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uncletimrob at 17:15 PM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 2)
Thanks John
again an article that takes me back to early undergraduate days when radio-dating was considered to be a very inexact science. In fact it was considered so ineaxact by creationists that the measurements were proof of creation. Thank you. Most infomative and another one to add to the "must read" list for my students.
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scaddenp at 16:30 PM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 1)
William, I havent run a specific model on that but based on lots of models for "normal" heatflows, I dont think can get remotely get to melt temperature. If there is an effect, I think it is dwarfed by variations in heat flow from mantle convection.
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Watchdog at 13:43 PM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Apology for duplicate post. A view of the Earth-Globes from 65MYA and Today can give a better sense of continental separation than a flat map. Note how continental separation of 65MYA are not overly dissimilar to Today's continental separation. As Tom Curtis pointed out with respect to the angle of Chicxulub's impact, the Chicxulub & Deccan Traps events do not have to be axial through Earth's center.
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Tom Curtis at 13:39 PM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Watchdog @49, they were for the most part situated in one hemisphere delineated by longitude (ie, like the western hemisphere). Theorist is correct on that point, if a little obscure.
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ranyl at 13:20 PM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 2)
Thanks John good articles.
A few things to consider though.
Heating affect from CO2 is relative to starting value, thus we going much faster than in those days in terms heating in.
Also the presence of ice increases warming further by a factor of ~2 due to alebdo effects.
Further the sun was significanlty dimmer back then, meaning we should warm more quickly again as get more input from the sun all the radiaitve components follow suit.
And lastly even though SO2 not as high as then, all the other toxic stuff we've introduced in the way of biocides, heavy metals, toxic wastes and endocrine disruptors probably aren't helping matters.
Then of course there is the gross overexploitation of biosphere resources, the widespread destruction of habitats done directly by human hands and there is the biodiversity lethal aspects of wars which seem on th eup again recently all which again aren't helping.
And aren't the current extinction quite remarkeable in the geological record?
No wonder the hedgehog is even feeling it!
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Watchdog at 13:11 PM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Theorist
65 MYA, the continents were _Not_ positioned in one hemisphere.
Please note India's position 65MYA wrt the Chicxulub's Impact site.
http://www.lpl.arizona.edu/~hubbard/PtyS195a/Mar06/Fig2-5globes.gif
Moderator Response:[JH] Link activated.
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william at 12:50 PM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 1)
Could it be that these gigantic outpourings of lava are a result of a bunch of continents coming together and forming an insullating layer on a big chunk of the earth's surface. Heat from radioactive sources builds and builds under these mega-continents until the melt is too much for the strength of the overlying, thick, continental rock. If this is so, one would expect such eruptions to occur around the middle of super continents and possibly lead to the splitting of the mega continent and the creation of a new ocean.
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ginckgo at 12:49 PM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 2)
There's possibly even more to this event than just volcanic 'pollution', and it's even closer to the modern pollution scenario.
Just recently researchers have used genetic clocks to pinpoint the timing when a group of methanogenic bacteria first acquired this trait to produce methane - and it falls just about bang on the end Permian time.
Methanosarcina- Role in the Permian Triassic extinction event
It looks like the isotope patterns favour this source of atmospheric carbon, over the volcanic one. The Siberian Traps, however, may have been the source of important elements, like nickel, allowing for Methanosarcina to bloom massively.
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Tom Curtis at 12:36 PM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Theorist @45, here are the continental configurations at the time of the K/T boundary according to Scotese:
Based on that configuration, the Decan traps were as far south of the equator as the impact site was north of the equator, but 130 degrees of longitude west of the impact site, not 180 as require to be truly antipodal. That compares with the modern arangement where they have approximately the same latitude but are approximately 180 degrees of longitude apart. That means the divergence from the true antipodal point is about the same in both cases, having shifted from a divergence in longitude to a divergence in latitude. Presumably the divergence is accounted for by assuming the impactor came in at a low angle, thus causing the point of focus to be shifted from the true antipodal point.
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Tom Curtis at 12:21 PM on 20 March 2015It's the sun
Leto @1141, for comparison, I took HadCRUT4 from 1880-2010 and used it as a model to predict GISS LOTI. To do so, I used the full period as the anomaly period. Having done so, I compared statistics with the Cowtan model as a predictor of temperatures. The summary statistics are (HadCRUT4 first, Cowtan Model second):
Correl: 0.986, 0.965
R^2: 0.972, 0.932
RMSE: 0.047, 0.067
St Dev: 0.047, 0.067
Clearly HadCRUT4 is the better model, but given that both it and GISS LOTI purport to be direct estimates of the same thing, that is hardly surprising. What is important is that the differences in RMSE and St Deviations between the HadCRUT4 model and the Cowtan model are small. The Cowtan model, in other words, is not much inferior to an alternative approach at direct measurement in its accuracy. Using HadCRUT4 as a predictive model of GISS, we also have a high standard deviation "error" (-2.5 StDev in 1948) with other high errors clustering around it.
This comparison informs my attitude to the Cowtan model. If you have three temperature indices, and only with difficulty can pick out that which was based on a forcing model to those which were based on compilations of temperature records, we are ill advised to assume that any "error" in the model when compared with a particular temperature index represents an actual problem with the model rather than a chance divergence. (On which point, it should be noted that the RMSE between the Cowtan model and observations would have been reduced by about 0.03 if I had adjusted them to have a common mean as I did with the two temperature indices.) Especially given that divergences between temperature indices show similar patterns of persistence.
Now, turning to your specific points:
"The bigger problem I have with the "It's chance" line of argument is that it seems to be largely devoid of explanatory power."
In fact, saying "it's chance" amounts to saying that there is no explanation, so of course it is devoid of explanatory power. In this particular context, it amounts to saying that the explanation is not to be found in either error in the measurements (of temperatures, forcings, ENSO, etc) nor in the model. That leaves open that some other minor influence or group of influences on GMST (of which there are no doubt several) was responsible. "Was", not "may be" because it is a deterministic system. However, the factor responsible may be chaotic so that absent isolating it (very difficult among the many candidates with so small an effect) and providing an actual index of it over time, we cannot improve the model.
"Asking why a particular patch of data-model matching is much worse than the rest is more analagous to the second situation, I believe."
Of course it is more analogous to the second situation. But the point is that the "it's chance" 'explanation' has a better than 5% (but less than 50%) chance of being right. That is, there is a significant chance that the model cannot be improved, or can only be improved by including some as yet unknown forcing or regional climate variation. The alternative to the "it's chance" 'explanation" is that the model can be improved by improving temperature, ENSO or forcing records to the point where it eliminates such discrepancies as found in the 1940s. On current evidence, odds on this is the case - but it is not an open and shut case that it is so.
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Theorist at 11:11 AM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Watchdog,
A better map can be found at www.scotese.com. Select "Earth History" and then "K-T Extinction" and you will see that the continents occupied close to one hemisphere. Also note the relative positions of Chicxulub and India.
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Watchdog at 10:29 AM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Theorist
65 MYA, the continents were _Not_ positioned in one hemisphere.
Please note India's position 65MYA wrt the Chicxulub's Impact site.
http://www.lpl.arizona.edu/~hubbard/PtyS195a/Mar06/Fig2-5globes.gifModerator Response:[PS] Fixed link.
Creating a link isnt hard people. If you want people to see it, please do it as you make comment. -
Theorist at 10:00 AM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Watchdog @44
Regarding your comments:
Point 1- At the time of the bolide impact, Chicxulub was not anti-podal to the Deccan Traps. All of the continents were still positioned on one hemisphere of the Earth.
Points 2 and 3 -Chicxulub and the Deccan Traps did have a profound effect on the Earth’s temperature. I’m not aware of any glaciation at that time. I wouldn’t conclude there was glaciation because of the drop in sea level because the theory I mentioned, I’ll call it the GTME, explains that when the Earth’s core elements move back toward Earth-centricity and surface gravity increases, sea levels near Pangea’s continental remnants must have lowered, as they did. The same type of massive sea level drop occurred at the P-T boundary for, I believe, the same reason it did at the Cretaceous-Triassic boundary. And, I’m not aware of any glaciation at that time.
The gravity anomolies that you refer to in Canada and elsewhere are caused by crust compression from overlaying ice. This is far different and significantly smaller than those caused by the movement of the Earth’s core elements theorized by the GTME.
Regarding your final statement about the dinosaur extinction, my belief, based on their gradual extinction throughout the Cretaceous and the rapid disappearance of the remaining dinosaur taxa at the very end, cannot be explained by the bolide impact nor the volcanic theories or by attributing the extinctions to their combined effects. Dinosaur fossils have been found near the Deccan Traps between major lava flows raising doubt whether worldwide extinctions could have been the result of volcanism.
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L. Hamilton at 09:55 AM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 1)
And props too for accurately including this caveat, usually skipped in popular geology:
That there is still much lively (and at times acrimonious) debate concerning the Plumes Hypothesis, including postulated alternative formation-mechanisms for LIPs, need not concern us here.
There is indeed a lively debate, including many recent papers (and presentations at last year's AGU) arguing that contrary to every textbook, deep-mantle plumes do not exist. Some of that work is cited in this more colorful piece describing the plume hypothesis as "zombie science."
http://www.mantleplumes.org/Zombie.html
Moderator Response:[PS] Fixed link
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mav1234 at 08:37 AM on 20 March 2015There is no consensus
wakeup @666: This survey is not the only evidence used "daily" to suggest an overwhelming consensus among climate scientists, and in fact, it references several other studies that support that position. I agree there are limitations of this study (hence my question), but the consensus is pretty clear from other sources as well.
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vrooomie at 08:36 AM on 20 March 2015The cause of the greatest mass-extinctions of all? Pollution (Part 1)
Speaking as a geologist, this is a very well-written and readable account. Kudos to you for assembling it all in such an easily-understood essay.
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mav1234 at 08:35 AM on 20 March 2015There is no consensus
michael sweet @664: Please re-read Cook et al and check the author survey sent - inconclusive was not a choice given to the authors of papers. I believe it is clear from the methods and the nature of the subset of abstracts receiving a treatment of inconclusive that Cooke et al realized their error late in the process and thus were unable to completely correct for this. I do not doubt that the number of scientists publishing papers indicating they are unconvinced is very low, but I was hoping someone was aware of such a study.
I am trying to find if anyone has quantified this in any way, that was all. I am not attempting to dismiss the consensus on AGW.
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Leto at 08:28 AM on 20 March 2015It's the sun
Hi Tom,
If you know of a mathematcal tool that could resolve whether autocorrelation is sufficient to explain the clustering of error years, I would be interested, though it is hardly an important point. (I confess I don't know the correct approach, myself, but eyeballing the graph did not at first suggest to me that simple autocorrelation was enough; looking at it again I am not so sure.)
The bigger problem I have with the "It's chance" line of argument is that it seems to be largely devoid of explanatory power. It is a truism that, within normallly distributed sets of data, a certain proportion will fall below a certain number of standard deviations, but it is a truism that applies as well to good models as to bad. It would remain true even if we added noise to the model to the point that it ceased to be useful. Even Pangburn could raise it in defence of the worst patches of his own model. The 2-SD yardstck is itself modified as the model deteriorates.
If the Minister for Education says: "We have to lift our game, 1% of schools are performing below ther 99th centile", then it is appropriate to point out to the Minister that 1% are always expected to perform below the 99th centile. Conversely, if the principal of a school says: "We have to lift our game, our school is performing below the 99th centile," or even just asks, in the boardroom: "Why are we performing below the 99th centile?", he would be rightly frustrated if his teachers said, "Don't worry, there'll always be 1% of schools below the 99th centile."
Asking why a particular patch of data-model matching is much worse than the rest is more analagous to the second situation, I believe. And while it may have been the case that there was no explanation other than chance, and I agree that thsi cannot be dismissed entirely, I am not surprised there are better explanations.
On the other hand, we have wandered off-topic and I greatly respect the work you do here so I wil leave it at that.
Regards, Leto.
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glennou812 at 08:26 AM on 20 March 2015Climate's changed before
It is amazing that so many experts think they know what happened millions, billions of years ago on the earth! Let alone that the techonlogy that is used to record the earth's temperature has only existed since the latter 1800s. Add to it in the 60s and 70s we endured a global cooling scare! When you take and issue and use it for an agenda you will you scare tactics! But in the end we dont even use the data attained during the 100 years of numbers collected but a brief 30 year period from 1950-1980 as our "average"! Yet we all know that this is the period of global cooling! Add to the alarmism of the 30/4,500,000,000,000 and science thinks it can answer every question with such a small sample, amazing! But I digress, let us take this one little degree over the past 100 years... now let us remove the co2 created by the mere existance of man and the population explosion.... next let us remove the co2 produced by the livestock explosion needed to feed the world.... let us remove the co2 from any additional solar activities.... let us remove the co2 that is created from all sources apart from fossil fuel usage! Next let us go to the remainder and break it down between countries in comparision to their production of co2 to run their economies... So now we in the usa are responsible for a fraction of one tenth of one degree! Let us now see what we can do to affec that number but also remembering that as we punish those who produce co2 one of two things will happen. They will increase the price of their goods or services and in the end punish the poorest among us or second they will move thier companies overseas where they will have fewer regulations and be able to increase production and co2 thereby eliminating any potential positives by attacking them in the first place... hmmmmmm!
Moderator Response:[TD] Only your first two sentences are on the topic of this post. If you want to discuss the topics of the other sentences, post them on the appropriate threads. In each of those original posts, after you read the Basic tabbed pane, read the Intermediate and then the Advanced tabbed panes, if they exist:
- "Add to it in the 60s and 70s we endured a global cooling scare!" That is a myth. See "What Were Climate Scientists Predicting in the 1970s?"
- "But in the end we dont even use the data attained during the 100 years of numbers collected but a brief 30 year period from 1950-1980 as our 'average'!" You misunderstand what a "baseline" period is. See "Of Averages and Anomalies."
- "Add to the alarmism of the 30/4,500,000,000,000 and science thinks it can answer every question with such a small sample, amazing!" See "Meet the Denominator."
- "Let us take this one little degree over the past 100 years," and "eliminating any potential positives": See "It's Not Bad."
- "Now let us remove the co2 created by the mere existance of man and the population explosion": See "Does Breathing Contribute to Buildup of CO2 in the Atmosphere?"
- "Let us remove the co2 from any additional solar activities": That doesn't even make sense.
- "Let us remove the co2 that is created from all sources apart from fossil fuel usage!": See "How do Human CO2 Emissions Compare to Natural CO2 Emissions," and for details of the mass balance evidence "The Independence of Global Warming on Residence Time of CO2" and "New Study by Skeptical Science Author Finds 100% of Atmospheric CO2 Rise is Man-Made."
- Yadda yadda "Let us now see what we can do to affec that number": See "Can We Fix Global Warming?"
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Watchdog at 06:29 AM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
Theorist @43.
In my posts above I've directly alluded to some of your 3 points.
Placing carbon isotope excursion and lower surface gravity on the side burner for a moment, the following factors are not negated by them.
Point 1 - There is evidence (not proof) that the shockwave of the Chicxulub Impact (which would have travelled in the direction of the Deccan Traps) must connect with effects upon Earth's Core-Mantle
Points 2 and 3 - There is strong evidence/agreement that the emissions of both Chicxulub and Deccan Traps ARE the Cause of the lowering of Earth's Temperature by as much as 8°C, which in turn caused a lowering of the Ocean Levels by c.40 Meters, which in turn is consistent with widespread glaciation, which in turn is consistent with significant llfe extinction.
Said another way, after all was said and done: If the effects of either/both Chicxulub's impact shock and thermal, along with the effects of its Ejecta upon Life - as well as - the probable greater effects from the larger volume of Deccan Traps Ejecta (including damaging respiratory effects on fauna and flora), the ensuing Global Freezing due to the blockages of Solar Radiation from both events - would have dealt an additional death blow to much of any remaining life. ----
In this current 'climate' of concern of Warming, the attention given to Abrubt Cooling Events - including their extent and effects upon Life - can be oft be cast aside.
Consider the last Glaciation period which ended c.12,500 yrs ago, created 10 Million Sq. Miles (in both hemispheres, including all of Canada) covered in ICE - all consistent with a 400' lower Ocean levels of the Oceans.
Consider now the contribution of that Glaciation event to Extinction:
Consider the Habitability of Life in Canada 20,000 years ago.
Recalling All of Canada was covered in ICE, how many species can survive during longterm periods of ICE and only ICE
Speaking of Gravity. Consider the decrease in Gravity in a large portion of Canada, particularly in the general Hudson Bay area. The ICE upon that area was as much as 3.7 km thick. This ICE depressed that area (which still slowly rises) by c.650'.
An agreed _part_ of the "cause" of the decrease in Gravity is:
The ICE compression pushed _aside_ some mass/material from underneath that area - thus lowering the mass/gravity of that area.Another theory of lowering "part" of the Gravity is referred to as "convection". Whereby moving magma currents pull tectonic plates downward thus removing mass and thus lowering Gravity from that area.
Both theories are now considered together as explaining the total "missing mass/lowered gravity" of that area.
ERGO: Getting back to Lower Temps, the abrupt decline in global temperature is the Cause of the increase of ICE; which ultimately affected - in part - the Gravity of some areas of Earth.
As with theories which approach Chicxulub and Deccan Traps as connected to each other, is that Glaciation Period and Magma Convection Process - possibly connected?
POINT? Again, there are multiple causes and climatic (and other) effects - often intertwined) which are detrimental to life.
WHY should the Overall Cause of Dinosaur Deaths be approached as if a new plausible theory _must supplant_ other existing plausible theories of detrimental-to-Life Causes and Effects?
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scaddenp at 06:14 AM on 20 March 2015There is no consensus
Well there are other ways to see whether Cook is on the right track. You can ask the climate scientists directly. That would be Doran 2009, which came up with the same figure. You could also look at all the scientists who contributed research surveyed by the IPCC - ie over 4500. By contrast wikipedia provides this helpful list of dissenters. Taking out the non-climate scientists and industry shills, you are left with a list of mostly scientists who have "gone emeritus" and/or are ideologues.
Frankly, anyone who doesnt believe that a consensus exists is pursuing an elaborate exercise in fooling themselves and I would suspect them to be ideology and/or identity driven.
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Theorist at 03:29 AM on 20 March 2015So what did-in the dinosaurs? A murder mystery…
This is an excellent up-to-date analysis of the current thinking of the mass extinction at the Cretaceous-Triassic boundary. It has been over thirty years since the bolide impact theory was proposed yet we still do not have a definitive answer to the extinction. I believe this is because neither the bolide impact nor the volcanic are the primary culprits in the mass extinction; they played a minor role and were caused by changes in the position of the Earth’s core elements.
I believe the Gravity Theory of Mass Extinction explains all mass extinctions, which have the following characteristics, in addition to the extinctions caused by changes in surface gravity:
1. Massive flood basalt volcanic eruptions which originate at the core-mantle boundary.
2. Massive fluctuations of sea levels.
3. Large carbon isotope excursion (the disassociation of methane from marine locations caused by the combination of low sea level and lower surface gravity and not by volcanism).
Scientists have ignored the coincidence of these factors, which accompany all mass extinctions prior to about 30mya.
https://www.youtube.com/watch?v=wHMAT_i3-KQ&feature=youtu.be
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PhilippeChantreau at 01:06 AM on 20 March 2015There is no consensus
I find the line of reasoning from wakeup so tenuous and the conversation so vacuous that this is coming really close to a DNFTT situation.
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One Planet Only Forever at 00:01 AM on 20 March 2015Fossil fuels are way more expensive than you think
Another consideration is that any developed activity based on a practice like burning up non-renewable resources fundamentally cannot be continued. The economic system response is that scarcity will make the activity cost more. What really happens is a few people figure out how to be the ones to benefit most to the bitterest of ends that they can get away with. That includes wars and overthrowing governments and setting up indebted poor nations so they can displace self-sufficient tribes to get the cheapest possible access to the limited resource they wish to be the maximum beneficiaries of in the short-term, the only term that matters to them in their financially focused pursuits (and a lot of research indicats thta people motivated by financial pursuits are less caring of the consequences of their actions. So all rich people are not a problem. Only those who strive to be richer any way they can get away with are a problem).
The lack of a future for such activities and the damaging actions taken by powerful wealthy pursuesr of more for themsleves needs to be included in the evaluation.
In addition, many economic assessments of the 'overall economics' claim that reducing the burning of fossil fuels 'costs more' than dealing with the consequences. Those evaluations are fundamentally flawed because there should never be any 'consequences to be faced by future generatons' created by the pursuits of personal benefit by any in a current generation. It should not matter how wealthy some people in a current generation can get if that wealthy way of life cannot be continued indefinitely on this amazing planet with all others developing to live that way if they wish to.
The current socio-economic-political systems are motivated by 'some trying to win what they want to the detriment of others'. The concept of developing an eternally enjoyable way of living that all humanity can enjoy if they choose as part of the robust diversity of life is contrary to the current systems that encourage a few to fight to dominate or 'win over' all others at the expense of others.
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curiouspa at 23:46 PM on 19 March 20152015 SkS Weekly News Roundup #12A
Back to Antarctic sea ice-had a moment to read again. I enjoyed this article in the Washington Post, which is posted this week. It seems to give a nice summary of possible explanations for sea ice extent. Even includes an opinion that this could be chance fluctuaton, from John Turner (who, on a quick search, seems to be an earnest scientist). It makes sense to me as a layperson that fluctuations will occur within geologic time frames. Monitoring overall ice trends, as with the NASA and NSIDC data, yields a more accurate picture, as individual fluctuations revert toward the mean. It also seems land ice is slightly harder to measure at this point, but progress is being made in measuring land ice thickness.
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There is no consensus
wakeup - By your standards, then, every science paper should also explicitly state that the sky is blue, gravity exists, green is not purple, and in essence recapitulate the entire sum of human knowledge, because otherwise that's all clearly up for debate.
Um, no.
Every bit of science exists within the body of shared knowledge assumed as a background. It's only when a work rests on other assumptions that it's necessary to state those, in a minority opinion - the better accepted a bit of knowledge, the less you need to start it to the readers. Meaning that climate 'skeptic' papers need to establish their (different) assumptions, but mainstream works not so much.
I suspect (personal opinion) you are fully aware of this, and are just looking for some semantic points to dismiss the consensus on AGW. That same argument has been raised before (read back in these threads), and it's still nonsense.
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Watchdog at 22:32 PM on 19 March 2015So what did-in the dinosaurs? A murder mystery…
Ranyl - Thank you for posting that selection. "" It’s weapons of death include a violent blast that destroys everything for thousands of miles around the impact, a heat flash from the blast that incinerates everything in a similar radius, followed by a near-global rain of red-hot ejecta that turns the sky into a broiler (“grill” if you are outside the US) inflicting fatal burns and igniting a global conflagration. The blast, centered in shallow ocean, generates a colossal tsunami across the juvenile Atlantic and the shock wave triggers earthquakes and tsunamis around the world far more violent than the 2011 magnitude 9 Tōhuku earthquake in Japan. Finally, the great quantity of dust and incinerated debris flung into the upper atmosphere blocks out the sun, turning the world dark and the climate frigid for years."" Please pardon me for my redundancy; however if you review that selection you can see it directly supports the fact that Chicxulub was a global event. One can only surmise the actual and complete extent of all its immediate destructive-to-life effects upon life in North & South Americas'. I.E. It's clear from that selection is that its impact upon E.G., Global Temperature aka Global Freezing which is Not due to CO2 (and similar Solar-Radiation reduction effects from Deccan Traps Ejecta) are but a part of All the overall causes of the deaths of the dinosaurs.
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MA Rodger at 20:08 PM on 19 March 2015There is no consensus
wakeup @666.
If your comment @666 is the substance of your enquiry (although it is more assertion than enquiry), perhaps the example of Whiskas cat food advertising will demonstrate where you are missing the point.
This is not to do with "whether or not global warming is human-caused" as you suggest @666. Rather it is to do with whether climate scientists agree it is human-caused. And they overwhelmingly do agree.
The UK Whiskas cat food advert of the 1980s initially used the phrase "8 out of 10 cat owners said they cat preferred it." This was adjudged to be deceitful because there were many who didn't express a preference and were not included in the "10". Thus the adverts was changed to say "8 out of 10 cat owners who expressed a preference said their cat preferred it."
Yet this still does not give the full story. How many cat owners (or more correctly cat feeders, because they are the ones in a position to know) responded that there was not a jot of difference between these various cat foods? It could be, say, that only a third could see any difference at all between premium cat food Whiskas and some budget moggy-snack.
What you are suggesting @666 is that all the papers reviewed are like cat feeders and so these papers would all allow an answer to the enquiry and that in the majority of cases the papers show a response "Don't know" or in the Whiskas analogy "I see no difference." Yet what that majority( that you wish to include within the results of the analysis) are saying is the equivalent of "I don't know because I don't feed the cat."
This explains why, contrary to your assertion, the 97% figure "is (properly) demonstrated by this survey."
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ranyl at 18:58 PM on 19 March 2015So what did-in the dinosaurs? A murder mystery…
" It’s weapons of death include a violent blast that destroys everything for thousands of miles around the impact, a heat flash from the blast that incinerates everything in a similar radius, followed by a near-global rain of red-hot ejecta that turns the sky into a broiler (“grill” if you are outside the US) inflicting fatal burns and igniting a global conflagration. The blast, centered in shallow ocean, generates a colossal tsunami across the juvenile Atlantic and the shock wave triggers earthquakes and tsunamis around the world far more violent than the 2011 magnitude 9 Tōhuku earthquake in Japan. Finally, the great quantity of dust and incinerated debris flung into the upper atmosphere blocks out the sun, turning the world dark and the climate frigid for years."
From main article Watchdog, not sure what your point that Howardlee hasn' taddressed really.
Yes a big impact makes a lot of waves, just not enough apparently to wipe out life all over the earth, that takes a global cultprit, according the evidence presented and mulled over by those who drawn the conclusions Howardlee presents.
That an impact of that size didn't induce the full mass extinction makes CO2 warming and acidification just more worrying really.
Although despite that, if a comet was again coming our way everybody would pull together to try and do something about if ways could be found. Yet when it comes to the greater threat posed by what we are doing, most people turn a blind eye, under the premise that an acclerated mass extinction won't happen really, the threat isn't that great, it won't happen to me or will take place in a far away place.
Every year we pump out enough CO2 to be equivalent of approximately 3 mega volcanoes erupting.
But the affects are too subtle as yet for most human's contemplation and threat reaction to be induced as we human's really only react to comet like threats, as we can identify the danger as an immediate impact and that is clearly life threatening.
Anyway the scale of change required to actually become a sustainable, non toxic, biodiversity enhancing global soceity is too great it seems and the majority of solutions are still toxicity producing, biodiversity impacting and totally none sustainable (e.g. larges scale dams, wind turbines, PV panels, Batteries, industrial scale biomass production) and don't address the issues of massive over exploitation of resources, population expansion, waste creation and inasive alien species.
We'd have more chance if a comet was going hit us!
Does anyone out there actually think transformational change is possible if that meant sacrificing the car, plane and mobile phone?
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alby at 18:47 PM on 19 March 2015Fossil fuels are way more expensive than you think
Social cost of goods or technologies is well known: economist call it externality. The problem is that is a type of indirect cost. It's really hard to change it in a direct cost (with a taxation or with law in order to avoid pollution). And this not only because population has to accept this change, but also because in a global market if only one nation (even if the first economic power one like USA) will support strongly (partially, with investment both on fossil both on revewable is not so effective) this change the other competitors (China, Brasil, Russia etc etc) will take commercial advantages avoiding (or simply delaying) this pollution tax.
Regarding Nuccitelli graph I hope that 2014 will not be an isolated year but the beginning of a new trend of decoupling. Looking through data there are also 1980-81 and 1992 with GDP increase (around 2%) and decreease of CO2 emission while durimng 1994 and 1998 a GDP increase at more or less 3% was done with a small CO2 increase (around 0,5%).
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BBHY at 17:46 PM on 19 March 2015Fossil fuels are way more expensive than you think
I like that studies of this sort help make people aware of the hidden costs of the fossil fuels we use. I wonder how much more would be added by including the cost of oil spills?
Then again, in a way the added cost is misleading. When parts of Antarctica melt from too much CO2 in the atmosphere, no amount of money can put that ice back. When a beautiful beach is submerged by rising seas it can't be replaced with a stack of $100 bills.
I think a lot of people don't realize that the effects of global warming as almost completely irreversible. When we limited sulfer pollution, the acid rains stopped and the forests and streams recovered. When we stopped emitting CFCs the whole hole in the ozone begain to shrink.
The changes to the climate caused by humans are not like that. They are pretty much permanent, unless you consider time scales greater than 1000 years.
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stephine at 17:17 PM on 19 March 2015Skeptical Science now an Android app
Apart from mobile games, there are plenty of useful apps available for everyday use. For example, Google itself releases new Android apps from time to time. One of the latest ones is Google reader, which allows the user to browse and read RSS feeds and news items from the different sites that are subscribed to using Google Reader from the web. best android apps
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Tom Curtis at 16:44 PM on 19 March 2015There is no consensus
wakeup @666, thankyou for opening my eyes. I had not realized the theory that the Earth is not flat was in so much difficulty. However, following your methods, I noted that there is virtually zero endorsement of the proposition that the Earth is a sphere (or oblate spheroid) in scientific papers. It follows, from your impeccable reasoning, that >>99% of scientists do not accept that the Earth is either a sphere or an oblate speroid and that, by inference they consider the theory that the Earth is flat to be at least as viable.
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Watchdog at 14:22 PM on 19 March 2015So what did-in the dinosaurs? A murder mystery…
howardlee @39 - Yes. Thank you. Returning to the topic of quantifying the impact effects and "region" size of Chicxulub I refer to a paper in _Meteoritics and Planetary Science_, "Earth Impact Effects Program: A Web-based computer program for calculating the regional environmental consequences of a meteoroid impact on Earth", by Collins, Meloth and Marcus, which includes various physical results from 3 sizes of impactors; one the size of Chicxulub. I note that its thermal energy alone estimated at a radius of 1,800 miles from its point of impact is 10 times the level which would cause 1st degree skin burns. My Point? I think we can agree that the 'regional' area of destruction wrought by Chicxulub covered a rather vast region; perhaps continentalish.
http://impact.ese.ic.ac.uk/ImpactEffects/effects.pdf -
wakeup at 14:12 PM on 19 March 2015There is no consensus
Tristan: Thanks for responding. At issue is whether or not global warming is human-caused. If the goal was to find out if a significant majority of scientists publishing in the field support the theory, it's unusual, to say the least, to discard 66% of the subject papers because they "made no statement of attribution" and treat the 34% who do as 100% to reach the conclusion that 97% validate the theory of human causation.
That would be fine if the 97% is declared for what it is: the percentage of the 34% of experts who have reached a conclusion, as it is (if you know to look for it) in the Science Project logo above. Unfortunately it is used daily to convince the public that 97% of climate change scientists agree that gw is human-caused, which, in my view, is not demonstrated by this survey.
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scaddenp at 14:05 PM on 19 March 2015Crowdfunding Support for Science: The Dark Snow Project
Tracking it back to the original figure you get caption of:
"Monthly mass anomalies (in Gigatonnes, Gt) for the Greenland ice sheet since April 2002 estimated from GRACE measurements. The anomalies are expressed as departures from the 2002-2014 mean value for each month. For reference, orange asterisks denote June values (or May for those years when June is missing)."
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TonyW at 13:35 PM on 19 March 2015Crowdfunding Support for Science: The Dark Snow Project
Quick question. What is that "Greenland Ice Mass Loss" graph actually showing? I'm a bit confused by the positive and negative numbers on the y-axis.
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Tom Curtis at 09:57 AM on 19 March 2015It's the sun
Leto @1139, temperature shows a level of autocorrelation across years. Because of that, clustering of high SD years is not unexpected. If follows that "just chance" cannot be excluded as an explanation for the cluster of high SD years. And even though it is more probable than not that it is not just chance, I certainly cannot claim that just chance is less probable than any or all of the other alternative explanations.
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Leto at 09:23 AM on 19 March 2015It's the sun
Thanks Tom and Glenn... Tom's list of "error years" (1938, 1943, 1944, 1963) do not appear to be randomly distributed - if we plotted a rolling 2-year or 5-year average of absolute (or squared) model-data mismatch, I suspect there would be a peak in the 1938-1944 period that stuck out well above the rest of the plot (more than 2 SD), so I was hoping there would be better explanations than "it's chance".
Clearly, there are several potential explanations and it seems more than likely that the data around that time is itself suspect (particularly given the association with WW2 and the change in coverage). That makes the performance of the model even more impressive.
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arationofreason at 09:09 AM on 19 March 2015There's no correlation between CO2 and temperature
Linear 'fit' to the last 38 years of ocean data yields 0.3 watts/m^2. Essentially the same as the Livitus et al results. This is ~93% of global warming power with a decent average time. Note this is only about 1/10 of the global warming power claimed by IPCC to reach 3C in a century.
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Tom Curtis at 08:15 AM on 19 March 2015There is no consensus
michael sweet @664, in Cook et al, self raters were not given an "inconclusive" option. Rather they were given a neutral option, without the possibility of distinguishing between "neutral because inconclusive" and "neutral because relevant issues were not addressed". The distinction is important because the former, but not the later, should be included in the denominator in determining the proportion of endorsements.
In the abstract rating section of the paper, a subsample of neutral papers were given a secondary rating to distinguish between "neutral because inconclusive" and "neutral because not addressed". Only 0.1% of neutral papers fell into the former category. Assuming that a similar proportion of papers self rated as neutral were "neutral because inconclusive", then 96.7% of self rated papers that had an opinion on the topic would have been self rated as endorsing AGW. That compares to the 97.2% found in the actual paper without the option of distinguishing reasons for the neutral rating.
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michael sweet at 06:07 AM on 19 March 2015There is no consensus
mav1234,
Read the advanced or intermediate tabs of the OP. All the studies allow the papers to be rated inconclusive. Cook had 7 ratings. Many of the papers were rated inconclusive.
Where did you get the idea that inconclusive was not a choice?? If you believe the "skeptic" blogs you will never understand the issues. Their primary purpose is to put out disinformation.
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mav1234 at 05:00 AM on 19 March 2015There is no consensus
Hello all,
Is anyone aware of a similar study in which authors were allowed to rate their studies as "inconclusive"? Given that this study asked authors to rate studies without the option to mark as inconclusive, I was just curious.
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howardlee at 00:59 AM on 19 March 2015So what did-in the dinosaurs? A murder mystery…
Watchdog @38 I assume you are referring to Ohno et al 2014. That's a paper looking at the nature of the aerosols generated by an impact. In the article you will see I reference newer research on the volumes of material and mechanisms of acidification showing that ocean chemistry rules out the impact as a feasible cause of the ocean acidification.
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DSL at 00:48 AM on 19 March 2015There is no consensus
The case is actually stronger, if I recall correctly. The 3% of publications addressing the human contribution are not actually comprehensive. If we were to include only studies that determine the contributions of the full range of natural and anthro forcings, feedbacks, and oscillations, the number would not be 97%. It would be 100%.
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CBDunkerson at 23:35 PM on 18 March 2015There is no consensus
wakeup, let's consider some different scenarios;
- If you look at all climate papers which stated causes of GW then ~97% said GW is mostly human caused.
- If you look at all climate papers then ~33% said GW is mostly human caused.
- If you look at all scientific papers then less than 1% said GW is mostly human caused.
- If you look at all papers on any subject (e.g. economics, philosophy, knitting) then near 0% said GW is mostly human caused.
- If you look at all written communication throughout human history then near 0% stated a position on any given single topic.
People who are not trying to kill their own capacity for rational thought should be able to see that looking at anything other than the percentage amongst those who actually addressed the issue (i.e. 97%) is meaningless. The only reason to favor a percentage including some pool of data which doesn't even address the subject is to deliberately delude oneself.
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There is no consensus
wakeup - When you write a paper, you don't waste time rediscovering gravity, or that the sky is blue, or Archimedes Principle. You spend your time on new work and how that relates to previous hypotheses. The more accepted something is as a background fact the less you will see it explicitly discussed in a paper. It would therefore be reasonable to include the 2/3 of papers not bothering to mention GW causes as agreeing with the consensus - not doing so is a conservative choice minimizing actual agreements.
If, on the other hand, your work disagrees with the consensus, with accepted background material, you're going to mention that and state why, whether you consider that background material to your work or central to the paper. Meaning that we should expect a higher percentage of attribution in minority papers on climate, a higher percentage of implicit or explicit claims of dominant natural causes in 'skeptic' papers, an overrepresentation of dissention.
And yet even with that potential overrepresentation, papers arguing against AGW still come in at less than 3% of the papers mentioning causes of climate change.
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MA Rodger at 20:36 PM on 18 March 2015There is no consensus
wakeup @657.
You say:-
"Many non-scientists are bewildered by the volume of conflicting information on this subject, by fuzzy numbers and apparently authoritative statements that amount to gobbledegook when subjected to rigorous analysis. Anyone?"
The volume of 'conflicting information' and the 'fuzzy numbers' may be less easy to get you to identify, but please do give your examples of 'apparently authoritative statements that amount to gobbledegook'. It is difficult for anyone to begin to address your question without knowing what you're on about.
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Tristan at 18:46 PM on 18 March 2015There is no consensus
"while the remainding two-thirds made no finding as to cause."
That's not quite accurate. Itd be accurate to say that those two-thirds made no statement of attribution in the abstract. That's not surprising, most climate science does not involve quantifying attribution.
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wakeup at 17:22 PM on 18 March 2015There is no consensus
Advance apologies if this question has been asked and answered many times. I just discovered the site while searching for the source of the oft-quoted 97% consensus and was disconcerted to read that the consensus refers to 97% of the 33% of authors who stated a position on human-caused warming, while the remainding two-thirds made no finding as to cause. The reality, then, is that twice as many climate researchers do not agree that gw is human-caused, do not know, or are unwilling to take a position. I read one comment here that seemed to say that the 66% didn't need to state an opinion because it is so obviously human-caused - the "everyone knows" argument. This wouldn't be acceptable in a courtroom or a school science project so I hope it is not the case.
Many non-scientists are bewildered by the volume of conflicting information on this subject, by fuzzy numbers and apparently authoritative statements that amount to gobbledegook when subjected to rigorous analysis. Anyone?
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