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Riccardo at 21:55 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
OPatrick I don't know where your 9 °C comes from. A 29% increase in forcing from 1990 to 2010 means that the equilibrium temperature anomaly would be 29% higher. If we take, for example, the equilibrium anomaly relative to 1990 forcing as 1 °C, the one relative to 2010 forcing would be 1.29 °C. -
Tom Curtis at 21:37 PM on 28 November 2011Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
Pauls @15, thankyou for the link to Sutton et al. The key claim is that:"These experiments are in equilibrium, and yet the warming ratio remains significantly above unity for all the available models (range 1.18 – 1.58; mean 1.33; standard deviation 0.13.)."
I note that the highest value is an outlier, with the next highest values being approx. 1.46. Indeed 5 out of 9 models group in the range of 1.18-1.3. This suggests to me that the high values are aberrant, and that refinements of the warming ratio will probably reduce the mean by reducing the top end of the range. Regardless, I must base my beliefs on the evidence before me, not on how I expect the evidence to develop in future. On that basis I have under estimated the equilibrium difference between land and ocean temperatures. That being said, Schmittner et al show a warming ratio 1.76 (if adjusted for sea level) or 1.65 (if not adjusted). Both values lie considerably outside the range we would expect based on Sutton et al. Therefore, although the difference between sensitivity estimates based on land, or ocean data only does not need as much explanation as I thought @1 above, it still indicates problems with the overall sensitivity estimate. -
skept.fr at 21:27 PM on 28 November 2011The Debunking Handbook: now freely available for download
#12 Tom: OK, this is a good point, like #6 and #7 but more clear. I totally agree that the cherry-picking one particular sensitivity is a misinformation for public, because it misrepresents climate science diversity of results on this question. (IPCC AR4 best estimate is rather 3,2 K for doubling, but a detail). #11 actually thought: yes but it seems to me there was some particular efforts to go beyond the author reservation (typically, to refer a tamino non peer reviewed critic suggesting the model is incorrect: climate science is not done on blogs! Even if I appreciate and read tamino). I myself suggest in commentaries some critics that went to be wrong, see for example Dr Schmittner's recent precisions about the proxies data (better than Shakun 2010). #10 muoncounter : of course denialists are trumpeting politically-biased and fanciful 'victories' on 'mainstream conspiracy'. My worry is that the counter-argument of denialists' myths translate in an unbalanced 'over-criticizing' of some works they unduly exploit (Schmittner is not Spencer!). -
perseus at 20:05 PM on 28 November 2011Economic Growth and Climate Change Part 1 - Factors Influencing CO2 Emissions
adelady @26 Last week I made this very point to a group whose arguments on population were degenerating along racist lines. I was the only male arguing that education and womens rights were the key to population control, a surreal experience! This was broadly encompassed under the term 'family planning and cultural changes' in the text. Perhaps it would have been best to mention female education and rights more explicitly! Sir David Attenborough recently covered these issues in the documentary 'How Many People can Live on Planet Earth' http://topdocumentaryfilms.com/how-many-people-can-live-on-planet-earth/ -
OPatrick at 19:42 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Moderator Response: [DB] CO2 increases do not cause linear increases in temperatures. Yes, but my naive understanding was that *radiative forcing* does cause linear increases in temperature (e.g. from AR4 "Radiative forcing can be related through a linear relationship to the global mean equilibrium temperature change at the surface" http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-2.html) I thought the nonlinearity part was between CO2 increase and resulting radiative forcing. -
LewisC at 17:59 PM on 28 November 2011Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
As a layman it is very hard to comprehend the plausibility of the Schmittner et al paper using the paleo record as an indicator of the planet's sensitivity to a doubling of CO2 without more clarity on just what factors are excluded from their analysis. Such factors might include: 1/- Disparities in the initial conditions due to other impacts, including: planetary tree cover - of which about a third has been lost in the last few centuries; and oceanic plankton stocks - of which perhaps 40% have been lost in the last century, and soil fertility - of which a substantial fraction has been lost in recent millenia, and the presence of rather large holes in the ozone layer over both poles; etc. 2/- The influence of the pace of initial CO2 release and its warming on the consequent additional warming from the several major carbon banks' destabilization - both in terms of changes in the rate of output and of the ratio of CO2 to CH4 released, and of the short residence period of airborne methane being extended wherever its concentration became sufficient to swamp other elements required for its normal reaction rate. 3/- The presence of substantial airborne volumes of additional GHGs, including anthro-methane, anthro-Nitrogen Oxide and fluro-carbons this early in the curve of warming that must affect the rate of warming, thus exacerbating item 2/- above. A further point of obscurity is the rationale for describing the positive feedbacks in just two classes, "fast and slow." This appears both to overlook the relevance of potential scale (allowing potentially large acceleration) and to oversimplify pace. If they were instead described respectively as "large, medium or small," and "fast, moderate or slow" then nine distinct classes of feedback would need to be assessed for their potential influence, along with some feedbacks' transitions from one class to another. This would be less arbitrary but is surely more problematic than simply assessing their potentials individually and iteratively ? In sum, I'd ask whether it is possible to use the paleo record to propose a scientifically credible figure for the extent of warming at equilibrium with a doubled airborne CO2 - without first identifying the consequences of the rate of the warming our society imposes ? Plainly, as dana makes clear, Schmittner et al's analysis is not comparing apples and apples, but to what extent do they attempt to compare bananas and next Wednesday ? Regards, Lewis -
garythompson at 17:06 PM on 28 November 2011Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
#93 Scaddenp, I read that post and (-snip-)Response:[DB] Please put your reply to that post on that post. Not here, where it is OT (OT portion snipped).
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OPatrick at 16:52 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
(Not any more!) -
OPatrick at 16:51 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
"Between 1990 and 2010, according to the report, there was a 29% increase in radiative forcing - the warming effect on our climate system - from greenhouse gases." Could someone contextualise this - a naive interpretation could be that there should have been a 29% increase in temperature due to greenhouse gases, or about 9C of warming. (I'm also getting reduced font size.)Moderator Response: [DB] CO2 increases do not cause linear increases in temperatures. The accepted sensitivity of the climate is about 3 degrees C per doubling of CO2 concentrations. And there is about a 40-year delay in temperature response of the climate due to the thermal inertia of the oceans.Thus, the temperature rise we see today is largely attributable to the CO2 emissions from the 1970s.
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dana1981 at 16:46 PM on 28 November 2011Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
Thanks for your comments, Dr. Schmittner. We went back and forth a few times trying to figure out which would be the correct temperature to use for an apples-to-apples comparison. It's possible we chose the wrong value, but as you note, it's difficult to ascertain whether the 5°C value refers to SAT only, or air and ocean surface combined. -
Stuart at 16:32 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Yep, subscript fix worked... (a few versions behind on Firefox here at work, hence the discrepancy). -
Stuart at 16:21 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Getting the font issue here as well, on Firefox. Looks to me like the subscript at the end of comment 4 wasn't closed (i.e. the subscripted 2 in CO2).Moderator Response: [DB] That was it; congrats (no prize tho). Still looks the same on my screen (Firefox 8.0). -
AndreasSchmittner at 16:06 PM on 28 November 2011Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
Sorry, your -2.6 K quote was, in fact, correct. But you didn't specify what it means. This number refers to the SST change over the ocean and SAT over land. Note that it is different from the global mean SAT change of -3 K. I don't know what Hansen and Sato refer to because they just talk about temperature change. The distinction between sea surface temperatures and surface air temperatures is important if you want to avoid comparing apples with oranges. Andreas Schmittner -
AndreasSchmittner at 15:46 PM on 28 November 2011Schmittner et al. (2011) on Climate Sensitivity - the Good, the Bad, and the Ugly
The Hansen and Sato (2011) paper refers to the dataset from Shakun & Carlson (2010) for the 5 deg C LGM SAT cooling. This dataset is a subset of our LGM temperature reconstruction. Please note that our dataset includes much more data (435 grid points) than the Shakun & Carlson dataset (~54 grid points). It remains to be seen if there are inconsistencies between the different datasets. This will be an important task to study in the future. But for now I would claim that because we use a much more extensive dataset our LGM cooling estimate is more reliable than the one used by Hansen and Sato. Your quoting incorrectly that our global mean cooling for the LGM is -2.6 K. Also I recommend to specify what exactly you mean by cooling. The -2.2 K number you quote from our paper is the global mean of SSTs over the ocean and SAT over land. This number is dominated by the ocean because (a) there's more data and (b) the land grid boxes are 2x2 degrees and the ocean boxes are 5x5 degrees. (Note that this is not our choice, but we adopted it from the MARGO and Bartlein papers). This leads to the surface area covered by land points to be only 1/10 of that covered by ocean points. Therefore the area weighted global mean is very close to the ocean global mean of -1.9 K. Our best estimate for the global mean surface air temperature change is -3.0 K. Andreas Schmittner -
skywatcher at 15:35 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
@mods - something's happened to the formatting around the start of comment 5 - the font size is smaller from then on. Also affects the 'recent comments 'page'. And a brief correction to the first sentence that introduces the post - it's World Meteorological Organization, not Association. Will have to let the Americanised spelling slide as the WMO go for that!Moderator Response: [DB] Sky, the fonts look OK on my screen (both locations). Will fix the other bit, thanks. -
scaddenp at 14:42 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Enginerd - as far as I know, carbon cycle feedbacks were factored into very few AR4 models and werent part of the CMIP. For this kind of feedback, I think you have to have new generation of Earth System Model (put into google) which will be part of the AR5 model reporting. -
Enginerd at 14:32 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Thank you for this post. It will be interesting (and perhaps very discouraging) to see what is causing the recent increase in methane levels and whether the increase persists, or perhaps worsens. While I understand that methane currently accounts for a relatively small fraction of the total radiative forcing, there is a tremendous amount of methane that could eventually be emitted from thawing permafrost. Just out of curiosity: To what extent is this positive feedback factored into the climate sensitivity estimates reported in IPCC? Or is this phenomenon too uncertain at present to quantify? -
Bob Lacatena at 14:19 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
14, Steve Case, You have multiple gross misunderstandings of the system in question. It is strong advised that rather than steadfastly applying what little you know to arrive at the answer you prefer, that you put your time into using this site and others to learn more about the science, so that you can make a reasoned and accurate evaluation of what is going on. -
scaddenp at 13:55 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
"I go back to what I know about thermoclines, and it doesn't warm below the thermocline. I don't much care what Schuckmann says." Sorry, you are saying you dont care what the data says, you will prefer your (mis)understanding of thermoclines? IPCC sensitivity are not transient sensitivities. If you want to evaluate a prediction you have to compare the observation to actual prediction. Since it takes a while to reach equilibrium temperature, then you are better to compare observation to predicted temperature from models since the model effectively include the lag. -
Steve Case at 13:31 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
IPCC claims for climate sensitivity vary but they are in the range of 2° to about 4°CResponse:[DB] Let the reader note that a number of Steve's recent comments did not survive moderation due to trolling and complaints about moderation.
Steve: Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit argumentative, trolling and complaints about moderation posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.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.
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scaddenp at 13:30 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
"Below 700 meters I expect that they aren't warming at all. " Instead of "expecting", then why not look up what 0-2000m is doing? See the Von Schuckmann paper in Rob Painting's post that he linked to above. -
scaddenp at 13:26 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Steve, you might like to look up what IS meant by climate sensitivity so you know what "claim is being made". What you are seeing so far is simply the fast feedbacks - but check out the proper SkS thread on this for more on this. -
Rob Painting at 12:48 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Steve, I believe this has been pointed out to you before, but the 2007 IPCC report has been superseded by more recent scientific research. Such as Church (2011) which the figure @7 is based upon. In fact if you continue in the same vein one can only presume you are either trolling, or have a memory like Guy Pearce in Momento See also SkS post: Ocean cooling corrected, again. And note the key graphic:
"And so regarding Rob Painting's chart, 10 to the 21 joules may be a big number, but 0.1°C isn't going to warm up anything very much"
This is a nonsensical statement. Small global changes in water temperature can mean vast local changes in water temperature over short periods, such as the extreme marine heatwave off Western Australia over 2010-2011, which devastated the local marine life.
These marine heatwaves will become more prevalent as more heat is added to the ocean. Sadly global warming hasn't stopped, and no amount of wishful thinking will avert the negative impacts we are all going to experience.
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Tom Curtis at 12:46 PM on 28 November 2011The Debunking Handbook: now freely available for download
skept.fr, there is a very clear difference between Skeptical Science and various denier sites on this issue. SkS mentioned two new papers that show a high climate sensitivity. However, when we employ climate sensitivity or answer peoples questions about what the climate sensitivity is, we continue to use the IPCC AR4 result of 2.8 (or 3) degrees C per doubling of CO2. As a case in point, in the recent article on Schmittner et al, the chart at the end showing various estimates of climate sensitivity (based on Knutti and Hegerl 2008) clearly shows the IPCC range of values at the top. No mention of Lunt or Paganini is made at all. So, while we did not undertake a thorough going critique of Paganini or Lunt, neither have we embraces their results uncritically. In contrast, deniers have not only embraced Schmittner et al uncritically, but they have used it as justification of very low values of climate sensitivity that Schmittner et al exclude. This difference results in a clear difference in treatment at SkS. The primary purpose of SkS is not to explain climate science. Rather, it is to debunk denier myths. Because deniers have been building a myth around Schmittner et al, it requires detailed treatment to debunk that myth. In contrast, Lunt and Paganini are merely mentioned so that people interested in climate sensitivity will be aware of recent papers. So while the two papers did receive a different treatment, that is because of how they relate to the stated purpose of SkS, not because of any bias. -
Rob Painting at 12:28 PM on 28 November 2011What's Happening To Tuvalu Sea Level?
Victul - "Rob Painting - I noted the 'hide the incline' post, however La Ninas don't run for 10 years. The 2010 La Nina was a big one but would not account for a 10 year trend." Perhaps large portions of the post were completely lost on you. Just to be clear: The long-term sea level trend at Tuvalu (over 1950-2009) is due to thermal expansion of the oceans, the addition of water volume to the global oceans by melting land ice, and the strengthening of easterly winds near the equator which pushes water mass into the tropical western Pacific. It is not related to ENSO - a large interannual fluctuation which hides the incline in sea level. -
Steve Case at 12:27 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Maybe this link will work http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5s5-es.html -
Tom Curtis at 12:27 PM on 28 November 2011Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
Thankyou, Robert Murphy @94. I believe the inference that "getting the science right" is Michael Mann's "cause" is certainly justified. What is distressing is not that he should have that cause, but that there are those (Curry, Spencer, Christy, Pielke Snr) who have forsaken that cause. -
Steve Case at 12:26 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Rob Painting at 12:12 PM on 28 November, 2011 According to the IPCC:- The oceans are warming. Over the period 1961 to 2003, global ocean temperature has risen by 0.10°C from the surface to a depth of 700 m.
IPCC AR4 Chapter 5Below 700 meters I expect that they aren't warming at all. And so regarding Rob Painting's chart, 10 to the 21 joules may be a big number, but 0.1°C isn't going to warm up anything very much.
Response:[DB] "Below 700 meters I expect that they aren't warming at all."
You expect wrong (and make yet another unsupported assertion). You must have missed these recent posts on the warming of the deep oceans:
http://www.skepticalscience.com/Ocean-Cooling-Corrected-Again.html
http://www.skepticalscience.com/Ocean-Heat-Content-And-The-Importance-Of-The-Deep-Ocean.html
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actually thoughtful at 12:20 PM on 28 November 2011The Debunking Handbook: now freely available for download
skept.fr - you conveniently ignore the fact that the Schmittner paper has MAJOR reservations, written by the author, and anyone NOT reporting that would be misrepresenting the science. I don' think there is a real issue here - you are putting SkS under a microscope that no "skeptical" site could handle - and at that SkS is coming through with flying colors. -
Steve Case at 12:13 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
topquark at 11:53 AM on 28 November, 2011- Of course, you know how the deniers are going to spin this:
"The fact that greenhouse gas percentages continue to go up but that temperatures have stayed flat [they get extra crackpot points if they say that warming stopped in 1998] just *proves* that AGW is a crock!"
Well sort of, over the last 160 years, temperature has gone up about 0.7°C and CO2 has gone up around 40%. Works out to a climate sensitivity of around 1.5°C per doubling of CO2 - far short of the claims that are made.
Moderator Response: [muoncounter] Or you could say that in the last 40 years, temperature anomaly is up more than 0.6 degrees C. Works out to a much greater sensitivity.
But this is neither a sensitivity thread nor a how fast is earth warming thread. Either can be found using 'Search.' -
Rob Painting at 12:12 PM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Yes, Topquark, but global surface temperatures do not follow a monotonic trend. Some studies have attempted to ascertain why (see Sks posts: Why Wasn't The Hottest Decade Hotter?, The Deep Ocean Warms When Global Surface Temperatures Stall and Ocean Heat Poised To Come Back And Haunt Us? Natural variation was never expected to simply disappear because humans have polluted the atmosphere with too much CO2. Indeed, seeing as over 90% of heat is going into the oceans, there has scarcely been a slowdown in global warming at all, even though surface temperatures in some datasets have not changed much. Check out the ocean heat content below:
This will likely come back to bite us in the backside.
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Eric (skeptic) at 12:05 PM on 28 November 2011Incredible time-lapse video of Earth from space
Skywatcher, you are probably correct about the orange glow being the sodium vapor lights. I figured I would pop this related question here (but not expecting an answer). My county requires sodium vapor lights (high or low pressure) for commercial sites due to our dark sky ordinance. I can only find 120 volt AC ballasts for HPS or LPS lights. Various Chinese companies have nice electronic (digital) 12/24 volt DC ballasts specifically for solar streetlights and similar uses. It doesn't make sense to use two inverters (from 12 DC to 120 AC and then from 120 AC to the various HPS/LPS voltages). I need around 35 Watts, and a couple of units. -
topquark at 11:53 AM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Of course, you know how the deniers are going to spin this: "The fact that greenhouse gas percentages continue to go up but that temperatures have stayed flat [they get extra crackpot points if they say that warming stopped in 1998] just *proves* that AGW is a crock!" -
muoncounter at 11:42 AM on 28 November 2011The Debunking Handbook: now freely available for download
skept.fr#9: I hardly think the degree to which a particular paper can be spun is a worthy criterion for rebuttal. If a paper is on a relevant topic and has some evident flaws, it is questioned. Why do you interpret that as bias? You are missing the bigger question: If Schmittner's sensitivity is within the 'classical range of sensitivities' - although they claimed to have lowered the uncertainty - why are the pseudo-skeptics running with 'new paper finds global warming overstated'? Isn't that an indication of just how bad things are in the literature of denial: A paper that makes no statistically significant change to our understanding is trumpeted like they've transmuted lead into gold? We saw this behavior with CERN CLOUD, Murry Salby, Spencer/Braswell, etc. In the vernacular, it's called 'clutching at straws.' Myths do not debunk facts. -
skept.fr at 11:18 AM on 28 November 2011The Debunking Handbook: now freely available for download
#8 Don't understand. Schmittner 2011 is in the classical range of sensitivity since Charney 1979, no extraordinary claim in it. #6, #7 : OK, so context... SkS treats information in a different manner if this information is susceptible to be deformed by denialist. I keep it, but fort that, it would have been sufficient to say that Schmittner 2011 is in the range of sensitivity of IPCC models (previous point), without trying to suggest there could be some particular uncertainties or flaws in their study (all the more so that it seems the tamino critic is irrelevant, because UVIc is not CCCMa). #5 Two papers, same subject, different treatment on SkS... Sorry, I do give a correct example (not apple and orange, not cherrypicking), the fact that there are many papers on ECS on SkS is not relevant if I choose to compare the treatment of these two similar papers in particular. Your answer is the less convincing for me, I prefer #6 and #7 as more plausible. A detail concerning the paper you link : the figure from Knutti and Hegerl 2008 in the conclusion is incomplete. In the original paper, the two authors not only gave the different sensitivity distributions (part a of the figure reproduced), but also a "partly subjective classification of the different lines of evidence for some important criteria" (part b of the figure, non reproduced). -
muoncounter at 10:47 AM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
CDIAC shows the lifetime of HFC-134a as 14 years, CFC-11 as 45 years, CFC-12 as 100 years. -
actually thoughtful at 10:29 AM on 28 November 2011The Debunking Handbook: now freely available for download
skept.fr - I suspect a very small amount of what you think you are seeing does go on. It is called confirmation bias, and it is very hard to avoid, even though the authors at Skeptical Science are very aware of the effect. Rather, what is happening in the main is papers that are counter to what science has established are treated more skeptically. So a paper that looks at high sensitivity (say 4.5 as the paper you referenced suggests) is completely in keeping with the understood science, that the most likely number is ~3C, bounded below at 2C (in other words, tons of evidence that it is NOT lower than that) and not well bounded above (meaning a paper that merely claims that, with the long term impacts baked in, the number is more like 4.5c - is well within the understood science). So you are seeing the case that extraordinary claims require extraordinary proof, not a case of bias. If a future paper claims 8-10C for the sensitivity figure, look for caveats similar to the Schmittner paper. Also note the paper itself urges caution, and beyond any concept of bias or proof there is the simple fact that the author would be misrepresenting the paper to not include the caution an a review of the paper. Everyone involved at Skeptical Science would love to see the accepted science overturned, but there is no credible evidence to support that position. Science means going where the evidence takes you. I know of no blog site that beats Skeptical Science in that regard. -
scaddenp at 10:27 AM on 28 November 2011The Debunking Handbook: now freely available for download
skept.fr - one big difference is the extent to which results have been spun by others. -
Pete Dunkelberg at 10:19 AM on 28 November 2011The Debunking Handbook: now freely available for download
The Schmittner came with commentary that is hard to ignore: A long interview with co-author Nathan Urban, some questions raised in New Scientist and more by James Annan. I don't recall the same degree of discussion before the SKS post on the other two papers skept.fr mentions. It is interesting though that sensitivity in warmer times (albeit Earth Systems Sensitivity, also discussed at Serendipity ) is high while at cool times it's low if this holds up. -
muoncounter at 10:00 AM on 28 November 2011The Debunking Handbook: now freely available for download
skept: There are many threads on climate sensitivity (use Search), but consider this one as a starting point. In it you find a review of many sources, offering estimates of climate sensitivity as high as 8C. However, the graphics shown remain consistent with the 2-4.5C range of estimates. Clearly, those papers arguing for 8C have not made their case. This continues to be a stunning example of false equivalence. Many posts here attempt to put multiple papers in context and consider multiple lines of evidence. Rather then posit the appearance of cognitive bias, please provide more concrete examples than the sensitivity question. -
Chemware at 09:57 AM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
I think that: These two classes of compounds [HCFCs and HFCs] are very potent greenhouse gases and last much longer in the atmosphere than carbon dioxide. is wrong. While they are potent greenhouse gases, HCFCs and HFCs were developed specifically to have much shorter lifetimes (about 10 years) in the atmosphere than CFCs (about 100 years). So their impact and lifetime is comparable to that of methane, and is one or more orders of magnitude shorter than that of CO2.Response:[DB] Closed subscript tag.
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John Hartz at 09:20 AM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Related article... Emissions of hydrofluorocarbons, heat-trapping industrial gases used in air conditioners and refrigerators, must be curbed to help combat climate change, according to the United Nations. The UN report today comes as governments adhering to the ozone-protection rules of the Montreal Protocol consider phasing out hydrofluorocarbon-23 production, whose warming potential per molecule of HFC is 11,700 times more powerful than carbon dioxide. The European Union this year banned as of 2013 its use in the emissions-trading program of credits linked to the industrial gas generated under the UN carbon market. “Keeping a global, 21st century temperature rise under 2 degrees Celsius (3.6 degrees Fahrenheit) will require urgent action” to reduce hydrofluorocarbons, the UN Environment Program said today in a statement. “By 2050, HFCs could be responsible for emissions equivalent to 3.5 gigatons to 8.8 gigatons of carbon dioxide, comparable to total current annual emissions from transport estimated at 6-7 gigatons annually.” Source: “Air-Conditioning Gases Must Be Curbed to Protect Climate, UN Says” Bloomberg, Nov 21, 2011 To access the entire in-depth article, click here. -
DrTsk at 09:02 AM on 28 November 2011Greenhouse Gas Concentrations Continue Climbing
Hydro-fluoro-carbons -
skept.fr at 08:27 AM on 28 November 2011The Debunking Handbook: now freely available for download
In an other thread, muoncounter gave me the advice to discuss my point here (off-topic where I initially posted). So, here is my point. Schmittner et al 2011 find a low sensitivity. In this article , SkS explains to its readers why there are some reasons to take the results with caution : you discuss in details the models, the proxies, the methods, etc. Lunt 2010 and Pagani 2010 find a high climate sensitivity. In this article , SkS doesn't explain to its readers why there could be some reasons to take the results with caution : you do not discuss in details the models, the proxies, the methods, etc. In my opinion, this is a potential double standard and without explanation from your part, it hurts the confidence I can place in your impartiality. Comparing these two articles on a very similar subject, it seems you deploy a high skepticism for a low sensitivity study but a low skepticism for a high sensitivity study. It looks like a cognitive bias in favour of the most alarming publications, and anyway an unequal standard of quality for the information you give to your reader. Could you explain me why I'm wrong? Thank you. PS : please, no strawman, I'm not denialist and I fully agree with IPCC WG1 conclusions. But I prefer to know if, beyond the very legitime and useful demonstration of denialists' misinformations, I will find on SkS a fullly impartial and convincing view on current climate science results, or a discretely biased presentation of these results.Moderator Response: [John Hartz} The articles posted on SkS speak for themselves. How you react to them is how you react to them. -
adelady at 08:08 AM on 28 November 2011The Debunking Handbook Part 4: The Worldview Backfire Effect
Never fear, actually thoughtful, I can't claim too many wondrous moments of enlightenment of others on websites. One did come back to me when reading - was it number 3 or 5? - graphs do work very well. With some people, when the ground is prepared thoroughly. Got a strongly positive response with graphs a couple of times - though it was with Arctic sea ice stuff, not much wiggle room there. As for the tsunami. My approach is simply to keep plugging away. The big thing is never to focus on the responders. Always work on the basis that the silent readers are your real audience. And the hardest of all? Never press for an instant response, nor claim credit for an apparent change of mind. I learned this one long ago as a union person in management discussions. If I wanted a certain approach adopted, I'd just raise it in ordinary conversation. If it had legs, it would turn into common knowledge or 'accepted management practice' in 6 to 18 months. 'That was my idea', or 'I told you so' were always tempting. But I knew perfectly well that good ideas are worth much, much more than my personal claim on them - and that claim risked a negative response. -
actually thoughtful at 07:30 AM on 28 November 2011The Debunking Handbook Part 5: Filling the gap with an alternative explanation
Apirate - on first glance your comment seems to indicate you think this article could be used to debunk the truth with myths. That raises two questions -the first, already asked by muoncounter - how can you use myths to debunk facts? The second, why would anyone, let alone a science teacher, WANT to debunk the truth about science? Please explain your post more clearly. -
Robert Murphy at 07:25 AM on 28 November 2011Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
Gary@90: "Why are climate scientists supporting causes? Is getting the science right not enough?" Why do you automatically assume that getting the science right isn't the cause he means? Mann did after all say (email 0071) "So please let me know if that would be ok ... As noted above, I want to get the science right, and if you think appropriate, go ahead." (ellipses in original) He's on record as wanting to get the science right. Is that not a cause worth defending? "back up trend claims with statistically significant data" "Skeptics" never do. That's why they obsess over very small sample sizes with trends they know are not going to be statistically significant and pretend they mean something. -
scaddenp at 07:23 AM on 28 November 2011Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
The "cause" would honest science and fighting misinformation from vested interest. Same way lawyers support the cause of justice; doctors support the cause of best medical practise; and with the same kind of funding. "It's good to know that AGW skeptics will no longer be required to use a particular software package, back up trend claims with statistically significant data or even do the actual data analysis. " At that sir is a wilful and dishonest extrapolation of what you read, utterly unsupported in the way that science has actually proceeded as shown by the publications produced, which of course back their claims with data analysis and statistical methods that others can reproduce. As to excel, I also am pretty much a non-user. Can you even calculate significance bounds properly with it in time-series with auto-correlation? The top experimentalist in this building is also pretty much handicapped in the excel department, wisely leaving the detailed statistical analysis to other but no one is suggesting he has no place in science - quite the reverse. And Gary, looking at other commentary you have made, perhaps you might like to take the challenge here to convince us that your skepticism is rooted in science rather than political concerns. -
Riccardo at 07:22 AM on 28 November 2011Climategate 2.0: Denialists Serve Up Two-Year-Old Turkey
"If there is a cause, then there appears to be those who are on the team and those who are not." The logic behind this claim is beyond me. "Is getting the science right not enough?" It used to, untill big-something lobbies decided to intervene on scientific issue. I'm sure you know very well that getting the science right is not enough when it touches "special interests". Overall, it appers that your idea of fighting for a cause means some sort of conspiracy or politically organized group, money, written documents and such. It ain't necessarily so. -
actually thoughtful at 07:22 AM on 28 November 2011The Debunking Handbook Part 4: The Worldview Backfire Effect
adelady - I am humbled by the hard-fought truth of your post 1t 17. How does that play out in effective communication on the internet on climate issues? I find my first instinct is to pull up facts and logic that refute the deniers untenable position. But, honestly, that approach is not working. I would appreciate your thoughts on specific approaches to combating/educating the tsunami of deniers out there.
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