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Comments 27301 to 27350:

27301. 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.

27302. 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.  

27303. 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.

27304. 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.

27305. 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.

27306. 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.

27307. 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.

27308. 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".

27309. 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.

27310. 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".
27311. 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.

27312. 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. 

27313. 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.

27314. 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?

27315. 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.

27316. 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.

27317. 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!

27318. 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

27319. 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

27320. 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.

27321. 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.

27322. 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.

        

27323. 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".

27324. 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.

27325. 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.

27326. ranyl at 00:15 AM on 16 October 2015
       Earth’s worst extinction “inescapably” tied to Siberian Traps, CO2, and climate change
       

       Dear Howard Lee,

       Thanks.

       In terms of doubling of CO2 for that 10C rise what are we ~ talking?

       Then considering no ice back then, and that equilibrium climate sensitivity is ~50% with no ice compared to when ice is present, and that we have ice today, what are looking at if that time period can be taken as an some sort of analogy of now?

        

27327. Tadaaa at 17:28 PM on 15 October 2015
       Meet The Denominator
       

       ah OK, thanks for the explanation

       My understanding of the science involved is embarrassingly low, but I do try and read/understand the explanations of the myths

       but what really helps though is reading though the comments at the end of each explanation

       it is here you see stunning examples of the “dunning kruger” effect, the inability to address the facts, and “do the math” – and if they do “do the math”, show how it is relevant to the actual issue at hand

       so to me they make the case they are arguing against, I may not be a scientist – but bulsh1t is a universal language – and I know it when I see/read it

       anyway, well done and keep up the great work

27328. One Planet Only Forever at 13:28 PM on 15 October 2015
       2015 SkS Weekly News Roundup #41
       

       A recent article in the NY Times "Faith in an unregulated free market? Don't fall for it." makes it clear that the power of deliberately unacceptable people to succeed through deliberately misleading marketing is a serious threat that has been understood for quite a while now.

       The comments on the article add points about the long history of understanding that has never been able to effectively block the understood to be unacceptable pursuits of personal temporary prosperity or grandeur.

       This is what 'fights' against the development of better understanding of climate science among the general population.

27329. Andy Skuce at 08:24 AM on 15 October 2015
       Methane release from melting permafrost could trigger dangerous global warming
       

       I agree that the headline is misleading. The permafrost feedback is mostly a CO2 story. Methanotrophs may well gobble up some or most of the methane in some soils, but in saturated, anoxic areas, methane will (and currently does) make it into the atmosphere. Increased vegetation growth rates probably make the Arctic a carbon sink for now, but most models do not see the vegetation keeping up once the permafrost starts to thaw in earnest. See my SkS piece on the recent Schuur et al review paper for more details. 

       I agree also that the text quoted by gws is potentially misleading. Anthropogenic methane emissions are about the same magnitude as natural biochemical sources. Fossil fuel emissions, in the US at least, account for about 40% of the anthropogenic methane emissions, whereas fossil fuels make up about 94% of the CO2 emissions. EPA

27330. Tadaaa at 06:41 AM on 15 October 2015
       Meet The Denominator
       

        

       Apologies I know this his is an old thread, but I have recently become interested in the whole debate around climate science, and I find this an invaluable and informative resource 

       I only today saw poptech's blog - fairly standard contrarian fair

       but I can't help thinking it is a mistake to delete poptech's post

       Moderator Response:

       [PS] Well it actually was a mistake. An mistaken push of "spammer" button which deletes posts and account. Given that poptech had long been in violation of comments policy, as well as tiresome troll who could not imagine any data that might change his mind, the effort to restore his posts wasnt worth it. If you think poptech has anywhere managed to say something worth discussing, feel free to comment on an appropriate thread.

27331. gws at 04:22 AM on 15 October 2015
       Methane release from melting permafrost could trigger dangerous global warming
       

       John,

       The headline is misleading, since the permafrost warming effect is largely one coming from carbon released as CO₂, not methane. As the soil thaws more methane can be formed, but also more methane will be consumed in the topsoil layer by methanotrophs. The text also does not consider the additional carbon taken up in permafrost regions as a result of changing vegetation, which is believed to counteract the soil carbon release due to increasing LAI and length of growing season.

       Furthermore, the text

       "Unlike carbon dioxide, which is emitted primarily through burning of fossil fuels, methane has a large natural emission component."

       is also misleading because the natural CO₂ sources to the atmosphere are also much larger than teh fossil fuel source. Lay people will misinterpret this. What you actually meant is that excess CO₂ on top of the natural carbon cycle is driven by fossil fuel emissions (roughly 90%), while excess methane (over the preindustrial methane cycle) has a larger variability of sources.

27332. digging_the_dirt at 02:18 AM on 15 October 2015
       Heat from the Earth’s interior does not control climate
       

       Thanks for this very thorough article as well as the discussion .

       I have run into a few other denier hypotheses; 1. That the weakening of the earth’s electromagnetic field is causing climate change. 2. That it is from HAARP. 3. That it is from climate warfare. 4. That it is caused by reduction in cloud cover. 5. That it is caused by chem-trails. Most of the above is easy to ignore.

       
       Here’s part of my response to the cloud cover and chem-trail hypotheses:

       Here is some science and math related to the purpose and weather out-comes from chem-trails. It also documents increased rather than decreased cloud cover: http://meteora.ucsd.edu/~jnorris/presentations/Caltechweb.pdf

       See:
       Page 19 for a chart that shows the type of clouds that reduce the green house effect.
       Page 29 for a discussion of anthropogenic effects that make clouds more reflective.
       Pages 30 and 31--charts that explain the above.
       Page 64 --last statement: "Cloud changes since 1952 have had a net cooling effect on the earth."
       (Of course we know that the net cooling the clouds are providing is not enough to offset global warming.)
       Important— on page 59 he states that the increase in the types of clouds which are reducing the effects of climate change cannot solely be attributed to anthropogenic sources.

       ~~~

       Thanks again, just thought if you hadn't seen this link or these hypotheses you might find the interesting.

27333. qedscience at 17:53 PM on 14 October 2015
       Understanding climate feedbacks
       

       @5,6,8

       I have responded to your comments on my blog, I have found them very useful and thank you all for commenting. You may wish to read all the responses as they interlink to a certain extent.

       Tom Curtis @5

       Thank you for that clarification on volcanoes. For that paragraph in general, I did address it in one of my responses. You are right in concluding it was overtly 'emotional', I'll try not to do that in future.

       Jim Eager & Glenn Tamblyn @6,8

       I agree that it is really a disgrace that he was allowed to make those kind of statements in a school textbook.

27334. DSL at 13:33 PM on 14 October 2015
       Climate's changed before
       

       NN1953VAN-CA, where are you getting the 800 year figure?  I suggest you read this post on the science of the lag.

27335. NN1953VAN-CA at 12:20 PM on 14 October 2015
       Climate's changed before
       

       DSL,
       If CO2 concentration lags behind temperature raise for  800 ± 200 years than, when temperature starts dropping, CO2 still raises so temperature would not drop ever. Temperature drops eventually, what  in that theory explains how CO2 concentration drops and what makes it drop.

       And on cooling cycle if CO2 lags, how higher CO2 level alows cooling, when it should be warming factor.That makes me think that  CO2 is not as significant as it looks in GHG theory,  there are more factors to take in calculation. Maybe physical mechanism established over a century ago needs some new  aspect to warming. 

       Moderator Response:

       [PS] Please see the myth "positive feedback leads to runaway warming". The basics of feedback apply here and the effective CO2 feedback parameter is way less than 1. Rather than being century old science, ice age cycles are very active research areas. I strongly advice you at least read Chapter 5 of Ar5 to see latest work and understanding before leaping to unwarranted conclusions. The paleoclimate chapter in Ar4 is also a good index to key results and papers. The negative feedbacks associated with milankovich-induced ice sheet growth include: increased albedo, reduced production of wetland methane, and greater absorption of CO2 by cooling ocean.

27336. Glenn Tamblyn at 11:05 AM on 14 October 2015
       Understanding climate feedbacks
       

       QEDSscience @4. I posted a comment on your blog. That he makes the comments he does in a Chemistry textbook is astounding.

27337. mancan18 at 10:08 AM on 14 October 2015
       Understanding climate feedbacks
       

       Thanks for this post. It is very informative.

       One of the issues that it highlights, however, is the nature of climate change uncertainty within the whole debate. It also highlights why the climate models aren't perfect, a feature common to all modelling. Even the economic models used for microtrading where shares are automatically bought and sold on stock markets in milliseconds aren't perfect.  Although the models do a good job, none provide a complete picture because certain compromises have to be made because not all feedback effects are understood as entirely as they need to be and the supercomputers used for the models do not have the capacity to deal with them all.

       Dealing with feedback effects is one of the main reasons that climate models do not have the necessary resolution to make predictions as precisely as the naysayers would have the models do. Because the impact of all feedbacks and the chaotic nature of the phenomena being studied means that no single model has perfect resolution. It also means no model makes perfect predictions. That is the reason why naysayers are able to sow seeds of uncertainty, create confusion and peddle their propaganda for political purposes. However, it does seems that all the models have one thing in common, if CO2 increases are taken out of the equation then the models aren't very good at simulating the real world. It also means that naysayers should be taking all the models into account, not just the ones that suit their anti-AGW and CC propaganda.

       As I undertsand it, Hansen, over a decade ago, asked for a satellite to be put into orbit to obtain data related to aerosols and cloud cover so he could further refine the climate models. This was seen as unnecessary by the Bush administration. I don't know if such satellites and others required to study the impacts of climate change feedbacks exist nowadays, however, the whole episode seems to indicate those prone to naysaying because of their political views and financial interests, don't see obtaining the data as necessary. They just don't seem to even want to know.

       The trouble with uncertainty related to CC due to an incomplete knowledge related to feedbacks, however, is that the outcome can be either good or bad. There is uncertainty where other more certain indicators show that something favourable should still result. This means there is no need to worry other than gaining more understanding and knowledge. Or there is an uncertainty where other certain indicators show that something undersireable may happen. This means we do need to be worried, and we do need to gain more knowledge and understanding so we can develop strategies to deal with it. Our imperfect understanding of how CC feedbacks will ultimately impact the world's climate, does have uncertainty attached to it. However, there are other indicators where our knowledge is much more certain. None of our more certain indicators show that the CC outcomes that are likely to be desireable. This is uncertainty that we should be wary of, uncertainty that even the naysayers should be wary of, and it does mean that we need to further diminish the uncertainty related to feedbacks and tipping points through further study so we gain more knowledge and understanding. This should allow the resolution of the various CC models to be further refined.

27338. Jim Eager at 04:51 AM on 14 October 2015
       Understanding climate feedbacks
       

       Qed, I have posted a comment at your blog. The author of your text, George Facer, seems to exhibit a disturbing pattern of injecting his biased and ill informed personal views on climate change into his textbooks.

27339. Tom Curtis at 03:56 AM on 14 October 2015
       Understanding climate feedbacks
       

       qedscience @4, technically questions like this should be posed on one of the Weekly Digest posts (where virtually all questions are on topic) rather than in other specific blogs where it is likely (and happens to be the case here) that they are not on topic.  That said, I will briefly respond.

       First, I consider it academic malpractise, equivalent in severity to plagiarism or fraud, to publish in text books work that you have not submitted and published in the peer reviewed literature.  It always represents the strategy of the charlatan, of trying to persuade those without the relevant skills and expert knowledge to properly to assess your claims when you know full well that you are unable to persuade, and have not even tried to persuade, those with the relevant skills and expert knowledge.  Where I a publisher, I would cease publication of all books authored by somebody who would stoop to this tactic.

       Second, your response is quite good, but you do make some mistakes.  In particular, volcanism was not a significant factor in build up of CO2 concentration from glacial peak to interglacial.  In fact increased global temperature will increase CO2 concentrations, at least partly by reducing the ability of water to dissolve CO2.  That effect probably results in a 10 ppmv increase in concentration per degree C increase in global temperature, although it may be as much as 20 ppmv per 1 degree increase.  What happens when the world starts warming from a glacial is that the increased temperature results in an increase in CO2 concentration, which in turn results in a further increase in temperature.

       Beyond that point, your response is very good.

27340. qedscience at 01:21 AM on 14 October 2015
       Understanding climate feedbacks
       

       mods, if this violates the comment policy, I'm sorry but I'm just asking for a little help.

       I'm an A-level student with a blog, and I posted something on 'science denial in school textbooks', along with an attempted (fairly brief) rebuttal to something I found in one of my textbooks. I'd really appreciate it if you guys had a look and check I haven't made a fool of myself :D

       https://qedscience.wordpress.com/2015/10/12/science-denial-in-school-textbooks/

       I've read from SkS for about 5ish(?) years now so I haven't just turned up to spam.

       thanks for reading.

       Moderator Response:

       [RH] Activated link.

27341. DSL at 23:31 PM on 13 October 2015
       Climate's changed before
       

       NN1953VAN-CA, one thing you need to take into account in your reasoning: increasing CO2 in the atmosphere causes the climate system to warm.  No paleo data is needed to confirm this.  We have direct surface observations of the greenhouse effect (downwelling longwave radiation), and the physical mechanism has been established for well over a century.  This is not about finding something to blame for the warming.  The theory was established first.  The warming was measured decades later.  

27342. ianperrin at 17:16 PM on 13 October 2015
       Understanding climate feedbacks
       

       The link to Prof. Wolff's article has changed to:

       http://www.carbonbrief.org/guest-post-understanding-climate-feedbacks/

27343. NN1953VAN-CA at 13:40 PM on 13 October 2015
       Climate's changed before
       

       My observation on warming

       Why to take el Nino effect together with CO2 effect, is there any connection with El Ninios and CO2 levels in the past?

       El Nino and tectonic activity may be linked, effect of el Nino is definitely more influential then CO2 as trend is shorter with more effects.

       How to blame CO2 when there were periods in the past of the planet when it was warmer with lower CO2 level and colder with CO2 higher.
       Another question is: How to get reliable trend out of 200 years of observation, when this planet has trend of warming or cooling which lasts several hundreds thousands years. It may give short trends at the best but hardly indicate global planet trend in long time perspective.

       There are sometimes polar wortex - when good part of continent freezes for several weeks, anyone tried to link to global trends.

27344. Tom Curtis at 07:04 AM on 13 October 2015
       It's the sun
       

       Pfc Parts @1153:

       1)

       "The paleo record clearly shows an upward trend in TSI. To counter the obvious conclusion reached from these measures, the author changes his reference to satellite observations, which show a locally declining trend. This is, without doubt, a choice biased by the author's ideology and his intention to refute a rising TSI either exists or is a significant factor in rising global temperature."

       This is transparently false.  The sunspot number shows the same decline since 1979 (ie, since the commencement of satellite observations) as is to be found in the PMOD TSI index.

       2)

       "In general, use of measures for either solar output (TSI) or surface temperature taken before the broad use of the telegraph should be discarded; these measures were taken by hand using uncalibrated instruments and communicated by horse drawn carriage and sailing ship. The are not accurate or precise to the levels claimed by the models based on them, which are defined in fractions of a Watt and degree Centigrade. It's frankly absurd to use these data. Reconstructions (Wang et. al.) are even more difficult to accept; the error of estimate exeeds the observed variation in the measured value."

       Uncertainty of the mean of n independent variables equals the uncertainty of the measurement divided by the square root of the number of measurements.  Therefore if we have a number of observations with an uncertainty of 2 then we have uncertainties of (with number observations followed by uncertainty:

       2 0.71
       5 0.45
       10 0.32
       20 0.22
       100 0.10
       200 0.07
       1000 0.03
       2000 0.02
       10000 0.01

       As can be seen, uncertainty decreases rapidly with multiple measurements.  Ergo, the uncertainty in such things as global means surface temperature due to even quite large instrument errors is small.  Uncertainty due to coverage biases are a different matter but that has nothing to do with the accuracy of instruments or the means of communicating results.

       Clearly your mathematical argument does not hold water (which is itself no surprise as the scientists doing the reconstructions are themselve competent mathematicians).

       @1154, the linear regressions in question are not thermodynamic equations.  Ergo your "point" is a simple non sequitur.  

27345. Pfc. Parts at 05:58 AM on 13 October 2015
       It's the sun
       

       And it could be useful for hte author to explain why the data reductions presented (the models) were based on multiple liner regression? By all accounts (and I do mean all) thermodynamic systems have the signature characteristic ov being non-linear.

27346. Paul D at 05:39 AM on 13 October 2015
       Understanding climate feedbacks
       

       A human positive feedback:

       http://www.bbc.co.uk/news/science-environment-34501867
       
       Yep, ignore the cause of climate change then use the excuse that people need help fighting climate change to justify more oil extraction to pay for the help.

27347. Pfc. Parts at 05:23 AM on 13 October 2015
       It's the sun
       

       The fundamental problem with this analysis lies in the measurements used. The author begins with a paleo record (Wang 2005), which provides an estimate of TSI based on theororetical reconstructions and concludes his argument with direct instrument measures of TSI using advanced orbital measures obtained over the period between 1978 and 2010.

       The paleo record clearly shows an upward trend in TSI. To counter the obvious conclusion reached from these measures, the author changes his reference to satellite observations, which show a locally declining trend. This is, without doubt, a choice biased by the author's ideology and his intention to refute a rising TSI either exists or is a significant factor in rising global temperature.

       In general, use of measures for either solar output (TSI) or surface temperature taken before the broad use of the telegraph should be discarded; these measures were taken by hand using uncalibrated instruments and communicated by horse drawn carriage and sailing ship. The are not accurate or precise to the levels claimed by the models based on them, which are defined in fractions of a Watt and degree Centigrade. It's frankly absurd to use these data. Reconstructions (Wang et. al.) are even more difficult to accept; the error of estimate exeeds the observed variation in the measured value.

       This is the root of the problem climateologists face when building models or presenting the results of them; they lack sufficient data. Climate change is a slow process that is detectable in very small changes. To be useful, measurements used must come from calibrated instruments with the accuracy and precision needed to build models capable of making predictions with error bars signigicantly smaller than +/- 1 degree centigrade. It is statistically impossible to use data such as those presented in this article to achieve that goal.

       Impossible. This is not an ideologically based argument; it is mathematical. The problem Climate Science faces isn't theoretical, it's based on measurement. Measurements with the necessary precision and accuracy simply are not available over the necessary time frame. There is no way to correct this problem.

27348. wili at 01:42 AM on 13 October 2015
       Understanding climate feedbacks
       

       Thanks for presenting these important studies. It sure would be nice, though, to have a better idea of exactly how they affect the range, and the most likely value, for climate sensitivity. It seems odd that the 'wide range' link in the last line pulls up an old slr chart that does not seem to incorporate the feedbacks discussed here.

27349. DSL at 23:51 PM on 12 October 2015
       NASA Retirees Appeal to their Own Lack of Climate Authority
       

       zoo58, I know what the qualifier "extreme" means, but it is a qualifier. It only works as a defined noun in well-estabished context. You have not established the context of your use. I have no idea what you think of as "extreme" in the context of climate risk aversion, and I'm still have no idea who you're responding to (these "extremists" you appear to be imagining).

27350. uncletimrob at 18:23 PM on 12 October 2015
       2015 SkS Weekly Digest #41
       

       Oh God!

        I  just read some of the comments on Eco-Watch about Cruz's lies.  How can anyone in their right mind believe a non-scientist when he is commenting about science.

       Frankly it beggars belief that if you want the facts - about anything - that you would believe opinions (Cruze the science illiterate in this case) before going to the people who have actually done some research.

       Stupidity is alive and well it seems.

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