers report in the journal Nature Geoscience that the ice is sustained by a unique and localized seasonal pattern that keeps the mountain range relatively cold and dry during the summer. Other Himalayan ranges and the Tibetan Plateau—where glaciers have increasingly receded as Earth's climate has warmed—receive most of their precipitation from heavy summer monsoons out of hot South and Southeast Asian nations such as India. The main precipitation season in the Karakoram, however, occurs during the winter and is influenced by cold winds coming from Central Asian countries such as Afghanistan to the west, while the main Himalayan range blocks the warmer air from the southeast throughout the year.

Researchers resolve the Karakoram glacier anomaly, a cold case of climate science,, Oct 22, 2014


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Comments 1 to 50 out of 55:

  1. How can a key player in climate change be recently discovered?   I thought the science was settled?   Except for all the aspects that aren't settled I guess.  Maybe it's a case of you don't know what you don't know. 

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    Moderator Response:

    [PS] Please drop the rhetoric.

  2. Donny @1, can you explain exactly which physical law relevant to global warming has been refuted or ammended by this discovery in biology?  (Or are you just making an empty rhetorical point?)

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  3. Donny...  Think of it this way. You're assembling a puzzle. You have a large number of the pieces in place and they fit together well. You have a strong understanding of the overall image but not all the pieces are in place. You've been trying to fill in a certain area and then you come upon a key piece that explains one area of the image.

    The image didn't change, you just understand it much better.

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  4. Tom.  The point is.... the science is not yet settled or complete for that matter . .... hence newly discovered key climate change player.   

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  5. I am not sure if you want to call the point rhetorical or not. ... but if you don't understand that the climate may not react the way we predict it will in response to increased CO2 because of factors like this that we are just discovering. .... then I don't know how else to discribe it to you.   Let me ask you ...if you think there are other key players in climate change that are still unknown or undiscovered?   Or was this the final piece of the puzzle? 

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  6. Donny...  When people say "settled science" they're referring to the fundamental principles. We understand that humans are warming the earth through emissions of greenhouse gases and that those emissions, unchecked, will likely cause serious issues in the future. That is settled science. 

    Science, though, is always pushing to better understand every aspect of the field of research.

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  7. Rob.... that would be true if everything else was a constant.... if nothing else changed.... it is pretty hard to isolate variables in nature. ... especially when studying the climate as so many systems are involved.  Geological systems,  biological systems, solar systems. The only thing that is settled is... that in a vacuum increasing CO2 will increase the temperature.   We however don't live in a vacuum.

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  8. Donny...  So, are you saying you think there is potentially something out there that would completely alter our understanding regarding the human causation of global warming?

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  9. Rob.... I understand what you are saying. ... but can't you see that there are biological mechanisms that very well could be "unchecking" our emissions as we speak.  And when I hear about the serious issues that warming is likely to cause. ... they don't seem overly scary.  These serious issues are also extremely weakly linked to warming.

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  10. Rob... I think it will become increasingly hard to maintain elevated co2 levels because of poorly understood biological mechanisms.   When mice are plentiful owls flourish until the mouse population declines.  I think the same thing will happen with co2.  CO2 is a food of sorts. 

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  11. Donny...  But you do understand, I hope, that the science on climate change approaches the theory from hundreds of different directions, and nearly all those approaches are in general agreement. Even if there is one new aspect that is interesting that pops up, it's unlikely to overturn the broader understanding of the science. It's merely going to reveal to us why things are the way we understand them to be.

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  12. Whether it's hundreds or thousands of approaches they all have the same problem of lack of enough time in the game.   They are all rookies.  

    You make it sound like we understand everything but we just haven't sorted out the details. ... in reality we don't understand much.   We think the ocean currents are a major player. ... but are basically clueless when it comes to understanding them.  And that's just the tip of the iceberg.   Sometimes the more you learn the more you realize how clueless you really are. 

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    Moderator Response:

    [PS] This is empty rhetoric. Not knowing 100% is not the same as knowing nothing. Unless you have something other rhetoric to offer, with data/papers to back your claims, then I would suggest this discussion is over. Either discuss the science or find some other blog for your entertainment.

  13. Not saying we understand everything. I'm saying we have 150 years of research on all the fundamental elements of this issue. We actually understand a great deal. It's highly unlikely that something is going to pop up to substantially alter our fundamental understand of man-made global warming.

    Understanding of ocean currents are not likely to change any fundamental conclusions. 

    Definitely the more we know, the more we understand what we can know. But I would have to reject that makes us clueless. Understanding more does not means what we've already come to know is of less value. The big issues are well understood. That is settled science. The nuances are what are fascinating to learn.

    For instance, at the turn of the 20th century Arrhenius made the earliest calculations for climate sensitivity. Those estimates have been shown over time to be fairly good. We are highly unlikely to suddenly discover sensitivity is below 1.5C or higher than 5C. 

    Improving our understanding of central climate sensitivity estimates from, say, 2.8C to 2.9C doesn't mean Arrhenius' estimates were clueless. It was his work that put us on the path to our current understanding.

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  14. Donny, @7:

    "The only thing that is settled is... that in a vacuum increasing CO2 will increase the temperature."

    Also @10:

    "I think it will become increasingly hard to maintain elevated co2 levels because of poorly understood biological mechanisms. When mice are plentiful owls flourish until the mouse population declines. I think the same thing will happen with co2. CO2 is a food of sorts."

    So, from these two examples we establish that Donny does not know the science he disputes.  Specifically, CO2 in an atmosphere warms the surface.  Adding the equivalent mass of CO2 to that in the Earth's atmosphere to the Moon in gaseous form would increase the Moon's surface temperature neglibibly.  Remember, ΔT = ΔAEff * Γ, where ΔT is the change in temperature, ΔAEff is the change in the effective altitude of radiation to space, and Γ is the lapse rate.  No atmosphere means no lapse rate.

    Further, change of CO2 concentration over time is not modellable as a predator/prey relationship.  Further, even allowing the facts that CO2 is plant food, and increased CO2 therefore results in increased growth of plants, deforestation has contributed <10% of total CO2 emissions and therefore a food model for eliminating CO2 requires forestation to the extent of >10 times the total deforestation from the industrial period to now (for which theres is simply not the habitat space); and further, plants certainly are food for insects and other animals so that a growth in plant biomass will result in a growth insect and herbivore biomass which will limit the capacity of simple biomass growth to remove emissions.  (From the last point we see that Donny does not even understand the science he mistakenly appeals to in order to believe that there is no problem.)

    If he does not understand the science, he is in no position to assess whether the evidence todate settles it with reasonable certainty.  His claim that it is not settled is, therefore, a faith claim.  He is required to believe it by his ideology, not by the evidence.  

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  15. Tom.... were you bullied as a child?   Grow up and stop insulting someone you don't know. I forgot Tom knows everything about every scientific field.   

    Tom.... when I used the term vacuum. ... I was implying that there were no other variables. .... not if it was done in an actual vacuum.  I'm sorry you were the only person to not understand that. 

    With regard to your deforestation rant.... thanks for allowing for co2 to be considered plant food as I am sure that is settled science.  Oceans my friend cover twice as much space as land and have huge potential to buffer available co2. 

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    Moderator Response:

    [PS]Everyone, please abide by comments policy. Inflammatory remarks do not move a debate forward. Donny, people are trying fill gaps in your understanding. You could do everyone a favour by familiarizing yourself with the basic science - start with either a textbook or the IPCC report.

  16. Rob.... I respect the way you discuss these issues. ... even though I know you disagree with my views on how things are likely to play out.

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  17. Donny, I don't believe I insulted you.  I said you don't understand the relevant science, which clearly you do not.  I concluded from that that when you make assertions about what we do, or do not know about the science you are not basing those claims on an understanding of the science.

    Now, I would be delighted to be proven wrong on either point.  Clearly we cannot do it with regard to the vacuum comment which you now claim was figurative (apparently never having heard of the phrase "all else being equal").  So, you claim the CO2 content in the atmosphere is modelled by a predator/prey relationship.  The obvious questions then are:

    1)  Which (set of) equation(s) to model the predator/prey relationship do you use?

    2)  Over what period have you modelled the CO2 content of the atmosphere using the equations specified in response to (1)? 

    (3)  What emperical evidence did you use to test the validity of those equations in modelling the CO2 concentration of the atmosphere?

    Absent answers to the above, you alternative theory of CO2 concentration is not scientific.  It is neither modelled (ie, you don't have an actual theory, just a phrase which can be trotted out to pretend its a theory) nor tested.  Ergo, absent answers to the above, my conclusion that your claims about the uncertainty of the science of global warming are not based on understanding the science are in fact borne out.

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    Tom.... this should help you understand the science that I am talking about. 

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    Moderator Response:

    [PS] Much more useful thank you.

  19. Donny @18, thankyou, but I prefer this version, from which:

    "Supplementary Fig. 4a depicts ΔDICorg as a function of atmospheric pCO2, with the present day value (ΔDICorg at 380 μatm) set to 1. Extrapolating the observed trend to pre-industrial CO2 levels (pCO2 = 280 μatm) yields a value of ~0.95; that is, for a given amount of inorganic nutrients, biological carbon consumption under pre-industrial conditions was about 95% of today's level. On the basis of this relationship, an increase in atmospheric CO2 from 280 μatm to 380 μatm (present day) corresponds to an excess carbon sequestration of 22 Pg (range 14-29 Pg) for the past 150 yr (Supplementary Fig. 4b). Without this negative feedback mechanism, atmospheric CO2 would be approximately 11 μatm higher than its present value. By the end of this century, this process would sequester an additional 94 Pg C to the deep ocean, bringing total excess carbon sequestration to 116 Pg C (range 76-154 Pg C). This reduces the increase in atmospheric CO2 by a total of 58 μatm at 2100."

    That is, by 2100, CO2 concentrations will rise to 700 ppmv rather than to 760 ppmv, with a total change of radiative forcing of 0.44 W/m^2, or a 0.2 C difference in temperature based on the transient climate response.

    Returning to your original claim, we see that the actual study on which you purport to rely does not back it up.  The study finds it very convievable that we will achieve and maintain high CO2 concentrations.  They have found an effect that may reduce the increase in CO2 concentration by a small amount (and hasten its decline over millenial time scales).

    I say "may" because their plots were essentially predator free, and the presence of planckton eaters may significantly reduce the effect.  Further, the algal blooms are significantly limited by the availability of nutrients so the generalization of the results to non-isolate plots and to non arctic waters must be considered tenuous.  Further, you assume also that there are no other effects currently not-known or poorly quantified that will balance out in the other direction.

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  20. Donny @19, it is easy for you to say.  You do not, however, do it.  Nor do you show examples from the copious literature on the determinants of CO2 concentration and rates of draw down that support your claim.  I have no inclination to treat the mere assertion of "random internet guy" as evidence, and you evidently have nothing better to offer.

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  21. Thank you for posting about this important new research on the role of microbes in thawing permafrost. If it is permitted to have a try to start a conversation about the actual contents of the study rather than just swatting at distractions, I'd like to point out the following passage:

    "Researchers suspected that it played a significant role in global warming by liberating vast amounts of carbon stored in permafrost soil close to the Arctic Circle in the form of _methane_, a powerful greenhouse gas trapping heat in the Earth's atmosphere. But the actual role of this microbe—assigned the preliminary name Methanoflorens stordalenmirensis, which roughly translates to "methane-bloomer from the Stordalen Mire"—was unknown.

    The new research nails down the role of the new microbe, finding that the _sheer abundance of Methanoflorens, as compared to other microbial species in thawing permafrost_, should help to predict their collective impact on future climate change."

    So if these microbes produce methane and if one of the main finding of the study concerns their 'sheer compared to other microbial species in thawing permafrost"--then can we conclude that thawing permafrost will produce methane in much higher portions than previously thought?

    And if so, do we have new calculations on what the consequences of such thawing will be on total global warming?

    To be more specific: A while back, you published an piece about an article by McDougal et al. that pointed out that, if you include just part of the permafrost feedback, we are already at the point where, even if all further human GHG emissions were stopped immediately, atmospheric CO2 levels would stay at current levels or even increase over the next couple hundred years (unless unrealistically low climate sensitivity was assumed).

    Modeling the permafrost carbon feedback

    Since that even that model optimistically modeled ONLY CO2 being emitted from the thawing permafrost, I would expect that in the light of this new research the graphs at figure 3 in the above-linked article would need to have steeper upward slopes for future atmospheric CO2 levels going forward, even if all emissions were stopped tomorrow. Or am I missing something?

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  22. Donny, it has been interesting to follow your persistent attempts to essentially claim that it is OK for already fortunate humans to continue benefiting from the burning of as much non-renewable buried hydrocarbon as quickly as they can get away with, because absolutely everything that might be related to the impacts of that activity is not known.

    This 'new' discovery adds to the concerns regarding the potential rate of climate change. And there are a substantial number of wealthy people who want to prove otherwise. In spite of their massive wealth and motivation to discover such proof they have failed to 'discover' any significant counter-claim. All that has been accomplished to date by that 'massive amount of money wanting to make more money any way it can get away with' is the development of creative attempts to discredit or dismiss the science, attempts that do not withstand careful scrutiny, claims that are ultimately as unsustainable as the unacceptable activities they attempt to prolong.

    Hopefully the unsustainability of such attitudes and actions regarding activities that are ultimately unsustainable and are, without significant doubt, harmful is clarified by the way I have presented the attitude that would lead a person to attempt to create and try to prolong the popularity of such thinking.

    Any activity that is unsustainable and harmful needs to be limited to the rapid development of a sustainable better life for the least fortunate. Anyone else trying to benefit from those activities, including trying to mislead thinking about the acceptability of what some powerful fortunate people try to get away with, is clearly certainly unacceptable.

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  23. So Donny quotes an article from Science Daily suggesting plankton respond to increasing carbon dioxide by increasing their ability to absorb CO2. The only problem is this has numerous negative side effects for the oceans so gets us nowhere. We wreck the oceans to save the planet. Wow, thats helpful.

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  24. wili @21:

    "So if these microbes produce methane and if one of the main finding of the study concerns their 'sheer compared to other microbial species in thawing permafrost"--then can we conclude that thawing permafrost will produce methane in much higher portions than previously thought?"

    No, we can't assume that.  In fact, this quote from the article suggests the opposite:

    "The models assume a certain ratio between different forms, or isotopes, of the carbon in the methane molecules, and the actual recorded ratio turns out to be different," said lead author Carmody McCalley, a scientist at the Earth Systems Research Center at the University of New Hampshire who conducted the study while she was a postdoctoral researcher at UA. "This has been a major shortcoming of current climate models. Because they assume the wrong isotope ratio coming out of the wetlands, the models overestimate carbon released by biological processes and underestimate carbon released by human activities such as fossil-fuel burning."

    What is not clear from the article is how significant that impact is.  To start, the decrease in expected emissions is only temporary:

    "Soil microbes can make methane two different ways: either from acetate, an organic molecule that comes from plants, or from carbon dioxide and hydrogen.

    "Both processes produce energy for the microbe, and the microbe breathes out methane like we breathe out carbon dioxide," McCalley said. "But we find that in thawing permafrost, most methane initially doesn't come from acetate as previously assumed, but the other pathway. This ratio then shifts towards previous estimates as the frozen soils are turned into wetlands and acetate becomes the preferred carbon source."

    (My emphasis)

    For a second, my (relatively ill informed) understanding is that permafrost is thawing more rapidly than model expectations, given which we do not know whether the reduced initial methane generation counters that more rapid melt (if my understanding is correct) decreases it beyond that.

    In essence, from the article we do not know the percentage impact on forcing over time of this discovery.  It is likely to be small, as in the case of Riebesell et al I discussed @19 above, but may not be.  I have not commented on it specifically in response to Donny because we would have to read the actual paper (and possibly additional related papers) to know.  We certainly do not know simply from a headline, which seems to be Donny's method of judgeing the issue.

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  25. NigelJ "We wreck the oceans to save the planet. "

    On a planet that's mostly covered by oceans, that is indeed a rather funny proposition...

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  26. One planet.... I never said we should continue to burn fossil fuels. ...   I think we should stop using fossil fuels for 3 reasons. ... 1. It will make the US less dependant on other countries.   2.  It is a finite resource.   3.  C02. 

    Humans being fortunate is nowhere on my list. 

    My problem is with the settled science rhetoric. 

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    Moderator Response:

    [PS] Let's be perfectly clear. The IPCC report is fully of statements about certainty and the extent to which to the science is known. The statement obviously lead to the conclusion that the science is sufficiently settled for it to inform policy.

    There has never been a claim that everything is known - otherwise no research would be needed. To claim that any new discovery somehow invalidates that, is to construct a strawman fallacy and thus is rhetoric. To seriously invalidate that claim would mean new science that countermands conclusion of the IPCC that would affect policy. Nothing presented remotely challenges any of that, but feel free to provide some serious evidence.


  27. Donny...  Look at your #3. 

    The reason we should stop using fossil fuels is because the science telling us that our emissions of CO2 are warming the planet is settled (enough) to take strong action.

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  28. Given his difficulty in actually defending his position, I'm going to try and unpack Donny's confusion about CO2 and predator/prey relationships a little.  Hopefully that will allow him to actually put his thoughts on a scientific basis, instead of relying entirely on assertions about how silly I am for not recognizing this obvious truth.

    To start with, as a matter of definition, phytoplanckton are not predators, they are autotrophs.  Predators, by definition, are "organisms that prey on other organisms".  CO2 molecules, it need not be said, are not organisms.  An autotroph, in contrast, "... is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) from simple substances present in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis)."  Donny appears to believe that the simple fact that plants (and phytoplanckton) consume CO2 makes their relationship to CO2 a predator/prey relationship, but that is simply not so.

    That does not, in itself mean that the relationship cannot be modelled as a predator prey relationship.  Several attempts have been made to mathematically model that relationship, and there is no a priori reason why the same mathematics should not effectively model CO2 concentrations.  In detail, however, all such predator/prey models give the "prey" a base population growth that is an exponential function of its current population.  Thus the population in a years time might be modelled as the current population times 1.05 less a predation factor, which in the absence of predation leads to exponential growth.  Clearly, however, growth in CO2 concentration is not a function of its current concentration.  What is more, in the absence of draw down factors, and ignoring anthropogenic contributions, its growth would be linear.

    Again I would welcome Donny's attempt to defend his ideas beyond the simple slogan of "isn't it obvious".  To that end, here is a generalized account of predator/prey relationships.  And here is an account of one of the more successful models of CO2 concentrations, including a complete list of relevant formulas in appendix 1.  I invite Donny to specify which equations in the model follow the generalized form of predator/prey relationships.  If he is unable to do so, perhaps he will have the grace to admit his error.

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  29. I think we are warming the planet, and the science is compelling. However playing "devils advocate" I think the use of the term "settled science" was unfortunate as it leads to obvious sceptical responses. Nothing is ever 100% settled in science, as in 100% proven or understood, so the term is a bad one. It would be more accurate to have said the science is strong, or simply that there is overwhelming agreement with climate scientists.

    And the science is certainly very strong on basic concepts like the greenhouse effect, as strong as any theory in science. And lack of knowledge on details does not invalidate basic findings about climate change.

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  30. nigelj @29, are you of the opinion that it is still an open question as to whether the Earth is a nearly flat plane, or an oblate spheroid?  Or that it is an open question as to whether the inner planets orbit the center of gravity of the solar system (which is usually inside the Sun's diameter) or the center of gravity of the Earth?  Or that the brain is a cooling mechanism for the blood rather than the center of thought?

    People often (thoughtlessly IMO) run the "nothing is settled in science" line simply because they have in mind only high end theories currently and actively disputed by the scientific community, or because they are overly impressed by the transition from classical physics in the early twentieth century (without properly understanding it).  In point of fact, however, science has resolved some issues to the effective limit to which any emperical issue can be resolved.  What is more, even such radical transitions as the shift between Gallilean and Relativistic kinematics, or from classical to quantum mechanics did not alter empirical predictions in normal situations beyond the error in measurement except in very few cases.  The underlying theory changed radically, but for the most part the predictions were conserved.  Given this, the idea that a science cannot be settled amounts to a claim that the only knowledge is deductive truth - a position not distinguishable from pyrhonian skepticism in its consequences.

    It is better to say that little of science currently being researched is settled (and that for the obvious reason that if it is settled, it is not researched).  On that basis, the claim that "climate science is settled" is obviously true if restricted to atmospheric physics.  It is true within limits for such things as climate sensitivity (which is known to lie in the 1.5-4.5 C range from paleoclimate as well as from models and current temperatures).  And is not true for some key aspects climate science for projecting future impacts of a changing climate.  Thus, I have a problem with the phrase (which I very rarely use) due to its ambiguity of scope.  The idea that radiative physics does not imply a greenhouse effect, or that the climate sensitivity could be very low (below 1 C per doubling) or even negative are simply unsuported nonsense.  With respect to such claims, the science is settled, and those claims are false.

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  31. Tom Curtis. No obviously I accept the world orbits the sun. Some things about the physical world are totally proven or settled to my satisfaction, at least for all practical purposes. Of course there is an argument that proof belongs only to mathematics, but I feel that is a pedantic argument.

    I was really thinking about your more advanced science concepts like relativity and quantum physics. While these clearly provide fully accurate predictions, neither is 100% proven. They are settled in some aspects, but not others.

    Yes atmospheric physics is arguably settled or highly proven. The Greenhouse effect is settled. You say climate sensitivity is settled by being in a certain range, and that it is settled as being in the middle of the range. However all we know is it is most likely in the middle of the range. I think that is stretching credibility to say climate sensitivity is settled, although I personally think it is in the middle of the range.

    My point is terminology and about perception. When climate scientists say to the public "the science is settled" the public assume all the science is settled down to the fine details and with total certainty. This leads the term open to attack by sceptics. I feel it was the wrong term to use in terms of communication to the public, however I suppose we are stuck with it.

    There is also another dimension. Humanity does not have the luxury of researching this climate sensativity issue for the next 100 years to get 100% certainty, because we are faced with making time dependent decisions. We have to go with good estimates, and this needs communicating better to the public.


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  32. nigelj @31, I think you have misunderstood what I was trying to say about ECS, although the fault lies in my poor expression.  Consider the following Probability Density Function for ECS:

    It is a log normal distribution with characteristics matched to fit the IPCC AR5 information for the probabilities of different values.  That is, there is a less than 5% chance of an ECS less than or equal to 1 (actually, 3.71%), an at least 66% chance of an ECS between 1.5 and 4.5 (66.64%), and a less than 10% chance of an ECS greater than or equal to 6 (7.87%).  It is very close to a best fit PDF for the IPCC values and may reasonably be taken as representing the IPCC AR5 PDF for ECS.  Out of interest, it has a mode of 1.99 C per doubling, a median of 2.72 C per doubling, and a mean of 3.18 C per doubling.  Its 95% range is 0.91-8.15, and its 90% range is from 1.08 to 6.83.

    My point is that substantial evidence and carefull consideration of that evidence has gone into that PDF.  A theory that proposes a PDF very greatly different from it, therefore, is likely to be in conflict with much of that evidence and hence not emperically supported.  This does not rule out alternative estimates.  Lewis and Curry (2014), for example, estimates a mode of 1.64 C per doubling, and a 90% range of 1.05-4.05 C per doubling.  So while there are a number of indentifiable flaws in that paper, all (as it happens) lowering the estimated ECS, we cannot look at that estimate and say it is absurd because it differs too much from the IPCC estimate and "the science is settled".

    In contrast, however, if we see estimates of 0.2 C per doubling (Eschenbach, WUWT), 0.67 C per doubling (Bjornbom 2013), or 0.39 C (Hockey Schtick misinterpretation of Levitus 2012), we can reasonably dismiss them on the grounds that the science of climate sensitivity is sufficiently settled to exclude such radical outliers.  A specialist discussing the issues could not be so dismissive, needing to actually identify errors in the estimates (which is in general trivially easy to do).  But for those estimates to be right, too many other reasonable estimates have to be too radically wrong.  Ergo we would require something more than a blog post from somebody known to not understand the science (Eschenbach) or a misinterpretation of TOA net radiative flux with radiative forcing (Hockey Schtick) to reject that other evidence.

    I note a similar issue applies with respect to Relativity, and Quantum Mechanics (a point you failed to note).  Underlying theories can be radically revised, but the predictions of the new theory must almost exactly match the predictions of the old theory under the range of normal (for middle size organic being) conditions.  If they did not, the new theory would be refuted by the very observations that were previously thought to support the old theory.  Thus, while theories are always in flux, and may always be supplanted, they will always provide good approximations to the results of the supplanting theories accross the range of normal conditions.  It is for that reason when NASA designed the grand tour of the solar system with Voyagers 1 and 2, they used Newtonian dynamics rather than General Relativity.  In essence, for any well developed theory, the theory itself may be in flux, but its predictions, ie, its actual scientific content, to a close approximation and across the range of conditions under which it was first successfully tested, are settled.  Ergo, if radiative physics were overturned tomorrow, we know that the new theory that supplanted it would still predict an atmospheric greenhouse effect.

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  33. Donny wrote "My problem is with the settled science rhetoric."

    try reading this article by climate modeller Gavin Schmidt

    Skeptic blogs and journalists frequently claim that climatologists say that the science is settled, but that doesn't mean it is true.  As Gavin says, science is not binary, it is almost never "settled" or "not settled", there are always varying degrees of certainty/uncertainty.

    "settled science" like "CAGW" is is essentially a straw man misrepresenting the mainstream scientific poistion by characaturing it as ignoring uncertainties, but you only need to browse the IPCC reports for a few minutes to find out that it is packed full of statements of the degree of uncertainty on a wide range of topics.  This is, to say the least, "inconsistent" with the idea that the mainstream scientific position is one of "settled science".

    If you don't like the "settled science" rhetoric, you would be better off asking the skeptics to stop using it! ;o)

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  34. Tom @ 30 last paragraph. ... I agree with your statement about scope.  I agree with the scope of "settled science" to include co2 as a greenhouse gas.

    I would have trouble with assertions of the science being settled to include exactly how much co2 increases will actually warm the planet. 

    I also have trouble with quantifying the effects of other known drivers as well  (obviously ) unknown drivers and saying we have these effects pinned down enough to consider them settled. 

    And I certainly don't think figuring out how all these factors are going to interact is anywhere near settled.

    So when politicians use the term settled science to back a policy that gives them another reason to raise taxes you can understand why it may frustrate someone who opposes tax increases.

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  35. Donny - "Settled science" is a term that came into popularity due to (primarily) the discussions over the impacts of tobacco, as a strawman argument raised by the tobacco industry to dismiss strong epidemiological results. It's essentially a claim that we can never know enough for absolute unquestionable certainty, hence we don't know anything, hence we shouldn't act on the less than absolute information we have. This use/abuse has been carried forth by denial arguments into discussions over ozone, CFCs, acid rain, EPA SuperFund site cleanups, and now climate change. The term is a shibboleth of denial, of avoidance, of sticking fingers in your ears and singing "la la la...".

    In short, the term "settled science" is a bit of rhetorical nonsense. And quite frankly the only reason it gets employed by anyone with evidence backing their argument is that the (do nothing) opponents shout it so much, trying to make it a term of the discussion. 

    In science, in any system of inductive reasoning or generalization, there will always be some uncertainty, some possibility of error. But the likelihood of a major reversal of inductive reasoning decreases hugely with increasing evidence, as whatever alternative explanation must not only further reduce uncertainty where it exists, but must also explain all the previous observations - a notable failure of climate 'skeptic' arguments. 

    Do we know the exact value of the gravitational constant, let alone how gravity interacts with matter on a quantum level? No, there is uncertainty there. However, do we know that objects in a gravitational field will drop if you let them go? Yes. Because uncertainty around the edges of a theory don't invalidate core principles. If we drop a bowling ball, we certainly know enough to move our foot out of the way. 

    So despite your doubts the direct warming of a CO2 doubling is about 1.1°C, as established by spectroscopy and line-by-line radiative codes (see Myhre et al 1998), something known to extremely high certainty and empirically verified within 1% (Harries et al 2001). As to the rest, the amplifying feedbacks, the impacts, etc., I would suggest looking at the literature, for example the IPCC reports - the 1.5-4.5°C per doubling of CO2, most likely value 3°C/doubling, represents the best estimates to date with only a 1/20 chance of being outside that range based on the evidence. 

    Settled? No. With bounds on uncertainties tight enough to provide information for deciding policy? Yes. We don't need absolute certainty to act, or we would quite literally never get out of bed in the morning. 

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  36. Donny"...when politicians use the term settled science to back a policy that gives them another reason to raise taxes you can understand why it may frustrate someone who opposes tax increases." And here we get to the gist of matters. 

    You seem to object to the science because you don't like the implications - you certainly haven't provided any reasons to disagree on scientific grounds. That's a logical failure. Discuss science with science, with evidence, discuss policies with policies, but policy implications have no impact on the reality of the observations whatsoever. 

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  37. To KR's point:  We really, really are not sure of the exact value of the gravitational constant.  Still.  Despite trying really, really hard.

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  38. Donny, the wider the range of the uncertainty bars, the greater the probability that the true value will lie within them.  Thus, I can confidently state that the science is settled that -1000 < ECS <1000.  The probability of that statement being wrong is so negligible as to be not worth considering.  We can go further.  If the ECS is negative, than increasing sunshine would make the temperature colder, which is absurd.  So we can state with scarcely diminished confidence that 0 < ECS < 1000.  Further, λ = ΔT/(ΔF - ΔQ) where λ is the climate sensitivity factor, ΔT is change in temperature, ΔF is the change in forcing, and ΔQ is the change in heat flux into the Earth's surface (including atmosphere, cryosphere and oceans).  Further, moving from equilibrium, to equilibrium, ΔQ = 0, so that λ = ΔT/ΔF, and hence, for a doubling of CO2 concentration with an ECS of 1000, λ = 270.3 K/(W/m^2), or put differently, a 0.0037 W/m^2 per degree K change in the TOA flux.  Ergo, the radiative imbalance given an ECS of 1000 and a 1 degree K increase in temperature since the preindustrial should approximate to the radiative forcing.  That, it plainly does not do.  Ergo the ECS << 1000.  Carrying the reasoning forward limits the ECS to less than 12 with very high probability (as do considerations about the very stable climates over the Holocene).  Ergo, 0 < ECS < 12 with near certainty.

    Now, you face an invidious choice.  You must either deny that the degree to which an issue is open to question depends on the range of its uncertainty bars, deny the patently obvious upper and lower bounds on ECS even before we begin serious exploration of the data (as determined above), or insist that the IPCC PDF as shown (approx) in 32 cannot be "settled science" in the sense that whatever value ECS turns out to have, it will be constrained by the 95% range of that PDF and will likely be within the 1.5 to 4.5 range even though the PDF differs from the obvious limits by only 0.9 K for the lower bound, and 3.8 K for the upper bound.  The question then becomes, why are you so confident that the evidence accrued to date cannot accomplish even so limited a narrowing of the bounds?  It sounds like a very dogmatic uncertainty to me, and a dogmatic uncertainty ultimately justified by your ignorance rather than your knowledge.

    Further, when you say:

    "So when politicians use the term settled science to back a policy that gives them another reason to raise taxes you can understand why it may frustrate someone who opposes tax increases."

    you exhibit your ignorance about the nature of uncertainty.  The expected utility of a policy is the probability weighted mean of all possible outcomes of the policy.  Given that uncertainty is far greater for the upper bound, that means great uncertainty inflates the relative influence of high values of the ECS on the expected utility of a policy.  If we are less certain about ECS than the IPCC suggests, then we must even more urgently take action to mitigate climate change.  (You probably don't recognize this because you assume implicitly that nearly all uncertainty is on the lower bound, when the reverse is the case.  And turning that about for my allies, they often don't recognize that constraining the upper bound as Nic Lewis purports to do therefore has a major influence on the advisability of mitigation, even if the mean or modal values of the PDF scarcely move.)

    If you really want to shape your science to suite your politics, then the more rational approach is to claim that the science is settled on a low value of ECS (as Nic Lewis argues).  The only problem with that line is all those inconvenient scientists whose science is determined by the evidence who clearly disagree.


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  39. Donny, "why it may frustrate someone who opposes tax increases." If your position is that  AGW = more taxes, therefore AGW must be wrong, then frankly dont expect to much respect for your views among rational people.

    If you dont like taxes and yet became convinced that it was better to mitigate than adapt, then what measures would you accept to reduce emission? Please tell us your answers here. The world desparately needs new ideas from right-wing idealogues. (Do you seriously think anyone likes taxes? That is the whole point of a carbon tax - you move to non-carbon energy to avoid the tax).

    If you dont like existing proposals for mitigation and cant think of better ones, then I would predict that there is no data, and no argument that would persuade you. Further discussions would be pointless.

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  40. Tom Curtis #32. Thanks for your information. I accept everything you say about climate sensitivity and other scientific theories. I personally think it is very unlikely climate sensitivity is low. And clearly the basics of climate change are settled.

    However I think you miss my point. The climate science community makes the claim “the science of climate change is settled”. They do not qualify this with any detail on levels of what is settled. The public understandably interpret this as lay people as meaning “all” the science is settled 100%.

    Now when research points out that some element is not perfectly understood, like the slowdown in warming from about 1998, the “public” perceive they have been misinformed and the science is not settled. This creates an opportunity for sceptics to say look it isn’t settled! So to make the claim “the science of climate change is settled” just seems an unwise choice of words to me.

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  41. Donny @34.

    You say “I also have trouble with quantifying the effects of other known drivers as well (obviously ) unknown drivers and saying we have these effects pinned down enough to consider them settled.”

    I think this is pretty settled. There is a massive amount of research on possible effects of solar energy and cosmic rays etc. Almost all the published research shows these play very little part in the warming period since about 1970. The science on this is very compelling, and is certainly 95% certain.Saying it is not 100% certain is a spurious argument as it is never possible to be 100% certain about this sort of thing.

    This year is shaping up to be either the hottest on record, or in the top group despite a distinct lack of natural short term warming cycles. El nino / la nina is in a neutral phase. It is therefore very difficult to see what natural cycle could possibly be implicated. 

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  42. "The climate science community makes the claim “the science of climate change is settled”."

    I am pretty sure that the climate science community make rather more nuanced statements. The quote appears to be from Al Gore to congress and the context.

    "The science is settled, Gore told the lawmakers. Carbon-dioxide emissions — from cars, power plants, buildings and other sources — are heating the Earth's atmosphere."

    Well no argument about that. Other quotes from environmentalists etc were similar but also qualified when looked at in their original context. A google search mostly brings up contrarian sites busily creating a strawman fallacy.

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  43. "The science is settled, Gore told the lawmakers. Carbon-dioxide emissions — from cars, power plants, buildings and other sources — are heating the Earth's atmosphere."

    A most unfortunate statement by Gore. The words "The science is settled" have been quoted out of context a million times, (without your carbon dioxide part) providing easy ammunition for sceptics. I see this all the time, and it is very frustrating. It also undermines Gores book, which is very good.

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  44. scaddenp @42, nigelj @43:

    "The science is settled, Gore told the lawmakers. Carbon-dioxide emissions — from cars, power plants, buildings and other sources — are heating the Earth's atmosphere."

    It may be an unfortunate statement, but Gore never made it!  What he did say, in response to questioning by Joe Barton was:

    "The planet has a fever. If your baby has a fever, you go to the doctor. If the doctor says you need to intervene here, you don't say, well, I read a science fiction novel that tells me it's not a problem."

    That comment was made after listing the scientific organizations that supported the concensus.  It was glossed by NPR's reporter, Andrea Seabrook.  From the transcript:

    "Vice President AL GORE: The planet has a fever. If your baby has a fever, you go to the doctor. If the doctor says you need to intervene here, you don't say, well, I read a science fiction novel that tells me it's not a problem.

    SEABROOK: In other words, the science is settled, Gore said. Carbon dioxide emissions from cars, power plants, buildings and other sources are heating up the Earth's atmosphere. If left unchecked, this global warming could lead to a drastic change in the weather, sea levels and to other aspects of the environment. And Gore pointed out that these conclusions are not his, but those of a vast majority of scientists who study the issue."

    It has been subsequently misattributed as a direct quote of Gore rather than a reporters (incorrect) opinion of what Gore was getting at by numerous "skeptics".

    On another occasion, Gore said that "the debate is over", but that was on one point only (attribution).  That it was a limited claim was not only mentioned but emphasized by Gore:

    "VICE PRESIDENT GORE: On the fact that there is a human factor in causing this? Yes. And not only in the administration, in the international panel on climate change, which has, what, 2,500 scientists from every country in the world, they have studied this for several years now. And just a couple of years ago they found what they call ''the smoking gun'' and came out with this consensus statement that there is now a discernible impact from human causes. Now, one of the other obstacles to broadening the consensus on that is that as you all know better than everybody, the noise level in the system is so profound that there are going to be very, very big changes just in the natural course of events. You take hurricanes. Back in the 1930s, as y'all can say better than me, there was a string of powerful hurricanes, more frequent, more powerful than what we're experiencing now. And there are other extremes that are natural. But out of that noise level, this consensus international scientific process has now said that they believe that debate is over, that yes, the human cause is now discernible. And as these concentrations grow it will become more profound and a much more significant part of the cause.

    Q And the administration accepts that fact that that debate is over.

    VICE PRESIDENT GORE: Yes, sir. Yes, sir. On that one point, yes, sir. Here, and then there."

    And speaking of which, here is the estimated IPCC Anthropogenic attribution PDF:

    And the IPCC's conclusion:

    "Overall, given that the anthropogenic increase in GHGs likely caused
    0.5°C to 1.3°C warming over 1951–2010, with other anthropogenic forcings probably contributing counteracting cooling, that the effects of natural forcings and natural internal variability are estimated to be small, and that well-constrained and robust estimates of net anthropogenic warming are substantially more than half the observed warming (Figure 10.4) we conclude that it is extremely likely that human activities caused more than half of the observed increase in GMST from 1951 to 2010."

    IPCC AR5 WG1 Chapt 10 p 887

    Gore's claim, with its limited scope, was true in 1997 when he made it, and is certainly true now.

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  45. Thanks Tom. Further evidence of "skeptics" attacking a straw man.

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  46. nigelj @40, I am having difficulty finding examples of the phrase "the science is settled" by climate scientists (or anyone supporting mitigation of global warming) in a way that is not clear from context.  Wikipedia has a list of such "quotes", but they notably consist of either unverified claims by "skeptics", or are clearly restricted (as in the case of the Al Gore example discussed above).  I am uncertain as to the identities of the various people quoted.  One is just a newspaper columnist (which shows how rare examples are).  One (by Cuffey) is definitely by a noted scientist, but not a climate scientist and the claim is very clear in context.

    In this case I think Dikran Marsupial @33 and scaddenp @42 are correct (except for scaddenp's misattribution of the purported Gore quote).  Climate scientists make nuanced statements that are clear from context.  Deniers misattribute or invent quotes without the nuance or context and try to morph "Not everything is completely certain" into "Everything is completely uncertain" by rhetoric.  

    It is the attempt to finagle uncertainty about a small issue into near complete uncertainty about major points by Donny that I resisted earlier in this discussion.  I am certainly not defending the idea that "the science is settled" except as nuanced statements about particular aspects of the science.

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  47. Tom Curtis @ 44, 46. Well I didnt realise Gore was being missquoted. In my country we get the mainstream media saying things like "climate scientists claim the science is settled", and the media dont go into specifics like "settled in respect of". Seems like the media are twisting things. This is half the problem and it causes confusion.

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  48. nigelj@43,

    Are you referring to Al Gore's "An Inconvenient Truth", "Earth in the Balance", "Our Choice: A Plan to Solve the Climate Crisis" or "The Future: 6 Drivers of Global Change"?

    I think his book "The Assault on Reason" provides a very good presentation of why there are so many people who still prefer to believe "the science isn't settled" or "climate scientists are wrong" or "the IPCC cannot be trusted" or "any other attempt to discredit or dismiss the science without any substantive basis for doing so".

    I agree with the assertions made in many of the comments here that the science and other avenues of investigation and consideration of what is discovered and observed will always continue to improve the best understanding of what is going. And the discussion of the science needs to focus on the science.

    And I agree that policy should be based on the best understanding of what is going on, meaning it must change as more is learned. It should not delay action to limit activity that is contrary to the development of a sustainable better future for all, no matter how popular or profitable that activity may be among the more fortunate, or those who want to develop to be like the more fortunate (therefore, all the wealthiest should be required to be competing to live the most sustainable life, to set the example to be aspired to by all others).

    It is important to add that leadership toward the development of a sustainable better future for all life on this amazing planet is the only leadership that has a viable future.

    Any other type of leadership will have to fight against the growing better understanding of what is going on. It will ultimately fail, as will the societies and economic activities such leadership attempt to promote and prolong.

    The problem is the way that popularity and profitability can empower unsustainable leadership, creating as much damage as can be gotten away with in the pursuit of short-term popularity and profitability that is ultimately unsustainable.

    Humanity failing to rapidly develop to be a sustainable part of the diversity of life on this amazing planet should not be considered to be an acceptable option by any leaders. The constantly increased understanding of what is going on will ultimately make any other type of leader unsuccessful.

    This leads to the rational conclusion that any unsustainable and damaging activity should be curtailed when its unacceptability is discovered. And when enough of the population actually better understands what is going on the curtailing could be swift. Which leads to "The Assault on Reason" to try to delay the necessary curtailing of popular and profitable developed activities that are harmful and ultimately unsustainable.

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  49. One Planet Only Forever @48

    You ask what book Im referring to? I was referring to one of Gores speeches where he apparently said "the science is settled". This seemed too sweeping to me, as not all the science is settled, and it leaves Gore open to obvious attack. However it appears Gore was missquoted. 

    You are possibly being a little defensive, and are not reading what I said or undestanding my point. I'm not questioning the climate science. I have read all Gores books and completely agree with them. 

    Please also read my post 47 above. Im not questioning Gores conclusions on climate science and I have read all his books. I do wish people would please read what is actually written. 

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  50. nigelj,

    My apologies if the way I presented my comment gave you that impression.

    I am well aware "the science is settled" is quoted out of context from a speech he gave, but it might also be quoted out of context from one of his books. I was asking about the last line of your comment @43 "It also undermines Gores book, which is very good." I am genuinely interested to know which book you are referring to because I have read many but not all of them.

    My addition of his book 'The Assault on Reason" was meant to build on your point, not critique it.

    I am genuinely interested in feedback about what I presented. It may seem semi-religious and in many ways I consider it to be a set of values to be guided by. I developed my understanding of these values from the learnings shared by so many who have written in different ways about the improved understanding that is constantly being developed. There is a growing litany of reports regarding the 'harmful activities that have developed and become popular and profitable even though they are ultimately unsustainable and they are clearly causing harmful consequences for people who are not enjoying the benefits'.

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