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q41019573 at 08:44 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
Amazing, interesting, informative, educational, and I'm 67. Thank you very much.
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scaddenp at 08:34 AM on 13 March 20152015 SkS Weekly News Roundup #11A
curiouspa - please see the link I provided on Antarctica sea ice for why Antarctica sea ice is expanding - it is paradoxical on first glance because sea temps are rising. However for overall Antarctic ice loss see here. Measurement is done with GRACE satellite or from height of ice sheet. As to assymetry between poles consider:
South pole is on land at around 2000m altitude - North pole in sea as is most of Arctic ice with exception of Greenland.
Antarctica is isolated to some extent from rest of planet by circumpolar current and winds. Arctic weather is influenced by air masses from lower latitudes.
Ozone depletion also plays a part in Antarctic radiative balance.
Sea ice in Arctic is year round phenomena. Because sea ice is at lower latitudes in Antarctica, (higher latitudes are covered by land) most of it is completely melted out in summer.
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villabolo at 08:06 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
Don't know if this is on topic but I've heard that the atmosphere may have been thicker during that epoch. If it were would that have made a difference? How would the atmosphere have been affected by such an impact?
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curiouspa at 07:14 AM on 13 March 20152015 SkS Weekly News Roundup #11A
For wili,
I think if both poles were heated about the same amount, both would lose a similar amount of ice. The Arctic would lose sea ice and the Antarctic would lose an equal amount of land and sea ice.
I'm not excluding that there can be variations with net overall global loss. I just want to know the facts-simply stated- is Antarctica gaining or losing ice? It may be there is overall loss of ice but increase in sea ice only. The only satellite data I can find is sea ice since 1979. Thanks.
Moderator Response:[JH] If you enter "Antarctica" into the SkS search box, you will find a wealth of information about what's going on there.
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scaddenp at 07:14 AM on 13 March 2015Measuring Earth's energy imbalance
Chpter 2 of IPCC AR5 discusses the measurement in 2.3.1. You might like to start with the references from there. I understand there are some difficulties with accuracy in the raw data though making it hard to get a precise measure of magnitude. ARGO data may be a more accurate way to get TOA imbalance.
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shoyemore at 06:43 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
I remember two articles in Scientific American in the 1980s explaining the rival theories. The Deccan Traps were advanced as the alternative to the asteroid. It was a little shocking to read a popular very media-friendly theory attacked. Over the years I assumed the volcano account had receded or been discounted. Great article.
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uncletimrob at 06:23 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
Thank you! A most interesting article that takes me back to early undergraduate lectures nearly 4 decades ago. Another for the recommended reading list.
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bcglrofindel at 05:58 AM on 13 March 2015Measuring Earth's energy imbalance
I'm not sure where the right place to ask this is, so please redirect me if I'm in the wrong place. Does anyone know where I can track down the Top-Of-Atmosphere net energy/radiation data from CERES and prior to that ERBE? I've been looking and looking for an easy referencable observed energy balance graph covering the satellite era and can't seem to find them. I can find summaries of the overall trend for CERES, and pieces of ERBE from sometime in the 80's, but nothing by way of a simple graph. Surely with one of the express purposes of these satellites being to measure incoming and outgoing radiation somebody has put together a net radiation graphic of some form already somewhere? If I could be pointed in the right direction it'd be greatly appreciated.
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ubrew12 at 05:55 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
I'm not a scientist so am free to speculate: If you tunnel through Earth to the spot opposite the Chicxulub Crater, you will be in the Indian Ocean. Hmmm.
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howardlee at 05:29 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
Yes there's a pretty strong pattern. I think the end-Ordovician is now perhaps the only exception of the phanerozoic, linked by some to the first spread of vascular plants causing CO2 reduction and Global Cooling, resulting in the Hirnantian Glaciation.
John Mason has a post due out soon on the Permian Mass Extinction - the most extreme example.
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wili at 05:17 AM on 13 March 2015So what did-in the dinosaurs? A murder mystery…
Thanks. I always find myself treating the end-Cretaceous extinction as the exception to the general rule that mass extinctions have been caused by GW, which was too bad, since it's the only mass extinction event that most people (think they) know something about.
Now I can just point to this article.
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Andy Skuce at 05:03 AM on 13 March 2015Consensus and geoengineering - how to convince people about global warming
I have been critical of Dan Kahan in a recent post here, but I think there's a lot of value in most of what he has written. I wrote a long post on SkS sometime ago that was broadly appreciative of his work. I think he is right to worry about getting more people, especially those on the political right in the USA, to accept the science. He's not alone in that.
Where I differ with him is that I see consensus (or information) messaging as part of a two-pronged approach, along with his cultural cognition stuff, whereas he seems convinced that consensus messaging is counter-productive. I think the study that Dana highlights in this post effectively removes that worry.
One irony is that the tone of some of Dan's informal remarks about consensus have themselves been rather harsh and they actually risk polarizing those of us who are trying to nudge public opinion in the direction of reality. If communicators are going to change the status quo, it's going to take all of us.
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scaddenp at 04:57 AM on 13 March 20152015 SkS Weekly News Roundup #11A
curiouspa - You might want to look (and continue any discussion) on this thread. Short answer - Antarctia is losing ice but there is a statistically significant increase in the sea ice around it. Just dont fall for idea that this somehow offsets arctic ice loss (it is small by comparison and has little climate impact since it occurs in winter). In particular, you need to look at why these things are happening. The skeptic argument is that its getting warmer in arctic but cold in Antarctic so cant be CO2/anything to worry about. Not true.
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swampfoxh at 04:44 AM on 13 March 2015Consensus and geoengineering - how to convince people about global warming
I suspect (and probably hope) that the science community can probably appreciate that the "personas" in the US political power structure are as much a part of the problem as the fossil fuel industry and the average voter himself. On the one hand, President Obama, gives the appearance that he supports blocking the XL Pipeline while he opens up the Atlantic offshore drilling sites and certain Arctic continental shelf areas for drilling. But, I don't see the scientific community (the hard science guys) saying much of anything about this hypocrisy. Could it be that the great majorities of scientists are political liberals and deign to criticize this guy? KR's looking for getting things done and wants the science to point the way to sensible public policies, but unless the scientific community is prepared to ridicule the inappropriateness of the power structure's "wacko" decisionmaking on climate remedies, even good science will give us nothing to bite into. Massive population reduction, for example, is a sensible public policy if we are going to fix the climate problem. Total curtailment of global coal fired power plants is another. A permananet moratorium on global land clearing operations is yet another sensible public policy. The shutdown of global synthetic fertilizer producers is yet another. Shutting down the global internal combustion engine manufaturers, yet another. But, the recent US-EPA 30% reduction mandated for coal-fired power plants is not a sensible public policy when the science realizes that just this one category requires at least an 85% reduction in emissions and that should have happened 12 years ago!
I think I know what y'all are going to say about my doomsday scenario, but I want to hear it anyway, so, fire back. I have class tomorrow and I'd like to tell my students what you have to say. Thanks.
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Jim Hunt at 03:42 AM on 13 March 20152015 SkS Weekly News Roundup #11A
OPOF @2 - There are a range of Arctic sea ice metrics, which peak at different values on different dates. I've been covering a range of them today, to coincide with The Economist's Arctic Summit:
http://GreatWhiteCon.info/2015/03/some-statistics-for-the-2015-economist-arctic-summit/
The "15% extent" ones are currently at their lowest level for the date by a considerable margin. Cryosphere Today area is also at a record low today, but only just.
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Consensus and geoengineering - how to convince people about global warming
swampfoxh - I completely agree, hard-core deniers will never be convinced. And I think that single fact makes all the Kahan-style whinging about 'polarization' ineffective.
Is the goal to convince everyone, including those invested in not listening? Only if your sole question is "Can't we all just get along?". Or is it (IMO) more important to simply get things done, to minimize the damage from climate change? If the latter, then properly informing public opinion about the science and expert views, rather than vested disinformation, should at the very least point the way to sensible public policies.
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wili at 03:15 AM on 13 March 20152015 SkS Weekly News Roundup #11A
Here's the link to a pdf of the original study on failing carbon sinks.
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wili at 03:13 AM on 13 March 20152015 SkS Weekly News Roundup #11A
This seems like a pretty important development.
curiouspa, the north and south poles are polar opposites in more than one way--the Arctic is an ice-covered ocean (mostly) surrounded by continents; the Antarctic is an icesheet-covered continent surrounded by ocean.You tell _me_ what you think the result of heating each of these up a bit would likely be. No agenda...just a question.
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swampfoxh at 03:09 AM on 13 March 2015Consensus and geoengineering - how to convince people about global warming
I have a Masters Degree in Government. This, perhaps, qualifies me to teach "Global Warming: Proof or Politics", which I do bi-monthly here in west-central Virginia. I point this out because, although I read SkS "religiously" I find the science pretty baffling (which most of you "hard scientists" would not find surprising). But, I am often struck by the many comments on the subject of "how to convince the Deniers to 'buy' the science", a science which is very solid and, frankly, needs no additional "evidence" to get people off their butts and out into the street to solve this climate problem. So, instead of fulminating over how to get the deniers to "get with the program" we should be getting the rest of us (the most of us) to get on with the solutions. We know people believe in God without the slighest scientific evidence so why bother with such subjects? People will believe in God and other fairy tales long after we have fixed the climate problem, so let's put managers and policymakers into positions of political power that can do what needs to be done here and stop wasting time and dialog on BS.
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It's the sun
Dan Pangburn - "...my analysis has found that CO2 has no significant effect on climate..."
Then, with all due respect, your analysis is simply wrong.
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It's the sun
Dan Pangburn - Reality doesn't care about beliefs.
With respect to the significance of CO2 concentration changes, I suggest reading the CO2 is just a trace gas thread. Your statement sounds like an argument from incredulity.
Atmospheric GHGs (active in the IR) have very little effect on how the oceans absorb sunlight. But by warming the surface atmosphere, they have a significant effect on how fast the the oceans lose energy to the atmosphere, and hence create a forcing imbalance on the oceans themselves. See the discussion here.
"...you are destined to wonder why the average global temperature isn't increasing."
What? How can you possibly claim this? There are short term variations in atmospheric temperatures, but if you look at the global temperatures including the oceans, or even just examine a sufficiently long period for statistical significance in atmospheric temperatures, they are indeed increasing. That statement of yours is nonsense.
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curiouspa at 02:23 AM on 13 March 20152015 SkS Weekly News Roundup #11A
Just a question-no agenda. I hear various things. Is Antarctic ice increasing, decreasing, or staying the same. The article seems to be definitive that Arctic sea ice is decreasing.
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Rob Honeycutt at 01:58 AM on 13 March 2015It's the sun
Dan @1113... It's not a matter of "belief." You have to understand the physics involved. For one, atmospheric concentrations of CO2 don't affect incoming radiation that warms the ocean.
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Dan Pangburn at 01:30 AM on 13 March 2015It's the sun
KR - I don't believe that atmospheric CO2 increasing from 3 parts in 10,000 to 4 parts in 10,000 has significantly changed the way that the oceans absorb sunlight.
My only point in this discussion is, to be a meaningful comparison, the temperature change should be compared to the time-integral of the forcing instead of the forcing itself.
Tom - It is puzzling why you declare that my definition of forcing is bogus when I have not even defined forcing. I assumed that everyone knew what cosntituted a forcing. My understanding is no different from AR5 (except my analysis has found that CO2 has no significant effect on climate).
I HAVE defined 'break-even'.
If you cannot see that the energy change (which, when divided by effective thermal capacitance, is temperature change) is the time-integral of the energy change rate (AKA net forcing) this isn't going anywhere and you are destined to wonder why the average global temperature isn't increasing.
Moderator Response:[PS] And your analysis is published where? Time to show us some data I think. It is pretty hard to accept the word someone who cannot calculate the radiative effect from an increase in CO2 without some pretty convincing mathematical analysis including all definitions used.
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One Planet Only Forever at 00:19 AM on 13 March 20152015 SkS Weekly News Roundup #11A
Here are a few clarifying points regarding the first arcticle "Arctic sea ice dwindling toward record Winter low".
The image in the article from NSIDC does indeed show the ice extents well below the average maximum and below the +- 2% standard deviation shaded area. However, the maximum ice extent of 14.522 sq km appears to have occurred on Feb 26. Perhaps the article is referring to the extent on March 12 when the average line is at its maximum.
However, the NSIDC webpage the image can be found on also includes a Chartic Interactive Sea Ice Graph that allows the user to see graphs of all of the previous years. And many previous years reached their maximum extents well after March 12. And some years there were early rapid declines in Arctic extents that were followed by expansion to that later maximum.
A more important point is that the extent reported by NSIDC is for at least 15% sea ice coverage. Temporary currents or wind conditions could pack brocken up ice into a smaller areas that could expand when current or wind conditions change.
So, the current Artcic Sea Ice extent is indeed well below any previous values in the NSIDC set of reported years. However, a lot can change in a short time. And the most recent extents are not continuing the rapid decline.
Time will tell what the resulting summer minimum will be. It may even be that the winter maximum extent of 15% or greater sea ice will exceed the 14.522 sq km that was measured on Feb 26.
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wili at 21:20 PM on 12 March 20152015 SkS Weekly News Roundup #11A
Thanks again for these, especially "Friction means Antarctic glaciers more sensitive to climate change than we thought "
So is anyone putting this together with other recent findings of faster-than-expected movement of various icesheets to come up with new estimates for the range of possible levels of slr we may expect by the end of the century and beyond? It would seem to me that such a project would be most important for policy makers (and for anyone living anywhere near the ocean).
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ryland at 19:56 PM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
Thank you for your comments KR. I am really rather flattered you should have spent time reading and dissecting what I write. However, careful reading of the piece shows how fictional geoengineering can be used to decrease polarisation on climate change. Equally of course fictional accounts could be used to increase polarisation. My comments are directed towards that aspect of the piece. And as for your comment about the MSM have you evidence that supports that? If so that would seem valuable in the cause of decreasing polarisation.
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Tom Dayton at 11:30 AM on 12 March 20152015 SkS Weekly Digest #10
Folks living near Santa Cruz, California: There is a Climate & Policy Conference this Friday night and Saturday day. Richard Alley will be keynote speaker Friday night.
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Tom Dayton at 11:28 AM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
I have responded to ryland's complaint about the insolation error in some models, on the Models Are Unreliable thread.
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Tom Dayton at 11:26 AM on 12 March 2015Models are unreliable
Responding to ryland's complaint (from an inappropriate thread) that models are wrong due to an error in computing insolation: Richard Telford in his blog Musings on Quantitative Paleoecology explained that it is a non-issue for global insolation (instead it is only a local issue), a non-issue for some models, a trivial issue for other models, and a small issue for a few models. In other words, what scaddenp and Kevin C already explained to ryland--but Richard has added a couple graphs.
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sailingfree at 10:36 AM on 12 March 2015Temp record is unreliable
Zeke's work should be the lead-off for this 'Temperature Records" article.
Since the raw data has been adjusted to show LESS warming than the raw data, the issue is resolved. No need to explain the science of the "adjustments". End of story, no Hoax.
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sailingfree at 10:32 AM on 12 March 2015Temp record is unreliable
The bottom line, trump, checkmate, is Zeke Housefather's plot showing that overall, the raw data has a HIGHER trend than the global adjusted data. That's right, the adjusted data shows LESS warming than the raw data. So much for a conspiracy to make a hoax.
Moderator Response:[PS] Fixed link
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Tom Curtis at 07:25 AM on 12 March 2015It's the sun
Dan Pangburn @1110:
You say:
"Until you get the 'trivia' right, it's not a distraction."
Yet I have now corrected for the trivial points you raised, and you are still not responding to the thrust of the argument. Ergo, your intent was not to correct the trivia but to distract from the thrust of the argument, which you are unable to answer.
You go on to say:
"A forcing must act for a period of time to have an effect on average global temperature (AGT). The forcing is not the difference between what it was at one time (1750) compared to what it is at another time (now)."
Except that is plainly false. I quoted from the IPCC AR5 WG1 glossary as to the definition of forcing. You can trace that definition back through the reports, and through the scientific literature if you want, but the definition is as I have given it. If you want to introduce a different concept into climate science, introduce a new term and define it explicitly. Stop using ambiguity to conceal the weakness of your argument. Alternatively, if you want to use the currently accepted term in climate science, "forcing", use it as currently defined, and stop trying to give it an idiosyncratic defintion.
I will note that there are very good reasons for the standard definition. Explicitly, your definition only works if there is no change in temperature due to other reasons (ie, no other forcings, and no internal variability). It also only works if the time integral of (OLR minus initial OLR) is zero over the "break even" period. Further, it depends on there being intervals of zero net change in OLR, temperature and heat flux to benchmark the 0 value of the forcings. When you show me that period over which we have reasonably accurate measurements of all relevant values, I might consider using your definition.
Finally, you comment that:
"If the forcing goes from .5 below break-even linearly to .5 above break-even during the time period, the time-integral for that time period is zero."
Well, yes. But the time integral over the first half of the period is negative, and the time integral over the second half is positive. Ergo, you are compelled (of you wish to be reasonable) to accept that even with your abberant and idiosyncratic definition of forcing, the temperature histories of scenarios A, B and C will be different. That being the case, only looking at the initial temperature and final temperature to determine whether a particular forcing could be the main driver of change in GMST is to simply avoid the majority of the evidence. It is to argue by hiding data, not by examining it.
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jameslouder at 07:14 AM on 12 March 2015There is no consensus
The Global Warming Petition Project is straight from the department of "Lies, damned lies, and statistics." On second thought, "damned lies" may be laying it on too thick. Their vaunted number of scientific supporters is so pitifully small, it's barely worth calling a silly fib. But since one hears their figure quoted so often by climate change deniers, let's break down the numbers, just for fun.
The signers of the Global Warming Petition number 31,487, all of whom are claimed to hold at least BS "or equivalent" degrees. (GWPP : Qualifications of signers)
9,029 hold PhD degrees
11,615 hold PhD &/or MD or DVM degrees
18,772 hold MS or higher degrees
31,487 hold BS or equivalent &/or higher degrees
The American population at large, aged 25 years or older, is around 203 million. Of these:
3.6 million (1.77%) hold PhD degrees
7.5 million (3.27%) hold PhD &/or professional degrees
25 million (11.8%) hold Master's &/or higher degrees
65 million (32%) hold Bachelor's &/or higher degrees(Educational attainments of Americans — USCB/Wikipedia)
Thus, the signers of the GWP represent the following percentages of each category:PhD degrees — 0.25%
PhD &/or professional degrees — 0.15%
Masters &/or higher degrees — 0.08%
Bachelor's &/or higher degrees — 0.05%Obviously, these levels are vanishingly small. The GWPP’s horizon of expertise recedes even further when we consider that only 3,805 of these people claim any qualifications in Atmosphere, Earth, and Environment sciences. Granting all of them the unlikely distinction of holding doctorates, they would still represent only 0.11% of PhDs. (More realistically, they make up 0.006% of the population with a Bachelor's or better.) But just sticking with PhDs as a whole, I would venture to guess there is not a single area of scientific study, not a single theory, not a single assertion for which one could not muster a level of dissent of 0.25%--not excluding excluding that the Earth orbits the Sun; or that the Moon is composed of rocks, not Roquefort.
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Consensus and geoengineering - how to convince people about global warming
ryland - I dislike saying this, but a number of your recent interactions on these threads have followed a certain pattern:
- A claim to the (broadly paraphrased) effect of "This article/link appears to pose a problem for AGW theory/models/statements",
- Multiple responses from other posters to the effect that the claim is nonsense, a misinterpretation, etc,
- Followed by your response of "Oh, just pointing out media coverage issues, not actually making a claim." And you express surprise at having been interpreted otherwise.
Whether you intend it that way or not, the pattern I've observed is quite reminicent of concern trolling. And given that pattern, the tone of the responses you have received are far from surprising.
I will point out that most of the claims you have raised (whether yours or someone elses) are easily answered by either a search on SkS (search box on the upper left) or a quick Google on the topics involved. And that if you were to make posts to effect of "What can someone tell me about this claim"?, rather than just saying"This is a problem" with the implication that it really is an unanswered issue, you would be very quickly - and politely - pointed to the relevant information.
In the meantime - yes, there are media misinterpretations and poor or even selective presentations of the science. And those errors may receive quite a bit of attention from the rather small group of vehement deniers. But those denialist misinterpretations are still wrong, and the MSM appear to be getting a clue about that.
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ubrew12 at 05:42 AM on 12 March 2015Review of Climatology versus Pseudoscience
"The administration will not accept and use appropriately the findings and conclusions of the national and international climate assessments, and it hinders and even prevents the climate science program from doing so." Rick Piltz (2005) in a whistleblowing memo about how the GW Bush administration edited scientific policy reports to minimize mention of 'climate change'. And, a decade later, it is now out that Gov Rick Scott of Florida basically threatened to fire anyone in his administration, especially scientists and environmental officials, who used the terms 'climate change', 'global warming', or 'sea level rise' in official correspondence.
As success in exposing the Pseudoscience behind Climate denial has grown, we see increasingly that the denial industry has turned instead to outright 'behind-closed-doors' muzzling of policymakers and science experts. Even in the so-called 'Land of the Free'.
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scaddenp at 04:41 AM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
Ryland, at a very basic level, physics tells you adding CO2 to atmosphere will result in more heating of the surface, and to the tune of 4x the magnitude of the solar cycle. That to my mind is a gateway belief. Furthermore it a rate of change far faster (couple of orders of magnitude) than Milankovich cycle forcings. You move to models to try and sort out what that will mean, and yes, to help sort out how much of observed climate change is due to CO2 versus other factors, but I would still say the core concept is completely independent of GCMs. -
ryland at 04:31 AM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
Sorry KR I was addressing the "Gateway Belief Model" and in particular the finding by social scientists that suggests "perception of the expert consensus is a “gateway belief” that opens people to the acceptance of other important concepts." The paper to which I was referring could cause some to doubt the consensus which in turn could impact on the gateway belief and the "acceptance of other important concepts". I didn't think this was off topic
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Consensus and geoengineering - how to convince people about global warming
ryland - Basic physics and paleo studies tell us what the general expected results of forcing changes will be. Models are quite useful in investigating the speed of change and to some extent regional effects of those climate changes.
However, this thread is on consensus, geoengineering, and communication. If you have issues you would like to discuss with models and their capabilities, I would suggest taking it to the appropriate thread for that discussion.
Communicating the science to the public is not (or certainly not just) an issue of model perception, but rather a question of communicating how certain the experts are of the science, of the evidence, and of the best information on options and trade-offs regarding climate change. And that in the face of some rather extensive lobbying to confuse the issues...
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It's the sun
Dan Pangburn - The integrated imbalance is of great interest, and is perhaps best seen in ocean heat content changes that in fact tell what what the long term imbalances have been. But the direction of change is driven by the sign (and magnitude) of that forcing imbalance against the thermal inertia of the climate, hence the graph in the (Basic) opening post showing changes in solar forcing is indeed quite relevant.
However, I have to say that it's very unclear to me what your actual point(s) might be in this exchange. Are you arguing for a larger influence from solar changes than is generally accepted? Do you have an alternate graph to in your opinion better display the information already presented?
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wili at 02:31 AM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
Others more knowledgable than I can pitch in if they wish, but my understanding is that predictions of future GW are based on three things: Basic physics (the asborptions spectrum of CO2 and CH4...);
Paleo-climate studies (how the earth has responded to increases in GHG levels in the past); and
Climate Models of various sorts.
Pseudo-skeptics love to reduce this to the just the last, and usually just one of the last points, and then pick apart how one particular model has 'failed,' even though no model can be 100% accurate, or it wouldn't be a model--it would be reality.
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ryland at 02:19 AM on 12 March 2015Consensus and geoengineering - how to convince people about global warming
scadddenp@6. The paper is paywalled so this thinking reader doesn't have access. With regard to your statement "but they are the not source of the pronouncements on why human activity is causing climate change" is surprising. I had thought that it was only when CO2 concentration was factored in to the modelling the hindcasting by models matched the observations.
This is what Skeptica Science said "Testing models against the existing instrumental record suggested CO2 must cause global warming, because the models could not simulate what had already happened unless the extra CO2 was added to the model. All other known forcings are adequate in explaining temperature variations prior to the rise in temperature over the last thirty years, while none of them are capable of explaining the rise in the past thirty years. CO2 does explain that rise, and explains it completely without any need for additional, as yet unknown forcings". http://www.skepticalscience.com/climate-models.htm
I had thought the forecasts by models showing how much the global temperature will increase in the coming decades was the corner stone on which IPCC pronouncements such as the increasing likelihood of extreme weather events, were based. Is this not correct?
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Dan Pangburn at 01:50 AM on 12 March 2015It's the sun
Until you get the 'trivia' right, it's not a distraction.
A forcing must act for a period of time to have an effect on average global temperature (AGT). The forcing is not the difference between what it was at one time (1750) compared to what it is at another time (now). To determine the effect that a forcing has on AGT requires the time-integral of the difference between the forcing and the break-even forcing. If the forcing goes from .5 below break-even linearly to .5 above break-even during the time period, the time-integral for that time period is zero.
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billthefrog at 23:53 PM on 11 March 20152015 SkS Weekly Digest #10
@ OPOF
The current "interesting" state of sea ice extent is eliciting more than a few comments on the Arctic Sea Ice Blog.
Your "wait & see" advice is well made, as, by way of a cautionary example, between Day 68 and Day 80 last year, sea ice area (as measured by UIUC on Cryosphere Today) went up by 600k sq kms.
The corresponding numbers for Day 68 of 2015 were posted a few hours ago on CT.
cheers btf
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Kevin C at 21:57 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
A quick comparison with AR5 WG1 fig 9.07 shows that the affected list includes some of the weaker models (bcc, INM) and some of the best ones (CESM, EC-EARTH). So it doesn't seem to be an impactor of general model performance, although obviously INM has a lower time resolution which is likely to impact both.
Similarly the affected list includes the model with the equal lowest ECS and equal third highest. Also equal second lowest and highest TCR.
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Kevin C at 21:34 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
Oh yes. That's the kind of obvious error I can see myself making. But it's easily fixed.
The authors are primarily concerned with getting the problem fixed, and so don't investigate the impacts of the problem - they presumably wanted to get this published as fast as possible. However given that they give a list of affected models, it would be pretty simple to check whether the affected models show different behaviour from the unaffected ones, e.g. in 21st century temperature projections.
I'm afraid I'm to busy to take it on right now though.
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CBDunkerson at 21:27 PM on 11 March 20152015 SkS Weekly Digest #10
swampfoxh, no idea if it is the "best" source, but Google found this.
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scaddenp at 17:02 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
Well a thinking person might read the paper. It affects regional predictions. Furthermore, models give you a way to predict future climate which are definitely more skillful than assuming nothing changes or reading chicken entrails, but they are the not source of the pronouncements on why human activity is causing climate change. Modellers (and IPCC) will tell you plenty about issues that they would like improved in models, but the models have been shown to have skill as Chapter 9 of AR5 shows.
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ryland at 16:26 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
In the opening paragraph this comment is made " Convincing people to change their beliefs and leave their cultural group is a challenge with any polarized subject.". This is correct. However convincing people is hindered when reports that the models on which the IPCC bases much of its pronouncements, are reported to have a flaw in their assumptions on incident solar radiation (http://onlinelibrary.wiley.com/doi/10.1002/2015GL063239/abstract)
The thinking person, whatever "Team" they support, might wonder if all is as clearcut as is claimed.
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bozzza at 15:59 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
The only way to convince people is for the indicators they believe in to tell the story. People, and for good reason, are prone to disbelief and slow to be convinced that they need to change their minds. Advertising knows this and some advertising is more effective at persuasion than others.
All human relations is politics and it is the regulation of industrialisation that is the problem and solution. The sheeple consumer can't do much except wait for physical indication that there is indeed a problem that they feel morally obligated to use their consumer power to solve, such as the melting of the Himalayas, otherwise they know it's the Governments problem as they write the laws that allow it.
If the Government allows disinformation to be consumed by the voting public then they have every right to be convinced they aren't empowered to act as they have deliberately not been given the tools to make such a decision.
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