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Comments 27451 to 27500:

27451. sjw40364 at 09:02 AM on 20 October 2015
       Other planets are warming
       

       Response to PhilippeChantreau.

       So those who claim to follow science are going to contiinue to ignore that during the same time frame that the earth became warmer - the Winds of venus increased - over the entire timeframe that the mission proceeded. And could still be but we don't know - we haven't sent another probe back to check yet.

       That Mars warmed up during this same time frame so that we can now oberve the effects of liquid water on its surface?

       That Jupiter lost an entire band - and if we are not talking climate - not just on small scales but ones that have lasted just how many years?

        

       Your 30 year scenario strawman is based upon then ignoring those flux ropes between the earth and the sun - knowing as we do that flux ropes transport superheated plasma from one end to the other. We will just ignore that fact too while we are at it I guess.

        

       Every single atmosphereic scientist in the world was stunned by what they found, yet you discount this newly discovered source of energy as unimportat????? Falsified every textbook you had on the subject - so of course it is unimportant to you, you still use them.

       You didn't even know that this energy source

       http://newsroom.ucla.edu/releases/scientists-discover-surprise-in-101025

       And this one even existed when the word global warming was even invented.

       http://science.nasa.gov/science-news/science-at-nasa/2007/11dec_themis/

        

       But you think you got it all figured out - whiloe you continue to ignore every actual observation in the entire solar system - and right in froont of your nose - you just couldn't see or detect it a few years ago. Mostly because as they admitted - they were not looking. So predictive power is out for sure.

        

       Now NASA knew something was up, knew enough energy was being generated to disrupt satelites, probes, etc. Energy you seem to think just magically adds nothing to the system. In direct opposition to the laws of thermodynamics.

       Your strawmen convince no one but yourself. Because of course you refuse to accept 99% of the data.

        

       And even when told of two newlt discovered sources of energy never added to any clculation - you think it's ok to dismiss them. The reality they would skew your hand-picked data - so they must be ignored. The shame you do to science.

       Moderator Response:

       [PS] Fixed links.

       Please note that posting comments here at SkS is a privilege, not a right.  This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

       Please take the time to review the policy and ensure future comments are in full compliance with it.  Thanks for your understanding and compliance in this matter.

       In particular: Provide a source for your "flux ropes". Watch your tone and no accusations of fraud.

       If you want to have a rant about AGW, there are plenty of other sites which would welcome your input. If you actually do want discuss the science then please observe the following:

       Read the sources people provide back to you and read them for understanding, not to dismiss.

       Acknowledge where you agree and where you not with explanation and sources - preferrably to peer-reviewed literature.

       Discuss the science rather motives. Say what you think rather than declaring what you think other people think.

       To any respondents, please likewise follow those guidelines before discussion goes west and I have to start deleting comments.

27452. gws at 08:19 AM on 20 October 2015
       Methane release from melting permafrost could trigger dangerous global warming
       

       Riduna, I do not question the "potential" (possibility) for a large methane release. There certainly is enough carbon making a potentially large emission of methane with a short time frame (10s-100s of years) possible. The question is, how likely is that? Current knowledge, AFAIK, suggests not very. We have yet to see representative measurements that would suggest that current or upcoming warming is likely to lead to this scenario. Is there is evidence for large outgassing from continental shelves, or evidence of large outgassing from lakes? If so, it has not yet affected atmospheric levels.

       So far, atmospheric methane is increasing again in midlatitudes, not high latitudes. You said it yourself, "The threat from Arctic CH4 emissions associated with permafrost decay may not be large or abrupt ...". I agree. I also agree that the potential is worrying, but it is one of those worst case, low probability, high impact scenarios. We do not want it to happen, but we should also not present it as something that is very likely to happen. Few people like to be scared by unlikely scenarios.

       We do need to work toward minimizing that worst potential. The "fat tail" as it is sometimes called, is not unimportant. It can be useful for certain audiences to work the fat tail (e.g. in insurance calculations), but I think it is generally more useful in working with people to consider the more likely scenarios.

27453. Tom Curtis at 06:57 AM on 20 October 2015
       CO2 effect is saturated
       

       fred.steffen @399:

       1)  when you say "as a model, [radiative forcing is] not fitting", the model from which radiative forcing is derived are Line By Line (LBL) or broadband radiative models.  The Line By Line refers to the fact that they calculate atmospheric transmission and emission for each wave number (a measure of frequency) seperately, giving a very fine resolution of radiative transfer.  Typically they also divide the amtosphere into about twenty layers or so, calculating in each direction (up or down) the radiation entering, the radiation absorbed and the radiation emitted based on the atmospheric composition at that layer.  As of 1969, they produced results with this sort of accuracy:

       

       One such model whose accuracy across a wide range of surface conditions, temperatures and latitudes was studied in 2008 showed the following scatter plot vs observations for 134,862 observations:

       

       If you are not familiar with scatter plots, they are plots of the observed value (CERES OLR) with the model predicted value, with perfect accuracy of prediction meaning the observations sit on the black line shown.  The accuracy shown here is absolutely astonishing.  The determination of radiative forcing of CO2 was done using models like this, or the lower resolution versions that are essential parts of all climate models (Global Circulation Models).  I can only presume that when you say the model is "... not fitting", you simply do not know what models are used for the theory.

       2)  You also say that "If CO2 makes up 20% of our greenhouse effect, light from stars at this wavelength should be diminished by 20%".  That assumes that absorption is the same at all frequencies, which is false (as can be seen in the first graph).  IR astronomers tune the frequency of the observatories to 10 to 13 micron (800 - 1000 cm^-1)band where there is minimum absorption by any atmospheric component as seen in the first grap above, and this emission spectrum from the University of Colorado:

       

        

       By doing so they avoid nearly all of the effect of CO2 and H2O on the incoming light.  Despite this, they still need to place their observatories high in the atmosphere (either on mountains, in planes or supported by balloons) or in space to get clear images.  So, your fundamental premise that absorption is equal across all IR bands is simply mistaken.

       Curiously, Goddard's "IR astronomer" friend refers to the 9.5 micron band as being absorption freed (it is in fact the frequency of maximum absorption and emission by ozone) and describes the actual atmospheric window as being a zone of significant absorption and emission by H2O, showing he does not even grasp the fundamental facts of atmospheric absorption and emission.

       3)  "Steven Goddard" and his (apparently fictional) source always makes a fundamental misake in examining radiation models.  He only examines the so-called back radiation.  Because H2O and CO2 emissions overlap, and because H2O is very abundant in the low atmosphere, CO2 emissions make up only a very small percentage of the overall back radiation.  That, however, is irrelevant.  What controlls the Global Mean Surface Temperature (GMST) is the balance of energy recieved and energy radiated to space.  Therefore it is radiation to space from the atmosphere which is the dominant driver of surface temperatures, and hence upper atmosphere concentrations that matter.  Because the concentration of H2O is controlled by temperature, and temperatures fall rapidly with altitude, CO2 completely dominates emission to space in frequencies of significant overlap with H2O.  Consequently, it is emissions to space that must be examined to determine the relative importance of different atmospheric components.

       As an aside, because H2O absorbs in more frequencies it still (along with clouds) accounts for 75% of the total greenhouse effect, with CO2 accounting for 20%.  Importantly, H2O varies rapidly with surface temperature, while CO2 varies only slowly.  As a result, increasing CO2 will result in a rapid rise in H2O, generating a positive feedback on the CO2 rise.  In contrast, a rise in H2O will result in only a small response from CO2, resulting in temperatures and H2O concentrations soon returning to their initial values.

       Finally, if you want to examine the basis of greenhouse effect in more detail, but explained very clearly, I recommend my post here.  It and the following comments also contain more detail on the first two graphs above.

       (Note to the moderator, I know that I am close to the point of dogpilling.  If that is a problem, I ask that you retain my post as the only one todate directly addressing the issues raised by fred.steffen (rather than his sources). Thankyou)

       Moderator Response:

       [PS] Tom, thank you for your considered and detailed response. I am sure that will be helpful. However, this is close to dogpiling so no more please.

27454. scaddenp at 06:34 AM on 20 October 2015
       CO2 effect is saturated
       

       Fred - so you would happily breath air with 0.04% Hydrogen Cyanide? Trying to dismiss an effect because it is a small number with without doing the maths to see if what effect it really has is more like an argument from Personal Incredulity. Does it sound better if you say the CO2 makes up 60% of the radiatively active gases in the atmosphere?

       Also, you suggest experiments to see the effect of CO2 - but this kind of thing has already been done. See the Advanced tab of Tom Dayton's link for the papes. The effect of CO2 on incoming radiation has been measured from the surface and also the effect on outgoing from satellite. Both measurements agree with theoretical model to a very high degree of precision. A direct measurement has also been achieved. See here.

27455. Phil at 04:27 AM on 20 October 2015
       CO2 effect is saturated
       

       The article on Tony Heller's (AKA Steven Goddard) states:

       Starting at 13 we get CO2 absorption but that wavelength corresponds to temperatures below even that of the south pole.

       
       So whoever he is, he doesn't seem to understand the earths emission spectrum (as a pseudo-black body) but appears to think the earth should emit at a single frequency for each "parcel" of the surface that is at a particular temperature.

27456. Tom Dayton at 03:31 AM on 20 October 2015
       CO2 effect is saturated
       

       fred.steffen: I don't know what you mean by radiative forcing not fitting as a model. Nor do I know what other model you claim is used by most climate models, so please explain.

       A response to that article you linked does a good job debunking that article, including the nonexistence of the supposed IR astronomer. However, I'd steer clear of its link to WUWT. Instead click the link on the Pierrehumbert article. For a more accessible explanation, see the Skeptical Science post "How Do We Know More CO2 Is Causing Warming?"--first watch the video at the bottom, then read the Basic tabbed pane, then the Intermediate tabbed pane, then the Advanced one.

27457. Rob Honeycutt at 03:30 AM on 20 October 2015
       CO2 effect is saturated
       

       fred.steffen... I did a quick google on the guy who apparently wrote the article for Goddard's blog. He says his name is Mike Sanicola, and he states that he is a "professional IR astronomer." In my google search I came up with this person who also checked into Sanicola's credentials. He says: 

       "Finally, I'm an astronomer and been around quite a while, and I've never heard of Mike Sanicola so I did a little checking. He is not in the American Astronomical Association directory (very unusual for a professional U.S. astronomer), nor is he one of the 10,727 astronomers worldwide listed in the International Astronomical Union (IAU) directory of professional astronomers. The link associated with his name in Goddard's post takes you to the GE (yes, that's General Electric) home page, where there is absolutely no mention of a Mike Sanicola. There are *no* papers in the Astrophysics Data System by anyone named "Sanicola", and this source indexes all papers that appear in the significant astronomy journals and conference proceedings. A Google search finds no reference to a Mike Sanicola, astronomer, other than to the same Steve Goddard article that Ajax quotes. I don't think Mike Sanicola exists, or if he does, he is not a professional astronomer."

       So, I don't know who this guy actually is but he's clearly not the expert he claims to be.

27458. Rob Honeycutt at 03:22 AM on 20 October 2015
       CO2 effect is saturated
       

       Quick FYI... Stevengoddard (not his real name) is probably one of the worst sources of information on climate change available on the internet. 

27459. fred.steffen at 02:29 AM on 20 October 2015
       CO2 effect is saturated
       

       Since CO2 is only present in our atmosphere at 0.04%, I've always thought it strange that it could have such a large impact. I've looked into "Radiative Forcing" and found out that as a model, it's not fitting, so there's another model that's more accurate that's being used instead for most climate models.

       At the center of it all tho, as this article describes, is the effective "greenhouse" effect of CO2. If CO2 makes up 20% of our greenhouse effect, light from stars at this wavelength should be diminished by 20%. 

       According to this article, it isn't even a concern in IR astronomy. 

       (I apologize for the tone of this article, I don't think it should be as inflamatory as it is, yet the points he makes seem valid to me)

       https://stevengoddard.wordpress.com/2014/01/25/ir-expert-speaks-out-after-40-years-of-silence-its-the-water-vapor-stupid-and-not-the-co2/

       If IR at CO2's wavelengths aren't affecting light coming from stars (almost undetectable amount) then IR at CO2 wavelenghts is free to radiate to space even from the surface. That should be easily measurable using a light source at that frequency pointed out to hit a sattelite, or even one of the mirrors we have on the moon. 

       If the article I listed or the premise I've asserted is false, please let me know.

        

       Thank you...

27460. outinthesnow at 02:22 AM on 20 October 2015
       Arctic sea ice extent was lower in the past
       

       I have been looking for reliable information on this specific issue.  For one it's kinda important, and another reason is I am buying a home in florida on the water and dont want it "underwater" in my kids lifetime.

       My worry about the northern ice cap is that if it gets too small it will "detach from underlying land masses" and essentially be a huge iceberg banging around up there.  If you have ever lived on (or near) a lake that freezes from shore to shore you think every spring "wow that is really thick this year its never gonna melt", then a little lake level rise from runoff "floats the solid ice", cracks form, huge ridges between two sheets pushed by wind rise up, and poof just like last year its gone and you are out fishing.

       I would like to relate this to a personal observation that happens when I have a party (lame I know but stick with me).  If I buy soda the day before and put it all in the fridge, and for the party take it out and serve chilled two liter bottles I dont run out of ice from my fridge's icemaker.  If I need to run to get more soda from the store I grab some bags of ice, because the warmer soda will need more ice in the glass to cool the drinks and my ice maker cant keep up.

       The Chart in the post above that tracks the ice through the season as the sun melts it and then cold temps in winter refreeze it (we are talking about sea water here, and I understand that the thermocline of the ocean is in play here), will the ice being able to rotate end up solving the problem as deeper colder water can mix to the surface faster, promoting earlier ice formation after the equinox?  Or the opposite, that mixing would not allow ice formation because the cooling surface water would sink faster before it crosses the 4C density inflection where cooler water starts floating above warmer?

       Sorry to ramble a bit, I am just projecting my little lake here in Colorado (Lake Dillon) melting in spring compared to an area larger than I can comprehend.

27461. wili at 22:11 PM on 19 October 2015
       2015 SkS Weekly Digest #42
       

       Thanks for continuing to cover El Nino. How big of a factor is it in these enormous peat fires in Indonesia?

       Carbon emissions from Indonesia’s peat fires exceed emissions from entire U.S. economy

       Moderator Response:

       [JH] I doubt that we can provide you with any information that is not contained in the excellent Mongabay article that you link to.  

27462. spunkinator99 at 19:56 PM on 19 October 2015
       Models are unreliable
       

       Tom,

       Thanks a ton! I'll take a look at your links. Should be helpful with my ultra-conservative friends!

       Mike

27463. robert_13 at 16:15 PM on 19 October 2015
       It's the sun
       

       Adding to the response to biocab at 03:45 AM on 13 September, 2007:

       In addition to the amplifying effect of water are three other very significant factors that keep water from swamping CO(2):

       1) The total water on the planet doesn't increase or decrease. Earth is an essentially closed system in terms of water, so this is why all water can do to increase warming is amplify some other factor that is changing. This is both logically trivial and utterly inescapable in big picture. The most severe amplification comes from increased ocean temperatures initially decreasing the solubility of CO(2) in the oceans to reduce their CO(2) sequestration, eventually followed by release of previously absorbed CO(2) in ocean water to increase atmoshperic CO(2) and accelerate the process past a tipping point of no return.

       2) Only water vapor is a greenhouse gas. Hardly any exists above 10 km altitude. CO(2) continues at 400 ppm all the way up to over 80 km. There is enough CO(2) above 10 km to be practically opaque to infrared at CO(2) spectral wavelenths. All but the 15 micron wavelength overlaps the spectral emissions of water vapor, absorbing and re-emitting them omnidirectionally, which includes back to earth, of course. The 15 micron wavelength comes from both the earth's surface, but more importantly, also from kinetic collisions that convert thermal energy in both non-greenhouse and greenhouse gases to radiant energy (IR) at all CO(2) and other greenhouse gas emissive wavelengths.

       3) This conversion of thermal energy in both greenhouse and non-greenhouse gases to radiant IR via kinetic excitation of CO(2) and other greenhouse gases is efficient, since the average lifetime of an excited CO(2) molecule (up to a few milliseconds) is much longer than the average time between collisions with non-greenhouse gases (~1 microsecond). The kinetic excitation of a greenhouse molecule is a field excitation phenomenon. The significant practical extent of the electric field of a greenhouse gas molecule is typically hundreds of times the size of the colliding non-greenhouse gas particles, so the easy target adds to the conversion efficiency.

       Therefore most of the energy radiated out into the perfect thermal insulator, space, from the upper atmosphere (just above the troposphere around 10 km and up) is radiated by CO(2) (~68%, with ~16% directly from the surface, and ~13% from water vapor, wth the small remainder by other greenhouse gases). This clearly implies that the upper atmosphere radiates just as much back down, making CO(2) the major factor returning radiant heat to earth from the upper atmosphere. Much of this reaches the atmosphere near the surface mediated by water vapor via the spectral signature in common with CO(2) and the earth's surface itself by conversion to thermal heat upon striking it.

       We can clearly deduce from the inevitably of omnidirectional radiation from CO(2) in the upper atmosphere that what goes out into space represents an equal amount going back toward earth. It's mediation by the other factors just referred to makes its very substantial contribution less obvious at the surface.

27464. PhilippeChantreau at 13:22 PM on 19 October 2015
       Other planets are warming
       

       Response to sjw40364 from inappropriate thread: I looked at all the links provided, and not a single one of them alludes to a warming of the climate of the planets mentioned. Suggesting that any of these articles indicates a warming climate on the planets considered indicates that sjw did not read or understand the articles.

       At best, the Venus and Mars articles underline how we can attempt to better understand their climates, emphasizing that we don't understand them well.

       Climate on Earth is defined by a baseline of 30 years. For Mars, Jupiter and other planets going outward from the Sun, 30 orbits translates into respectively 56, 356, 884, 2522, 4947 and 7435 years. That is what would be required to establish a baseline, if we had instruments capable of reliably measuring enough climate parameters. Then we would need proxies to establish the true existence of any significant departure from normal conditions. We are not even fully understanding weather events happening on these planets.

       The argument that other planets are warming is one of the most ridiculous ever spewed by fake skeptics.

27465. PhilippeChantreau at 12:57 PM on 19 October 2015
       Other planets are warming
       

       MagicWizard, why would forces that we can not detect have more of an effect than the forces that we can detect. We can detect freakin's neutrinos for God's sake, why would something that we can't detect have such a hufe effect, which is perfectly explicable by the forces we can detect?

27466. PhilippeChantreau at 12:49 PM on 19 October 2015
       There is no consensus
       

       Response to sjw40364 on the appropriate thread.

27467. Tom Dayton at 12:44 PM on 19 October 2015
       Models are unreliable
       

       spunkinator99: See also Bart Verheggen's post "John Christy, Richard McNider and Roy Spencer trying to overturn mainstream science by rewriting history and re-baselining graphs." And a new comment I just posted on the satellites SkS post.

27468. Tom Dayton at 12:44 PM on 19 October 2015
       Satellites show no warming in the troposphere
       

       Relevant to the lower troposphere and satellites:

       • Ed Hawkins, "Is there a pause in the temperature of the lower troposphere?," Dec. 2014
       • Jos Hagelaars. "Klotzbach Revisited," explaining briefly the expected relationship between the surface temperature and the lower troposphere temperature, the uncertainties about that, and the issues with the satellite measurements
       • Isaac Held, "54. Tropical tropospheric warming revisited: Part 1," giving much more detail on what is expected and what has been observed
       • Christopher Hogan's comment at RealClimate, giving a short list of reasons to be properly skeptical of any purported pause in the lower troposphere, and links to more thorough explanations
27469. Tristan at 10:03 AM on 19 October 2015
       2015 SkS Weekly Digest #42
       

       Meanwhile, over at Gina Rinehart's favourite website, Dr David Evans, PhD has gone full Galileo, and his wife has so far devoted 13 posts to it.

27470. grindupBaker at 07:11 AM on 19 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       @Me#10 I know that I have a mismatch between 1a) & 2) because I've intentionally omitted any feedbacks already started and underway in 1a) and I've included them in 2). Too much time spent on some analysis in response to a trite non-useful comment #3 above that must itself have consumed all of 10 seconds of the commenter's time.

27471. grindupBaker at 07:03 AM on 19 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       @fletch92131 #3:

       1) Your "probably only in the models themselves" is incorrect unless you are basing it upon your assumption that no carbon will be burned from next year until 2100 (you didn't say). It certainly isn't "probably only in the models" for two independent reasons.

       1a) The ocean surface is currently 0.3 degrees cooler than it needs to become because it's been kicked hard the last 45 years and it needs up to 100 years to re-stabilize at its new higher steady temperature. So that's 0.9+0.3=1.2 degrees is to be the actual surface warming since ~1880 in 2100 if no carbon was burned from tomorrow until 2100. That's at the 54% of the known logarithmic effect for 560 ppmv atmospheric CO2 so if there is no additional heating from methane from permafrost melting, and no additional heating from dark land and sea being revealed to the Sun when there's less Arctic ice, and if the greenhouse effect from moister air that's kept this planet surface warmer for 600,000,000 years should just happen by utter luck to plateau at today's GMST and go flat, and if the industrial pollution that's seen blocking out the Sun in major cities in China and elsewhere actually doesn't block out the Sun at all (an optical illusion ?) or if future humans really like bronchitis and so increase industrial pollution, then it's to be a definite 1.2 * 46% / 54% = 1.0 degrees more warming by the year that atmospheric CO2 reaches 560 ppmv with an extra 0.3 degrees warming over the next 100 years if coal stops being burned cold-turkey at 560 ppmv. That's a lot of "ifs". It's essentially certain that all my preceding "ifs" are incorrect. How can dark land and sea not warm more than with ice and snow ? How can methane not be released from the permafrost that's definitely melting ? How can air pollution not block sunlight ? Should humans intentionally double or triple the air pollution to hold to your ridiculous +1.0 degrees ? Why did the warming effect of moister air that worked fine for 600,000,000 years stop working this century ?

       1b) A variety of analyses of paleoclimate over a variety of long periods indicates that the temperature change in degrees has been anywhere between 0.6x and 1.2x the TOA forcing in w/m**2 after the system has balanced. It is known by physics that the TOA forcing of doubling CO2 is 3.7 w/m**2 so that's a range of 2.2 to 4.4 degrees based on what has happened over long time scales in the past. Nothing whatsoever to do with computer simulation climate "models". The climate "models" show a similar range. The main purpose of climate "models" is to improve in the shorter term so that they can inform what will happen over a very short period such as a decade and perhaps even give some good insight into specific regional effects.

       2) Your comment is senseless and thus cannot be responded to by persons who actually think and analyze, because you've failed to state additional carbon burned quantity, which is the entire topic. We are obliged to assume that you've computed that GMST will increase by 1.0 degrees in 2100 if no carbon was burned from next year until 2100. Okay, not bad then. I think you might be a tad high with +1.0 degrees if no carbon was burned from next year until 2100. If no carbon was burned from next year until 2100 then it's +0.3 degrees ocean surface balance plus +0.4 degrees because the Chinese people get completely fed up with bronchitis and anyway solar, hydro, nuclear, wind, geothermal and tide powers make no smoke, plus some fraction of a degree for albedo change & methane feedbacks. Actually, you are just about correct. GMST will increase by 1.0 degrees in 2100 if no carbon was burned from next year until 2100. Good thinking.

       3) If GMST increases by 1.0 degrees by 2100 then this will be 0.9 (the current rise) + 1.0 = 1.9 degrees by 2100. This requires the oceans to warm by 1.3 degrees in order to keep up ( at which point the oceans would almost completely stop warming. This will take ~300 years. Ocean average temperature is now 3.2 degrees. When ocean average temperature is 4.5 degrees in ~300 years with your low-balled additional +1.0 degrees GMST by 2100 then it will be a vastly different (and vast) heat content in the oceans underpinning the surface climate.

       By 2200 with your low-balled value oceans will need to reach 5.4 degrees average temperature if carbon is still being burned at present rate. More still by 2300, more still by 2400, more still by 2500 and then the coal ruins out. So why do we care about climate in 2100 and have no interest in climate of 2110 ? What's the logic ? The point is that there's ~4,000 GtC (1,800 ppmv) burnable carbon, mostly coal, and how much do you think S.B. burned ? Give a number. So how much do you think S.B. burned and how much have you computed that will warm the oceans from their present 3.2 degrees and have you determined that your suggested cut-off point will not create a disaster for much of the existing mix of species ?

       Once the additional heat is in the oceans it cannot be removed on time scales less than tens of thousands of years. In the most recent example the oceans lost 3.5 degrees of temperature over 85,000 years (the last glaciation "ice age") and in order to do this it was necessary to hold GMST down as much as 6 degrees lower than today (so ~3 degrees average) for the 85,000 years and this caused ice sheets to cover the northern hemisphere pretty much all the way down to Spain. So, if future humans find that oceans averaging 2.2 degrees warmer than today create a disaster then how do they cool them in less than 85,000 years ? Do they intentionally create a quadruple-strength ice age for 20,000 years in order to undo the climate change ?

       The bottom line on the above is that ocean average temperature has been kept within ranges of small fractions of 1 degree over eye-blink time scales such as a couple of thousand years. This ocean heat change speed that's starting is going into uncharted territory.

       4) Re your confident science-based comment, please list details of your disagreement with scientists (as seen by me at IOS/DFO on Vancouver island) that river salmon would die out if river water temperature increased by 1.0 degrees on average.

       5) To your actual topic "It's so unfortunate that people feel the need to label other individuals" what are our choices when individuals are so lazy as to make trite comments that add nothing whatsoever to the discussion ? Do we assume that the person is pleasant but lazy ? The nicest assumption within our range of choices is that the individual is an intelligent shill (I suppose genius shill would be the utter nicest), one of the more apt of our species projecting its superiority. If the individual were to comment such as "I've seen a paper/blog/video talk/lecture/discussion by Dr. Cleverpants explaining clearly how TCR with 560 PPMV CO2 will be 0.8 to 1.2 degrees warmer than today (you can read it *here*) and it appears very comprehensive and sensible and I've found nothing indicating that'll cause much problem for present species including humans" then others of us could appreciate that individual is carefully pondering this and might be correct and warrants discussion (even if the response should be "Dr. Cleverpants is a known paid denier and his science has been debunked *here* and *here*") but fact is that "individuals" so rarely do that thing. Individuals do a lot more of providing unexplained non-facts without some explanation that could be pondered and refuted such as mine above, and with an air of false authority that smacks of denier or actual shill, don't they #3 ?

       Moderator Response:

       [PS] To all commentators. Please note the Comments Policy "No dogpiling" rule. We have had quite enough. Fletch92131 comment does not need more than 5 responders.

27472. Mal Adapted at 04:04 AM on 19 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       fletch92131: "Anything larger than that increase is probably only in the models themselves, not in any real likelihood based on science or history of climate."

       fletch92131's mistaken assertion clearly demonstrates the Dunning-Kruger effect, but doesn't reveal his underlying motivation for preferring his own ignorance to the lopsided consensus of working climate scientists.  A quick search for "fletch92131" led me to a blog with a single post titled Saving California.  The author makes his position clear at the outset:

       California IS the Worst-Run State in the Nation. Included in this assessment is the state's attempt to lead the nation/world in fighting what the state calls “Climate Change”, as if any person or entity (state or federal government) can control climate!...

       The explicit declaration of AGW-denial is tangential to the thrust of the post, which is that many functions of government should be performed by private, for-profit businesses. The author strongly approves of "efficiency", and while deploring subsidies for renewable energy, calls for California to increase its fossil-fuel production, dismissing both the cost of climate change that the FF industry has externalized, and the subsidies it receives.  He argues that internalizing climate change costs in the prices of fossil energy is regressive, citing the George C. Marshall Institute, the cold-war defense think tank.

       The blog site offers a brief biography of the author, which may also be of interest.

       It appears that fletch91231's AGW-denial is motivated by pro-market ideology. Presumably his ideological commitment won't allow him to acknowledge a problem that the "free" market can't solve, namely that of externality. That would fit the definition of term "denial" in the specialized vocabulary of Psychology,

       in which a person is faced with a fact that is too uncomfortable to accept and rejects it instead, insisting that it is not true despite what may be overwhelming evidence.

       Since fletch91231 has accepted the denier label, I'll leave it at that.

27473. Tom Dayton at 02:01 AM on 19 October 2015
       Models are unreliable
       

       spunkinator99: Be sure to read the comments on that satellites post, especially the ones in 2015, and follow my comments' links to Tamino's blog that examines balloon radiosonde temperature measurements and their curiously increasing discrepancy from satellite measurements beginning around the year 2000. And read Glenn Tamblyn's comment on Spencer's blog.

27474. Tom Dayton at 01:13 AM on 19 October 2015
       Models are unreliable
       

       spunkinator99, see also the post countering the myth that satellites show no warming.

27475. Tom Dayton at 01:09 AM on 19 October 2015
       Models are unreliable
       

       spunkinator99: Among other problems with that graph, it is baselined improperly so that the UAH and RSS lines begin near the model mean and diverge over time. Spencer used the same deceptive tactic in later constructing a graph of 90 model runs, as Sou explains at Hotwhopper. Tom Curtis pointed out why 1983 was such an obvious choice for Spencer's distortion.

       Ed Hawkins at Climate Lab Book updates his comparison graph frequently. John Abraham's recent article's graph is bigger and so easier to read, and shows the earlier (CMIP3) model runs as well as CMIP5.

       None of those shows the correct model lines, because those model lines were for surface air temperature despite observations being of surface sea temperature where not ice covered. The correct model lines are shown in an SkS post.

27476. spunkinator99 at 00:04 AM on 19 October 2015
       Models are unreliable
       

       Hi,

       I was wondering if anyone could help me here. I've been inundated by this chart and others like it from my skeptic friends. It compares computer models to observed temperature only using UAH and RSS. Obviously it's cherry-picking since there are other temperature sets but does anyone have a chart similar to this that shows all the major data sets?

       

       Moderator Response:

       [TD] Resized image.

27477. michael sweet at 20:18 PM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       fletch92131,

       Since the NASA GISS data show that temperatures have already increased 1C since 1880, do you mean that another increase of 1C before 2100 is normal?  At current rates of increase (0.16C/decade), it will increase at least another 1C by 2100 (2C total, at least).  

       Since the increase in temperature is expected be faster in the future without serious action to reduce CO2 emissions, the actual increase could be a lot more.  Can you put an upper bound on what you would consider a "normal" increase in temperature?  Don't bother to look at Tom's data, it indicates that we would expect temperatures to be cooling due to natural causes.  

27478. michael sweet at 20:00 PM on 18 October 2015
       It cooled mid-century
       

       LowneWolfe,

       Please read the OP again.  I believe you mean CFC's not CFS's.  As you claim, CFC's warm the planet.  The OP does not mention CFC's.

       Sulfate aerosols cool the planet.  These aerosols were emitted in large quantities during the mid centuary industrialization due primarily to coal burning.  When the USA and Europe got tired of toxic air pollution in the 1970's and controlled aerosols the underlying warming became evident.  

       China and India currently emit large amounts of aerosols which cool the planet and mask part of the CO2 caused warming.  Unfortunately, these aerosols are poorly measured and the exact magnitude of the effect is poorly bounded.

       If you want to learn more post again, we are happy to help you increase your AGW knowledge.

27479. LowneWolfe at 16:24 PM on 18 October 2015
       It cooled mid-century
       

       So NOW cfs's are going to COOL the planet?  This is the FIRST time I've ever heard anyone make that claim.  CFS's area  greenhouse gas and were linked to warming not cooling.  Make up your mind.

27480. Tom Curtis at 13:15 PM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       fletch92131 @3, for myself, I am highly skeptical that an increase in Global Mean Surface Temperature (GMST) of 1 degree C in a century is "normal".  Indeed, Marcott et al (2013) show a 1000 possible temperature histories given uncertainties with regard to time and temperature across a range of proxies:

       

       In very few instances over periods of 100 years or less is there a gap of 1 degree C between the minimum and maximum value in any realization over that period - let alone the same one.  From this data, any centenial temperature increase greater than 0.66 C is a very low probability event.  That is, it is not normal.

       Suggestions to the contrary seem universally to be based on either proxies for single regions (such as GISP 2), or hemispheric or sub-hemispheric reconstructions.  That is, they are not based on global temperatures at all.  Often they are not even based on such misinterpreted evidence, but on mere anecdote.

       Yet here you are, apparently so confident in this unsupported claim that you are prepared to use it as a foundation for a "knock down argument" against AGW.

       That strongly suggests to me that you are a denier.  For what characterizes deniers is not what they disagree with, but with their employment of selective standards of evidence to support their claims.  In short, on their reliance on pseudoscience rather than science to reject scientific claims.

       By all means, if you have actual evidence that global means surfact temperatures normally vary by 1 C in a century, please present it.  Or alternatively, acknowledge your lack of evidence in support of your key premise, and withdraw your argument as unfounded.  But if you are unwilling to do either, then you merely demonstrate that the term "denier" applied to you is no insult, but mere description.

27481. mancan18 at 12:59 PM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       Congratulations. This accolade is well deserved. The SkS site was and is a breath of fresh air in a country like Australia where the dialogue of Climate Change is dominated by the Institute of Public Affairs (IPA), the likes of Ian Plimer and Bob Carter, the Mining Council of Australia, the conservative contrarians in the ruling Liberal National Party of Australia and the Murdoch Press. I can at least now say to those who have been influenced by their contrarian line to go to SkS and do a bit of extra reading.

       However, it is not all done and dusted. Even today, the Sunday Telegraph has run a column by Miranda Devine (one of the big three along with Andrew Bolt and Piers Ackerman) that extols the virtue of digging up fossil fuels to save poor people in poor countries, and that global warming is not happening and it is all a conspiracy. I am not sure how you overcome such an overwhelmingly one sided view in the popular media. Usually the contrian debate goes along political lines or merely pays lip service to perhaps there has been some mild warming but it isn't a problem. The only response you can make to such arguments is that the person needs to understand the science more and they need to do more research. Sks is an important reference for that reason.

       Unfortunately, there seems to be two types of contrarians. There is the doubter, who may well argue with you on a purely scientific level, which is Ok. They are just demonstrating the natural skepticism of science, so Sks is important in giving them extra information; AND then there is the doofus, the blind denier, who just doesn't want to know, totally ignores it all, just isn't able to understand the scientific arguments, thinks it is all political or thinks it is all some sort of greenie/socialist conspiracy. You can easily tell who they are. They will call you a "warmist" or a "carbonite" or something. Not sure that Sks is going to be helpful informing people like these. Those people wouldn't go to the Sks site anyway and are likely to use derogatory language to describe the site and the scientists who write for it. Matt Ridley did, when describing John Cooke's 97% Consensus project as being discredited, in his recent contrarian article in the June 2015 edition of "Quadrant", by using parts of the IPAs latest contarian publication "Climate Science - The Facts" to make his case.

       Anyway SkS and John Cooke, well done. Keep it up, even though I sometimes feel that some of the discussion in the threads becomes a bit too esoteric for the lay public to follow at times. Mind you, I do understand why this is. It is because Sks still has to maintain scientific integrity so it can remain a valuable resource in the continuing AGW CC debate.

27482. One Planet Only Forever at 12:44 PM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       @fletch92131

       Please clarify why you chose the label "agnostic". The label is defined in my old 1985 copy of the Concise Oxford Dictionary and on the current Oxford Dictionary web source as "a person who believes that nothing is known or can be known of the existence or nature of God or of anything beyond material phenomena; a person who claims neither faith nor disbelief in God".

       That religious related label does not seem applicable to a 'scientific evaluation of observations' such as the rapid recent increase in CO2 in the atmosphere and the corresponding increase of the global average surface temperature consistent with the understanding of what would happen if the concentration of CO2 in the atmosphere were to increase.

       I understand that Oxford lists skeptic as synonym for agnostic, but that is a label intended to be applied in the context of a skeptic of the existence of God.

27483. One Planet Only Forever at 11:57 AM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       @fletch92131

       Please calrify what you meant by "... normal temperature increase ...". I am particularly interested in your explanation of your use of the label "normal".

27484. fletch92131 at 09:31 AM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       It's so unfortunate that people feel the need to label other individuals. I admit to being Agnostic, because I have not yet seen any compelling argument for why we should be trying to stop a normal temperature increase of approximately 1°C between now and 2100. Anything  larger than that increase is probably only in the models themselves, not in any real likelihood based on science or history of climate.If that makes me a denialist, then so be it.

27485. One Planet Only Forever at 09:29 AM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       Congratulations! Well deserved recognition.

       It may be helpful to develop categories among the Deniers.

       Anyone choosing to not accept the developing best understanding of what is going on is a Denier.

       • When it can be clearly shown that a person is creating or spreading information contrary to the expansion or improvement of the best understanding of what is going on they could be called "Unhelpful".
       • And if it can be shown that they are deliberately acting contrary to fully informing the general population regarding what they actually do understand is going on they should be called "Harmful", because they are willfully, not accidentally or without awareness, behaving contrary to the improvement of understanding what is going on.
       • And if a "Harmful" actor is promoting expansion of, or trying to prolong, an understood to be damaging unsustainable activity then they should be called "Criminals".
27486. Nick Palmer at 05:35 AM on 18 October 2015
       Skeptical Science honoured by the Committee for Skeptical Inquiry
       

       "this is largely because denialists get cranky when their behaviour is accurately identified".
       
       "What to call those who reject mainstream climate science (to borrow the terminology of Associated Press) is a topic of hot debate"
       --------------------------
       I have sometimes managed quite well with "rejecter" or "disbeliever". If I get away with that, I then follow up by describing them as indulging in unreasonable rejection of the science or unreasonable disbelief. For some reason this seems to go down better than the "d" word.

27487. Mal Adapted at 04:27 AM on 18 October 2015
       So what did-in the dinosaurs? A murder mystery…
       

       I was a doctoral student in Ecology and Evolution when the bolide-impact theory for the K-P extinction event was gaining currency.  Since then I'd come to consider the matter "settled", but Howard Lee's argument is convincing, on a preponderance of the evidence he presents. 

       Now, on the "red-hot ejecta" question:

       The photo in the OP, credited to Gerta Keller, is from a site in NE Mexico, several hundred miles from the Chicxulub site.  It shows "spherules bent round each other showing they were still hot and soft when they settled." 

       One imagines that where those spherules landed, falling thickly enough to bend round each other, ambient temperatures might well rise to levels lethal to most or all above-ground organisms. 

27488. Tom Dayton at 03:07 AM on 18 October 2015
       Models are unreliable
       

       Ed Hawkins has posted a good article on how choice of baseline matters, including a neat animation.

27489. Riduna at 18:02 PM on 17 October 2015
       Methane release from melting permafrost could trigger dangerous global warming
       

       The author is quite right for the following reasons:

       1. When permafrost melts on flat land it causes a waterlogged landscape because underlying, unmelted permafrost prevents drainage and the result is anoxic conditions. In those conditions methanogens thrive on decaying biota and produce CH4, which passes through a shallow water column or vents directly to the atmosphere with little or no oxidation.

       2. Methanogens are active in sub-zero conditions and are able to produce CH4 from surface and subsurface biota prior to permafrost thawing and this gas may accumulate in frozen soils until they thaw when CH4 is released, again with little or no oxidation. Methanotrophs may be present but in the absence of sphagnum moss are likely to be active on the surface rather than in the soil.

       3. The article refers to permafrost melting in the north which presumably includes the Arctic continental shelf – a vast offshore area mostly covered by seawater <50m deep and a water column too short for oxidation of methane produced from decaying biota washed onto the seabed surface by the great Siberian rivers. The result is CH4 supersaturated seawater and significant venting to the atmosphere.

       4. Biota and CH4 gas are trapped in and under the permafrost cap which covers most of the continental shelf seabed and this is decaying, resulting in the release of CH4 from depths, at present in excess of 50 metres beneath the seabed surface where silts are thawing more rapidly due to salt content. Warming of waters covering the Arctic continental shelf have been shown to be warming at ~1°C/decade since 1980, a process likely to accelerate, together with the rate of CH4 emissions, due to Arctic Ocean warming.

       The threat from Arctic CH4 emissions associated with permafrost decay may not be large or abrupt – yet – but it is unquestionably a positive feedback. It has the potential to result in dangerous levels of CH4 accelerating Arctic amplification and global warming. What should be of equal concern is that this process has been initiated by anthropogenic greenhouse gas emissions but, once initiated is beyond human control, other than by untested and possibly dangerous geo-engineering.

       Where Dr Abraham and I differ is in regard to the power of CH4, stated to be 30 times greater than CO2. I assume this refers to the GWP of CH4 over a 100 year period. However CH4 only has a life of ~12 years in the atmosphere - though this is increasing. The point I make is that in conditions where the presence of CH4 is increasing (it has increased by over 250% since 1800) it is more appropriate to refer to its GWP over a 20 year period which is now 85.

       It adds some gravity to the problem posed by Arctic CH4 emission growth don’t you think?

27490. Joel_Huberman at 01:40 AM on 17 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Thanks, HowardLee. Your summaries of evidence regarding past extinctions--mostly pointing to changes in greenhouse gases--are fascinating as well as frightening.

27491. howardlee at 22:38 PM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       ... but to your other points:

       Martínez-Botí et al suggested that climate sensitivity in cold climates with ice is about double that of sensitivity in warm, low-ice climates. Ie today should be more sensitive than the end-Permian.

       The scale of end-Permian warming was a factor in the extinctions - studies have calculated that it left tropical latititudes lethally hot for complex life. Rate is crucial. It seems that if the rate exceeds the ocean overturn rate the long term negative feedbacks dont have time to mitigate the effects.

       A recent study by Dutton et al suggested that based on CO2 levels about todays level we should eventually get Pliocene-like sea levels of tens of meters above today:

       

       The rate of that SL rise is hard to constrain but ive read that would probably take a few centuries to reach those levels. But Paleo studies of the Miocene suggest strong hysterisis in Antarctic ice sheet response with forcing levels at CO2 levels similar to today.

        

       Moderator Response:

       [RH] Fixed image width.

27492. howardlee at 21:24 PM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Ranyl - no worries, it's better than most of the things I have been called and it made me smile!

27493. ranyl at 17:07 PM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Dear Howardlee,

       Please excuse my calling Howardless, it was a typing error with no intent and I didn't see it, e and s are close on the keyboard.

       Maybe the moderator could edit it, as there is nothing less about your excellent blogs and posts.

       Ranyl

27494. CBlargh at 16:55 PM on 16 October 2015
       The History of Climate Science
       

       You forgot Eunice Foote!  She seems to have beaten John Tyndall to the discovery of the infrared absorption bands of greenhouse gasses by a few years:

       www.searchanddiscovery.com/documents/2011/70092sorenson/ndx_sorenson.pdf

27495. RCB at 12:01 PM on 16 October 2015
       Propaganda trumps journalism in conservative media climate reporting
       

       Thanks for addressing this.  I saw this in the Express last week, as well as a couple of other amazing claims about how glaciers aren't melting or something.  I looked around a little bit, and I wondered if maybe the supposedly earth-shattereing revelation in this piece was linked to the idea that more isoprene would generate more clouds, and coupled with the belief that clouds are a significant negative feedback, thereby negatively affecting temperature rise.  That was my take, but of course that depends upon ignoring the studies regarding cloud feedbacks that do not support them as creating a strong negative feedback.

27496. Tom Curtis at 06:17 AM on 16 October 2015
       Water vapor is the most powerful greenhouse gas
       

       TheNumberOne @220, no!

       What the OP is saying is that an increase in temperature due to CO2 will cause an increase in temperature due to WV of 0.5 C, which will cause a further increase in temperature due to WV of 0.25 C, which will cause a further increase in temperature due to WV of 0.125 C, and so on, with the entire series of increases adding up to a total increase due to WV of 1 C, with feedbacks on feedbacks on feedbacks already included.

       Mathematicaly,  G = 1/(1-f) where G is the total response, and f is the initial response of the feedback.  Provided f is less than 1, G is finite.

27497. ranyl at 05:13 AM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Thanks Howardless,

       So a crude 6C for equilibrium with no ice (12C with ice), quite high really and you get ~60-80% in 100 years with equilization over millenium.

       And were at ~0.43 of a doubling at 400ppm if starting at 280ppm with ice.

       Having said that the Antartic contential freezer was absent so maybe that increased the sensitivity??

       Although an early Pliocene CO2 of 350ppm (0.4 of a halving), as many suggest, at 3C-5C hotter than pre-industrial implies a ECS of 7.5C to 12C, with 60-80% in 100 years implies that 350ppm should induce a warming of between 1.125C to 2.4C taking 350ppm to be 1/4 of doubling from 280ppm. However if take past to equal future and take earth to a perfect climate model, then 3-5C for 350ppm implies 1.8C to 4C by 2115.

       Considering the extreme weather recently at 0.75C and it all seems rather daunting even at 350ppm therefore, and we are at 400ppm with no prospect of this lowering any time soon due to permafrost melting and the like. 

       And the rate is so fast, and this is a chaotic system.

       Do wonder if the rate will induce unexpected shifts in the global weather systems or new extreme events, isn't it sort of like sticking the heating ring on max for 5 minutes compared to slowly adding the heat over hours, you always to get a more turbulent response.

       And I can't help thinking a more turbulent response isn't a good idea in global weather.

       Does the rate as well as the scale of warming count in these mass extinctions?

       Can't help thinking it might.

       In these terms 350ppm means we have a carbon debt not a budget, and that has some deep implications, for it means all emissions add to the debt, rather than just using up a bit of a safe budget.

       Moderator Response:

       [PS] Excessive white space removed.

        

27498. TheNumberOne at 04:58 AM on 16 October 2015
       Water vapor is the most powerful greenhouse gas
       

       What you are saying is that if the global temperature increases by 1 degree, water vapour will then increase global temperature by another degree. But won't that degree cause water to increase the global temperature by another degree. And won't that degree cause water to increase by another degree ... and so forth? Either that means that your assumptions are wrong, or global warming is not caused by humans but by a run away water effect.

       Moderator Response:

       [PS] Please see the myth "Positive feedback leads to runaway warming".

27499. Arnaud Delebarre at 02:04 AM on 16 October 2015
       Methane release from melting permafrost could trigger dangerous global warming
       

       I do not agree about the comments mentioning a misleading "headline". "Methane release from melting permafrost could trigger dangerous global warming" whatever is the cause of the release, seems real. Perhaps "trigger" might have be changed to "enhance" or "contribute". But my English is not good enough to conclude.
       I do not understand precisely "Lay people will misinterpret this" but I think this paper only deals with the potential increase of GHG emissions and the stock of CH4 in permafrost. As well as it would not be wise to extract all coal, gas and oil, or to emit all stocks of CH4 captured in the permafrost.

27500. howardlee at 01:45 AM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Ranyl,

       Tang et al (2013) estimated:-
       8.5 × 10^7 Tg CO2, 4.4 × 10^6 Tg CO, 7.0 × 10^6 Tg H2S and 6.8 × 10^7 Tg SO2 (Tg, Trillion grams)
       But they only sampled the igneous component, whereas it looks like baked sediments were a considerable contributer of additional carbon.
       Svensen et al (2009) extimated the additional contribution from such pipe eruptions to be:-
       CO2 equivalent flux of 0.8–2.1 Gt CO2/y for 6400 years, with subsequent 0.7–2.0 Gt CO2/y over a 50 ky period from contact metamorphism.

       Clarkson et al (2015) modeling from ocean acidification and the isotope signal estimated 2 × 10^18 mol C over
       10,000 years, ie emission of 24,000 PgC at a rapid rate of 2.4 PgC/year.

       That compares to modern rates of ~ 4.27 ± 6.83 PgC/y and total fossil guel reserves at ~5000 PgC (average rates of 2.2GtC/y since 1750 is a similar flux). They calculate Permian pCO2 jumping from about 3PAL to about 20 PAL, (about 2.5 doublings) with a warming of 15 Celsius, and an ocean acidification event lasting around 10,000 years.

       Just crudely taking Clarksons numbers that suggests an Earth system sensitivity of ~ 6C per CO2 doubling. Thats a very crude estimate and I would look to climate modelers to refine that or derive an ECS from it.

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