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Comments 43001 to 43050:

  1. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    If you don't accept that the climate is changing or that we are causing it or if we are causing it, it will only be good for us then forget Climate Change.

    http://mtkass.blogspot.co.nz/2010/10/forget-climate-change.html

  2. 2013 SkS Weekly News Roundup #33B

    This article documents changes in apple taste and firmness caused by AGW in Japan.  Apples don't taste as good and are less firm.   At the start of the article they reference about 20 other articles documenting changes in fruit and food production worldwide.  They say that changes in care of plants and cultivars grown  make it difficult to document these changes in many areas (if cultivation practices have changed it is difficult to separate changes from AGW and changes from cultivation practices).  In their orchard they have the same trees and care for them the same way.

  3. Global warming games - playing the man not the ball

    Hi John,

    I have added most of the relevant posts to rbutr now, but can you submit your original presentation as a rebuttal to any instances of Monktons original talk which you can find online? Or at least let me know where they are, and I will submit them.

    Thanks.

    http://rbutr.com/rbutr/WebsiteServlet?requestType=showLinksByFromPage&fromPageId=140127

  4. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Regarding plane crashes etc.

    Really the issue is survivability. If you happen to be on a plane that does crash the probability of surviving is far less than say that of being in a train crash.

    eg. if you compare the worse case scenarios of different types of transport. Some are better than others.

    It boils down to whether imagination wins over statistics.

    If you imagine yourself in a crash, your better off in a train.
    If you check the math, it probably doesn't matter much (although I haven't checked!).

  5. Toward Improved Discussions of Methane & Climate

    Have we been looking at Climate Sensitivity all wrong? We've been focused on global temperature sensitivity to CO2 doubling, but shouldn't we have been focusing on global temperature sensitivity to input radiative forcing? Atmospheric methane increases occurred in the ice-core data in tandem with temperature increases with just a 0.5W/m2 increase in input radiative forcing due to the Milankovitch cycle. The resulting feedback exacerbated the rise in temperature to around 5degC. Why should the planet's store of methane now NOT react when humanity has created a 3W/m2 increase in input radiative forcing (minus the aerosol component) by burning fossil fuels and deforesting the planet?

    I don't understand this "what me worry" attitude among prominent climate scientists on the methane issue. Is it subconsciously linked to their consumption of beef?

  6. A grand solar minimum would barely make a dent in human-caused global warming

    Although the informaion has received a fair amount of criticism because of source,

    and even though I don't believe it either:

    there is another innaccuracy, perhaps arising from pedantry, which I will eruct:

    quote:"We're fortunate that the amount of solar radiation reaching the Earth's surface is very stable"  endquote.

    I would say that the author should report back on the accuracy of this statement the next time we're hit dead center by a solar flare.

    Oh wait, he won't ba able to, as much of the electrical distribution system, and much of the electronics connected to it, 

    will be fried.

    ===============

    I would agree that the cycle of the sun's output will have no significant  net effect on our CO2 scenario

     

     

  7. Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink

    KR, whatever Skeptical Science decides is appropriate is fine with me.

     

    In point of fact, I am loathe to look at "geoengineering" wiith anything but a seriously "jaundiced eye", as in general they (the techniques) smack of just more wild-eyed demonstration of  the human intellect's capacity to dick around with things we really have a poor understanding of:   trying to use a hammer to adjust a wristwatch.

     

    That being said, "this" technique takes a natural process (mineralization of CO2) and enhances it, in a natural way.  (Spraying water in the air, duh!)

    "This" technique, if shown to be harmful in any way whatsoever, can be discontinued, modulated,

    :  and if shown to be valuable,  enhanced, expanded, etc..

    ============

    It is an unfortunate fact that the "intellect / ego" has ignorantly gotten us into this mess,

    but unlike what the flower children might want, which is to return to teepees and hunter-gathering,  (which by the way might be OK in the long run, I've no opinion on the matter..)

    what WE have to do is employ the SAME imagination and intellect, but in a different way, to reduce the ramifications of the die we've already cast.

    "What do we do to make life prosper????" on this planet, whose wholeness is sometimes called "Gaia" by some: (although it does expose onto some abuse in these parts. )..THAT's the question we each should be continuously tryiung to answer and act on. .

     

    So how do we decrease circulating CO2? 

    This methodology, utilizing the weathering products of granite, to both sequester CO2 and increase water vapor in the air, appears to be the best, most innocuous, route suggested, to the best of my  knowledge of specific geoengineering suggestions, such as the others in your response. .   

    All speculative, but if there's a better speculation out there, let's hear it!

     

    Thank you.

  8. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    @mike roddy

    agreed. To me this is a good statement of the obvious and we should all do our bit to lower our carbon footprint. I found www.navitron.org.uk/forum/ a good place for me in the UK for advice and help to do our bit.

    I dispair of the USA. It was such a fantastic country when I lived there in the late '70s whilst doing my PhD at the Harvard Smithsonian Observatory. It seems however to have lost its way. Al Gore's book "The Future" is quite interesting in its analysis of the current disfunctionality of the US. For me its deeply saddening that a country I held in the highest regard seems to have become more part of the problem rather than the solution in a number of areas in particular CC

    StB

  9. A vicious cycle: Could droughts and storms make climate change worse?

    Too bad there isn't a satellite or some such device that measures the Earth's total biomass from week to week and year to year.   It would probably show a negative correlation with the Earth's average surface temperature.  As the temperature rises, the total biomass dimminishes. 

  10. Toward Improved Discussions of Methane & Climate

    We should not forget that our future course of action- whether to massively switch to renewable energy sources or continue on our fossil fuel trajectory- is an economic problem as well as a scientiic problem.

    The methane in the methane hydrates is worth hundreds of billions, perhaps trillions of dollars.

    The methane in the methane hydrates could also arguably kill the biosphere.

    A scientific paper which mentions the economic factors associated with the methane hydrate problem is linked to below:

    Gas hydrates: entrance to a methane age or climate threat?

    Methane hydrates, ice-like compounds in which methane is held in crystalline cages formed by water molecules, are widespread in areas of permafrost such as the Arctic and in sediments on the continental margins. They are a potentially vast fossil fuel energy source but, at the same time, could be destabilized by changing pressure–temperature conditions due to climate change, potentially leading to strong positive carbon–climate feedbacks. To enhance our understanding of both the vulnerability of and the opportunity provided by methane hydrates, it is necessary (i) to conduct basic research that improves the highly uncertain estimates of hydrate occurrences and their response to changing environmental conditions, and (ii) to integrate the agendas of energy security and climate change which can provide an opportunity for methane hydrates—in particular if combined with carbon capture and storage—to be used as a ‘bridge fuel’ between carbon-intensive fossil energies and zero-emission energies. Taken one step further, exploitation of dissociating methane hydrates could even mitigate against escape of methane to the atmosphere. Despite these opportunities, so far, methane hydrates have been largely absent from energy and climate discussions, including global hydrocarbon assessments and the Fourth Assessment Report of the Intergovernmental Panel on Climate Change.

    Intense localized methane plumes could perhaps be captured, burned using (for example) oxyfuel combustion to generate electricity, and the resulting CO2 deep injected into fractured basalt sediments, I think. The resulting electricity could be transmitted to shore using submarine electrical cables- a new but farily well developed technology. This would be carbon neutral remediation of the captured methane, if it works.

    On the other hand, trying to capture the methane would be like trying to catch soup in a net, in my opinion. Vast quantities of methane would go into the oceans, contributing to ocean acidification, leading to probable widespread anoxic areas, and perhaps even a dead arctic ocean- one incapable of oxidizing much of the methane released into it by the hydrates, according to modeling by the DOE/LBNL/LANL modeling done by the IMPACTS (Investigation of the Magnitudes and Probabilities of Abrupt Climate TransitionS (IMPACTS)) group. Check out their publications link:

    Investigation of the Magnitudes and Probabilities of Abrupt Climate TransitionS (IMPACTS) Project

    As an inhabitant of the Earth, I don't think that a "methane age" of abundant energy is worth the risk of low level or greater runaway destabilization of the climate system.

    Fossil fuel corporation executives and major stockholders of fossil fuel corporations may disagree. 

    In such an environment, there is the potential for enormous profits to skew the scientific debate. 

  11. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    This is an excellent summary, but overlooks our problem: Here in the US, money trumps all when key decisions are made. As long as the oil and gas companies are raking in such vast amounts of cash- and sprinkling it around to politicians and media companies- we will continue to bake.

  12. Global warming, Arctic ice loss, and armchair scientists

    Thank you, Philippe.  I knew there was a name for that lightless spot in my memory.

  13. Philippe Chantreau at 14:09 PM on 16 August 2013
    Global warming, Arctic ice loss, and armchair scientists

    "Neither has, IIRC, any president of the US. "

    Andrew Jackson is known to have killed opponents in duels.

  14. Global warming, Arctic ice loss, and armchair scientists

    I would note that ajkuiper has not responded to requests to support some sloganeering here. I hope he/she is more ready to engage with some actual science in this discussion.

  15. Global warming, Arctic ice loss, and armchair scientists

    Deep, AJ, deep.  Poverty's never killed anyone either.  Neither has, IIRC, any president of the US.  

    The drop in ASI can change global weather patterns (hard to avoid doing that), and the resulting changes have undoubtedly led to specific deaths that wouldn't have occurred otherwise.  Perhaps you should be more specific, AJ.  Are you actually suggesting that changes to general circulation have no impacts on human life?

  16. Global warming, Arctic ice loss, and armchair scientists

    davidnewell - (-SNIP-)

    Moderator Response:

    [DB] Repetitive sloganeering snipped.

  17. How much will sea levels rise in the 21st Century?

    jja @35.
    Concerning radiative forcing and energy imbalance. The difference is actually rather great. For instance Hansen et al 2012 the discussion of energy imbalance and net forcing leading to their conclusion "Measured Earth energy imbalance, +0.58 W/m2 during 2005-2010, implies that the aerosol forcing is about -1.6 W/m2" and thus a net forcing of +1.4 W/m^2.

    The crucial point is that radiative forcing is a change over a period (say 1750 to date) and is a theoretical quantity while energy imbalance applies to a particular point in time and is an actual physical phenomenon.

    Its a bit like a kid kicking a ball along a road. The forcing, the kid's kicks, can be expressed as increases in speed imparted into the ball by his boot and can be added up over a period of time when he kicks the ball many times. This 'forcing' will always increase adding up with each kick (unless the kid kicks it backwards). The ball will usually be slowing due to air resistance etc and on its own will come to a halt in the gutter. But until that point it will have a speed along the road which in this analogy would represent the energy imbalance. (The distance along the road would perhaps represent temperature.)
    The definition of "forcing" given by the IPCC is given here. The altitude it is attributed to (ie the tropopause) is less important than the concept that it is "with surface and tropospheric temperatures and state held fixed at the unperturbed values" (in the analogy, not accounting for the slowing of the ball due to air resistance etc).

     

  18. How much will sea levels rise in the 21st Century?

    Agnostic @34.
    Indeed. Small increases in global temperature will result in very large SLR. And yes, the cause will be due to melting of land ice from Greenland & Antarctica. So the question is - how "rapid" or how slowly will that melt occur? Or how big will be the "heat" flows in that melting process?
    The total global energy imbalance gives a value for the energy entering the global climate system. Polar amplification may suggest that a disproportionate amount of that energy is arriving at the poles but (1) That is not entirely the same as energy available for melting land ice (although it will be in part), and further (2) The vast majority of the global energy imbalance ends up heating oceans and thus not into melting ice. This suggests that the energy available to melt Greenland & Antarctica can only be a minority of the global energy imbalance. And small energy fluxes has to mean small melts and small resulting SLR.
    I have yet to see anyone describing how an energy flux can be created large enough to melt enough ice for anything like a 5m SLR by 2100. The literature still shows findings that project sub-1m SLR although they are usually not entirely reassuring in these findings. The Ice2Sea project, for instance, tells us that with a 3.5ºC global temperature increase (A1B emissions), the total SLR contribution from land ice will be 350mm to 368mm by 2100 (so a 700mm total SLR) but but do not rule out higher SLR (5% chance of +840mm SLR from ice) saying "even the state-of-the-art models do not simulate all the processes and feedbacks that might be significant." Perhaps more reassuring is Pfeffer et al 2008 who find that 2100 SLR greater than 2m is "physically untenable."
    Myself, I see it that however large the 2100 SLR proves to be, it is less the problem in itself. Rather the rate of SLR by 2100 will set the SLR for the following century when SLR greater than 2m probably will no longer be "physically untenable." And if global temperatures remain high SLR will continue at that rate for many more centuries to come.

  19. A grand solar minimum would barely make a dent in human-caused global warming

    John, dating the LIA is anything but simple.  The Maunder may have been responsible for the worst of the LIA, but the Wolf and Spörer mins preceded it.  There is also the volcanic factor to account for.  This article addresses the skeptic claim that a new Maunder would cancel global warming.  The article does not attempt to explain the LIA. 

  20. A vicious cycle: Could droughts and storms make climate change worse?

    OK the pictures are showing up properly now.

  21. A vicious cycle: Could droughts and storms make climate change worse?

    Don't know if anyone else has the same problem, but the pictures are coming up as broken links when I view this post.

  22. A grand solar minimum would barely make a dent in human-caused global warming

    If the LIA started 500 years ago, then that precedes the start of the Maunder minimum by about 150 years. So where's the evdience that a grand solar minimum triggers colder climate?

  23. What makes ice sheets grow and shrink?

    Terranova,

    Since the Milankovich forcing has been cooling for the past 5,000 years, what has warmed besides human interventions?  Your claim of "contributing" not "causing" is splitting hairs.  Humans have changed the climate for 8,000 years.  The question is how much.  You are being inaccurate with your pedantic hair splitting.  Stop complaining that others have a minor issue until you no longer have the same problem, or worse.

  24. What makes ice sheets grow and shrink?

    Terranova@17,19

    Can you explain in non-inflamatory terms (so that your post is not snipped) the point you're trying to make?

    Your emphasis about CO2 being "not determinative" to glacial cycles does not add anything new to the discussion and your focus on "manmade CO2 emissions" does not mean anything in this context. We already know that CO2 was the feedback rather than causality of pleistocene glacial cycles. And it's also obvious to us that manmade CO2 emissions have overriden the glacial cycles, because said emissions are 100 times faster. So to me, there is no logical value nor point in your post.

    Your question about the "Where Are We At Today" section wherabouts can only be answered by Dana. But to me, the section is truthful and valuable, irrespective where it came from: it explains to the possibly unfamiliar reader the context and rate of current climate changes in relation to the changes the original study focussed on.

  25. Understanding the long-term carbon-cycle: weathering of rocks - a vitally important carbon-sink

    davidnewell - Sites vary, but on SkS most visitors follow the Recent Comments page, leading directly to conversations in progress. 

    I would opine (personal opinion) that weathering and the long term natural carbon cycle are quite distinct from geoengineering, whether that involves granite chips or artificial aerosols or orbital mirrors or iron seeding of oceans, etc. And that discussions of natural checks and balances are a very different topic from modifying nature for our goals. 

  26. What makes ice sheets grow and shrink?

    Michael Sweet @ 18

    There is a difference between contributing and causing.  Read your link again.   There is nothing there that implies that humans are the main cause of climate change over the party centuries or millenia.    Furthermore, the query about the statement being a part of the referenced paper is still not answered. 

  27. What makes ice sheets grow and shrink?

    Terranova:

    There is substantial evidence that Humans have been causing climate change for 8,000 years.  Primarily due to farming and deforrestation.  The last that I recall, scientists were coming to a consensus that this explaination was the best way to model the recent climate changes.   The rate of human caused climate change has substantially increased in the last 150 years. Your cries of "inaccuracy" would be a lot more convincing if you did your homework.  Please read up on the past 4-8 millenia and retract your comment above.

  28. What makes ice sheets grow and shrink?

    From what's available on the nature website: "This fast retreat is governed mainly by rapid ablation due to the lowered surface elevation resulting from delayed isostatic rebound14, 15, 16, which is the lithosphere–asthenosphere response. Carbon dioxide is involved, but is not determinative, in the evolution of the 100,000-year glacial cycles."  Emphasis mine.

     

    From the article above: "Of course, on top of these epic natural cycles manmade carbon emissions are having an effect on the climate. Over short timescales (geologically speaking) of centuries and millennia, greenhouse gas emissions from human activities are the main cause of climate change."  (-snip-).  

    I asked, but did not get a reply ( -snip-), about the final section of this post "Where Are We At Today".  It appears to be an add-on from the article author and not part of the paper referenced.  

    If in fact it is not part of the paper represented in the post, then we are back to the "inaccurate" topic.  If it is part of the paper, then I would like to see it and I will retract my statement.  

    Moderator Response:

    [DB] Argument from personal incredulity snipped.  Inflammatory snipped.

  29. What makes ice sheets grow and shrink?

    IanC @14, yes.  I realized essentially the same point last night just before going to sleep.  The key point is that given the rate at which heat propogates by conduction, the current warming will not yet have impacted basal ice except by means of surface melt water carrying warmth to the base of the ice sheet (where it is able to do so) or at the edges of the ice sheet.

  30. What makes ice sheets grow and shrink?

    I think Freya Roberts post fails to mention that the most important feedback according to the research paper is geological - the delayed isostatic rebound. This keeps the ice elevation low and therefore ice loss remains high while the ice sheet retreats. It is this delay which is responsible for the 100 kyear cycle. Other feed backs, dust feedback, oceanfeedback are less important.

    The 100 kyear cycle can  be reproduced in models even if CO2 levels are kept constant, although CO2 does influence the size of the ice sheet. If the rebound is instantaneous  the 100 kyear cycle is no longer dominant.

  31. A grand solar minimum would barely make a dent in human-caused global warming

    Chaps agreed a bit disappointing regarding the Irish Times, when I lived in Ireland it was easily the best paper - in the UK the Guardian is my paper of choice. I know Ian Elliott, or at least knew him when I was an undergraduate in Physics at UCD (1970ies). He was vwry good at public engagement. I can't really comment on him professionally as after becoming a graduate student in astronomy our paths never  crossed.

    StB

  32. A grand solar minimum would barely make a dent in human-caused global warming

    cynicus,

    Correct, and what is disquieting is that the newspaper in question if far from being the usual Murdoch lowest-common-denominator or Daily Mail rag. Like the Economist and the New York Times, even the quality publications are inconsistent. I suspect the Environment correspondent and the Science correspondent of the Irish Times do not seem eye-to-eye.

  33. What makes ice sheets grow and shrink?

    Tom @ 13,

    It is true that geothermal heat is trivial at the ice-air interface, but not so at the ice-land interface. I think 'surface' here is meant to be the surface of the lithosphere and not the surface of the ice; with this interpretation the abstract is correct.

  34. What makes ice sheets grow and shrink?

    p4gs @11, I would also be interested in such an article.

    Just from looking at the abstract, it is a very interesting paper.  Evidently, the weight of continental ice sheets causes a thining of the crust under the ice sheet, allowing enhanced geothermal heat flow.  The effect can be seen in the upper right of the diagram below, shown with increased detail in the inset.  As can be seen, heat flow reaches a minimum (green colours) during interglacials, and a maximum during glacials when the ice is thickest.  As an aside, that suggests a very significant melt back of the greenland ice sheet during interglacials, to relieve the burden of ice mass and allow thickening of the lithosphere beneath the Greenland Ice Sheet.

     

    WUWT appears to want to beat this up into a major factor, claiming:

    "The Greenland ice sheet is melting from below, caused by a high heat flow from the mantle into the lithosphere."


    They assert his despite their cutaway view of the Greenland Ice Sheet showing no temperatures above freezing. However, the diagram below should put paid to any such denier fantasies. The range of geothermal heat flux shown is from 0.043 to 0.061 W/m^2. That compares to a global average of 0.087 W/m^2, and is relatively small even for continental plates as can be seen below:

    (Units are mW/m^2)

    The peak rate, is therefore less than a 10th of the TOA energy imbalance caused by AGW, and the change in heat flow between glacial and interglacial is about a sixth of that again.

    I must admit that having actually seen the figure shown, I am surprised that the abstract states:

    "At the Earth’s surface, heat fluxes from the interior1 are generally insignificant compared with those from the Sun and atmosphere2, except in areas permanently blanketed by ice."

    It would have been rather more accurate to state:

    "At the Earth’s surface, heat fluxes from the interior1 are generally insignificant compared with those from the Sun and atmosphere2, except including in areas permanently blanketed by ice."

  35. What makes ice sheets grow and shrink?

    p4gs - Looks like references to this paper are already showing up on the denial sites, in the apparent hopes of yet another claim that "it's not us". 

    Those claims would only make sense if there had been recent changes in the heat from the lithosphere - long standing heat patterns would be part of pre-Industrial conditions as well, and not causes of recent melt acceleration. Not to mention that observed changes in GHGs already account for the Greenland changes we've seen, and such "not us" claims would have to somehow explain those away...

  36. Where SkS-Material gets used - Coursera's Climate Literacy Course

    Just now received the Coursera email that the 2nd iteration of Climate Literacy will start on September 30, 2013!

  37. What makes ice sheets grow and shrink?

    I want Skeptical Science to do an article on this newly published research:

    http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1898.html

    Moderator Response:

    [JH] See: Greenland Ice Is Melting -- Even from Below: Heat Flow from the Mantle Contributes to the Ice Melt, ScienceDaily, Aug 11, 2013. 

  38. A grand solar minimum would barely make a dent in human-caused global warming

    chriskoz @2, you calculated the equilibrium climate response, wheras Dana calculated the transient climate response.  The difference is in the factor of 0.67 Dana introduces for that purpose.  Absent that, his value would have been 0.45 (or 0.48 with a less aggressive rounding).

    One twist on this is that radiative forcing is calculated at the tropopause rather than the top of the thermosphere.  Most UV radiation is absorbed above the tropopause, and the UV component of sunlight will varies in greater proportion with changing TSI.  The effect is that with reduced TSI, relatively more of TSI will reach the surface than currently does.  The solar forcing will still reduce, but not as much as the reduction in TSI so that the cooling will be even less than calculated.

    Conversely, for the same reason, it requires a greater than 1.55% increase in TSI to generate a 3.7 W/m^2 increase in solar forcing.

    Finally, it is possible that some such mechanism as that proposed by Svensmark would result in a greater reduction in temperature than simple calculations from TSI would suggest.  His theory as it stands has been pretty much ruled out.  Clouds form with great facility even in the absense of cosmic rays, and therefore cosmic rays are not the dominant force governing climate over the history of the Earth.  However, cosmic rays may facilitate the generation of additional cloud nucleation particles thereby decreasing the average droplet size in clouds and hence increasing cloud albedo.  This may amplify the direct TSI forcing by as much a factor of 2.  Of course, there is as yet no solid evidence that this is the case.  It just cannot be ruled out either.

  39. 2013 SkS Weekly News Roundup #33A

    New discovered Mesospheric Polar Clouds possible indicator of Global Warming Link

     

    Save the Earth Link

  40. What makes ice sheets grow and shrink?

    chriskoz #8, fair enough, Though i thought the video was also good, since it points out rate of changes (natural vs human attributed forcing) also explains why there cannot be a runaway snowball earth. 

  41. A grand solar minimum would barely make a dent in human-caused global warming

    One often encounters articles like this where some cherrypicked-out-of-context-but-original quotes from bonafide scientists (like Lockwood in the Irish Times article) is mixed with the breathtaking slay-of-hand conclusion by a fake authority and presented as a compelling picture to the public. In this case the fake authority who makes the final headline claim is Ian Elliott, an ex-astronomer who pensioned 12 years ago and has only few papers published during his professional career, none of which about the solar influence on Earths climate.

    Judging by the wide circulation in the denial echo chamber this article is a perfect rehash of the old tobacco tactics.

  42. A grand solar minimum would barely make a dent in human-caused global warming

    Dana,

    I think your final formula to calculate ∆T is unreadable due to too many factors used. In the end, reading it, I'm confused which number is which factor.

    I did my own calculation with simpler numbers as follows.

    In my calculation, I don't need to consider ∆TSI. I can take amount of sun energy absorbed by Earth (∆TSabs) and assume it changes by the same percentage as ∆TSI. I think your calculation makes the same assumption, although I'm not sure. Then, from (Kiehl and Trenberth, 1997), I look at this picture:

    Earth Energy Balance

    and find out the amount of Sun energy absorbed by Earth is 168+67 W/m2 = 235W/m2 (ground + athmosphere absorbtion on the left side of picture).

    So ∆TSabs = 0.25% * 235W/m2 = 0.5875W/m2

    With the equilibrium sensitivity of 0.75K/Wm2, the corresponding ∆T is 0.5875*0.75 = 0.44K

    So, my number is larger than yours (0.3K), other suties you quote. Why is that? Did I make a mistake?

  43. A grand solar minimum would barely make a dent in human-caused global warming

    I am glad the Irish Times article came to your attention. The newspaper has actually a reasonably good record at reporting on climate change. The article on the solar minimum was an aberration because it did not mention CO2 at all, or the effect solar changes might have on global warming.

    I intend to mail the link to this post to the science correspondent.

  44. 2013 SkS Weekly News Roundup #32B

    Peter Lang:

    I've begun to notice a trend:

    People interested in clear, effective communication tend to "show their working", or provide sources which have the same effect. You'll notice Aristarchus quotes passages from the report that the LA Times article discusses, and Tom Curtis quotes the article itself; they both lay out the flow of their argument, clearly and concisely.

    By contrast, you appear to have acted in a manner consistent with attempting to obfuscate and confuse:

    First, when asked to show your working and/or provide examples, you simply don't. You have not provided any reason to accept your claim about the LA Times article (which is hardly necessary since Aristarchus and Tom Curtis' comments would render such reason irrelevant on account of being factually false), you have not provided any reason to take your word over, say, the IEA's, and you do not provide any reference clearly showing the misbehaviour you attribute to the renewable energy industry.

    Second, as a substitute for clearly making your case, you rely on bluster. You have no basis to make any assumptions about the physics knowledge of other participants in this forum.  You also rely on the lazy "do your own reading" tactic, which I personally find very tiresome - after all, there's no prima facie reason to believe that someone going off and doing more reading will come back and agree with you. (*)

    Finally, you make a pedantic, and apparently false, distinction between energy and power. Some rather basic definitions show that power and energy are in fact very nearly interchangeable, as power is simply a measure of energy transfer over time:

    In physics, power is defined as the amount of energy consumed per unit time.

    The dimension of power is energy divided by time. The SI unit of power is the watt (W), which is equal to one joule per second.

    Power is the rate of doing work or the rate of using energy [...]

    Ultimately, to speak of power is to speak of energy. Little surprise, then, that these terms are (colloquially) interchangeable when used outside of STEM circles. And, I might add, so much for your claim that they are "totally different".

    (*) Like the appeal to authority/expertise, this sort of claim is not always a failure of logic or argument - sometimes someone really just needs to read up more on a subject. However, such exhortations should be made in response to obvious nonsense, such as when someone argues that, say, vaccines cause autism, or, topically for Skeptical Science, when someone argues that, say, the greenhouse effect violates the laws of thermodynamics.

  45. What makes ice sheets grow and shrink?

    I have a technical question that I cannot figure out because I don't have access to full text.

    I'm interested in knowing some more details: how they ran their simulation and what parameters did they establish to be the "tipping points" moving the climate in and out of glaciation.

    In particular I'm interested how their model differ from Archer's CLIMBER model, that argues the minimum solar insolation at 65N be  the triggering factor for gradual continental icesheet buildup.

  46. What makes ice sheets grow and shrink?

    Chris@2,4,

    You should be aware that the Hansen video you've linked to and the paper - subject to this post - are talking about different timescales. Hansen talks about 65Ma cenozoic timescale (and by implication of that context, he does not bother to consider the time granularity less than some 1Ma), while the subject paper talks about the pleistocene glacial periods of last 400Ka-1Ma.

    Different factors influence average climate over those timescales. In particular, 100ka long Milankovic cycles considered by the paper override the Hansen's tectonic forcings that act on 500ka+ timescales. Therefore, although "the melting cryosphere" appears on your video, I would argue that this video has nothing to do with the article at hand.

    It is very important to distinguish the timescale of changes, e.g. while debunking common "climate has changed before" myth.

    - rock weathering/volcanoes with tectonic forcings: 500ky+ up to several Ma

    - Ice ages with Milankovic forcings: 10ka - 100ky

    - AGW: 100y (at least 100 times faster than any natural forcings)

    We must make clear distinction about timescales involved, otherwise we fall into the same trap the ignorant "skeptics" have fell with the myth I recalled above.

     

  47. Toward Improved Discussions of Methane & Climate

    Paul Beckwith's response as a link.

  48. Toward Improved Discussions of Methane & Climate

    Here's Paul Beckwith's response to this SKS article:
    http://arctic-news.blogspot.com/2013/08/toward-genuinely-improved-discussions-of-methane-and-climate.html

  49. What makes ice sheets grow and shrink?

    Dana1981,

    Is the section entitled "Where We Are Today" directly from the study itself, or an add-on from Freya Roberts?  The paper is paywalled unless you have another link available.  

  50. Global warming, Arctic ice loss, and armchair scientists

    It is interesting to note the "sea change" beginning to be noted in local papers, and at cocktail partys.  Much less "denying" of the facts:  the most dominent response to the rising reality is "Oh well, I'll be dead and gone, WTFrack..."

    So now begins the penetration of the psyche of the reality that life on this planet is threatened:  at the very least, "civilization" is at risk.

    Not an easy transition to accept, everyone lives here.

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