Last Friday, NASA GISS and NOAA NCDC had a press conference and jointly announced the end-of-year analysis for the 2014 global surface temperature anomaly which, in both analyses, came out top. As you may have noticed, this got much more press attention than their joint announcement in 2013 (which wasn’t a record year).
In press briefings and interviews I contributed to, I mostly focused on two issues – that 2014 was indeed the warmest year in those records (though by a small amount), and the continuing long-term trends in temperature which, since they are predominantly driven by increases in greenhouse gases, are going to continue and hence produce (on a fairly regular basis) continuing record years. Response to these points has been mainly straightforward, which is good (if sometimes a little surprising), but there have been some interesting issues raised as well…
Records are bigger stories than trends
This was a huge media story (even my parents noticed!). This is despite (or perhaps because?) the headline statement had been heavily trailed since at least September and cannot have been much of a surprise. In November, WMO put out a preliminary analysis suggesting that 2014 would be a record year. Earlier this month, the Japanese Meteorological Agency (JMA) produced their analysis, also showing a record. Estimates based on independent emulations of the GISTEMP analysis also predicted that the record would be broken (Moyhu, ClearClimateCode).
This is also despite the fact that differences of a few hundredths of a degree are simply not that important to any key questions or issues that might be of some policy relevance. A record year doesn’t appreciably affect attribution of past trends, nor the projection of future ones. It doesn’t re-calibrate estimated impacts or affect assessments of regional vulnerabilities. Records are obviously more expected in the presence of an underlying trend, but whether they occur in 2005, 2010 and 2014, as opposed to 2003, 2007 and 2015 is pretty much irrelevant.
But collectively we do seem to have an apparent fondness for arbitrary thresholds (like New Years Eve, 10 year anniversaries, commemorative holidays etc.) before we take stock of something. It isn’t a particularly rational thing – (what was the real importance of Usain Bolt’s breaking the record for the 100m by 0.02 hundredths of a second in 2008?), but people seem to be naturally more interested in the record holder than in the also-rans. Given then that 2014 was a record year, interest was inevitably going to be high. Along those lines, Andy Revkin has written about records as ‘front page thoughts’ that is also worth reading.
El Niños, La Niñas, Pauses and Hiatuses
There is a strong correlation between annual mean temperatures (in the satellite tropospheric records and surface analyses) and the state of ENSO at the end of the previous year. Maximum correlations of the short-term interannual fluctuations are usually with prior year SON, OND or NDJ ENSO indices. For instance, 1998, 2005, and 2010 were all preceded by an declared El Niño event at the end of the previous year. The El Niño of 1997/8 was exceptionally strong and this undoubtedly influenced the stand-out temperatures in 1998. 2014 was unusual in that there was no event at the beginning of the year (though neither did the then-record years of 1997, 1990, 1981 or 1980 either).
So what would the trends look like if you adjust for the ENSO phase? Are separate datasets differently sensitive to ENSO? Given the importance of the ENSO phasing for the ‘pause’ (see Schmidt et al (2014), this can help assess the underlying long-term trend and whether there is any evidence that it has changed in the recent decade or so.
For instance, the regression of the short-term variations in annual MSU TLT data to ENSO is 2.5 times larger than it is to GISTEMP. Since ENSO is the dominant mode of interannual variability, this variance relative to the expected trend due to long-term rises in greenhouse gases implies a lower signal to noise ratio in the satellite data. Interestingly, if you make a correction for ENSO phase, the UAH record would also have had 2014 as a record year (though barely). The impact on the RSS data is less. For GISTEMP, removing the impact of ENSO makes 2014 an even stronger record year relative to previous ones (0.07ºC above 2005, 2006 and 2013), supporting the notion that the underlying long-term trend has not changed appreciably over the last decade or so. (Tamino has a good post on this as well).
Odds and statistics, and odd statistics
Analyses of global temperatures are of course based on a statistical model that ingests imperfect data and has uncertainties due to spatial sampling, inhomogeneities of records (for multiple reasons), errors in transcription etc. Monthly and annual values are therefore subject to some (non-trivial) uncertainty. The HadCRUT4 dataset has, I think, the best treatment of the uncertainties (creating multiple estimates based on a Monte Carlo treatment of input data uncertainties and methodological choices). The Berkeley Earth project also estimates a structural uncertainty based on non-overlapping subsets of raw data. These both suggest that current uncertainties on the annual mean data point are around ±0.05ºC (1 sigma) [Update: the Berkeley Earth estimate is actually half that]. Using those estimates, and assuming that the uncertainties are uncorrelated for year to year (not strictly valid for spatial undersampling, but this gives a conservative estimate), one can estimate the odds of 2014 being a record year, or of beating 2010 – the previous record. This was done by both NOAA and NASA and presented at the press briefing (see slide 5).
In both analyses, the values for 2014 are the warmest, but are statistically close to that of 2010 and 2005. In NOAA analysis, 2014 is a record by about 0.04ºC, while the difference in the GISTEMP record was 0.02ºC. Given the uncertainties, we can estimated the likelihood that this means 2014 was in fact the planet’s warmest year since 1880. Intuitively, the highest ranked year will be the most likely individual year to be the record (in horse racing terms, that would be the favorite) and indeed, we estimated that 2014 is about 1.5 to ~3 times more likely than 2010 to have been the record. In absolute probability terms, NOAA calculated that 2014 was ~48% likely to be the record versus all other years, while for GISTEMP (because of the smaller margin), there is a higher change of uncertainties changing the ranking (~38%). (Contrary to some press reports, this was indeed fully discussed during the briefing). The data released by Berkeley Earth is similar (with 2014 at ~35%~46% (see comment below)). These numbers are also fragile though and may change with upcoming updates to data sources (including better corrections for non-climatic influences in the ocean temperatures). An alternative formulation is to describe these results as being ‘statistical ties’, but to me that implies that each of the top years is equally likely to be the record, and I don’t think that is an accurate summary of the calculation.
Another set of statistical questions relate to a counterfactual – what are the odds of such a record or series of hot years in the absence of human influences on climate? This question demands a statistical model of the climate system which, of course, has to have multiple sets of assumptions built in. Some of the confusion about these odds as they were reported are related to exactly what those assumptions are.
For instance, the very simplest statistical model might assume that the current natural state of climate would be roughly stable at mid-century values and that annual variations are Gaussian, and uncorrelated from one year to another. Since interannual variations are around 0.07ºC (1 sigma), an anomaly of 0.68ºC is exceptionally unlikely (over 9 sigma, or a probability of ~2×10-19). This is mind-bogglingly unlikely, and is a function of the overly-simple model rather than a statement about the impact of human activity.
Two similar statistical analyses were published last week: AP reported that the odds of nine of the 10 hottest years occurring since 2000 were about 650 million to 1, while Climate Central suggested that a similar calculation (13 of the last 15 years) gave odds of 27 million to 1. These calculations are made assuming that each year’s temperature is an independent draw from a stable distribution, and so their extreme unlikelihood is more of a statement about the model used, rather than the natural vs. anthropogenic question. To see that, think about a situation where there was a trend due to natural factors, this would greater reduce the odds of a hot streak towards the end (as a function of the size of the trend relative to the interannual variability) without it having anything to do with human impacts. Similar effects would be seen if interannual internal variability was strongly autocorrelated (i.e. if excursions in neighbouring years were related). Whether this is the case in the real world is an active research question (though climate models suggest it is not a large effect).
Better statistical models thus might take into account the correlation of interannual variations, or have explicit account of natural drivers (the sun and volcanoes), but will quickly run into difficulties in defining these additional aspects from the single real world data set we have (which includes human impacts).
A more coherent calculation would be to look at the difference between climate model simulations with and without anthropogenic forcing. The difference seen in IPCC AR5 Fig 10.1 between those cases in the 21st Century is about 0.8ºC, with an SD of ~0.15 C for interannual variability in the simulations. If we accept that as a null hypothesis, the odds of seeing a 0.8ºC difference in the absence of human effects is over 5 sigma, with odds (at minimum) of 1 in 1.7 million.
None of these estimates however take into account how likely any of these models are to capture the true behaviour of the system, and that should really be a part of any assessment. The values from a model with unrealistic assumptions is highly unlikely to be a good match to reality and it’s results should be downweighted, while ones that are better should count for more. This is of course subjective – I might feel that coupled GCMs are adequate for this purpose, but it would be easy to find someone who disagreed or who thought that internal decadal variations were being underestimated. An increase of decadal variance, would increase the sigma for the models by a little, reducing the unlikelihood of observed anomaly. Of course, this would need to be justified by some analysis, which itself would be subject to some structural uncertainty… and so on. It is therefore an almost impossible to do a fully objective calculation of these odds. The most one can do is make clear the assumptions being made and allow others to assess whether that makes sense to them.
Of course, whether the odds are 1.7, 27 or 650 million to 1 or less, that is still pretty unlikely, and it’s hard to see any reasonable model giving you a value that would put the basic conclusion in doubt. This is also seen in a related calculation (again using the GCMs) for the attribution of recent warming.
Conclusion
The excitement (and backlash) over these annual numbers provides a window into some of problems in the public discourse on climate. A lot of energy and attention is focused on issues with little relevance to actual decision-making and with no particular implications for deeper understanding of the climate system. In my opinion, the long-term trends or the expected sequence of records are far more important than whether any single year is a record or not. Nonetheless, the records were topped this year, and the interest this generated is something worth writing about.
References
- G.A. Schmidt, D.T. Shindell, and K. Tsigaridis, "Reconciling warming trends", Nature Geoscience, vol. 7, pp. 158-160, 2014. http://dx.doi.org/10.1038/ngeo2105
#247 Hank, your post scared me a little because I realized at one point that I actually understand what you’re talking about, forcing and feedback wise. So I’m actually learning a bit about climate science in spite of myself. Yikes!
#222 Hank Roberts
Thanks, Hank, for sharing the excerpt from the England et al paper. However, the cooling La Nina effect to which they refer is not what’s I’ve been puzzling over in my last few posts. I did reference it, true, and I must say I’m skeptical, but the argument that most puzzles me is best exemplified by what Stefan wrote here: https://www.realclimate.org/index.php/archives/2013/09/what-ocean-heating-reveals-about-global-warming/
I.e.: the claim that the growing heat content of the oceans tells us that “the greenhouse effect has not taken a pause.” Which means, I assume, that the heat that would normally have been produced at the surface via the greenhouse effect, prior to 1998, has somehow moved from the atmosphere to the oceans. And I’m trying to understand how that could happen. Most of the responses I’m seeing here are attempts to explain, very literally, and largely in technical terms, how heat is transferred to or from the ocean. That’s all very interesting, but as far as my basic question is concerned, beside the point. I’m not interested in the mechanics per se, I’m interested in the logic behind what seems like a contradiction.
And before I start hearing again about how stupid my questions are and how little I understand about climate science, this is in fact a concern expressed by many of the climate scientists I’ve been reading and listening to. Most of them simply dismiss theories of that sort as crude attempts to get around the “fact” of the hiatus. I’ve seen that referred to as the “Ocean ate my global warming” theory, as though it was some sort of excuse. And I must say, it sounds like some sort of “just so” story.
I guess you could say I’m giving you and the others an opportunity to clear it up. But so far I’ve read nothing that actually addresses the problem at hand, only descriptions of heat transfer in technical terms.
Victor wrote at 78,
“What I see, therefore is not a long term warming trend, covering all or most of the 20th century,……..So, if one wants to claim that only long terms trends really count, then I see nothing to take seriously as far as “global warming” is concerned, since I see no long term trend at all……..the present temperature was NOT arrived at via a long-term trend.”
You clearly do not understand what the term “trend” means. You are wrong – and part of why you are wrong is that you wrongly think that cause and effect relationships must create real world data that forms graphs of one-to-one or even just monotonic functions, even after smoothing techniques are used such as running means. Even after smoothing techniques they can form nonmonotonic functions. See
http://en.wikipedia.org/wiki/Trend_estimation
for an introduction. There is an upward trend starting since the late 1800s, and to see it, see graph of the 30 year running mean here
http://www.skepticalscience.com/global_warming_still_happening.html
and at other such sites. You should know that smoothing techniques such as running means help to uncover underlying trends in data, where it’s usually better to have longer terms in the moving averages. Here, a 30 year running mean does a better job than a 5 year running mean to show trends, which is why I showed you a graph of global warming under a 30 year running mean. Within these nonmonotonic functions we can obtain the underlying trend curves. (The term “curve” is a general mathematical term that includes straight lines.)
This leads us to what Victor wrote at 91:
“The correlation between CO2 emissions and “global warming” suddenly vanished………it became increasingly clear that the earlier correlation had been misleading. There was in fact no longer much evidence that CO2 emissions were the cause of the warming trend over the last 20 or so years of the 20th Century……… causality always implies correlation.”
And now consider what Victor wrote at 243 in reply to my 120:
“My position can be stated very simply: correlation does not in itself imply causation; causation requires correlation………..It is not up to a skeptic to prove the correlation you see couldn’t possibly be real.”
Couldn’t possibly be real? Proof that what I said you say is true – you do claim that cause and effect relationships cannot be expressed via nonmonotonic functions. By how you use the term “correlation”, your claim that “causality always implies correlation” is false. Utterly false. The problem is the term “always” combined with how you use the term “correlation”. This use of the universal quantifier implies that what you mean by “correlation” is that the real world data for a cause and effect relationship must always form a perfect monotonic function that is also a perfect one-to-one function. You do wrongly use these terms “trend” and correlation” – it means that you do claim that cause and effect relationships can never express themselves in real world data as nonmonotonic functions, even though they can and in fact many times do. As I in 156 pointed out and in 231 gave an example, there many times are exceptions in real world data due to competing cause and effect relationships that can cover even long intervals. Again: You wrongly think that we can’t have long term cause and effect relationships that express themselves in real world data as nonmonotonic functions. The correlation that you claim is not real is in fact there and is expressed as an underlying trend curve within a nonmonotonic function.
By the proper use of the terms “trend” and “correlation”, we do in fact have the established physics that shows the cause and effect relationship of greenhouse gases and heat in many observed correlations in the laboratories and in the universe – and this includes Venus. (Are you one of those who deny that the greenhouse gas effect explains the vast majority of the heat on Venus? It seems to me that you might be, by taking all of what you say here in the aggregate.) This gives us the established physics of greenhouse gases and their causal relations to heat in the literature of the reputable professional monographs, textbooks, and refereed or peer-reviewed journals.
By the proper use of the terms “trend” and “correlation”, we do have expressed in data a long term correlation using a 5 year running mean – it forms a nonmonotonic function that does in fact have an underlying upward trend since the late 1880s and even since 1970. And if we use a 30 year running mean since the late 1800s we have the data giving us a nonmonotonic function with an underlying upward trend.
And so far, you still have not replied to my points in 156 and 231 that explain where the heat increase in the total system of ocean and atmosphere comes from and that demonstrates the physically impossibility of your main causal claim that all the ocean heat content increase since 2000 is merely due to a transfer of heat from the atmosphere, where you claim that all this heat was in the atmosphere in 1979. (I pointed out in 231 that if all that heat that makes up the increase in ocean heat content since 2000 was in the atmosphere back in 1979, then it would have heated up the atmosphere on the order of 15 degrees C.)
[edit – OT and tedious]
Victor,
All of your questions have been answered here several times over. You now say that these answers don’t count because they’re too scientific and you’re not interested in learning the science. Then how exactly do you expect people to answer your questions? What do you expect to learn if not the science behind these questions?
The things you say aren’t getting under people’s skin because you are making good points, as you appear to think, it’s because they’re frustratingly wrong and people are trying to make you understand that, but you show no signs of learning anything from their responses (and indeed, you now say that you have no interest in learning). So I now propose the following:
1. Realize that questions about science will have scientific answers
2. Learn the difference between heat transfer by “conduction” and “radiation”
3. Realize that as long as the Earth accumulates heat, there is no pause in warming regardless of what part of the Earth the heat goes to
4. Learn about specific heat capacities of different substances (specifically the difference between air and water)
5. Once you have done all of these things (which will take far less time than the time you’ve already spent on this thread), then you can read this thread from the top and understand that the answers you seek have been here all along.
Victor has admitted that he is not here to learn about climate science but rather to pull your chain for as long as you let him do so. Do not feed.
> … I am NOT here to learn Climate Science …
> … explanations interest me and I’m learning from this process.
Here to polish your logical arguments against math and science, then.
Boring.
http://1.bp.blogspot.com/-Vac3kUiR4NI/VLa59w0T19I/AAAAAAAAJxE/77rX7jJEpCw/s1600/Bast%27s%2BLaw.jpg *hat tip to Russell
Victor,
No one is asking you to leave. We are merely suggesting that
1)your education would proceed more rapidly; and
2)you wouldn’t come across as such an arrogant and clueless pratt
if you considered that maybe people who have studied this subject for longer than you’ve been alive might have a better understanding of it than you do.
Expertise matters. And the fact that you don’t even have a firm understanding of what a trend is suggests you might have a bit to learn before you should be pontificating.
Victor, once again I’m going to take what you say seriously, in the face of many examples indicating that that is not necessarily a productive thing to do. Call it faith, or maybe incurable optimism.
What ‘rubs me the wrong way’ about your recent bout of comments is that, in the past, I and others have taken considerable pains to offer you straight answers to your concerns, yet the net learning on your part appears to be zero–even though in some cases, you’ve apparently ‘got’ some points, only to ‘forget’ them later. That’s unpleasant, because it seems to put the time and energy invested firmly in the category of “wasted.” No-one likes to waste their time, obviously.
The two most prominent topics exemplifying this in the last batch of comments are, IMO, 1) the point that the oceans are not simply one big homogenous pot of water, but extremely dynamic environments constantly interacting with the atmosphere, and 2) the point that proper interpretation of statistics, including graphs, demands more than “well, it looks to me…” That second point is really, really, important, and you were previously walked through it a great length (a process Barton, bless his heart, appears ready to recapitulate–and good luck, I say. It would be a mitzvah.)
Yet after all that, here you are, saying things like “Looks like an oceanic warming trend corresponding to the atmospheric warming trend from 1979 through 1998 begins around 2000, suggesting a delay of ca. 21 years.” (Comment #104)
Catch what you said there? “Looks like.” No analysis. No real critical thought–as, for instance, a careful consideration of the implications of the SkS example you’ve quoted repeatedly. (More specifically, you’ve read it as supporting a *lag* in response, without considering that perhaps (given the physics of a high mass/high specific heat system like the oceans) what is really implied is, rather, a slow *rate* of response–but one which nevertheless ‘starts’ immediately.) Witness comments like this one:
“…we would expect any trends in the atmosphere to be followed by corresponding trends in the ocean, at a distance of: decades.”
I’d suggest that we wouldn’t expect that at all. What we would expect, all other things being equal, is that the rate of oceanic warming is going to be slower, permanently, which means we’ll never get a ‘corresponding trend’ (if by that is meant a trend of similar rate.)
And what have we seen in the real world? Well, this isn’t a perfect graph to answer that question, but it’s quick and perhaps indicative, showing the BEST land-only record and trend since 1950 (filtered with a 13-month running mean) and the HadSST3 sea surface record and trend for the same period (3-month mean):
http://www.woodfortrees.org/plot/best/from:1950/mean:13/plot/best/from:1950/trend/plot/hadsst3gl/from:1950/mean:3/offset:-0.1/plot/hadsst3gl/from:1950/trend/offset:-0.1
I’d have done OHC, but unfortunately, that data isn’t on Woodfortrees. But it’s certainly possible to go back and look at graph from the Curry post, here:
https://curryja.files.wordpress.com/2014/01/presentation12.jpg
Now, a proper statistical analysis of this is beyond me, and I don’t pretend otherwise–though I recognize the importance of such analysis for drawing reliable conclusions. But I will say that ‘it sure looks to me’ like the land and the ocean are basically responding on similar time scales, but the rate of warming of the ocean surface is slower. And while you may understandably give less weight to my opinion than your own, if you aspire to be a proper skeptic you are obliged to actually think about my point–as this criticism shows me to be thinking about yours.
So–going back to the bigger narrative of how your comment thread has been playing out–you grab one interpretation without thinking things through. And then what do you do?
You latch onto the ‘looks like’ delay like grim death, and utterly refuse to consider any criticisms thereof. I showed with what I find to be a rather vivid example that the thermal coupling between atmosphere and mixing layer of a large body of water (be it salt or fresh) is active on timescales of days. (The same point, by the way, is made by the WfT graph I created above, but globally rather than locally.)
Another commenter came up with a rather neat reductio ad absurdum of the delay: had the amount of heat required for the observed ocean warming been stored in the atmosphere for 21 years, the implied atmospheric warming would have been such as to render this conversation impossible.
Still others cited material explaining various facets of ocean/atmosphere/irradiation interactions: direct SW warming of the oceans, advection of heat below the mixing layer, and possible LW warming of the ‘skin layer,’ and so forth.
It all got blown off–no pun intended. Zero meaningful response. What you said was ‘no-one has pointed out any error…’
I beg to differ, and I trust I’ve said why I differ clearly enough here just why.
Which leads to my last point, and this is meant a straight feedback. You have said that you are here to learn, and that you do that by asking questions. I’m taking your word on that. But it’s common enough in human relations that first-person and third-person perspectives can differ quite drastically. And, honestly, I don’t see you trying trying to learn, or for that matter predominantly asking questions. I see you trying to ‘debate’ and predominantly making (mostly ill-founded) assertions, and then refusing to reality-check them.
Again, if you aspire to be a true skeptic, you are obliged to consider that feedback. And if you don’t, I for one will certainly do exactly as you suggest and stop responding. I may be optimistic, but I won’t waste my time indefinitely–though I will say that this thread hasn’t been a complete waste. While I can’t so far see that your education has progressed any, mine has, as I’ve been motivated to think through some of the points made, and look once again at some of these issues in a critical way.
Perhaps that’s why you’ve (so far) avoided the Borehole: you’ve asked fewer questions than you think, but nevertheless, for me at least, you’ve provoked some interesting ones.
@Victor #252 2 Feb 2015 at 12:39 AM:
Which “climate scientists” describe the claim that the “missing heat” is in the oceans as “Ocean ate my global warming”?
When I Google that expression I get an awful lot of denialist sites come up; nobody on the first page of hits looks like a climate scientist – unless for example you’re counting Viscount Monckton of Brenchley, whose scientific qualifications end at O-level (if he even got an O-level); or perhaps Joanne Nova, who has more scientific qualification, but isn’t a climate scientist unless a bachelor’s degree in microbiology qualifies her as such?
I think it’s fair to say Victor is pretending to read the suggested papers.
England et al.: the abstract says
yet Victor says he doesn’t see how the paper logically explains something.
It’s not clear what logically fails to be clear — to anyone who does the arithmetic or trusts those who’ve published their work.
“I just can’t believe it because Logic” isn’t convincing as a denial.
And Victor asserts that
Scientists? Cite their work. I think you’re misled or misleading us.
‘oogle the phrase “Ocean ate my global warming” — that’s straight out of Watts’s blog.
Boring, Victor. This isn’t logic, it’s rhetoric.
KeefeandAmanda — may I suggest you try for shorter words and a lower grade level reading comprehension?
Check Victor’s quoted sources with ‘oogle to see where he’s coming from, and the reading level appropriate
e.g.
this phrase.#253 KeefeAndAmanda
OK, first of all, the formula “causality always implies correlation” is a universal principle of science, it’s not just something I came up with. If A is the cause of B, then it should be possible to demonstrate the existence of a correlation between them. Must such a correlation be monotonic? No. But the burden of proof for demonstrating that a non-monotonic correlation exists is on the framer of the hypothesis. Just because you claim to see a correlation does not mean that one exists. The correlation needs to be critically analyzed first, and reasons for the divergences need to provided. While it’s true that I cannot deny the existence of the correlation simply on the basis of its being non-monotonic, that doesn’t relieve you of the responsibility of providing those reasons.
Here we see a commonly exhibited graph representing global land and ocean temperatures since 1880: http://upload.wikimedia.org/wikipedia/commons/a/ab/Warming_since_1880_yearly.jpg
It is non-monotonic, yes. But that in itself doesn’t rule out the possibility of an underlying trend that would correlate with the monotonic trend we see in graphs representing the steady increase in CO2 emissions.
Using a linear regression method, you could construct a trend line over this period, implying a “long term” trend during which heat increased by ca. 8 degrees centigrade. And you could argue that the fact it isn’t monotonic can be ignored because by using a 30 year running mean, the underlying trend becomes evident.
However, I see the graph very differently, though not simply because it’s non-monotonic. For one thing I have a problem with your 30 year running mean because it looks to me like an all too convenient method of obscuring significant data. If a long term underlying trend actually exists then it should be apparent even when the data is displayed on a year by year basis. As I see it, there is nothing to be gained by hiding data. Unless of course that’s the only way to make the point you wish to make. Omitting data to highlight an alleged “long term underlying trend” is always dangerous. To establish such a trend one would need to do more, based on a careful analysis of the data in some detail.
Examining the graph in more detail, we can see, simply by eyeballing, that no trend whatsoever exists prior to ca. 1979. Yes, one could construct a trend line from 1880 to 1979, representing a temp. increase of about 2 degrees C. But a trend line produced from some statistical procedure, such as linear regression, is meaningful only if a trend actually exists. Because one can construct a trend line from any assortment of data whatsoever. The ability to construct such a trend line is by no means proof that a trend actually exists.
The only clear trend I see is from 1979-1998, following the annual mean — or from 1979-2001, following the 5 year mean, a period of roughly 20-23 years. This does indeed look like a meaningful trend, not because it’s monotonic, which it isn’t, but because it’s obvious. You don’t need a weatherman to tell which way the wind blows. And you don’t need statistics to spot an obvious trend.
And if you insist on a long term trend of +8 degrees regardless, then you would have to admit that most of that increase, fully 6 degrees of it, occurs only during the last 20 years or so of the century.
Considered from this perspective, what we see is not so much a long term trend followed by a short term pause, from ca 1998-present, but a short term (1979-2001) trend preceded and followed by periods of little to no trend.
“As I said, I’m here to understand. And debating with you guys sharpens my understanding because it forces me to think more precisely. And by the way, I am NOT here to learn Climate Science, so do yourselves a favor and stop expecting me to.”
Here we have maybe the plainest statement from V. yet that he’s just not engaged in the same game everyone else here is. That V. is apparently oblivious to the crying contradiction in the statement shows the wisdom of the path of his own suggestion: just stop replying. The moderators are not going to show this discipline for us. Unless folks think that there is some value in posting info for lurkers (like me) not named “Victor.” Perhaps they should make that motivation clear in their comments.
Excuse me, I forgot to add the decimal point. The “long term” trend would be .8 degrees, not 8 degrees, thank God.
1) What Slioch said at #241.
2) There’s a nice discussion of the various ways the ‘hottest year’ figures are calculated over at SkS:
http://www.skepticalscience.com/cowtan_way_2014_roundup.html
It would be great to have a conversation about this and about the lead post, rather than the tail-chasing people seem to default to so easily here.
Sorry, Victor. You are stuck with logic, and it’s failed you. It’s not the sharpest tool nowadays.
http://www.sandi.net/cms/lib/CA01001235/Centricity/Domain/2596/Cartoon_guide_to_Statistics%20large.pdf
Victor, let me try something. Let’s take a look at one of your statements:
“I.e.: the claim that the growing heat content of the oceans tells us that “the greenhouse effect has not taken a pause.” Which means, I assume, that the heat that would normally have been produced at the surface via the greenhouse effect, prior to 1998, has somehow moved from the atmosphere to the oceans. And I’m trying to understand how that could happen. Most of the responses I’m seeing here are attempts to explain, very literally, and largely in technical terms, how heat is transferred to or from the ocean. That’s all very interesting, but as far as my basic question is concerned, beside the point. I’m not interested in the mechanics per se, I’m interested in the logic behind what seems like a contradiction.”
Every once in a while you post something that reveals (and this is not an insult) your lack of understanding of physical processes (you pretty much admit your lack of interest in the physical systems). And while you might be only interested in the logic of the situation rather than the mechanics, without a basic understanding of the physical processes your logic is resting on vapor. So, in this case let’s start with the basics, so maybe your logic has something firmer upon which to rest.
How does the greenhouse effect warm the earth? It does so by causing an imbalance, with more heat entering the Earth system than leaving the Earth system. (We know this. On this point, the science is settled. If you want to contest this then I think we’re done here.) So, it’s no that heat is being produced, as you say; it’s just accumulating in the system.
Let’s describe this in a conceptually simple system (it’s really simplistic, but please follow along anyway — I think it might help you out and it leads somewhere). Imagine a tank of water. As long as the amount of water entering the tank through the input valve is the same as the amount leaving the tank through the output valve, the total amount of water in the tank stays the same. Imagine that maybe there’s minor, random variation in the amounts entering and leaving. As a result the amount of water in the tank at any instance varies a little bit. But it’s white noise, so averaged over a reasonable period of time, the amount of water is fairly constant. And, by the way, the amount of water entering and leaving the tank in any given period can be really large relative to the amount in the tank. That’s actually an important point, as we’ll see below.
That’s a really simplistic model of the climate in equilibrium. The amount of water in the tank is the heat in the Earth system and the input and output valves are incoming and outgoing energy.
Now, imagine that there is a minor blockage in the exit valve. As a result, slightly less water leaves the tank than enters it. The amount of water starts increasing. But very slowly. Obviously, that’s representing the accumulation of heat in the Earth system due to the greenhouse effect.
Let’s extend this model. Imagine our system of one tank of water actually has two tanks that have water sloshing back and forth between the two of them (LOTS of water). The smaller tank represents the atmosphere, and the larger is obviously the ocean. So, when we get this imbalance between our tank system and the outside, the amount of water increases in both of them, Because it’s so much larger, the ocean-tank accumulates more of the increase. This is the observed increased in the heat in the ocean being much larger than that in the atmosphere.
So, what happens if the valves connecting the two tanks change a little bit so that the flow of water from small tank to big tank increases relative to the flow from big tank to little tank? Obviously, the rate of increase in water in the small tank slows and can even go to zero if the inter-tank shift is large enough (i.e. as large as the system-wide imbalance). The total amount of water in the system is increasing at the same rate as before, but now all the increase is going into the large tank. THAT’s what’s being proposed when scientists say they think the heat that is not warming the atmosphere as quickly is instead warming the oceans.
Actually, I kinda hope that everything I just said has absolutely annoyed you because you knew it already.
But let’s get a little more real about that last part, the exchange of heat between the atmosphere and the ocean. Well, that’s going on ALL THE TIME. In some places heat is moving into the ocean, and in some it’s moving from the ocean to the atmosphere. These fluxes are substantial, and they’re caused by different mechanisms at different times in different places. Imagine if conditions change to cause one of those mechanisms in a particular place to increase relative to the others. It can shift the balance, causing more of the heat buildup in the system to accumulate in one reservoir rather than the other. One of those proposed and observed mechanisms involves changes in Pacific winds which cause more heat to be transferred from the atmosphere to the ocean (you can read a paper if you want the details). It’s not a HUGE shift, but since the fluxes between the atmosphere and the ocean are large, it doesn’t necessarily take a huge shift to upset the balance. And the other thing to keep in mind is that it’s instantaneous. It doesn’t take years of buildup, because it’s just a minor shift in the balance of flows.
There. I’m done. I’ve said too much. I hope I haven’t confused you. And frankly, unless you come back with a genuine question rather than just a rhetorical quibble, I won’t engage any further.
Just for the record, if anybody’s counting, Victor’s deficit about trends should have been cleared up back around response 100 or so, in particular by these pointers to high school level explanations that are quite clear and don’t pontificate but rather walk the student through the math for, e.g., deciding how many years of data are needed to determine the likelihood of a trend _in_that_particular_data_set_ (that’s how statistics works):
https://www.realclimate.org/?comments_popup=18042#comment-624122
Kids, do try this at home. You’ll see the world better than eyeballing can when you understand variation and trend detection (and the lack thereof) for any _particular_ bunch of numbers you may be curious about.
The answer’s specific to the data. Arithmetic, not magic.
But, alas, this is repetition.
http://theconversation.com/ocean-depths-heating-steadily-despite-global-warming-pause-37047
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2513.html
Nature Climate Change | Letter
Unabated planetary warming and its ocean structure since 2006
Dean Roemmich et al.
Naure Climate Change (2015)
doi:10.1038/nclimate2513
The comment @259 “If A is the cause of B, then it should be possible to demonstrate the existence of a correlation between them.” reminds be of Russ Ackoff who famouwly ‘proved’ smoking prevented colera. His point wasn’t so much that smoking was in any way a good thing, but damned if he was going to have an idiot using statistical methods in such a stupid way to announce that a “proof” that smoking caused cancer. So Ackoff used the identical analysis but for colera. I’m sure the likes of Ackoff would be the first to agree that it is not required “to demonstrate the existence of a correlation” for causality to exist or even to be shown to exist, especially if you attempt very hard not to find such a correlation solely by naively ‘eyeballing’ a graph that plots less than half the relevant data and then backing it up by the announcement “Stupid … in fact I’m not.”
VICTOR
http://www.reportingclimatescience.com/news-stories/article/global-warming-pause-due-to-pacific-says-trenberth.html
Read this please and then you wont need to post here so much perhaps :)
AMO and PDO and ENSO feature a lot in heat transfer between atmosphere and oceans.
Victor wrote at 259 in reply to my 253,
“OK, first of all, the formula “causality always implies correlation” is a universal principle of science……….”
This could be true only in some abstract world in which there are no competing cause and effect relationships. But it’s false in the real world, since the world is full of examples where we have known cause and effect relationships not showing themselves in data as correlations that we would expect in the absence of competing cause and effect relationships. Example (gave another one in 231: Suppose we put a stove with a pot of water on one of its heating elements into a very powerful walk in freezer, already on. We turn the stove on and at a setting sufficient to boil the water. We now have two competing cause and effect relationships – we are simultaneously trying to boil the water and freeze the water. Depending on the settings of the stove and freezer, we probably will have at least one known cause and effect relationship not showing itself in the data in which case we will not have a correlation that we would expect in the absence of competing cause and effect relationships.
The same idea holds for the Earth’s global temperature and the known cause and effect relationships with respect to its temperature.
It should be common knowledge that it is common in the real world to have competing cause and effect relationships yielding real world data that does not always express all these relationships as correlations.
Victor, that part of your whole comment at 259 that uses the term “trend” takes as an assumption a fundamental rejection of a large area of important mathematics (virtually all of statistics) and what many professional mathematicians do for a living. This is clear from how you use the term “trend” and how you reject the use of smoothing techniques – and by what you said in other comments, belittling the uses of various statistical techniques to get at underlying patterns in data.
In addition to the Wikipedia article I cited in 253 on trend analysis, this Wikipedia article below is a good introduction to a small part of this mathematics, and shows why mathematicians and scientists use these techniques:
http://en.wikipedia.org/wiki/Smoothing
Quote from the article: “In statistics and image processing, to smooth a data set is to create an approximating function that attempts to capture important patterns in the data, while leaving out noise or other fine-scale structures/rapid phenomena………….. One of the most common algorithms is the “moving average”, often used to try to capture important trends in repeated statistical surveys.”
Victor, it seems that you are hung up on the term “trend” in such a way that disallows you to pull back from the subintervals and see what’s potentially happening over a longer interval. *For purely the purposes of illustration*, let’s move this into a purely mathematical realm: Take function f(x) = x^(1.9) – the Google Chrome browser automatically will graph the right side of the equation – you don’t have to go the Google search engine. To obtain a new function whose graph shows a fluctuating behavior around f, add function g(x) = 17cos(x) so that h(x) = 17cos(x) + x^(1.9) is the result. Function f is the underlying increasing trend curve for h. To see this, take all the values of x in f and g for which g(x) = 17cos(x) = 0. Now look at the graph of h from x=0 to roughly x=14. It seems that what you are doing in your claims on trends is mathematically equivalent to claiming that roughly from x=9 to x=13, there is an upward trend, but that from x=0 to roughly x=9, there is no underlying upward trend curve at all, even though there is – it’s f. (See again f by itself.) And it seems that your claims on trends is mathematically equivalent to claiming that a slowdown from x=13 to x=14 and little further means that f is no longer the underlying trend curve for h when it still is. That is, you do the mathematical equivalent of taking the fluctuating behavior of h around f given by the interaction of f and g to mean that the upward trend curve underlying h given by f doesn’t exist when it does.
Finally, I note that you have not acknowledged the falsification I gave in 231 of your claim that all the energy of the ocean heat content increase since 2000 was first sitting in the atmosphere in 1979. (If it was in the atmosphere in 1979, then it would have heated up the atmosphere on the order of 15 degrees C. There has been that much increase in ocean heat content since 2000.)
Victor,
You say you are here to debate rather than learn about climate science. Problem is that the purpose of this website is precisely to teach interested laymen about climate science. It is specifically not intended to be a debating society.
So you find yourself in the position of a person trying to hammer a nail with a predision micrometer. It is no wonder that people are responding with derision and hostility.
Some observations [resubmitted because they somehow got lost]:
1. Increasing the atmosphere’s GHG concentration increases the amount of backradiation reaching the ocean’s surface.
2. All else being equal, (1) will cause ocean surface temperatures to rise.
3. But if something causes heat to be transferred from the ocean surface into its deeps more rapidly than usual, ocean surface temperatures could rise more slowly, not rise at all, or even fall despite the increased backradiation.
4. Even if ocean surface temperatures fall as in (3), heat continues to accumulate in the earth system until the amount of outgoing radiation at the top of atmosphere equals the amount of incoming radiation there.
5. Heat accumulation as in (4) can take decades, because the heat capacity of the oceans is far larger than that of the atmosphere.
6. (5) is what is meant by “warming in the pipeline”.
7. That is, each molecule of GHG emitted immediately increases the amount of backradiation at the surface, but because of the surface’s heat capacity, the surface’s temperature takes a long time to reach equilibrium with the increase in backradiation.
P.S. To this: I understand how the CAPTCHA is supposed to work. The problem is that most of the images that it gives me are nearly impossible to decipher.
V (259): The only clear trend I see is from 1979-1998
BPL: Victor, in statistics there is a precisely defined meaning of trend. A time series exists a “trend” if the slope of the series regressed on elapsed time is statistically significant. By that definition, there is a very definite trend upward of surface temperatures since at least 1850. It isn’t really something subject to personal opinion.
Re- Comment by Meow — 3 Feb 2015 @ 1:54 PM, ~#272
For the second time, I don’t have to solve any CAPTCHA riddles now approaching 90% of my submissions. In only one in ten of my comments am I required to decipher a word or number.
Steve
I had a lengthy, but, I thought, rather good comment go missing.
From it, I’ll only address the SkS ‘thermal inertia’ quote, which Victor took to imply a lag in response: the proposed 21-year delay between atmospheric warming and oceanic warming.
Considering the physics, my point was that it implies not a lag, but rather an immediate *but slower* oceanic warming. And if you compare land temps (BEST, smoothed with 13-month mean) with SSTs (Hadley3, 3-month mean), guess what you get?
http://www.woodfortrees.org/plot/best/from:1950/mean:13/plot/best/from:1950/trend/plot/hadsst3gl/from:1950/mean:3/offset:-0.1/plot/hadsst3gl/from:1950/trend/offset:-0.1
OK, so SSTs, aren’t OHC, but the latter aren’t on WFT, and anyway would pose scaling issues I’d rather not confront.
@3 Feb 2015 at 10:20 PM: I use the same procedure you do, but still am required to decipher a new puzzle with each message I submit. Perhaps one of us (probably I) has blocked some script that the CAPTCHA uses.
Re #201 Victor:
[…]
#192 “For example a strengthening of wind over some oceanic region
Marcus, your invocation of effectively instantaneous heat flow reminds me of an amusing theory known as “Morphic Resonance.” Check it out, it’s fun: http://skepdic.com/morphicres.html”
[…]
Instead of playing the clown you could kindly explain what kind of “instantaneous heat flow” you are talking aboút. Such a thing has been not been postulated or required.
[…]
The paper you’ve linked us to is, by the way, yet another instance where climate scientists acknowledge the hiatus as real.
[…]
As we all know very well (you too), “hiatus” is an ambiguous word. No one doubts that there is a slow down of surface temperature rise after the 1998 El Nino,
which is probably an artefact due to internal variability of one or the other kind.. some scientists label that “hiatus” to refer to discussions.
Science does not agree to the denialosphere narrative that this is a “hiatus” in global warming.
[…]
My questions regarding atmospheric to oceanic time lag are based not only on common sense, but also on what I’ve been reading in the cli. sci. literature
[…]
You should learn to read this literature properly and avoid unqualified interpretations and twists of it, if (if!) you intend to understand something.
You cite
[…]
“The reason the planet takes several decades to respond to increased CO2 is the thermal inertia of the oceans. Consider a saucepan of water placed on a gas stove.
Although the flame has a temperature measured in hundreds of degrees C, the water takes a few minutes to reach boiling point. This simple analogy explains climate lag.
The mass of the oceans is around 500 times that of the atmosphere. The time that it takes to warm up is measured in decades.”
[…]
Note that this explanation refers to the thermal intertia of the oceans, but not really to thermal mass of the atmosphere. Reread the posting you have answered too,
that explanation would work out perfectly even if the atmosphere had no thermal mass at all (this is not the case). The elevation of the atmospheric temperature is
due to a shift in the radiative equilibrium, i.e. more back radiation absorbed by added gases, selective to IR radiation. This leads to a higher equilibrium temperature,
but balance is reestablished again in a sense that time averages of energy in-and-out are equal for each volume element, given some fixed elevation of
greenhouse gas concentration. Thermal mass of the oceans on the other hand is huge, so they follow with some principal lag of decades, but they follow “noisy” as
decadal variations like ENSO or changes in weather patterns due to climate change overlay that.
This omits many details of course, but there is nothing here that challenges the principal concept
After some applause for the recent moderating actions,
Wili @266,
yes, some on-topic grown-up comments.
The C&W result presented by Kevin Cowtan is interesting. They place 2014 in second place behind 2010 and point to both their infilling and the CRU’s data reducing 2014 temperature compared with 2010.
Their second place slot for 2014 is obviously provisional in nature as Cowtan concludes “So was 2014 the hottest on record? We don’t know yet, but we know one of the places where we need to look for the answer,” the place mentioned being Antractica.
In troll-speak:
‘Debating’ means trolling.
‘Logic’ means sophistry.
Logic is a good thing. Sophistry is a steaming pile of you-know-what. And as we’ve already learned there’s NO meaningful debate about what’s being trolled here. Don’t let yourselves be conned out of your language.
#275
Your reliance on back radiation at the sea surface seems to me to be incorrect. The main physics going on there is that the ratio of specific heats in the atmosphere is not one. http://en.wikipedia.org/wiki/Heat_capacity_ratio This lead to a thermal lapse rate in the atmosphere that is not zero. http://farside.ph.utexas.edu/teaching/sm1/lectures/node56.html
Because the lapse rate is not zero, changing the altitude near the top of the atmosphere where infrared radiation escapes freely to space allows adjustment of the surface temperature by means of the addition of greenhouse gases. Heat exchange between the ocean and the atmosphere is mainly mediated by the blowing wind, evaporation and condensation not infrared radiation.
In case anyone is wondering why I haven’t responded to your posts, it’s because my comments are now being relegated to the borehole. And the most recent ones aren’t even posted there, though hopefully they’ll show up soon. OK, fair enough. The moderators have been very indulgent for some time, so I won’t complain.
I will ask, however, that this post be permitted to go through if for no other reason than respect for those who’ve taken the time to engage with the issues I’ve raised and deserve some sort of response, however brief. I will be brief.
On the topic of trends and statistics, as I see it, statistics is primarily a computational tool, not an observational one. It enables us to evaluate data quantitatively and perform computations based on that data. But it can be very deceptive when attempts are made to use it as an observational tool, which is a very different matter. That’s all I’ll say on that topic.
As far as the time delay issue is concerned, I’ll once again quote from the Skeptical Science post: “The reason the planet takes several decades to respond to increased CO2 is the thermal inertia of the oceans.” NB: the statement already assumes that several decades are required for the planet to “respond to increased CO2,” which makes it difficult for me to understand why the notion of a delay has been so vociferously attacked here by so many. Is this sentence incorrect? If so, then I urge someone to take it up with whoever runs that blog, because I might not be the only one to be misled by it.
That’s all I have to say. I won’t be posting here anymore. If you have further questions or issues you are welcome to post them on my blog. Thanks for your (im)patience.
http://marvelclimate.blogspot.com/2014/09/i-am-so-bored-with-hiatus.html
http://2.bp.blogspot.com/-pW34irCG4DQ/VA4tDywV7aI/AAAAAAAAA1g/OMUB2fDCrwk/s1600/OHC.png
All this talk of a hiatus is obsolete anyway. Remember that for the first time we have had a maximum(or near one)without a strong El Nino. So last years temperature could be something like the new normal. Sooner or later there will be a strong El NIno and the high will be well over 0.7 on the Nasa Giss scale.
I guess by ‘instantaneous heat flow’ Victor means much faster than 21 years. Co2 can’t cause such a flow, it will off course heat the surface first and flow of heat to the sub-surface will lag over years, decades and even centuries (not sure why 21 years gets a special mention?) But Co2 isn’t the only thing affecting climate. Changes in winds and currents can push warm water from the surface into the deeper ocean – therefore providing an ‘instantaneous heat flow’. It might take days or weeks or months, but it can be much faster than 21 years. Without Co2 warming such a change would result in a cooler surface and warmer subsurface. Combine with Co2 warming the surface and it can just so happen that the two effects cancel at the surface for a ‘pause’ while the wind/current driven heating of the subsurface causes extra heating in the subsurface.
@4 Feb 2015 at 9:45 AM:
This is incorrect. Most of the heat entering the ocean arrives via backradiation, as with land, though the microphysical mechanism is somewhat different. Trenberth et al, “Earth’s Global Energy Budget”, http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.210.2513&rep=rep1&type=pdf at Table 2b shows that backradiation contributes ~343 W/m^2 of heat to the ocean, averaged globally and annually. This is about twice as much as absorbed solar radiation (~168 W/m^2), over 3x as much as evaporation (~97 W/m^2), and about 30x as much as sensible heat loss (~12 W/m^2). The table shows that the ocean’s primary heat loss mechanism is also radiation, at ~401 W/m^2.
You need to do a subtraction there to get the net. http://eesc.columbia.edu/courses/ees/climate/lectures/o_atm.html
I note there was another cry from the borehole. It protested that this comment thread was paying too much attention to Victor & was ignoring the questionings @42, @58 & @89, and that despite the commenter getting two in-line reponses. I would hate that somebody felt they were being ignored because of a troll.
Keith Woollard, it is not so difficult to stretch one of the graphics you link to and make it the same scale as the other and then to superimpose the pair, one on the other. The re-scaling achieved isn’t entirely spot-on but that actually assists in comparing the data which would otherwise be difficult to see. The superimposed line of interest is the blue GISStemps line.
Gavin et al., thanks for consigning Victor to the borehole. I couldn’t believe his response to my comments on what “trend” means–essentially, Humpty-Dumpty’s approach to vocabulary. You can’t argue with someone like that, which is the point. I should have realized much earlier that Victor’s intent here was not to learn or even to argue, as argument is normally construed, but to waste people’s time. Sabotage. Thanks for being more on the ball than I was.
The linked WSJ article (www.wsj.com/articles/2014-ranks-as-earths-hottest-year-since-1880-1421427411) is indeed surprising. On could almost say that the most skeptical remark in this WSJ piece is one by a certain Dr. Schmidt (““Why do we think this is going on? The attribution of these long-term trends is a complicated fingerprinting exercise,”). Other than that, there is “Some skeptics, however, have suggested that the rise in global temperatures has actually slowed since 1998, which was itself a record-warm year.”
As the global warming trend continues, one would think that the WSJ will no longer be able to even weakly attempt to hang their hat on 1998. So what’s trend at the WSJ? Mere uncertainty? I think the trend at the grass-roots is to claim yes the climate is warming and no it’s not man-made, but the WSJ did not play that card this time.
[Response: The news pages and the op-ed pages are often in different universes, though obviously editorial influence extends across both. An occasional straight story does slip in though. – gavin]
Ray Ladbury:
The wonder is that people respond at all. DNFTT, for cryin’ out loud!
Well, at least Victor got one thing right, that SkepticalScience piece requires some editing as it can be misleading. I did add a comment to the article but have had no response. An earlier comment (linked in my comment), along similar lines, did get a response which says the right things but the article was not edited at that time.
Re #284
“As far as the time delay issue is concerned, I’ll once again quote from the Skeptical Science post: “The reason the planet takes several decades to respond to increased CO2 is the thermal inertia of the oceans.” NB: the statement already assumes that several decades are required for the planet to “respond to increased CO2,” which makes it difficult for me to understand ”
What makes everything difficult to understand for you is that you confuse reading with quotemining. Set in context it is immediately clear what they mean with “decades to respond”, the time it takes for the system to arrive at a new dynamic equilibrium, a lag caused by the thermal inertia mainly from the oceans. One could find a better wording for that, but it is not really prohibitive for those who want to understand.
@Mal Adapted #293 5 Feb 2015 at 9:51 PM:
“The wonder is that people respond at all. DNFTT, for cryin’ out loud!”
You’re forgettign how many enthsiastic amateurs read and contribute to threads on this site. The beauty of this community is that even when feeding trolls there’s plenty of meat given for others to chew on. #288 & #289 have shown me quite how wrong my understanding of the mechanisms (see my #233) was. You might say I should have learnt/known that anyway, but this thread firstly made me formalise my understanding and, as a result of others responding to the troll, improve it.
All,
I was completely wrong, I will write a comment when I work through my previous thinking and decide how I fell for such an obvious optical illusion. I suspect pre-conceived ideas and edge effects had something to do with it.
sorry
With respect to “The reason the planet takes several decades to respond to increased CO2 is the thermal inertia of the oceans”, blog comments are now speculating Ken Caldeira’s new paper – Warming reaches maximum 10 years after carbon dioxide emission – means there is no warming in the pipeline.
[Response: This is nonsense. The reason why there is ‘warming in the pipeline’ is because there is a significant imbalance in radiation at the top of the atmosphere. The planet needs to warm in order to neutralise that imbalance (assuming no further changes in forcing). Of course, forcing is actually increasing, so even more warming is anticipated. – gavin]
Robin Levett:
Quite right, as long as those feeding the troll aren’t simply repeating themselves ad nauseum. I still hope he-who-wishes-to-remain-erroneous honors his pledge not to post here again, though. For the sake of your own learning, I encourage you to continue posting your wrong understandings freely 8^D!
#298–Yeah, such a contention would be vaguely analogous to the old “climate has warmed before, therefore humans can’t be warming it now” hooha.
Some folks seem to have real trouble determining just which question is being addressed at a given time–or, maybe more likely, they want to obscure the point (just about any climate-related point!) for the unwary out there on the Intertubes.