Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: watsisname on September 30, 2013, 01:53:59 pm
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It has been six years since AR4, and the IPCC's latest Physical Science Basis Report (http://www.ipcc.ch/report/ar5/wg1/#.Ukt3QBATmZk) on climate change is now available. Note this is the final draft, so there are a lot of figures to be added and presumably an aesthetic pass to make it less eye-unfriendly. It is also over 2200 pages long, so the summary for policy makers is recommended for those who don't want to dive into what is basically a textbook the size of Texas.
Some big points:
-Warming of the climate system is unequivocal, and is evident on land, sea, troposphere, and by ocean heat content. (I add that observed changes in the upper atmosphere are also consistent with this.) There have been many climate changes throughout Earth history, but as far as we know there was never one with the rapidity that we are seeing now. This isn't surprising; atmospheric greenhouse gas concentrations have never changed this rapidly.
-The human influence on current climate change is clear. It is extremely likely that human activity has been the dominant cause of the observed warming since the mid-20th century. (Note: ‘extremely likely’ means 95 to 100% confidence). This is an increase from the ~90% confidence level in AR4.
-Globally averaged land/ocean surface temperature, calculated by linear trend, shows a warming of 0.65 to 1.06°C, median of 0.85°C, since pre-industrial times. As far as the goal of keeping temperature rise below 2°C goes, we're almost half way there by temperature, and a lot closer than that by emissions / time-frame.
-Slight change in estimates of climate sensitivity. The new range is 1.5 to 4.5°C temperature rise for a doubling of CO2, compared to the previous estimate of 2 to 4.5°C, with the most likely value unchanged at 3°C. This reflects new estimates across the lower range of sensitivity. Also, the likelihood of values below 1°C and above 6°C have been cut dramatically. Contrary to some media claims; 1.5°C as the new lower bound should not be reassuring -- it still yields >2°C temperature rise by 2100 across a broad range of emissions scenarios. This level of warming is unacceptable by international agreement. The upper limit of 4.5°C for sensitivity is also just as likely as the lower limit, and under the same emissions scenarios would be disastrous for us.
-Evidence of changes in extreme weather: daily max/min temps, heavy precipitation events, heat waves, etc. Nothing too surprising here since AR4/SREX.
-Ocean warming accounts for >90% of energy accumulated in the last 3 decades, with 60% being in the top 700 meters.
-It is about as likely as not that rate of heat uptake in oceans was slower in the last decade than the one prior, but it is unlikely that there was any change in the lower layers, where interannual variability is smaller. What this means is that media reports of global warming having slowed down or paused this last decade are not supported by evidence. What is happening is a slowdown of surface/tropospheric temperature rise as heat is being transferred to the deep ocean, combined with reduced solar luminosity during this deep solar minimum. Similar slowdowns, and speedups, can be seen in the past, and will continue in the future, and are simple consequences of natural variability.
-Ice sheets globally are losing mass, and it is very likely that the Greenland Ice sheet’s mass loss rate has accelerated. It is likely that the Greenland Ice Sheet will disappear, on a timescale of millenia, if global temperature rises above some threshold between 1 and 4 degrees warmer than pre-industrial levels. What this means is that we may find ourselves being committed to the irreversible loss of Greenland's ice, and the many meters of long term sea level rise that comes with that, if we do not act very soon.
-There is high confidence that climate change is affecting permafrost, leading to increased polar methane emissions. This is quite a nasty feedback effect, as methane is a very efficient greenhouse gas.
-There are many lines of evidence showing substantial Arctic warming since the mid 20th century, in agreement with climate model predictions and the ice-albedo feedback effect.
-Quantification of sea level rise and updated projections for the future.
-Improved climate modelling since AR4, and with greater spatial resolution. (woo!)
-The net climate feedback from all types of clouds is likely positive. (I thought this was a little surprising).
-Improved understanding of carbon cycle feedbacks.
Much more.
edit: Huh, I thought I had put a link to the report in this post. Fixed.
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many meters of long term sea level rise that comes with that, if we do not act very soon.
gg coastal cities
Better move inland.
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-The human influence on current climate change is clear. It is extremely likely that human activity has been the dominant cause of the observed warming since the mid-20th century. (Note: ‘extremely likely’ means 95 to 100% confidence). This is an increase from the ~90% confidence level in AR4.
The IPCC is hoping that if they shriek more loudly, more people will pay attention to them. It isn't working because no matter how you dress something up with fancy academic language and impressive statistics, you can't cover up observable reality.
The global warming charade is already crumbling. Another decade should suffice to put a stake through the heart of it.
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Observable Reality (http://www.ncdc.noaa.gov/indicators/)
I dunno, maybe you don't live on Earth or something.
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I hope (assume) that was sarcasm?
Been reading some of the watered down versions of this, about to dive into the full version in my physical climatology class. Kinda excited. Yay science. Bad Climate change. On a random note a found it entertaining that I had to ask a chem prof why methane was a much better (as in worse for us) greenhouse gas than say CO2 instead of my Climatology prof. It makes sense, just unexpected
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The IPCC is hoping that if they shriek more loudly, more people will pay attention to them. It isn't working because no matter how you dress something up with fancy academic language and impressive statistics, you can't cover up observable reality.
The global warming charade is already crumbling. Another decade should suffice to put a stake through the heart of it.
Soooo
Do you have actual data to back that up?
Also, "fancy academic language"? Really? That's a reason to dismiss findings now?
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Soooo
Do you have actual data to back that up?
Also, "fancy academic language"? Really? That's a reason to dismiss findings now?
If there's nothing to back it up, fancy language is just hand-waving.
Read this (http://dailycaller.com/2013/09/29/top-mit-scientist-un-climate-report-is-hilariously-flawed/), for instance:
“I think that the latest IPCC report has truly sunk to level of hilarious incoherence,” Dr. Richard Lindzen told Climate Depot, a global warming skeptic news site. “They are proclaiming increased confidence in their models as the discrepancies between their models and observations increase.”
And...
The I.P.C.C. also glossed over the fact that the Earth has not warmed in the past 15 years, arguing that the heat was absorbed by the ocean.
“Their excuse for the absence of warming over the past 17 years is that the heat is hiding in the deep ocean,” Lindzen added. “However, this is simply an admission that the models fail to simulate the exchanges of heat between the surface layers and the deeper oceans.”
The fact is that the predictive models of the IPCC and other organizations are simply flawed, with their predictions failing, or being retracted, in a spectacularly laughable manner (viz. the claim that the Himalayan glaciers would disappear by 2035). And there are flaws in the process itself, as revealed by the various Climategate leaked emails.
Feynman is turning over in his grave.
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Goober here seems to be testing the limits of Poe's Law, yet I can't help shake the feeling he is actually being serious...
On a random note a found it entertaining that I had to ask a chem prof why methane was a much better (as in worse for us) greenhouse gas than say CO2 instead of my Climatology prof. It makes sense, just unexpected
I've been curious about that yet never looked it up -- I mean I know greenhouse gases tend to be molecules with dipole moments, such that they have vibrational modes that correspond to infrared wavelengths, but why one molecule is so much better at absorbing/transmitting than another is unknown to me. What'd your professor say?
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Ahah I think this thread is gonna be hilarious. I am slightly inclined to agree with Goober, although I'm not going all the way with the same rethorical tone. I do think the IPCC is in some pains to explain why we are simultaneously even more sure than in 2007 that we know what is the case when in fact all the models have almost failed miserably to produce the slowdown of the past 20 years in warming. Any Bayesian-like minded folk would be "huh?" on that one.
My favorite blog post so far on this work has been, however, Judith Curry's:
My original intention for this thread was to go through and try to map the IPCC’s logical argument. I quickly got dizzy owing to seemingly unwarranted assumptions and incomplete information (such as: did the climate models use the correct external forcing for the first decade of the 21st century, or not?). I was then going to illustrate how any reasonable propagation of uncertainty of individual assertions/arguments through their main argument would produce much lower confidence in their overall conclusions. For example, they seem to have eliminated high CO2 sensitivity as a problem. Not to mention high confidence in increasing trend following 2012 (this high confidence comes right after blowing the prediction of the previous decade). And of course not to mention the relevant journal articles that didn’t get mentioned.
Apart from these obvious flaws, reading that text and trying to follow it is positively painful. Can someone remind me again how and why all this is supposed to be useful?
http://judithcurry.com/2013/09/30/ipccs-pause-logic/
Go read it, it has a direct quote from the IPCC on the "pause". It's amazingly long and inhumanly written! It's as if they don't want no one on their right mind to read it and actually understand it.
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Goober here seems to be testing the limits of Poe's Law, yet I can't help shake the feeling he is actually being serious...
On a random note a found it entertaining that I had to ask a chem prof why methane was a much better (as in worse for us) greenhouse gas than say CO2 instead of my Climatology prof. It makes sense, just unexpected
I've been curious about that yet never looked it up -- I mean I know greenhouse gases tend to be molecules with dipole moments, such that they have vibrational modes that correspond to infrared wavelengths, but why one molecule is so much better at absorbing/transmitting than another is unknown to me. What'd your professor say?
Nevermind that the methane "problem" isn't a problem whatsoever and that methane levels aren't going anywhere. The IPCC itself doesn't regard it as a big issue as well. (But I guess being against the mainstream is only "bad" if you do it in one predetermined direction!)
I must also congratulate the IPCC for getting the science right in what comes to the issues of extreme weather events and the non-observed link between them and global warming. They were already right in 2012 in their interim report on the subject matter and they continue to do so, despite all the rantings of activists and pseudo-scientific bloggers who still make these silly proclamations today.
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i dont really care. if we get another good summer like this last summer keep ****ing up the environment. its an improvement for me.
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My original intention for this thread was to go through and try to map the IPCC’s logical argument. I quickly got dizzy owing to seemingly unwarranted assumptions and incomplete information (such as: did the climate models use the correct external forcing for the first decade of the 21st century, or not?). I was then going to illustrate how any reasonable propagation of uncertainty of individual assertions/arguments through their main argument would produce much lower confidence in their overall conclusions. For example, they seem to have eliminated high CO2 sensitivity as a problem. Not to mention high confidence in increasing trend following 2012 (this high confidence comes right after blowing the prediction of the previous decade). And of course not to mention the relevant journal articles that didn’t get mentioned.
Apart from these obvious flaws, reading that text and trying to follow it is positively painful. Can someone remind me again how and why all this is supposed to be useful?
http://judithcurry.com/2013/09/30/ipccs-pause-logic/
Go read it, it has a direct quote from the IPCC on the "pause". It's amazingly long and inhumanly written! It's as if they don't want no one on their right mind to read it and actually understand it.
Sounds like Ms. Curry is really struggling to comprehend it. I haven't a clue why; it's really quite simple:
-Large volcanic eruptions provide a negative forcing. There have not been many large eruptions lately, so this is not an important factor to the 'pause'.
-Solar luminosity has been lower than average during this deep solar minimum -- this is a negative forcing.
-Internal variability accounts for much of the rest -- decadal cycles of heat transfer between the atmosphere and oceans.
-Put it all together (http://iopscience.iop.org/1748-9326/6/4/044022/pdf/1748-9326_6_4_044022.pdf), we find that global warming has not paused, just as I said in the OP. Such slow-downs, and speedups, are an expected phenomenon. You can see them in the past and they most assuredly will continue in the future, with the underlying trend being that of ongoing warming for as long as radiative forcing continues to be enhanced.
A blog commenter also pointed out this passage:
“However, it is very likely that the climate system, including the ocean below 700 m depth, has continued to accumulate energy over the period 1998–2010 (Section 3.2.4, Box 3.1). Consistent with this energy accumulation, global-mean sea level has continued to rise during 1998–2012, at a rate only slightly and insignificantly lower than during 1993–2012 (Section 3.7). The consistency between observed heat-content and sea-level changes yields high confidence in the assessment of continued ocean energy accumulation, which is in turn consistent with the positive radiative imbalance of the climate system (Section 8.5.1; Section 13.3, Box 13.1).
Bad Astronomer Phil Plait has an excellent commentary on this as well. (http://www.slate.com/blogs/bad_astronomy/2013/09/26/climate_change_denial_james_delingpole_tells_it_like_it_isn_t.html)
Nevermind that the methane "problem" isn't a problem whatsoever and that methane levels aren't going anywhere. The IPCC itself doesn't regard it as a big issue as well. (But I guess being against the mainstream is only "bad" if you do it in one predetermined direction!)
Thankfully, rising sea levels are actually helping to stabilize oceanic methane clathrates despite the warmer temperatures, but high latitude and shallow sea methane sources are at risk and expected to be an ongoing source of enhanced radiative forcing, as the IPCC report discusses, particularly in section 12.5.5.5. The actual concentration of methane is also not the only metric of its global warming potential, as it has very important disequilibrium chemistry associated with it which has other effects on climate. See 8.2.3.3 for more information.
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Aw, ****. I had a big long post explaining it and my mobile browser ate it. Le sigh. Will redo it later
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I don't doubt that there is a potential for anthropogenic climate change. Hell, I'd be willing to concede that it even is most likely the case.
However, I do have to take a slight issue with the general methods employed by the study (I have not read the study directly, but I have gone over a summary on Ars Technica).
Claiming to have data on temperature variance over the whole surface of the earth dating back to 1901 is a very bold claim, and one that I am instinctively inclined to doubt. Climate data from most land areas? Sure, I can believe that. But claiming knowledge of temperature variance in ocean areas is something I find very hard to accept, especially if this supposed data reaches back over a century.
I could go on with some other procedural issues I have with a lot of "high-visibility" climate studies, but I think I'd betray my relative ignorance in the field. To be clear, I don't patently doubt the underlying thesis of climate change. Rather, I am skeptical of some specific claims and I feel that highly rigorous data collection (grid of temperature stations across the whole earth's surface f.ex) would make me personally a lot more comfortable with the claims.
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We obviously do not have a complete global grid of temperature measurements before the satellite era. So a lot of work has to be done to produce a global temperature dataset, involving the use of the instrumental data that we do have, plus a wide range of proxies. From this we can reconstruct global temperatures from now to thousands and even hundreds of thousands of years ago, and these reconstructions are remarkably reliable. The thermal history of the oceans can also be determined through a range of methods.
Also note that the IPCC is not performing original research; they are reporting a synthesis of all available climate studies. You may think of it as being like a huge literature review, the most extensive of any scientific field.
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Phil Plait hasn't had any good commentary on the climate discussion for years now. He's a rabid blogger with pals such as Michael Mann and John Cook as his primary sources. Anyone who quotes Sceptical Science as a source isn't credible in my book (and I would think everyone would agree by now, ever since their debacle over the 97% idiotic study and the Lewandoski affair, etc.)
And yes, I'd say that those paragraphs are indeed terribly written and if one is a bit cynic one would even say it's designed to be that way. I was obviously exagerating, it is possible to read them. The conclusion that the system hasn't stopped warming is inane, and it merely encompasses the very ad hoc method of changing one's parameters and metrics to get the foregone conclusion one begins with. They went on looking for the missing heat everywhere and alas they found it. Statistics are awesome like that.
I also noticed that the usual GW deniers' arguments of "climate variability", "PDO" and so on are now embebbed within the IPCC analysis as reasons for why the warming paused. Not even a hint that the warming of the nineties might have been caused by a symmetric variation, nor a recognition that perhaps this argument isn't as inane as we've been told icessantly through the years as "denier myths" and so on. It only seems to work one direction.
The written sentence that was required of the scientists to take out for political reasons, the one that mentioned that the reasons for the pause were more or less unknown is the real truth that is missing here. It's also missing some good papers from last year (and this one) that mention one of the biggest hypothesis for the current pause: a slower sensitivity than was previously thought.
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Phil Plait hasn't had any good commentary on the climate discussion for years now. He's a rabid blogger with pals such as Michael Mann and John Cook as his primary sources. Anyone who quotes Sceptical Science as a source isn't credible in my book (and I would think everyone would agree by now, ever since their debacle over the 97% idiotic study and the Lewandoski affair, etc.)
I see you pathologically dismissing any information that doesn't conform with your world-view, Luis, and not providing much in the way of a refutation of the material I have posted which is based on evidence and links to journal articles.
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I do read Phil's blog posts, and they are always about whamming the deniers' most derpish comments, instead of providing an actual informed and nuanced discussion over these matters, which are I think, quite important to be debated in the whimsical polarized and idiotic manner that Phil is all too happy to provide. He lives in a world where science is being fought by rabid GOPers and fundamentalist christians, either by creationist ideas or anti-vaxxers or moon hoax believers and because of this "experience" he really reads like someone who thinks his usual DEBUNK! EXPOSE! DENOUNCE! hammer works on every problem.
It does not, and the climate is the one issue where his discussing methods really fail spectacularly.
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Your dislike of Phil Plait's blogs is noted, but you still haven't tackled the argument, let alone provide evidence or sources to back yourself up.
Come on, Luis, you're an intelligent individual with an obvious scientific orientation. We're looking at global warming, and noting that over 90% of the thermal energy added to the system ends up in the oceans. So if the claim is that global warming has slowed down, paused, or whatever you call it, is true, then why is the ocean's heat content still increasing, with the associated ongoing thermal expansion? What is wrong with the physical explanations for the differences in radiative flux and energy transfer between the different earth systems? Why does an examination of global temperature, when accounting for these factors, yield the continued and unabated signal expected under standard global warming theory? What is the cause of the other decelerations and accelerations observed in the last century of global temperature?
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Take 2, this time with laptop.
@ Scotty:
So It sounds like you have a solid grasp of science so I can explain this well I believe. I apologize if this comes off as lecturing or goes over what you already know, both are tendencies I have when explaining things. I will be using Methane and Carbon Dioxide for this explanation.
Structure
First keep in mind the geometric structure of each of these molecules. CO2 is linear due to having two double bonds, and CH4 is tetrahedral. (diagram 1 on attached pic illustrates the structures both as bond line drawings and in their correct 3D orientation). It is important to keep in mind that in CO2 the pi bonds restrict rotation around the axis as well as making the bond shorter and stronger.
Vibration States
We draw molecules as unmoving, but in reality the bonds constantly move. Vibration states occur as a result of this natural proccess. (diagram 2 shows how vibration states work for carbon dioxide). They stretch and bounce around. In order for energy to be absorbed the molecule must have a dipole (I'm not 100% sure why this is yet, but as a wild guess, I would say that having a dipole means concentrated electrons and exciting the area with light has a higher chance of hitting all/most of the electrons). Neither CH4 or CO2 have natural dipoles, but as seen on diagram 2, the last two vibration states do have dipoles. The first occurs due to "asymmetrical stretching" and the second by "bending". The number of vibration states is given by 3N-6, where N is the number of atoms. This only holds true in the case of molecules that do not have double bonds, they are modeled by 3N-5. So CO2 has 4 vibration states, and CH4 has 9 (To lazy to draw that many). As the number of vibration states increases, so do the number of dipoles. Each molecule and their dipoles can be excited only by a certain quanta of energy. This energy is modeled by lamda = (hv)/E. lamda is wavelength, h is planck's constant, v is frequency, and E is energy. The more vibration states exist, the more wavelengths can be absorbed (larger absorption spectrum). Same equation applies to emission. Note absorbed radiation is longwave. There is one more factor:
Concentration
As you know the concentration of CO2 is higher than that of CH4. The wavelengths that CO2 absorbs at are already "cluttered" with CO2 so to speak, at least in comparison to CH4. Increasing the concentration ([CO2]) has little impact (comparatively) on positive radiative forcing because some of the light at that wavelength is already taken in by existing CO2. Basically there is less light to excite CO2. This actually works on a log scale, you have to exponentially increase the concentration of CO2 in order to get continuously increasing positive radiative forcing (It should be noted this is what humanity is doing). On the other hand you have a lower concentration of CH4, and therefore more light is available for absorption by it. The end result is that slight increases in CH4 has a large impact on forcing. Additionally, CH4 stays in the atmosphere longer than CO2.
@Luis
And that is why CH4 is a problem. Both CO2 and CH4 are important and need to be controlled. A little bit of CH4 goes a long way. Additionally there is quite a lot of methane trapped in sinks all over the world (particularly in the northern latitudes) that (According to everything we know now) will release as a secondary feedback mechanism as a result of climate change.
I will add some more details and particularly numbers later tonight
[attachment deleted by ninja]
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Way to SCIENCE! :yes:
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(http://i.imgur.com/mzmGMUF.gif)
Thank you very much for that information Beskargam. Very interesting! :)
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HE WANTS TO DEVOUR MY SOUL!!!! :eek:
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Climategate
I'll just leave this here. It seems appropriate. (http://www.factcheck.org/2009/12/climategate/).
rest of post
and this too (http://www.examiner.com/article/koch-funded-study-finds-global-warming-is-real-and-humans-are-the-cause). The coffin has been shipped back.
Also, not sure if Goober is a) Poe's law, B) really into this, or C) Trolling us to get the best out of some of this forum's members, who have some splendid ways of explaining things.
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goober doesn't concern me, he's just being his reactionary conservative self and it's unlikely he'll ever change; it's luis whom i find worryingly evocative
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Luis has always expressed these kinds of views and failed completely to back them up with anything even remotely approaching science or even valid discussion techniques.
This (http://www.hard-light.net/forums/index.php?topic=82721.msg1651682#msg1651682) is a great example.
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I do recognize that criticism and take it. I do have very little time to peruse, list and aggregate the things I've been reading and the papers I've been exposed to regarding this issue. I do not ask anyone to believe what I say at face value and accept wholeheartedly that you in fact do not precisely for the lack of sources that I provide, etc.
I also notice that despite the recent requests for me to "back up" my criticisms to what has been said, what has been said in this thread is either non-controversial or irrelevant. I do accept whatsisname's lists of explanations for the pause but with the giant grains of salt that I mentioned. If you do not understand my criticisms or only accept them if they have the seal of peer-review approval that is your problem, not mine.
I just leave this here and then leave to work: the IPCC does indeed ignore one very big hypothesis for the pause, which is about the sensitivity of CO2 being lesser than the one they calculated before. Innumerous papers have been claiming this for the past year and two (I am indeed sorry for not providing them), and I have yet to find any answer to Nic Lewis' really relevant criticisms for the IPCC's wrongheaded bayesian analysis of the models and the CO2 sensitivities, which when properly corrected takes a big bunch of the warming out of the picture (even reaching values below 2.0º). See here his relevant paper: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00473.1
I haven't found a non-cryptic answer to this perhaps because I haven't had the time to find it. That is indeed possible.
e: (Oh and of course then there's the social phenomena of this: http://www.sfgate.com/technology/businessinsider/article/Meteorologist-Breaks-Down-In-Tears-After-Climate-4853538.php?cmpid=twitter
which is insane if you calculate how many miles any low brow GW activist fly every year, let alone the big shots).
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which is insane if you calculate how many miles any low brow GW activist fly every year, let alone the big shots
Most don't, actually. Most climate science is done in local weather stations. The "big shots" do go to the artic ocasionally, although that's travelling by boat, and staying there for 6 months.
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I said "activists", not "scientists" Joshua. Some of the high brow are also scientists.
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I sort of agree with Nuke, if the last May was of any indication, then bring on the climate change!
On a more serious note, it is still sort of unclear to me whether I'll agree with IPCCs findings or not. So far I have taken the attitude that since I really don't have time to figure this myself, I'll have to (grudgingly) trust what they say. However, a lot of the message has been diminished the way it was brought up to the general public, not to mention some of the loudest policymakers recommending actions against it owning shares of companies that rely on technology that (supposedly) reduces CO2 emissions. This is a conflict of interest, and something like that is too good at driving up any sort of suspicion of the motivations behind.
Also, I haven't seen a scientifical review of the real world actions caused by the IPCCs recommendations. Now this is all completely speculative, but I'm sort of thinking that what actually happened to industry in Europe increased the world's total CO2 emissions than reduced them. Now that they have composed a 2200 page document, how long would it take them to analyze what has actually taken place?
You see, I think that the way they approached the CO2 issue seems to be completely wrong. They went to politicians, instead of industry first. Or perhaps they went to industry, but failed to realize that the industry is usually quite conservative by default. So instead of prohibitions and regulations, I think they would have been better accepted had they shown there are some other gains being possible by using processes that produce less CO2.
I'm also a bit curious if we took a bit more dickish attitude towards the rest of the world in what it comes to the greenhouse effect and said screw it, it only makes OUR lives better; this place being one of the few of them that actually benefits. This thought comes from acknowledging that jealousy is a powerful motivator :lol: They might not like us after saying something like that, but perhaps that would cause a bigger change. And besides, I wouldn't mind having a Riviera beach next to my door.
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I just leave this here and then leave to work: the IPCC does indeed ignore one very big hypothesis for the pause, which is about the sensitivity of CO2 being lesser than the one they calculated before. Innumerous papers have been claiming this for the past year and two (I am indeed sorry for not providing them), and I have yet to find any answer to Nic Lewis' really relevant criticisms for the IPCC's wrongheaded bayesian analysis of the models and the CO2 sensitivities, which when properly corrected takes a big bunch of the warming out of the picture (even reaching values below 2.0º). See here his relevant paper: http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00473.1
As I pointed out earlier, the IPCC does not perform original research -- they report the current state of knowledge about climate change according to the most recently available literature. The paper you have linked is an example of the very same kinds of studies that the IPCC is referencing when describing why the lower bound for climate sensitivity was reduced from 2°C to 1.5°C. (Look at the report, and you even see that very study being referenced!) The consensus about climate sensitivity is that it is extremely unlikely to be below 1°C, very unlikely above 6°C, likely between 1.5° and 4.5°C, and most likely around 3°C. The 3°C is also the best fit to paleoclimate data. The IPCC also has this to say:
The rate and magnitude of global climate change is determined by radiative forcing, climate feedbacks, and the storage of energy by the climate system. Estimates of these quantities for recent decades are consistent with the assessed likely range of the equilibrium climate sensitivity to within assessed uncertainties, providing strong evidence of our understanding of anthropogenic climate change.
Which is exactly what the study I gave earlier shows -- an accounting of natural variability with internal and external forcings yields a steady signal of global warming. Whereas to only examine tropospheric/surface temperature trends is to neglect over 90% of the energy flow.
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I'm also a bit curious if we took a bit more dickish attitude towards the rest of the world in what it comes to the greenhouse effect and said screw it, it only makes OUR lives better; this place being one of the few of them that actually benefits. This thought comes from acknowledging that jealousy is a powerful motivator :lol: They might not like us after saying something like that, but perhaps that would cause a bigger change. And besides, I wouldn't mind having a Riviera beach next to my door.
The problem is that ocean's ecosystems are very fragile, and built around very gradual temperature changes. The IPCC predicts that the closer we get to 3c, the more the ecosystems there start getting damaged, with catastrophic and irreversible damage starting from roughly two degrees, and with quite a lot of bad stuff happening from three degrees onwards. With the continued accidification of the ocean due to higher CO2 levels and the rising temperature, several of the organisms that live at the bottem of the food chain (pterapods, IIRC) are already at risk.
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I'm happy to know they did reference Nic Lewis' corrections on the last report, although the numbers they provide (3ºC as the main prediction) still fall higher than his own calculations and what is observed. Again, the rationale is that the warming is currently being stored in the oceans and that a big El Nino in the future will bring the warming speed up to their predictions (like in 98 or something to that effect).
What is also true is that the models have been constantly predicting a warmer world than what we have been having, and if this trend keeps going for too long they will have been seen as crying wolf too many times and too harshly.
It also does not help that any real measures to downsize CO2 are actually bemoaned and vilified by the greens, who are very much still in bed with the editorial edifice of the IPCC, and all the political shenanigans that go with it (the usual green lobby who are paid by governments to lobby the governments and the EU), like shale gas or nuclear power. The ignorance on basic facts is astonishing. Just yesterday I had to suffer a Lawrence Krauss (I'm really getting tired of that guy on innumerous vectors) piece saying that shale gas would be responsible for the increase of CO2. Let's forget the obvious fact that mankind needs power as never before and that if we don't get it by the low-density CO2 power source that is gas, we will get it with coal.
Constant BS like that always written in editorial pieces and so on, always aligned with moralistic lessons from the high priesthood of the IPCC... we will wake up from this idiocy with a lot harm done but only one or two decades from now. By then everyone will have forgotten the zealotry and the idiocy being done and propagandized today and new forms of fearmongering and "anti-science war" will be waged.
Sigh.
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I'm happy to know they did reference Nic Lewis' corrections on the last report
Yes, they reference and discuss his work in several sections. In the future I would advise fact checking before claiming with such confidence that the IPCC is ignoring stuff. ;)
although the numbers they provide (3ºC as the main prediction) still fall higher than his own calculations and what is observed.
Lewis is not the only one who studies climate sensitivity, nor is it estimated only by modelling and instrumental data. The 1.5 to 4.5 degree range of likelihood is arrived at by looking at all available studies and methods:
(http://i.imgur.com/JCHnDVB.jpg)
Also, recall from the OP that even a 1.5°C value for climate sensitivity still yields over 2°C of temperature rise under a wide range of emissions scenarios, so all the focus on the reduced lower estimate is truly missing the point.
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Ad w.r.t. this
What is also true is that the models have been constantly predicting a warmer world than what we have been having, and if this trend keeps going for too long they will have been seen as crying wolf too many times and too harshly.
Why do you feel justified in making this argument when it has been demonstrated repeatedly now that the Earth is accumulating heat at a steady pace consistent with an understanding of natural variability and internal/external forcings? A review of posts 11, 18, and the second half of 30 would be helpful here.
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Ad w.r.t. this
What is also true is that the models have been constantly predicting a warmer world than what we have been having, and if this trend keeps going for too long they will have been seen as crying wolf too many times and too harshly.
Why do you feel justified in making this argument when it has been demonstrated repeatedly now that the Earth is accumulating heat at a steady pace consistent with an understanding of natural variability and internal/external forcings? A review of posts 11, 18, and the second half of 30 would be helpful here.
"posts"? I don't have the same understanding of "demonstrated" that you do. To me "demonstrated" is a hard concept that only gets its own authority when sufficient empirical testing was made, and non-trivial predictions being shown to work. They haven't. What happens again and again is that models are made, proclamations about the future are said with "very high degree of confidence", and then as the years go on we find these absolutely lacking and failing. But of course they haven't failed at all, because the "real" explanation is that a dog sea ate the homework the warming, and if we account for the whole ocean + air, we then see that the warming goes on as before.
Except that this accounting is novel and ad hoc, and it only came to light as a way to explain the absence of the actual thing we should be so concerned about: the warming of the atmosphere. It all "makes sense now", the same way that in 2007 "all made sense" then. This ad hoc(ian) approach and the constant change of goalposts and metrics (if we add this and that to that metric we used to point as the final evidence for our theory it works! Who denies this?!) validates my deep rooted skepticism about not only the main theory (I consider the "main theory" not the idea of Greenhouse Gases warming up the atmosphere, but the idea that we are looking at a catastrophic anthropogenic phenomena) but also the ways we are looking at the problem.
Of course, we can all be multitudes in our various degrees of skepticism and acceptance and this would mean little in the way of actually dealing with the risk which I agree is non-zero and should be tackled. I am extremely much more skeptical on that front about all the things the UN and all the international bodies are conjuring up, and that would be a really different discussion, one where I suspect we would get a wider consensus here than in this particular discussion.
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*head scratch* what you are describing sounds exactly like science. Propose model for complex system. => run model, find results slightly different than observed phenomena => re-evaluate model, find phenomena that were not counted on in the model => refine model, incorporating new bits => model now closer to observed results. Sounds like running a chemistry experiment. Sounds like honing a theory.
Correct me if I'm off base, but the point of climate change theory is not warming of the atmosphere. The atmosphere itself will be the very last thing to warm. Think of it instead as an increase in energy of the system, or more heat is being retained by the system
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Correct me if I'm off base, but the point of climate change theory is not warming of the atmosphere. The atmosphere itself will be the very last thing to warm. Think of it instead as an increase in energy of the system, or more heat is being retained by the system
Precisely; global warming is not only the warming of the atmosphere. :)
In general, though, the additional energy actually goes into the lower atmosphere first, as that's where the radiative imbalance leads to heating. (The upper atmosphere also cools by the same mechanism, but that's a different subject. I can talk more about that in a later post if anyone is interested.) The key is that the additional heat doesn't only go into the atmosphere or stay there. It also goes towards heating the surface, heating the oceans, evaporation of water and melting of ice. The heat accumulated and retained by the atmosphere accounts for less than 10% of the total, and because so much of it is in the oceans (high heat capacity), transformations between ocean and atmosphere are very important.
@Luis:
Is the heat uptake by the oceans an ad hoc explanation? Not at all. Atmospheric and climate scientists have known about the importance of the ocean for quite a while now.1 (http://www.sciencemag.org/content/287/5461/2225.short), 2 (http://i.imgur.com/fTM7i0R.jpg) It's also observable and quantifiable. Quite frankly I don't think you have any good argument against it, and so far it seems that you're simply regurgitating the criticisms from skeptical websites without actually giving them much critical thought.
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(The upper atmosphere also cools by the same mechanism, but that's a different subject. I can talk more about that in a later post if anyone is interested.
I am! I was going for the air in the trophosphere is heated by the ground. Additionally by where the upper atmosphere cools by the same mechanism, that is past where ozone generates heat?
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@Beskargam:
Sure! Let's start with a basic yet oft-forgotten principle of radiative physics:
Any substance which is a good absorber of some wavelength of radiation is also good at emitting it.
The idealized version of this statement is what leads to the concept of a blackbody.
It is often said that CO2 is a good absorber of infrared wavelengths of light, but what is also true is that it is an equally good emitter of those same wavelengths. But if that's the case, then why is it a greenhouse gas at all? The reason is because the atmosphere is not a two-dimensional object; it has depth. Sunlight, peaking in the visible spectrum, penetrates the Earth's atmosphere easily (and thankfully for us), with some of it absorbed by the ground and heating it. The ground then emits radiation back up to space, and by Wein's Law that radiation is longer-wavelength infrared. On its path upward, some of this radiation is absorbed by the greenhouse gases.
Those greenhouse gases aren't just going to hold on to that energy, as we noted that they emit just as easily as they absorb. Some of it get re-radiated back downward, heating the ground further. Some of it also goes upward, and then a portion of that again is absorbed by the layers above it, then getting re-radiated again. You can probably see where this is going: if you treat the atmosphere as being made up of a bunch of thin layers, then the temperature at any layer is determined by how much flux it is absorbing from above and below vs. how much it can freely radiate away. At low altitudes a slice of atmosphere absorbs more from the surface as well as from the layers above, so it is hotter than it would be without greenhouse gases. At high altitudes there is less absorption, but efficient emission since there is a clearer path to space. Therefore the upper atmosphere is cooler than they otherwise be.
The result then is that the presence of greenhouse gases in a planet's atmosphere increases the temperature near the surface and decreases the temperature higher up. There should be some particular altitude where the fluxes balance and the temperature is equal to the equilibrium temperature that you would calculate for the planet if it did not have an atmosphere. (Though clouds and other atmospheric chemistry, e.g. ozone, can complicate this further).
A very nice way to show this observationally is by looking at the strongest greenhouse atmosphere we know of -- Venus. Everyone knows that Venus sports the hottest surface anywhere in the solar system (she's a sexy goddess), despite not being the closest planet to the Sun, because of its dense CO2 atmosphere. But look at the temperature profile:
(http://i.imgur.com/tKIoceX.gif)
The upper atmosphere is really cold, in fact about equally as cold as the coldest parts of Earth's atmosphere, despite being closer to the Sun.
Thus by increased greenhouse gas concentrations in the Earth's atmosphere, we should expect to see an altitude-dependent change in temperature; with a warming of the surface and a cooling higher up. Sure enough, this is just what we observe. :)
Additionally by where the upper atmosphere cools by the same mechanism, that is past where ozone generates heat?
It contributes a cooling effect at the height of the ozone layer as well as altitudes above that. There is also an additional cooling effect at the ozone layer due to reduced ozone concentrations, among other sources, and it is possible to disentangle these effects by examining altitude dependence and relevant chemistry.
Here's a good website for more information (http://www.atmosphere.mpg.de/enid/20c.html). Surprisingly (or perhaps not) the cooling of the upper atmosphere is a topic that does not receive a great deal of study, though there are a few journal articles about it here and there.
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@Luis:
Is the heat uptake by the oceans an ad hoc explanation? Not at all. Atmospheric and climate scientists have known about the importance of the ocean for quite a while now.1 (http://www.sciencemag.org/content/287/5461/2225.short), 2 (http://i.imgur.com/fTM7i0R.jpg) It's also observable and quantifiable. Quite frankly I don't think you have any good argument against it, and so far it seems that you're simply regurgitating the criticisms from skeptical websites without actually giving them much critical thought.
That's somewhat facetious. I could say the same about you: you are only regurgitating what the editorials of the IPCC tell you.
While it is true that everyone "knew" that the oceans were important, the argument is quite different this time, and you should not ignore this point. Of course you can always delude yourself and tell yourself that eurasia was always at war with eastasia and lesser thought crimes :), but what is true is that this argument of "the oceans ate the warming" is quite recent and new, coming after some discussions in 2009 by Trenberth et al:
"Global warming is still happening - our planet is still accumulating heat. But our observation systems aren't able to comprehensively keep track of where all the energy is going. Consequently, we can't definitively explain why surface temperatures have gone down in the last few years. That's a travesty!"
This is clearly an indication of the usual troubles that science must go through to eventually get to the best answers. I have zero problems with it (unlike many deniers / skeptics / whatever). What I have more problems with is this whitewashing after the facts and for the reports for politicians that "we always knew this, this was always taken account for, skeptics' lies, etc". What is true is that this explanation is recent and it still lacks any predictive power. The models still depend on many prejudices that may well turn out to be as false as the travesties that were plaguing climatology in 2009.
*head scratch* what you are describing sounds exactly like science. Propose model for complex system. => run model, find results slightly different than observed phenomena => re-evaluate model, find phenomena that were not counted on in the model => refine model, incorporating new bits => model now closer to observed results. Sounds like running a chemistry experiment. Sounds like honing a theory.
That's only the first step. If you only do what you are referring to you aren't getting a true theory, you are only capturing fine tuned and fudged models that represent the past exceedingly well. The real thing only comes when you actually predict data that is not in your present bucket of data and you get it right. Ensuring your models capture past data is trivial. Ensuring your model will be able to capture future unseen data is the Real ****.
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The problem is that ocean's ecosystems are very fragile, and built around very gradual temperature changes. The IPCC predicts that the closer we get to 3c, the more the ecosystems there start getting damaged, with catastrophic and irreversible damage starting from roughly two degrees, and with quite a lot of bad stuff happening from three degrees onwards. With the continued accidification of the ocean due to higher CO2 levels and the rising temperature, several of the organisms that live at the bottem of the food chain (pterapods, IIRC) are already at risk.
That, on the other hand, wouldn't be the first time humans have extincted something. And the additional heat is going to cause similar changes also on ground, not only in seas. Both land and ocean ecosystems are fragile, the more specialized you become the more vulnerable you are for changes - which might on the other hand be exactly the kind of changes that boosts your species.
Luis Dias has a point here too, I'm a bit curious on what are the legal consequences towards the people who pushed for regulation towards CO2 if it turns out that the very same regulations have increased the CO2 levels world wide. Not to mention, what are the legal consequences towards the people if the warming doesn't actually occur as planned. Remember that Italy did sue the researchers who provided "wrong" information, no matter how scientifically sound that wrong might have been at that point of time.
I do recall skeptics actually catching one glaring error in the IPCC report, which was the Mann's hockey stick graph. Skeptics inserted random data to the routine and it still produced the rising curve... I think that has been taken out of the reports as far as I have seen (thought I really cannot be bothered to read a 2200 page document). Additionally, I recall somebody started to take a better look on the current state of the weather stations, which revealed several problems in the measurements (including changed surroundings). This contribution from the skeptics should be considered positive by the scientifical method.
I'd say that in about 10 years we probably know a lot better what way the climate is going.
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Luis Dias has a point here too, I'm a bit curious on what are the legal consequences towards the people who pushed for regulation towards CO2 if it turns out that the very same regulations have increased the CO2 levels world wide. Not to mention, what are the legal consequences towards the people if the warming doesn't actually occur as planned. Remember that Italy did sue the researchers who provided "wrong" information, no matter how scientifically sound that wrong might have been at that point of time.
Would you want there to be legal consequences for those people who ten years ago claimed that there was no such thing as Global Warming? Cause the fact that the Earth has warmed has reached the point were even the people who denied that with every breath had to concede and change their claim to "The Earth has warmed but it's natural and not man-made). Surely we could start locking those people up now or taking their money if you think it should also go the other way?
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Luis Dias has a point here too, I'm a bit curious on what are the legal consequences towards the people who pushed for regulation towards CO2 if it turns out that the very same regulations have increased the CO2 levels world wide. Not to mention, what are the legal consequences towards the people if the warming doesn't actually occur as planned. Remember that Italy did sue the researchers who provided "wrong" information, no matter how scientifically sound that wrong might have been at that point of time.
Would you want there to be legal consequences for those people who ten years ago claimed that there was no such thing as Global Warming? Cause the fact that the Earth has warmed has reached the point were even the people who denied that with every breath had to concede and change their claim to "The Earth has warmed but it's natural and not man-made). Surely we could start locking those people up now or taking their money if you think it should also go the other way?
Well, speaking as a scientist who can and does face legal consequences of his actions, this is nothing new for me - it is OK that both sides are held responsible for their actions. It is a matter of amount of damage inflicted, and I'd classify the warming skeptics as scientifical inertia for that time, their actions would be seen just causing inaction. Mainstream view is different in my books since they have already prompted actions which seemingly have increased CO2 output world wide (and still promote that), affecting the lives of thousands of Europeans as industry migrates outside EU area. Admittedly, this is indeed a gray area, and should be judged case by case.
I'll have to say that some excerpts in the IPCC's report though are starting to worry me. I probably do need to read through it myself as it sounds to me rewriting the document to allow no warming at all scenario.
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@Luis:
Nonsense. It has excellent predictive power. It predicts that a full accounting of the energy accumulated by the Earth system should correspond to the change in radiative forcing. By extension, it predicts that the tropospheric/surface temperature observations should show an increase corresponding to the change in radiative forcing after accounting for the heat flow between the atmosphere and other systems (natural variability).
So you can test this prediction through future measurements, and you can also test it by looking at past measurements. (http://iopscience.iop.org/1748-9326/6/4/044022/pdf/1748-9326_6_4_044022.pdf)
The quote you provided from Trenberth relates to the state of knowledge and observational capability in 2009, which was that the full energy budget determined through observations came shy of what would be expected, mostly due to the insufficient data from the deep ocean, below 700m. But even well before then we understood that the ocean accounted for much of the heat gained via global warming, as seen by the literature.
I probably do need to read through it myself as it sounds to me rewriting the document to allow no warming at all scenario.
By observation the warming is continuing and is still expected to continue. Even under a zero emissions scenario, the Earth will likely continue to warm due to the thermal inertia of the system (particularly the oceans, which take a long time to reach thermal equilibrium).
And yeah, I would recommend at the very least reading through the Summary for Policymakers. It's only 36 pages, the last 9 of which are figures.