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Matthew L at 01:21 AM on 21 March 2013Lessons from Past Climate Predictions: Syun-Ichi Akasofu
Thanks Tom for taking the time with those comments. The first one went over my head somewhat, but the second with the history on the sunspot cycle research and backwards projection of Akasofu's chart was very informative.
This example has also clarified in my mind that climate prediction isn't amenable to simple linear models - there are just way too many factors involved.
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Albatross at 01:08 AM on 21 March 2013David Rose Hides the Rise in Global Warming
Thanks OPatrick @14,
Someone in the comments section summed up part of the problem nicely:
"[Dr. Myles Allen] "But if climate scientists refuse to talk to Mail on Sunday correspondents, then their only information sources left are bloggers and David Whitehouse."
And the problem with that is? "The Mail story is based on bloggers and a non-expert" doesn't have much credibility in comparison to "The Mail story is based on an interview with climate scientist, Myles Allen". You gave their lies credibility."Exactly, therein lies the problem and scientists need to wake up to that fact. If scientists do elect to speak to a journalist, then they need to insist that they (the scientist) record the interview.
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OPatrick at 00:40 AM on 21 March 2013David Rose Hides the Rise in Global Warming
Myles Allen has responded in the Guardian.
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Philippe Chantreau at 23:36 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"In OECD countries, nuclear waste was always handled, has hurt noone and poluted nothing."
Fair enough, and mostly accurate, although I haven't researched it. However, you're talking about making a drastic switch to global scale production in which nuclear will be the dominant source and inevitably will be undertaken by most countries, including non OECD. Kabul can't even keep up a decent sewer system and people there get exposed to this lovely thing known as "fecal dust", you feel like taking up a nuclear energy contract in this human environment? Hmmm...
Furthermore, we have not yet moved beyond storing away that waste with the assumption that we will continue to do so for 20K years or so. Perhaps we should reserve definitive statements on our ability to handle it until that time has gone by.
You didn't adress the supply issue. At current consumption rates with current technology, it would last about 200 years. Projecting from current rates of growth, the MIT study below sees a peak in 2076, only about 60 years away, depending on what's really in Australia. Of course, they're too busy extracting coal right now.
http://dspace.mit.edu/handle/1721.1/54467
However, with the rate of growth you suggest, it's anybody's guess how much earlier that would happen, even with immense undiscovered Australian deposits. Some of the equipment might not have too much of a chance to become obsolete. Of course, we could extract U from seawater but then how closer are we to a commercially viable solution of that kind than to energy storage solutions that would solve the curtailment problem?
Bottom line is, while nuclear in its current form is probably an indispensable step, it is still only a transitional solution. It may be good for 70 years, or a couple of hundreds, but to be a longer term panacea it has to be different than what we have now, different enough that a radical transformation will be necessary again. There is no silver bullet, unless we get fusion going. This is a finite world.
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gws at 23:17 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
JvD, thanks for coming back and explaining your position better.
I think there is an issue here, which your assertiveness suggests you have not accepted yet, namely that your position is not the ultimate one. While climate science itself is consilient and displays a remarkable consensus, how best to go forward to address our climate and energy problem is not settled. But it is a needed discussion, so you are welcome to argue the way forward.
Statements such as "... which is the scientific position" (JvD @353 and your whole post at @351) suggest that you seem to assume you know a truth few other people have realized yet, while several people here have put reasonable arguments forward suggesting you are not entirely consistent, or correct. Thus, so far the conversation is not goal oriented, which is also your fault. Too many assertions, too little focus on either side. Everyone should focus on a smaller issue first, say "why is the economic forecast (in the EU paper link you gave) so bleak?" and "is that an accepted fact we cannot hope to change?", or "how can we (best) make renewables provide baseload power?", I suggest. Then take it from there.
On the nuclear discussion: You will not likely see a statement on SkS in favor or against nuclear energy. As there are many arguments for and against that technology, so there are many views among folks here, quite democratic. Your posting style only alienates in this case.
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Michael Whittemore at 22:55 PM on 20 March 2013Science vs. the Feelies
Great video series by David Archer, but you have to wonder if a mass release of Methane was able to drive up the temperature, it might be able to increase the amount of water vapour in the atmosphere like seen on Venus and also warm the Tropopause just enough to start a runaway Greenhouse Effect. It may not have happened on Earth before, but Earth has never had humans until now.
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John Mason at 22:31 PM on 20 March 2013Death in Jurassic Park: global warming and ocean anoxia
@ Magma - I can append the following, if it's helpful - elemental abundances in typical seawater by ppm and % as opposed to atomic:
Element ppm Percentage Oxygen 883,000 86.0341% Hydrogen 110,000 10.7177% Chlorine 19,400 1.8902% Sodium 10,800 1.0523% Magnesium 1,290 0.1257% Sulfur 904 0.0881% Calcium 411 0.0400% Potassium 392 0.0382% Bromine 67 0.0066% -
John Mason at 22:06 PM on 20 March 2013David Rose Hides the Rise in Global Warming
@ John, St Barnabas - have sent them a link to this page.
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StBarnabas at 21:53 PM on 20 March 2013David Rose Hides the Rise in Global Warming
@John Russell
Not a report as such. Just a regular slot what is in the papers early Sunday morning, where it got a mention. Sadly half asleep in bed at the beginning- had a rude awakening!, Possibly I can find it on BBC I-player but it was just a 30s or so summary going through the main points of Rose's article. Job done as far as the Skeptics are concerned of course...
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CBDunkerson at 21:15 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
JvD, setting aside the fact that your analysis is at odds with findings by numerous studies... it also seems to be at odds with itself.
You argue that there is so much excess renewable power that it must regularly be given away to neighboring countries for free and that renewable power cannot be used to power various forms of energy storage facilities because they would frequently sit idle due to the lack of excess power.
These scenarios cannot both be true. Indeed, my understanding is that they are both false, but it is clearly impossible for there to be both 'too much' excess renewable power and 'too little' at the same time. Thus, surely you must acknowledge that at least one of these arguments is allowing hyperbole to run amok?
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JvD at 19:53 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
My comments don't seem to be published anymore ... will come back later.
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JvD at 19:52 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
Excerpt from Barry Brooks analysis, which describes my position (which is the scientific position):
"The critique of the future global role of renewable energy by
Trainer (2010) underscored many important limitations associated
with variability, dispatchability, large-scale energy storage, the need
for overbuilding and geographical replication (and the likely consequence: ‘dumping’ of unused excess energy), energy returned on
energy invested, and other key points. The meta-analysis by
Nicholson et al. (2011) also considered technological maturity, cost
and life-cycle emissions as constraints on renewables’ capacity to
displace fossil fuels. Although I support Trainer’s (2010) conclusion
that renewables alone will not be able to ‘solve’ the greenhouse
problem, I argue that his dismissal of a major role for nuclear fission
energy, working in complement with other low-carbon energy
sources, was unjustified.
The principal limitations on fission energy are not technical,
economic or fuel supply—they are instead tied up in the complex
issues of societal acceptance and public education (Adamantiades
and Kessides, 2009; Pidgeon et al., 2008), fiscal and political
inertia (Hyde et al., 2008; Lund, 2010), and inadequate critical
evaluation of the alternatives (Jeong et al., 2010; Nicholson et al.,
2011; Trainer, 2010). Ultimately, as the urgency of climate change
mitigation mounts, and requirements for sustainable growth in
developing economies and replacement of aging infrastructure in
the developed world come to the fore, pragmatic decisions on the
viability of all types of non-fossil technologies will have to be
made. Engineering and economics realities point to a large role for
fission in this new energy future." -
JvD at 19:48 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"And... you consider your assumption of 100% curtailment of excess renewable energy to be 'honest'?"
Excess energy from intermittent renewables will follow the following path:
1. First, it will be forced exported. It may even be exported at negative price, which already happens sometimes in Denmark and Germany. In that case, foreign energy consumers are actually *paid* to take the electricity. That is because destroying electricity costs money, so sometimes it is cheaper to pay energy users to take it. Of course, using energy export as a way of mitigating the problem of oversupply of intermittent renewables simply transfers the problem to the neighbouring country. For example, in my country, the Netherlands, the liberal politicians are reducing the targets for intermittent renewables build because we are already getting more and more imported electricity from Germany. In fact, we are getting this energy very cheaply, because the Germans have to underbid our local energy suppliers. Sometimes, we literally get 'free' electricity from Germany in this way. Obviously, increasing amounts of curtailment and forced export will bankrupt the energy suppliers sooner or later, which is the kind of problems Germany and Denmark are currently grapling with, although almost nobody realises this. Still, as long as German taxpayers are willing to ignore how they are being exploited, Dutch consumers will happily consume their expensive electricity for free.
2. Second, if 1 is not an option, and if it is possible, the intermittent energy source will be taken offline. Modern wind turbines have the ability to shut themselves off precisely for this reason, which reduces the need for costly stand-alone electricity destruction facilities.
3. Finally, destruction. If 1 and 2 are tapped-out, and if large, prompt supply shock occur (which happens when cloud front pass over solar farms, or when storms hit wind farms, when demand drops quickly, or when there is no where to go for the excess electricity for some other reason, the electricity is then destroyed in load banks. Load banks may consist of large resistence circuits or steel shafts drilled into the ground to dissipate electricity in the ground. This is currently used in Denmark and Germany. Note that those countries still only have a minority penetration of intermittent renewables, yet the problems of curtailment are already glaring. As they increase those sources further, they will need larger and larger electricity destruction facilities. Moreover, the tax-payers in those countries always pay for the full production cost of the renewable electricity that is being destroyed in this way, thereby also destroying their own pocketbooks and failing to reduce their coal use. in fact, Germany used 5% more coal last year, even while intermittent sources grew. Closing nuclear power plants is of course a massive own-goal of the Germans and a hit against the health of the planet and the German people. The increasing coal use in the EU will kill an additional 900 people every year (5% of 18000 per year current), which is 15 times the number of people killed in total by Chernobyl.
Finally, the concept of using the excess electricity for hydrogen or synthetic liquid fuels production or some other worthy cause will not work, for a simple reason. Such facilities are extremely capital intensive and need to be used 24/7 in order to have a hope of recovering investment costs. Certainly, if such facilities would sit idle until such time as there is an excess of intermittent energy, the unit cost of the hydrogen or synfuel produced will multiply.
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JvD at 19:20 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"You are putting some blame on SkS in your last post @340. If you want to improve the post and get people to do it, because you are convinced of being correct regarding the "faulty and baseless treatment", you need to be more convincing, maybe even do a selective rewrite for consideration."
The post should be rewritten using Ted Trainer's conclusions, which are credible. Subsequently, SkS should indicate that nuclear power can allow a decarbonised energy supply when it is used rather than fossil fuels, such as explained by Barry Brooks in the above link.
Thank you,
Joris
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JvD at 19:18 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"What is your alternative scenario (to 100% renewables)? What alternative scenario do the sources you cite offer (quoting Ted Turner from that blog you cited: "It is also my view that we should transition to full dependence on renewables as soon as possible…although this will not be possible in a consumer-capitalist society.") ?"
Ted Trainer does not include nuclear power in his assessments, which is why he concludes that we must move to a 'simpler way'. That is: economic collapse. As is happens, there is a good article that discusses how Ted Trainer's research conclusions would change if the nuclear option was added. I'm going to present the following paper as a good description of my 'alternative scenario'. In my scenario, economic collapse is not a feature, but something that is successfully avoided without harm to the environment.
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JvD at 19:12 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"IMHO, your arguments did appear a bit unfocussed, and you moved the goalpost throughout the discussion and addressed few of the questions posed to you to understand the background assumptions you seemed to make."
IMHO i moved no goalposts and addressed all relevant questions. Note that I was asked four individual times to point to scientific literature before it was acknowledged that I had in fact provided such. It is difficult for me to understand why now I am the one ignoring questions.
By 'moving goalposts throughout', if you mean that I excluded war-zones from suitable sites to build nuclear power plants, then I must dismiss this criticism as simply being argumentative. For that matter, in a war-zone, wind farms and solar farms will also not likely be built. Arguably, wind farms and solar farms less suitable, because micro nuclear power can be trucked-in to provide power where it is needed, whereas solar and wind farms are fixed location assets that are extremely vulnerable to small weapons fire and sabotage.
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JvD at 19:07 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"As you cited only 1-2 sources though, I wonder what makes you think the contents of these are superior to what others have written?"
In the sources I mentioned, numerous additional sources are mentioned in the references. This is normal science, i.e. reading scientific literature rather that suggesting it's not there. Normal science also shows you can't run an aluminium smelter (24-hour operation) using solar or wind power (intermittent). Therefore, it is up to the deniers of this common knowledge to come up with research that shows aluminium smelters *can* be run on solar power. Instead, all I see is handwaving and references to pumped storage. However, pumped storage is far to small to help in providing storage for a 100% intermittent renewables scenario. There just aren't enough sites to built pumped storage. -
JvD at 19:03 PM on 20 March 2013A Detailed Look at Renewable Baseload Energy
"One obvious one is that, on the long term, there is only so much uranium on the planet, so very large scale nuclear generation using that as a fuel has the same basic problem as fossil fuels, GW notwithstanding. The other is that the same very large scale (global) generation will multiply the problem of waste which I already stated I wasn't so sure we handle well. "
This is a popular myth produced by fossil fuel pushers. It needs to be stamped out for there to be any kind of serious discussion about stopping AGW economically. Nuclear waste handling is far easier than handling co2, nox, sox and heavy metal waste from alternative energy sources. Even solar power and wind power produce waste. For example, the solar and wind farms built in the USA in the 20th century were never decommissioned and still sit there rusting and leaking heavy metals into the ground water. Presumably, modern windfarm and solar farms will also rust and leak after they are broken or after subsidies stop. This is not speculation, but demonstrated by history. In OECD countries, nuclear waste was always handled, has hurt noone and poluted nothing. Strong indication that we know how to handle it.http://www.mcgill.ca/files/gec3/NuclearFissionFuelisInexhaustibleIEEE.pdf
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John Russell at 18:35 PM on 20 March 2013David Rose Hides the Rise in Global Warming
@SCM
Actually this was the first of two complementary (note: with an 'e' not with an 'i') articles written by David Rose and published by the Mail on the same day. This is 'No 2'. 'No 1' sets up the con that justifies No 2.
As to whether these are a continuing series: based on both the Mail's and Rose's history to date, I fear so.
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SCM at 18:07 PM on 20 March 2013David Rose Hides the Rise in Global Warming
The title of the original Mail on Sunday article is "The Great Green Con no. 1 :...."
I wonder if this means we can expect a continuing series of articles in the same vein. If that is the case you're going to be kept busy playing whack-a-mole.
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Dikran Marsupial at 17:59 PM on 20 March 2013Lessons from Past Climate Predictions: Syun-Ichi Akasofu
Following on from Tom's comment, another difference between Schwabe and Akasofu is that Schwabe did not ignore generally accepted physics (such as observed changes in solar, GHGs and aerosol forcing) that already adequately explain the observations. For Akasofu's hypothesis to be correct, we would need to be wrong on a fair amount of existing physics (which would then make a lot of paleoclimate very hard to explain).
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Klapper at 15:21 PM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@Soundoff #37:
Since we've discussed this before, you know there's a step in the land SAT circa 1945 too. However, as I've been informed to take my commentary to a dormant thread, I'll leave it at that.
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SoundOff at 14:44 PM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
The root cause behind Klapper's Komplaint may be another case of the models being correct and the observations being wrong.
SST Instrumental Biases in 1945
“A large discontinuity in the mid-twentieth century in observed global-mean surface temperature”
David W. J. Thompson, John J. Kennedy, John M. Wallace & Phil D. Jones
Nature, 29 May 2008
Data sets used to monitor the Earth’s climate indicate that the surface of the Earth warmed from ~1910 to 1940, cooled slightly from ~1940 to 1970, and then warmed markedly from 1970 onward.
The weak cooling apparent in the middle part of the century has been interpreted in the context of a variety of physical factors, such as atmosphere–ocean interactions and anthropogenic emissions of sulphate aerosols. Here we call attention to a previously overlooked discontinuity in the record at 1945, which is a prominent feature of the cooling trend in the mid-twentieth century. The discontinuity is evident in published versions of the global-mean temperature time series, but stands out more clearly after the data are filtered for the effects of internal climate variability.
We argue that the abrupt temperature drop of ~0.3 °C in 1945 is the apparent result of uncorrected instrumental biases in the sea surface temperature record [since it is only apparent in SSTs].
Corrections for the discontinuity are expected to alter the character of mid-twentieth century temperature variability but not [alter] estimates of the century-long trend in global-mean temperatures.
Apply this correction and the observed 1910 to 1945 warming rate will decrease to what models understand should have happened according to known forcings.
Moderator Response: [RH] Fixed link. -
andylee at 14:36 PM on 20 March 2013February 2013 Arctic Sea Ice Death Spiral Update
Nice graphs Jim! ;-)
Kevin, the spiral lines in fig1 are the contours of averaged months in fig2, moving from back to front, or what you see in the animation when the graph rotates.
CBD, re sharp angles.. the lines are virtual, because they can't exist - halfway between Jan 2012 and Jan 2013 is Jun 2012 - another series!
I hope to make it clearer in a future animation.
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Tom Curtis at 11:46 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Klapper @35, the a significant portion of combustion in WW2 would have produced black smoke, and hence Black Carbon (BC), a warming factor. In fact, the less controlled the combustion, in general, the higher the proportion of aerosols is in the form of BC. This is likely to have contributed to the spike in warmth in 1940, but there is insufficient BC in glacial records at that time for it to be the primary explanation.
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Klapper at 10:44 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@Bob Loblaw #33:
Previous to this conversation I'd downloaded both PMOD/ACRIM data, binned them by month and calculated correlation coefficients against SSN (Sunspot number). The R-Squared for PMOD is 0.80, for ACRIM it's 0.61 for all months 1992 to 2012. I used the reconstructions which splice the data from different satellites by correcting as they see fit the baseline shifts between them. My guess is the PMOD people adjusted the baseline shifts to maximize the correlation with SSNs. No problem with that. Maybe ACRIM went more on first principles and said this is our best guess of the shifts, irrespective of the correlation with SSNs. Either way the correlation is still pretty good. In both datasets, the scatter is much lower for lower SSN months. In the period 1910 to 1945 we generally had lower SSNs through the cycle peaks, than post 1950.
As for aerosols, the volcanic record is what it is, after Katmai there are no major eruptions, so that simplifies the aerosol record somewhat. As for man-made aerosols, 2 facts aid the interpretation of the limits of aerosol change in the 1910 to 1945 period. Number 1, the was no major regulation of emissions in that period, so unit emission per unit consumption did not change much, although there was some displacement of coal by oil. Number 2, the consumption was fairly linear for both oil and coal through this period, the big inflection point in consumption being about 1950.
All that being said, what forcing parameter could we expect to change by a lot in the period 1910 to 1945. My argument, as elaborated above, is that no known climate forcing parameter changed by a lot in this period and the ones that did, we have a reasonable handle on. At times I've thought the aerosol output from WWII is one of the wildcards (burning cities/towns/millions of tonnes of high explosive kicking up particulate matter etc.), but if anything that would have cooled things down, yet there is a distinct temperature peak during the war.
So that brings us back to the question at hand. What caused the rapid warming from 1910 to 1945, given we can't realistically see rapid changes in anthropogenic or solar forcings during this period, which is also more or less free from major vulcanism?
Moderator Response: [DB] Please refer to both the Comparing past climate change to recent global warming and the What caused early 20th Century warming? threads for reference. If you still wish to then pursue this line of inquiry, take it to one of those threads, not here. -
Tom Curtis at 10:32 AM on 20 March 2013Lessons from Past Climate Predictions: Syun-Ichi Akasofu
Matthew L @54, in fact the sunspot cycle was not hypothesized until 1843, and that on the basis of observations of around one and a half solar cycles. Heinrich Schwabe reported that:
"From my earlier observations, which I have reported every year in this journal, it appears that there is a certain periodicity in the appearance of sunspots and this theory seems more and more probable from the results of this year."
There is a marked contrast between Schwabe's tentative "seems more and more probable" and Akasofu's rather definite "We learn that the recovery from the LIA has proceeded continuously, roughly in a linear manner, from 1800-1850 to the present".
Schwabe's conjecture did not attract widespread interest until 1850, when the number of observations had been extended to three solar cycles. Early interest lead Rudolf Wolf to not only continue the observations himself, but to reconstruct the cycle from historical observations back to 1745, a task completed in 1868. That means that before the hypothesis of sunspot cycles was accepted, there existed known observations of a total of around eleven cycles.So using your chosen example, yes, you can establish the existence of a regular pattern in science without having a physical explanation; but no, you can't do it on just one or two cycles. At the very least, Akasofu should have compared his theory with known variations in past temperatures:
Unfortunately, if he did so, it would be evident that neither the straight line "recovery" from 1800-1850 to the present, nor his regular fluctuations are supported by evidence of past temperatures. In fact, the retrodiction of the linear trend appears to fail at any date prior to 1880; and while there are small fluctuations in the temperature record, which might be regular (and might just as easilly be pure chance), they are nowhere near the magnitude required by Akasofu's theory. (Note, the reconstruction used was chosen as most acceptable to "skeptics", and is biased towards the North Atlantic, and hence is likely to overstate rather than understate fluctuations in global temperature.)
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John Russell at 09:47 AM on 20 March 2013David Rose Hides the Rise in Global Warming
@StBarnabas
I'd be interested if you could point us to that Radio 4 report.
As for the new PCC. I must admit I don't have great hopes. It neeeds testing. In theory newspaper articles must not print falsehoods, but I agree their remit seems very people-oriented. Science seems to be seen as fair game for spin. Is the view 'nobody got hurt': which is maybe true for the short term, but will it in the long term?
It now appears (See Leo Hickman's Tweets for today) that the Mail on Sunday have today been changing Rose's article—for instance by acknowledging the origin of Ed Hawkins' graph (see end of the article). The cynical might say this marks a new tactic... write your story (as deliberately error-strewn as you like); wait until it's been seen by a few million people; then water it down to make it acceptable to the PCC. Voila! Job done. How can you print a retraction of something that's already been retracted—or indeed, appears to have never existed?
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John Russell at 09:17 AM on 20 March 2013David Rose Hides the Rise in Global Warming
I just came across another recent quote from Prof Myles Allen (University of Oxford) that shows how grossly Rose distorts his views ...
“While every new year brings in welcome new data to help us rule out the more extreme (good and bad) scenarios for the future, it would be equally silly to interpret what has happened since the early-2000s as evidence that the warming has stopped.”
That link also contains statements from a number of other climate scientists who reject any suggestion that ‘global warming has stopped’.
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StBarnabas at 09:10 AM on 20 March 2013David Rose Hides the Rise in Global Warming
Of course this is the normal Sunday Mail nonsense. What horrifies me that in the interest of balance it was reported on BBC radio 4 (probably the best news radio station in the UK).
What is of most interest in the new Levinson related legislation - big brinksmanship in Westminster yesterday to curtail lies being printed by the press. Of course this is related to individuals - there have been a few horrific cases recently, but I need to digest if the new complaints procedure can be used.
John Russell any thoughts?
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CBDunkerson at 08:37 AM on 20 March 2013February 2013 Arctic Sea Ice Death Spiral Update
Kevin wrote: "If this is representing the same data, obviously this can't be, so correct me where I've gone wrong interpretting the second figure."
Did you notice that figure 2 shows smooth curves while figure 1 shows sharp angles? That's because figure 1 has one data point per month (the monthly average) while figure 2 has one data point per day. Hence the difference.
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scaddenp at 08:13 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
With unlimited computing power - maybe. The different runs produce outputs from different initialisations. Changing parameterisation adds another dimension as would changing the forcings. I am not convinced that early 20th C forcing are well enough known to make statements that evaluate model skill independent of forcing uncertainities. What you can say is the observed temperatures are consistent with model outputs giving a particular set of forcings. There may well be other forcings at work or various forcings might be incorrect but the model runs do not supply evidence to support this.
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Tom Curtis at 08:04 AM on 20 March 2013Lessons from Past Climate Predictions: Syun-Ichi Akasofu
Two quick points. The first is an erratum. My graph of the "Akasofu prediction" @41 displaces the my reconstruction of Akasofu's prediction upwards by 0.04 C. This has no effect on the trends, but improves the fit with temperaure anomalies in the late twentieth century. For the record, the fit is established by ensuring the linear trend of the Akasofu reconstruction has the same mean as the observed data.
Second, coming from a background in philosophy and logic, I consider the usage of "hypothesis" and "theory" in science thoroughly inconsistent and confused. This is, firstly, because in practise scientists and historians of science do not reserve the term "theory" only for well established hypotheses, and in some cases continue to refer to hypotheses as hypotheses even once they are well established. What variouse theories are called is more a matter of historical accident than of consistent usage.
Further, it is because in logic (and in my usage) a "theory" is a set of propositions closed under logical implication. That is, the theory includes all propositions that are logical implications of any subset of the propositions in the theory. On that basis, all hypotheses are theories, assuming they are not logically inconsistent. Some hypotheses are well established, and would be better called "well established hypotheses" or "well confirmed hypotheses" (but not "well verified hypotheses") than ellevating "theory" to a usage that is inconstent with the use in philosophy and in common usage. Just my two cents worth.
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Bob Loblaw at 08:02 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Klapper @ 29:
I would agree that errors in our knowledge of CO2 forcing in the period 1910-1945 are likely small, simply as a result of there being no reason to think that it varied significantly.
Would you care to explain to me why you are confident about the estimates of atmospheric aerosol levels that are available for that period? Perhaps you'll wish to compare the methods used during that period with the kinds of estimates we can obtain today with networks such as AERONET, or satellite data?
As well, perhaps you are willing to explain how accurate the measurements of solar output (you've used the acronym TSI, wich is Total Solar Irradiance) for that period are? Please feel free to compare that accuracy to those recently available from satellite data used in this PMOD analysis. Feel free to be as technical as you wish - I have worked with people from PMOD, and I am quite familiar with the types of instruments used to measure TSI on these satellites.
Note that I consider phrases such as "the correlation between TSI and SSN are pretty good so I can't see a large error in that parameter" to be nothing more than handwaving (regardless of what you are referring to as SSN, which is an acronym that escapes me at the moment). A correlation with something that is not the item of measurement is not a fundamental estimate of the accuracy to which that element (TSI) is measured.
I suspect that you are confusing the accuracy of an input to a model with the accuracy of the model, but I can't be sure where you are going wrong until you give a more elaborate explanation of your thought process.
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Magma at 07:46 AM on 20 March 2013Death in Jurassic Park: global warming and ocean anoxia
"Oxygen of course makes up over 30% of seawater, but that oxygen is the 'O' bit of the H2O that makes up the sea."
Might want to change that. Accounting for salinity, oxygen makes up about 85.8% of seawater by mass. Making the calculation on an atomic basis seems a bit odd and is open to misinterpretation. -
Klapper at 07:44 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@scaddenp #26:
Please re-read my posts. I am completely aware the ensemble envelope is not any kind of 2 sigma error boundary. This psuedo-error boundary is used over and over in graphics presented by the IPCC, and also at sites like RealClimate.org. Yet it's statistical validity is murky at best.
There has to be a better way of rationalizing model output against observations, whether in the period 1910 to 1945, or the last 15 years. I've put some rough ideas on the table in my post to Dana (#22).
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Klapper at 07:34 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@KR #25
The ensemble "envelope" as presented in Figure 2 is not the 2 sigma range of the mean ensemble trend. I've been saying this all along. This is what I meant in my post #15. "Within the squiggles" has no statistical validity. I clearly stated that I was not claiming the 2 sigma range of the ensemble trend was a valid way to disprove the models (tempting as it might be).
On the topic of CMIP5, I have downloaded a number of 20th century runs from different models and do not agree with your statement: "models tend to settle down to a near mean-centered behavior after only a few years of the run". Put some numbers on that and we can discuss further. Keep in mind my period of interest is 1910 to 1945. This is a good time interval for checking your assertion since it is long enough to detect the climate signal, but not so long that agreement is guaranteed.
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Jim Pettit at 07:27 AM on 20 March 2013February 2013 Arctic Sea Ice Death Spiral Update
On 17 March, 2013 at 07:48 AM, LarryM wrote: Another permutation that might complement it and more clearly show the differences between seasons is for the radial scale to show, rather than absolute volume in km3, the percentage of the volume in 1979 that remains. I think it would show that the summer/fall ice is disappearing exceptionally fast.I thought so, too, so drew up the following very telling graph:
And for kicks, I also created one showing the same data in a normal line chart. It's also very telling--if not perhaps even more so. (Click either image to enlarge):
As Mr. Tamblyn worded it so eloquently and succinctly above: "It doesn't matter which variation of a graphic you use, they all show the same thing. The Arctic sea ice is exiting stage left..."
Indeed...
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DSL at 07:25 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Kevin, Jungclaus et al. (2010) may answer your LIA-carbon cycle concerns, and Lemoine et al. (2010) may also be informative.
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Klapper at 07:18 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@Bob Loblaw #24:
I doubt the error bars on CO2 growth rate in the 1910 to 1945 interval are significant to the discussion we are having here. There is one major aerosol event (Katmai) at the very start of the period but none after. The correlation between TSI and SSN are pretty good so I can't see a large error in that parameter. It would be better if the major SAT datasets were truly independent which would allow us to check the confidence on the observations, but since SSTs in the Southern Hemisphere are pretty sparse that is somewhat of a weak link.
In short, while I acknowledge your point of data accuracy weakness in the 1st half of the 20th, I think the period in question is a very interesting one that deserves more investigation.
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scaddenp at 06:56 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
You absolutely get an H2O feedback. Carbon feedbacks however are very slow - most AR4 models assumed them to be zero for purposes of predicting climate 100 years in advance. For longer periods you would have to consider them.
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Kevin8233 at 06:29 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
So, basically, natural forcings drove the warming from the first half of the 20th century and earlier, via the sun and solar cycles.
After the solar cycles and temp response diverges in the late 70's, it was anthropogenic ghg that drove the warming. I know it wasn't a switch, and there was some ghg before the 70's, but relatively minor.
What happened to the feedback loops for CO2 and H2O? According to other debunking threads here (CO2 lags/leads temp - Coming out of LIA - Water is greatest ghg) there should be a feedback warming contribution from both of the gasses.
If there was 0.8 C warming from LIA to 1940, shouldn't there also be about the same warming from these feedback loops? If there was, it can't be both natural and anthropogenic.
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scaddenp at 06:29 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Klapper, as a further note, I would say it is wrong to confuse the envelope of multiple model runs with a 95% confidence interval. Also, there is no way that you expect any actual climate to follow an ensemble mean. This would imply dont think climate interal variability is present. You do however expect 20-30 trends to match the 20-30 trend of the model mean. You also expect the actual to be within the envelope. You dont have evidence of an unknown forcing unless it is outsite. I would also second Bob's comment - estimating early 20th C forcing is plain difficult.
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New Study, Same Result - Greenhouse Gases Dominate Global Warming
Klapper - Looking at Fig. 2, which represents the models run with all of the forcings both natural and anthropogenic, I would have to say that the model mean and standard deviation matches the observations quite well. Observations for that period are well within the 2-sigma model range, and mostly within the 1-sigma range, with two 10-year excursions above/below the model mean at about 1905-1915 and 1935-1945.
Please remember, as others have pointed out, that observations are a singular run of the real thing - which statistically has a 1/20 chance of exceeding a 2-sigma range. In addition, while the models appear quite good, they certainly are not perfect. They just might, however, be very useful.
So I won't rationalize the models fail to replicate the climate signal in the period 1910 to 1945 based on regression statistics of the ensemble compared to the observations.
Odd - that appears to be exactly what you are doing - over multiple comments...
My guess is they don't even necessarily use identical inputs for forcing and/or initial conditions...
Then you have clearly not reality-checked your assertions - see the CMIP5 Model Intercomparison Project for the forcing data used, and A Summary of the CMIP5 Experiment Design for details on the various runs of the comparison project. Initial conditions do vary, but given the boundary constraints of energy balance all of the models tend to settle down to a near mean-centered behavior after only a few years of the run. Which is part of what makes them useful - inter-model variation helps establish the range of possible climate responses bounded by forcings, feedbacks, and conservation of energy.
I'm sorry to say this, but your complaints strike me as concern trolling.
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Bob Loblaw at 06:18 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Klapper:
You keep beating the horse of model comparisons to observations in the period 1910-1945. Unfortunately, until someone invents a time machine, we're not going to get greater accuracy on our values for such things as solar output, atmospheric aerosol loading, surface albedos, vegetation cover, etc. for the period. We may be able to improve on proxy reconstructions of some of those things, but there will always be greater uncertainties in model inputs for that period (compared to now).
One could always play around with various bits of the model in an effort to reproduce a particular historical pattern, but there are diminishing returns from this excercise (as far as science is concerned). At some point, you just have to accept that there are uncertainties in the input, and thus uncertainties in the output. It makes more sense to look at more recent periods with greater input data availability to focus on model improvements.
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Bob Loblaw at 06:06 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Actually, Dana, I think Clyde is just trolling - trying to get your goat. Earlier in the thread (currently #8), he quotes you as using the phrase "is consistent with", and then tries to pretend that this means that the referenced paper had nothing new in it beyond "settled science". I'm quite sure that Clyde is not so stupid as to think that they mean the same thing, so he must have had some other reason for posting.
Relativity is consistent with Newton's laws - i.e., they give pretty much the same results within the region of overlap of speeds much less than the speed of light - but relativity is obviously a significant extension of the science imbedded in Newton's laws.
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Klapper at 05:19 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
@Dana1981 #17:
I think the best way to test the hypothesis that the models replicate the climate signal in the period 1910 to 1945 is to compare individual models with fixed parametizations, with the input varying according to the 95% confidence we have on intial conditions and forcing magnitudes. Of those runs, how many would pass conventional regression statistical comparisons against the observations is a very good question.
As noted above the ensemble "envelope" is a very murky number, coming as it does from 20 or so different models, with different parametization factors, and different levels of resolution/sophistication. My guess is they don't even necessarily use identical inputs for forcing and/or initial conditions, although hopefully they're close since the runs are part of a model intercomparison process.
Doing model by model, run by run statistics against the observations might allow you to reject some models and tighten up the ensemble envelope. Right now I don't see a good fit between the model ensemble and the observations in the period 1910 to 1945. Climate science should be digging deeper as to why that is.
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william5331 at 05:14 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
At some point, the Chineese people are going to force their government to clean up their air. There goes a large part of the aerosols. The other elephant in the room is CH4. While it is 20 times more powerful than CO2 on a hundred year basis, it is more than 100 times more powerful in the short term. Methane is at present at about 1.7ppm and rising. It only has to reach about 3.5ppm to equal the effect of the present concentration of Carbon dioxide. I seem to have read about kilometer wide patches of methane bubbling to the surface north of Russia and enough clathrates around just the coast of America to supply her energy needs for centuries.
http://mtkass.blogspot.co.nz/2013/03/the-real-strength-of-methane.html
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dana1981 at 05:01 AM on 20 March 2013New Study, Same Result - Greenhouse Gases Dominate Global Warming
Clyde @18 - so basically your complaint is that I didn't just copy and paste the abstract?
As I already explained, aerosols are the primary negative anthropogenic forcing. Also "0.5°C cooling" and "-0.5°C" mean exactly the same thing.
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dana1981 at 04:59 AM on 20 March 2013David Rose Hides the Rise in Global Warming
tmac57 @4 - no, we attempted to contact Myles Allen but have not received a reply.
XRAY @5 - if you refer to Figure 1, it ends in 2009 because it's a 5-year running average. The data are up-to-date.
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