Arguments
Recent Comments
Prev 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 Next
Comments 30601 to 30650:
-
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).
-
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.
-
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.
-
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.
-
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.
-
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.
-
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
-
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.
-
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.
-
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.
-
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'.
-
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
-
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...
-
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?
-
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.
-
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?
-
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.
-
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
-
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.
-
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.
-
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.
-
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.
-
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.
-
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.
-
One Planet Only Forever at 12:52 PM on 11 March 20152015 SkS Weekly Digest #10
wili,
Related to Romm's post and the El Ninoish condition that has developed and may continue through the spring, the current Arctic sea ice extents here appear to be starting to decline early. However, as with any near term climate matter 'wait and see'. A few other years have had similar early dips followed by regrowth of sea ice extent.
-
One Planet Only Forever at 12:33 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
I like Andy Skuce's presentation/rebuttal regarding geoengineering (which is like Naomi Klein's views on geoengineering in her book "This Changes Everything").
Unlike an airbag, there is no way to test and prove that any geoengineering action would be as beneficial as hoped and would cause no harm anywhere to anyone, just making things sustainably better for all. And those 'solutions' would be abused to excuse making a bigger problem for future generations. And the lack of action to reduce the real problem because of 'faith' in those potentially damaging 'solutions' would potentially have massive disasterous consequences if they were implemented then briefly unable to be continued. And a 'desire to enjoy your life in ways that make problems for others because you can get away with it' is one of the least acceptable attitudes that has ever developed.
The thoughtless application of science just for the unjustifiable short-term personal benefit gained by a few is not just unacceptable, it can be incredibly damaging.
-
One Planet Only Forever at 12:10 PM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
wili,
I share your preferece for a different comparison to geoengineering. However, with all the recent airbag recalls because they did and could kill rather than save, the 'airbag with that clarification' would be appropriate.
-
swampfoxh at 07:44 AM on 11 March 20152015 SkS Weekly Digest #10
Anyone:
Where is the best information on the Gulf Stream? I'd like it for a class this Friday in Virginia. Current flow rate (in Sverdrups), historical flow rates and trends, ancillary effects, theories, peer reviewed publications, effects of El Nino or La Nina events, other thermohaline circulation factors, of note, affecting the Gulf Stream, etc
Thank You
-
swampfoxh at 07:33 AM on 11 March 20152015 SkS Weekly News Roundup #10B
Anyone:
What are some of the better sources of valid information on the current and medium history (say, 25-30 years) of the Gulf Stream, flow rate in Sverdrups, pattern of the flow, assessments of the causes of changes, etc.?
-
swampfoxh at 04:59 AM on 11 March 2015New Series: Science Communicators – Why We Love Communicating Science
chriskoz,
Twenty years of fying the worlds oceans and continents (except Antarctica) and noticing the changes would take a book, but let me describe one example: On December 15, 1993, (very early winter), I ferried an aircraft from St Johns NFL to Cherbourg France. The North Atlantic from St Johns to Shannon IRE was populated with tens of thousands of icebergs the size of tractor trailers. On February 2, 2012, (quite late winter), I ferried an aircraft from St Johns NFL to Nottodden, Norway via Narsasuraq, Greenland, then Rejkavik, Iceland and on to Norway. There were NO icebergs in that route structure until I arrived approximately 70 miles south of Narsasuraq, Greenland. Between about 50 miles south-east of Greenland on the way to Iceland there were NO icebergs in that part of the North Atlantic.
Regards,
-
wili at 02:41 AM on 11 March 20152015 SkS Weekly Digest #10
Thanks for the El Nino updates.
Romm just posted something on likely increases in rates of warming: thinkprogress.org/climate/2015/03/10/3631632/climate-change-rate/
-
wili at 01:49 AM on 11 March 2015Consensus and geoengineering - how to convince people about global warming
All analogies are imperfect, of course. But comparing geoengineering to an airbag seems particularly inappropriate. If it is one, then it's one that has never been and can never be accurately tested before the crash.
So if it's an airbag, it's one that we're not sure, when activated, whether it will actually do much at all toward cushioning the blow, or whether it will rather smother us, or perhaps it is filled with deadly spikes that will eviscerate us.
We just don't know for sure.
And preliminary studies are not particularly hopeful (unless you only listen to the 'airbag' salesmen). -
Tom Curtis at 01:33 AM on 11 March 2015Ivar Giaever - Nobel Winning Physicist and Climate Pseudoscientist
Ivar Giaever:
"But in 2008 I was in a panel here about global warming and I had to learn something about it. And I spent a day or so - half a day maybe on Google, and I was horrified by what I learned."
Nephre @70:
"The truth is, that the true science is being discerned by collections of disciplines that include physicists, chemical engineers, biologists, and so on. So the idea of summarily attempting to invalidate the credibility to reason of someone ... is just shit."
I don't no about you, but I think spending just half a day (or perhaps a whole day) googling a topic, and then using the results of whatever blog posts you found in that google search to dismiss the work of thousands of scientists is an excellent example of "summarily attempting to invalidate the credibility of someone". So if Nephre is consistent (which they won't be) they will consider Giaever's foray into climate science as "just shit".
Well who could disagree with that assessment?
What is more important, however, is that the OP did not "summarilly attempt to invalidate" Giaever. Rather, it went in detail through the claims and in detail rebutted them. And the rebutals were not based on half a day on google, but (given that the author was Dana) a detailed knowledge of climate science built up by years reading climate science papers, IPCC reports, books and (I am sure) the occasional blogpost. The fact is that on Climate Science, Giaever by his own admission is completely inexpert. He lacks relevant domain knowledge and familliarity with the relevant literature. Dana can reasonably claim to be an expert on the topic. Nephre, however, is quite happy to summarilly summarily attempt to invalidate the credibility to reason of someone whose boots they are unlikely be able to fill themselves, without for a moment actually engaging with the relevant evidence.
We know what Nephre's conclusion would be - if there were any consistency in their reasoning. Unfortunately there is not. It is just more pointless denier crap.
-
Tom Curtis at 01:16 AM on 11 March 2015It's the sun
Dan Pangburn @1108:
1) ΔQ is actually average rate of change of heat content per unit area. That means all units on the right hand side are in terms of Watts per meter squared, and on the left hand side the units are Degrees Kelvin times Watts per meter squared per degree Kelvin = Watts per meter squared. I apologize for the mistatement. My mistatement in no way, however, justifies your failure to account for either OLR or ΔQ in your formulation.
2) Forcing is by definition "...is the change in the net, downward minus upward, radiative flux (expressed in W m–2) at the tropopause or top of atmosphere due to a change in an external driver of climate change, such as, for example, a change in the concentration of carbon dioxide or the output of the Sun" (AR5). As the forcing is a change, it must be specified relative to a particular index time. By convention, and by specification in AR5, that time is 1750. It can, however, be any time. There is no need for it to be the start time of any given period. Ergo, your definition of "break-even" is satisfied by my examples on condition that ΔQ = 0 at the initial point.
That, however, is entirely a distraction. My example can be easilly reworked so that the forcing in Scenario A is 0, that in Scenario B it starts at - N, and ends at + N, with a linear trend throughout, and so that in Scenario C it starts at + N and ends at - N, with a linear trend throughout. Once N, and the duration is specified, the logical consequences are the same. That, I believe is self evident so I wonder why you are distracting with irrelevant (and fallacious) trivia rather than actually trying to deal with the argument.
-
Nephre at 01:15 AM on 11 March 2015Ivar Giaever - Nobel Winning Physicist and Climate Pseudoscientist
Kind of interesting: The clear evidence that the writer of this article is a pseudo-climate-scientist ... or even just a pseudo-scientist is the use of an ad hominem attack against Ivar. It gets worse immediately because Ivar's credibililty as a thinker is attacked. Is it not understood that "climate science" is not the product of a University-awarded degree in "climate science?" Indeed, when you hear the neighbor's kid is getting his undergraduate degree in "climate science" don't you role your eyes (at least to yourself)? I do, because if there is one very likely scam degree it would be one so named - "climate science." The truth is, that the true science is being discerned by collections of disciplines that include physicists, chemical engineers, biologists, and so on. So the idea of summarily attempting to invalidate the credibility to reason of someone whose boots you are unlikely be able to fill yourselves is just shit. Sorry. By doing so, you really just smeared feces all over your own petty faces. You can't make the data go away and the data is the basis of reasoning if you pretend to science at all. Instead, by using ad hominem is the opening, and then pretending that the complexity of the data "goes your way" you simply undermine your own blog. I can't help you there.
Moderator Response:[DB] Fake ad hominems and inflammatories struck out.
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 submit offensive or off-topic 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.
-
Dan Pangburn at 00:38 AM on 11 March 2015It's the sun
Tom - It appears that your equation has forcing, in Joules per sec (aka watts) subtracted from energy, in Joules. That would be like subtracting your speed in mph from your distance traveled, in miles.
Perhaps it is unclear that the beginning and ending temperatures are the same in the definition of break-even. Given that requirement, the time-integral of the forcing from beginning to end must be zero. Then each of the periods A, B, and C must (by definition) begin and end at the same temperature and the time-integral of the forcings for each of them must all also be zero.
This has only to do with the meaning of the word 'forcing' as used in discussing climate change.
-
Summary of climate change impacts
uncletimrob - It's very good to hear that your students are becoming more aware of the issues.
I would suggest that if interested you go to the IPCC reports (the most recent AR5 here) and read through the individual sections 'Summary for Policymakers' for overviews of the science, impacts, mitigation, etc. Those are written for non-experts, and present a good layout of what we know. Follow up with the 'Technical Summary' for any report you have more detailed interest in.
As an example, here's Figure SPM.2 from AR5 WGII showing the distribution of climate change impacts:
-
uncletimrob at 17:44 PM on 10 March 2015Summary of climate change impacts
Thanks for this post. Some of those high level reports are heavy going so I am reluctant to recommend them to my (high school) students. Your post is a good summary that I am more than happy to add to the recommended reading list. Slightly off topic but I'm getting more enquiry about AGW from my students than I have in the last few years. I have a science background but not in climate science so summaries like this are good for me too!
Tim
-
Tom Curtis at 06:48 AM on 10 March 2015It's the sun
Dan Pangburn @1106:
1) Your formulation ignores Outgoing Longwave Radiation (OLR), which is to a close approximation a linear function of Global Mean Surface Temperature (GMST). You also ignore change in heat content. Specifically:
αΔT = ΔQ - ΔF,
where ΔT is the change in temperature, ΔQ is he change in heat content, and ΔF is the change in forcing, and α is the climate feedback parameter, ie, the change in OLR in Watts per meter squared per unit change in temperature in degrees Kelvin. (The climate senstitivity parameter should not be confused with the climate sensitivity factor, λ, which is 1/α.)
Because OLR is a function of temperature, you can in theory have identical forcing histories with different temperature histories and end up with a different final temperature as a result. Ergo, your concept of "break-even" is undefined. There is no unique integral of forcing history such that given that forcing history the temperature will always be the same at the initial and final points of the period of integration.
2) Ignoring point (1), if your analysis is correct, then if we have a period, t, over which we have an integral of forcing, then we also have two non-overlapping periods of lenght t/2 in which the same reasoning applies.
Now consider three possible forcing histories, each with the same integral of forcing. In history A, forcing is constant over the full period at "break even". In history B, forcing stars at half of the level in history A, and increases linearly to 1.5 times the forcing in history A. In history C, forcing is the mirror image of history B, starting high and ending low. In each case, the integral of forcing over the full history is identical, and at break even.
Given your reasoning, however, the integrals of forcing for the first half of t are 0.5, 0.375 and 0.625 for A, B and C respectively, treating the forcing integral over the full period as being 1. Conversely, the integrals over the second period are 0.5, 0.625 and 0.375 respectively. Ergo, according to your reasoning, temperatures will stay constant in history A, initially fall, and then rise in history B, and initially rise and then rise in history C. Ergo, according to your theory we can distinguish as to whether a given forcing is an adequate account of a temperature change by tracking not just the integral, but the integral over subunits of the total time.
Indeed, according to your theory, if we make the subunits the smallest value for which we have clear resolution of the data, temperatures over those subunits should track the integral of forcing over those subunits. In fact, ignoring noise, if a given factor is the dominant forcing, temperature should track the actual forcing with high correlation.
But, of course, temperature does not track TSI with high correlation. That is why you introduced your theory to begin with. Ergo, your theory actually disproves your contention unless you deliberately avoid applying it critically. That is, your argument only looks good by avoiding detailed analysis.
-
scaddenp at 06:09 AM on 10 March 2015The oceans may be lulling us into a false sense of climate security
I think the ocean cycles are quasi-periodic and thus do not have the predictability which would allow prediction of when they would next reinforce.
-
william at 04:53 AM on 10 March 2015Does providing information on geoengineering reduce climate polarization?
The danger of discussing geo-engineering is that the public will then think they have a get out of jail card. We can continue to pollute - no need for developing renewable power supplies because the engineers will come up with a solution. Even supposing that we could find a solution, what happens at the next economic chrisis when geo-enginering is the first item to be cut. Doesn't bear thinking about.
-
william at 04:48 AM on 10 March 2015The oceans may be lulling us into a false sense of climate security
Presumably, if the authors have a handle on the periodicity of these two waves that influence climate, they should be able to predict when will be the next time that they reinforce each other in the warming direction for the climate.
-
David Kirtley at 02:57 AM on 10 March 2015Summary of climate change impacts
Good post, Anders. You (and SkS readers) may be interested in the series of posts I did at Global Warming Fact of (the Day last May on the impacts of climate change. I also used the WG II report as a rough guide to specific impacts around the globe.
-
Dan Pangburn at 00:23 AM on 10 March 2015It's the sun
KR - To have an effect, forcings, must exist for a duration. The time-integral of the forcing accounts for both a variation in magnitude and the duration.
Break-even is defined (by me) as the constant net forcing that would result in the same average global temperature (AGT) at the end of a duration as existed at the beginning. For example, the duration could start at some time during the MWP and end at a more recent time when the AGT was the same.
If net forcing exceeds break-even, AGT will rise (AGT at the end of the duration will be higher than it was at the beginning) or if it is less than break-even, AGT will decrease. (Break-even is not the static (steady-state) solution to a dynamic heat transfer problem)
The net (or total) forcing is the algebraic sum of all constituent forcings. The constituent forcings could each vary but the algebraic sum of the time-integrals of the individual constituents is the same as the time-integral of the algebraic sum of the constituents (for the same time period).
The time-integral of the algebraic sum of the constituent forcings is the energy change of the planet (for the duration of the forcings) and the energy change divided by the effective thermal capacitance (sometimes called thermal inertia) of the planet is the AGT change (during the time period).
If TSI is considered to be one of the constituent forcings, then its effect on AGT (as one of the constituents, its contribution to the total AGT change) is determined by its time-integral. To be conceptually correct, when on the same graph, the time-integral of TSI is the correct metric for comparison with AGT change.
-
CBDunkerson at 22:47 PM on 9 March 2015There's no empirical evidence
Talvar is almost certainly referring to data from the Swarm satellites which recently showed that magentic field strength was changing ~10 times more rapidly than expected over a six month period. The expected rate, based on research suggesting that a magnetic pole reversal is underway, was approximately 5% per century... multiplied by ten yields his 5% per decade. However, as noted, that is based on six months worth of data from a new system. There is no evidence whatsoever that this has been going on for a long time as he implies.
Further, it just isn't relevant because this cannot "very easily account for elevated temperatures". To my knowledge no one has even suggested a mechanism to explain how variations in the Earth's magnetic field would cause massive planetary warning. If anyone ever tries they will have a fun time explaining why there seems to be no connection between the pattern of magnetic variation and the pattern of warming... e.g. during that six month period the magnetic field over the entire North America continent actually strengthed greatly (that change being offset by declines elsewhere around the globe), yet the western part of the continent was warmer than normal and the eastern portion colder.
-
Talavar at 16:08 PM on 9 March 2015There's no empirical evidence
I find it rather odd that nobody ever brings up the fact that our Magnetosphere has been steadily weakening during all of this "climate change" nonsense.
It has been weakening by 5% per decade, this could very easily account for elevated temperatures and erradic weather patterns. Just food for thought.Moderator Response:[PS] Please substantiate your claim of 5% per decade and that this has only started happening over period of global warming, and how a weakening magnetosphere can warm the earth. Unsupported claims are sloganeering and violate comments policy.
Further - if you are linking to Svensmark cosmic ray hypothesis, then please see here for what the science has to say about this
-
One Planet Only Forever at 06:05 AM on 9 March 2015The oceans may be lulling us into a false sense of climate security
Rob P, The Kelvin wave appears to be significant and has grown since the Mar 4 image you shared in response to the first comment. It will be interesting to see what ultimately develops. It will also be interesting to see if the SOI values grow more suportive of El Nino. The Prelimiary SOI values here indicate that the SOI may be returning to steady negative values. Time will tell.
Also, a further clarification of my comment about the Australia Bureau of Meteorology ENSO forecasts of last year compared to this year. The history of their ENSO Tracker levels is here. The February 2014 level was El Nino Watch. The February 2015 level was El Nino Neutral. The current ENSO Tracker level on the most recent ENSO Wrap-up here has reterned to El Nino Watch
-
Jim Hunt at 03:45 AM on 9 March 2015Arctic sea ice has recovered
Re @73 & @74 - A whole range of Arctic sea ice metrics, now including Cryosphere Today area and DMI extent, are currently at their lowest ever levels for the date in their respective historical records:
-
One Planet Only Forever at 01:45 AM on 9 March 2015The oceans may be lulling us into a false sense of climate security
Regarding my previous point about how the El Nino season of 2014 started not beaing an indication of how it will develop, I was referring to the strong SOI values in early 2014 whish are often precursers of a developing El Nino. THe SOI history is here. In the SOI history the March value was strongly negative at the time of the season an El Nino condition has historically been seen to begin. That SOI was very short lived and the ONI never reached +0.5 C. However, the Australia Bureau of Meteorology ENSO forecasts for 2014 were for a higher probability that an El Nino would develop in 2014 than they are currently indicating for 2015 (current report is here).
Moderator Response:[Rob P] - Current status of the Kelvin wave making its way east across the equatorial Pacific Ocean...
Prev 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 Next
