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CBDunkerson at 23:53 PM on 25 September 2014The 97% v the 3% – just how much global warming are humans causing?
Tom, sure the level of consensus is slightly lower... but still very high and far far from the 'no consensus' view some 'skeptics' push.
Whether they are "intrinsically" or "closely" connected seems likely to be a largely semantic argument. Indeed, I'd actually describe 'closely connected' as suggesting a stronger link... 'intrinsically' just means that the connection between the two is 'inherent in their nature'. That is, most of the science underlying the two is the same, so anyone familiar with the facts behind one is also familiar with most of the facts behind the other... an intrinsic / natural connection.
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Firgoose at 22:09 PM on 25 September 201497 Hours of Consensus reaches millions
@John: Talking of personal, or perhaps it's more personable, I really love the way that a 97's hand shoots up and their face lights up, with the smile turning into a big "Me, me! I know the answer!" grin. :-D
And the way that the 3%, having nothing to contribute, frown and avert their eyes. Nice touch! ;-)
You say that "second time around, we'll do things a little differently". Does this mean reusing the same animation or are you planning something different?
One other small question. Maybe I missed it somewhere but what does "nsh" stand for? Is it supposed to be lowercase? With my eyesight I kept seeing is as the equally mysterious "rish".
Response:[JC] nsh - ninety seven hours
Like any riddle, obvious in hindsight :-)
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MA Rodger at 20:26 PM on 25 September 2014Antarctica is gaining ice
I was intrigued by jetfuel's comment @282 concerning McMillan et al (2014):-
"I did read it, and the bold quote of Tom's from the paper is not visible to me in the report. ... The paper does state that for the period from 2010 to 2013, the avg ice level is falling at 1.9 cm per year and that there is a 105-130 Gt per yr loss of ice mass."
How to make sense of that? The quote is apparently quite promanent within the "report" (as quoted @284) and, with Antarctica being 14 million sq km, an annual 1.9cm fall in ice level would of course result annually in 7mm SLR and 2,660 Gt mass loss. Further the 105-130 Gt figure is not the finding of McMillan et al. and also is not specifically for the period "from 2010 to 2013." This comment from jetfuel is totally nonsensical, something not of this planet.
And so it proved.
I tracked down only one potential source and that is where you would expect to find it - the planet Wattsupia. There, back in May, they gathered all the populus at the feet of an idiot called Larry Hamlin who was greatly angered by the reporting provided by The Guardian about McMillan et al. It is Loony Larry who quotes from McMillan et al. in which he doesn't provide sight of the "bold qulte from Tom." However the 105-130 GRACE figures appear, as does the mention of "the exceptional snowfall event of 2009, which saw an additional ~200 Gt of mass deposited in East Antarctica," just as jetfuel has been banging on about down this thread. And while the "falling at 1.9cm per year" is absent, a 0.19mm SLR contribution is mentioned which presents a possible source of a grossly misquoted figure.And if anyone is in the slightest bit interested by Loony Larry's thesis, it can be summarised thus:- The Guardian is outrageously alarmist. There is no "doubling" of ice loss and obviously so. Does not McMillan et al. state that it' findings are "consistent" with other studies, so it can't have found a doubling. The Guardian confuse "two distinct issues." The "doubling" is not the rate of ice loss but the SLR contribution which has doubled from 0.19mm pa to 0.45mm pa. Of course Loony Larry says it better than I do. When I summarise his argument, I seem to make him sound like a congenital idiot.
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michael sweet at 20:05 PM on 25 September 2014Antarctica is gaining ice
Jetfuel,
It would be nice if we could use the rate of ice loss from three years ago as the rate loss for the future. Unfortunately, the data MA Rodgers provided at 279 shows a continually increasing loss of ice. You must include the rate of increase of ice loss. Then we see that it will not be so long before Miami no longer drains after heavy rains. Your fact free ramblings are not convincing.
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TonyW at 15:18 PM on 25 September 2014The Wall Street Journal downplays global warming risks once again
CBDunkerson
Albert Bartlett's lecture can never go out of date (other than the data used to illustrate points) because it's based on maths and physical realities. Growth destroys the environment, as we've seen, but growth can't continue indefinitely, even if we could figure out how to grow without destroying the environment. The price of solar energy is irrelevant to this, though I doubt the world could convert to solar, due to resource issues and emissions of solar panel production. If it could, the world would have to operate on a much lower EROEI, so growth would end anyway. Kevin Anderson's analysis hasn't been shown to be in error either. By 2020, it will be obvious that either nothing will be done about the problem or that doing something about it unacceptably harms economic growth.
KR,
As I understand it British Columbia was already on a downward track with emissions, before introducing that tax, so it's unclear what the impact of the tax has been, or how it has affected emissions in surrounding regions. However, BC is not the world. I'd welcome a revenue neutral carbon tax but it isn't likely, on it's own, to reduce emissions by the 10% per year needed to have half a chance (not 100% chance) of not exceeding the very dangerous level of 2C, though we'd breeze through the dangerous level of 1C.
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ubrew12 at 15:03 PM on 25 September 2014The Wall Street Journal downplays global warming risks once again
Tom Curtis@9: You said "So, by mid century the direct increase may be only 1 or 2%, but the total increase as a result of that direct increase will be a 5 - 10% increase in the total greenhouse effect... So, Koonan is not incorrect per se, but his claim is framed to cultivate confusion" And where might we find that confusion first expressed, and most loudly, for the viewing public? Today on Faux News (2:39 of a 5min video).
Gee, that didn't take long...
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Composer99 at 12:55 PM on 25 September 2014Antarctica is gaining ice
Tom Curtis @285: Deniers making themselves look the fool is well and good, however enough exposure to the same commenter who trots out the same shtick, over and over, eventually just wears out my patience.
Skeptical Science does a good job of not being overrun with deniers in the comments (as compared to, say, dana1981's blog at The Guardian) but even so I am sure I am safe in assuming there will be no shortage of deniers posting here to maintain a more-or-less constant flow of foolishness (to say nothing of any foolishness posted by yours truly).
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To keep this comment on topic, I did a Google Scholar search with the terms 'antarctic sea ice history' and found a few papers that might be of interest when it comes to Antarctic sea ice and its extent (especially in light of jetfuel's claims with respect to same):
- Gersonde and Zielinski 2000 (link), which reconstructs Antarctic sea ice during the late Quarternary
- Crosta et al 2004 (link), which does the same in a geographically limited area (the Southern Ocean - Indian Ocean boundary, effectively)
- Rayner et al 2003, already referred to by Tom Curtis upthread (via Tamino - Tamino's blog post has a link to the paper).
These papers are unfortunately behind paywalls for me, but as I said they may be of interest when thinking about the current state of Antarctic sea ice, especially any part of the G&Z and Crosta reconstructions occurring in the Holocene.
My apologies in advance if someone else has already shared one or both papers in a previous comment on this thread. (I have performed a cursory search and believe that not to be the case, though.)
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scaddenp at 12:03 PM on 25 September 2014Antarctica is gaining ice
Jetfuel has still not actually revealed what point he is trying to make. Obviously the increasing sea ice around Antarctica is significant for him but he has failed to communicate why. The latest seems to be because the trend has continued, somehow a contributing factor (ice sheet melt) must have stopped. This is consistant with other behaviour that places enormous significance on an individual point rather but ignores the trend (eg 2009 ice fall is latest but see also the cherry picking here). Comment 282 would imply he either hasnt looked at or doesnt understand the graphs helpfully posted by MA Rodgers. Unless jetfuel actually articulates his case, I dont think there is much point continuing. We just see repetition and a complete resistance to learning anything.
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Tom Curtis at 11:25 AM on 25 September 2014Antarctica is gaining ice
Composer 99 @283, I take it then, you do not subscribe to the theory that deniers making themselves look utterly stupid is not a good antidote to the disease in other readers?
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Tom Curtis at 11:24 AM on 25 September 2014Antarctica is gaining ice
jetfuel @282, googling a sentence is not the same as reading the article. Nor is failing to read the article is not evidence a sentenc is not in that article. It is only evidence that your approach is evidence free. For your benefit, however, here is the sentence with sufficient context to easilly locate it within the article:
"Introduction
With a capacity to resolve detailed patterns of elevation change at the scale of glacier drainage basins [Shepherd et al., 2002; Davis and Ferguson, 2004; Pritchard et al., 2009; Remy and Parouty, 2009; Shepherd et al., 2004; Wingham et al., 2006; Zwally et al., 2005], repeat satellite altimetry has transformed our ability to study the polar ice sheets. Nevertheless, direct measurements of elevation change have been restricted by the latitudinal limits of satellite altimeter orbits (81.5° and 86.0° for conventional radar and laser systems, respectively), by the reduced performance of conventional radar altimeters over the steep terrain that is typical of ice sheet margins and by the irregular temporal sampling of satellite laser altimeter data due to the episodic nature of ICESat mission campaigns and due to the presence of clouds. These limitations have precluded, for example, comprehensive assessments of Antarctic Peninsula volume change, and altimeter data omission may also explain differences in mass balance estimates for other ice sheet regions [Shepherd et al., 2012]. CryoSat-2 was designed to overcome several of the limiting factors that previous satellite altimeters faced, with an orbital limit extending to 88° and a novel synthetic aperture radar interferometry mode providing measurements of fine spatial resolution in areas of steep terrain [Wingham et al., 2006]. Here we use CryoSat-2 data acquired between November 2010 and September 2013 to produce the first altimeter-derived estimates of volume and mass change for the entire Antarctic ice sheet.Data and Methods
..."
(Bolding of section headings in original, bolding of relevant sentence mine.)
Jetfuel @281, your pet theory.
That NBC made the same error as you six days after you made it does not prove you derived your theory from them. Nor does NBC claiming something relating to science to be fact prove it is, given the notoriously poor standard of scientific reporting by MSM.
Further, trying to score rhetorical points of a point where you have already acknowledged your error (@274) just makes you look silly. Are you now trying to take that back (with a complete absence of relevant evidence)? Or are you just trying to sow as much confusion as you can? Either way you have just ratcheted your credibility another notch lower.
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Composer99 at 11:13 AM on 25 September 2014Antarctica is gaining ice
I for one would say that jetfuel's 'science by news headline" in #281 and disingenuity in #282 are a sign that jetfuel has worn out his welcome.
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jetfuel at 11:01 AM on 25 September 2014Antarctica is gaining ice
michaelsweet@280 says:
"Thank you Tom.
I note that Tom actually read the cited peer reviewed article. Jetfuel did not read the paper he was criticizing."
I wasn't criticizing it. I did read it, and the bold quote of Tom's from the paper is not visible to me in the report. When I googled his quote, I got SS as result?
The paper does state that for the period from 2010 to 2013, the avg ice level is falling at 1.9 cm per year and that there is a 105-130 Gt per yr loss of ice mass. Considering there are 30,000,000 Gt of ice there, and a single 2009 snowfall in East Antarctica deposited 200 Gt of snow, and the report stating that the vast majority of Antarctica is stable, forgive me for thinking that this years 1960'sish sea ice levels down there could have made West Antarctic land ice more stable. How many years of -100 Gt per year until we can round 30 million down to 29.9? 10 centuries by my math.
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jetfuel at 10:15 AM on 25 September 2014Antarctica is gaining ice
tomcurtis@268 states: "So, Antarctic sea ice extent is in uncharted territory, but only if you are carefull not to look at charts that might bust your pet theory."
per NBC news: "More sea ice than ever around Antarctica,"
Whose Pet theory?
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bill4344 at 09:16 AM on 25 September 201497 Hours of Consensus reaches millions
Yes, this is a really nice piece of work! And the Richard Alley caricature is, indeed, the stand-out. Congratulations and I think you'll find there'll be a lot of people happy to find themselves in this pool of talent in the future (and a tiny handful who won't of course!)
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Pat O'Dea at 08:50 AM on 25 September 201497 Hours of Consensus reaches millions
Oscar Wilde once said; "If you tell people the truth they will hate you for it.
But if you tell it to them with humour they will love you for it."
Congrats for this marvelous initiative, to all those who worked on it and to all those scientists who participated.
Keep up the good work.
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scaddenp at 05:46 AM on 25 September 2014The Wall Street Journal downplays global warming risks once again
As far as I can see Anderson's analysis is based on historical data for economies. This is not a good guide to what will happen if you try a something completely different (eg a pigovian tax on carbon). As KR points out, you now have data from BC to back that position.
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PhilippeChantreau at 02:27 AM on 25 September 20142014 SkS Weekly News Roundup #39A
Worth mentioning inthis thread:
"The Netherlands are going to invest 20 billion Euros to protect against the rise in sea level."
Excerpt from the article: "About 9 million Dutch people live today in floodable areas of the kingdom, where are also concentrated 70 % of economic activity, sea ports and airports. Chemical plants, natural gas and nuclear installations are present as well and will be the subject of much strengthened protection measures. For public planners, the goal is to avoid a catastrophe that could threaten a potential revenue of about 2 trillion Euros."
Non official translation by myself.
It is my conviction that the arguments about how costly addressing the problem now would be have their numbers wrong.
Moderator Response:[PS] Fixed link
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The Wall Street Journal downplays global warming risks once again
TonyW - British Columbia implemented a revenue-neutral carbon tax in 2008. A 5-year review found that the province had reduced carbon emissions by 17%, with no discernable difference in GDP growth from the rest of Canada. And as a result of the carbon tax they how have the lowest personal income taxes in the country.
Every economic change has winners and losers - the Montreal Protocol for CFC's and protecting the ozone layer is a good example. While some established CFC manufacturers lost out, the cost/benefit analyses of that phaseout range from 1:2 to 1:11 depending on assumptions, not even counting the effect of reducing GHGs or a number of economic benefits. This represented a significant boost to the world economy by removing numerous costs to fishing, agriculture, and health.
Every economic indication for revenue neutral carbon taxes is positive - and they represent perhaps the most organic and least bureaucratic method of correcting the current lack of accounting for the externalities in fossil fuels.
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Johnb at 22:47 PM on 24 September 2014The Wall Street Journal downplays global warming risks once again
I only picked up yesterday from a Crikey column that News International's second largest stockholder is Saudi Prince Al- Waleed Bin Talal Al Saud, the Kingdom's wealthiest Prince. Saudi Arabia's official International position is not unalighned to the current News Corp editorial policy.
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Tom Curtis at 22:32 PM on 24 September 2014The 97% v the 3% – just how much global warming are humans causing?
CBDunkerson @106, while I agree that they are closely connected, and that in fact BAU will be harmful, possibly catastrophically so, the fact remains that the consensus supporting the later is about 10% less than that supporting the former based on Bray and von Storch's surveys (which are the only ones to test it, SFAIK). "Intrinsically connected" overstates their relationship, IMO, in part because what counts as harmfull is partly subjective, and also because the evidence of future impacts is not so strong as that for current attribution.
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CBDunkerson at 21:45 PM on 24 September 2014The 97% v the 3% – just how much global warming are humans causing?
The arguments about 'what the scientists in consensus XYZ really agreed to' exemplify a common denier mental block wherein they seem able to believe that each fact exists in isolation of all others.
That is... they concede that the Cook et al study found a 97% consensus for human greenhouse gas emissions having caused most of the observed global warming... but then argue that there is no consensus that continuing those emissions will be harmful. Which is just plain illogical.
If we accept that human greenhouse gas emissions have caused most of the observed warming to date then we know that future warming from continuation of the same factors will be harmful. It's like arguing, 'ok yes everyone agrees that smoking caused some people to die prematurely of cancer, but that doesn't mean that anyone agrees more smoking will lead to more cancer in the future'.
In short, they're treating intrinsically connected things as completely separate. That's a level of crazy even the tobacco apologists never reached.
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CBDunkerson at 21:17 PM on 24 September 2014The Wall Street Journal downplays global warming risks once again
TonyW, you might want to check your facts before declaring people "delusional".
http://newclimateeconomy.report/
Kevin Anderson and Albert Bartlett are out of date. The price of solar energy has been dropping by 50% every few years. When you consider the economic benefits of stopping global warming (and ocean acidification), ending wars over fossil fuels, improving human health by reducing pollution, eliminating the massive global subsidies to the fossil fuel industry, et cetera... solar is already cheaper than any other major power source. Ergo, simply converting to solar will cause economic growth... and that's not even considering the near certainty that the cost of solar will fall by 50% again in the next few years... and another 50% within a few years after that. The costs of wind power and battery storage are also plummeting. It has been obvious to me for a few years now that these changes would inevitably make fossil fuels no longer cost competitive. Most economic analysts have now reached the same conclusions. Only the 'delusional' and mis-informed still argue otherwise... and by 2020 it should be obvious even to them.
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TonyW at 16:29 PM on 24 September 2014The Wall Street Journal downplays global warming risks once again
"For example, a revenue-neutral carbon tax could create jobs and grow the economy. Two recent studies by the New Climate Economy Project and the International Monetary Fund likewise found that reducing carbon pollution could grow the economy, as summarized by The Guardian."
That's delusional. Growing the economy and tackling climate change are incompatible, as Kevin Anderson has shown. More broadly, economic growh destroys the environment, as the late Albert Bartlett so expertly pointed out.
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michael sweet at 08:54 AM on 24 September 2014Antarctica is gaining ice
Thank you Tom.
I note that Tom actually read the cited peer reviewed article. Jetfuel did not read the paper he was criticizing.
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MA Rodger at 08:30 AM on 24 September 2014Antarctica is gaining ice
Regarding recent ice loss data from Antarctica, I was surprised Figure 5 from Williams et al (2014) hasn't made its appearance on this comment thread yet. For the present on-going chatter, it doesn't advance the data beyond that mentioned by jetfuel @270 but it do allow sight of what is the actuality by way of, as jetfuel puts it @274, "Things can change significantly in one year," and perhaps may also stop the trolling on whether years are inclusive or exclusive to some time period.
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Tom Curtis at 07:35 AM on 24 September 2014Antarctica is gaining ice
jetfuel @276, from McMillan et al (2014):
"Here we use CryoSat-2 data acquired between November 2010 and September 2013 to produce the first altimeter-derived estimates of volume and mass change for the entire Antarctic ice sheet."
CryoSat 2 was launched in April 2010, and became officially operation in October 2010. The reason for the "overlap" in 2010 is simply that McMillan et al relied on earlier studies which extended into 2010. It is not clear, however, that those studies extended their data up to include Nov 2010 in any event, in which case there is no overlap.
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scaddenp at 07:34 AM on 24 September 2014Antarctica is gaining ice
Jetfuel, you seem to be implying that continuation of a predicted trend is somehow evidence for something new and different in Antarctica. Do you seriously believe that ice loss from the ice sheets has stopped? What is going to be your reaction to the next cryosat result? Do we get a retraction?
Again, it would help if you would actually state the point you are trying to make here. Why are you so hung up on Antarctica sea ice?
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jetfuel at 06:58 AM on 24 September 2014Antarctica is gaining ice
I disagree that 2013 is included, otherwise the quotes: "Between 2010 and 2013", "We use 3 years of Cryosat-2 radar al..",
and:
"are now 31% greater than over the period 2005–2010".
imply that 2010 gets counted twice, once in each dataset?
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michael sweet at 05:54 AM on 24 September 2014Antarctica is gaining ice
Jetfuel,
I read 2010-2013 as inclusive so that all the data up to last December is included. You cannot expect to have peer reviewed data about this winter available yet since the winter is not yet even over. A single snow event is weather. We are interested in the trend.
Of course scientists rapidly proposed explainations for the increase in ice: it had been predicted years ago. When events come to pass that were predicted long ago those papers are brought back and the proposed explainations look good. Predictions are not comparable to excuses.
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howardlee at 05:39 AM on 24 September 2014The Perplexing PETM
Timing and dating uncertaintly are a constant theme here. The apparently annually-layered ("varve") deposits reported on by Wright and Schaller are just the sorts of detailed record that should - eventually - resolve the controversy. Dating and correlation have constantly been improving in precision, but we are still dealing with vast timescales. My unscientific hunch is that the section reported by Wright and Schaller may turn out to be a short-lived blip within a much broader signal (like a fractal pattern - wiggles within wiggles). But you are right - more papers are sure to come on the PETM.
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jetfuel at 05:31 AM on 24 September 2014Antarctica is gaining ice
Again, 'between 2010 and 2013' excludes the last 21 months that includes the last 2 southern winters. Curiosity about the last 2 winters is not rhetoric.
Curiosity just uncovered that there was a 200 Gt snow event in East Antarctica in 2009. Things can change significantly in one year.
I acknowledge that there was more Ant. sea ice than now in the middle of the last century. I misspelled uncharted as unchartered. I don't even know what unchartered would mean in the context I used. 1966 seems about when actual winter max numbers were annually charted and that looks like about 22M sq km back then.
Breaking 20M for the first time since the mid seventies. Being quick to propose blaming this on reduced salinity and shifting wind patterns may be rhetoric. Those excuses were ready to go on the day the record from last year was broken.
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sidd at 04:48 AM on 24 September 2014The Perplexing PETM
Wright and Shaller reply to Stassen, Zeebe, Pearson in doi/10.1073/pnas.1321876111
Some of their retorts: that Zeebe's ocean model is inappropriate for shallow shelves, that drilling contamination is unlikely for various reasons, and that Stassen's argument assumes deeper water than was present at the site during the subject period. There is more, of course. I am personaly not yet convinced either way, but i eagerly anticipate more work.
sidd
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Tom Curtis at 04:02 AM on 24 September 2014The Wall Street Journal downplays global warming risks once again
jja, from David Archer at Real Climate:
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Paul D at 03:22 AM on 24 September 2014Upcoming MOOC makes sense of climate science denial
Good luck with the course.
Yet another great project from Skeptical Science! -
The Wall Street Journal downplays global warming risks once again
correction:
this comprehensive database indicates that global northern hemisphere peat north of 45' latitude contains 436 GT of Carbon. So the estimate given above is too high (for just Finnish peat carbon).
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The Wall Street Journal downplays global warming risks once again
The IPCC should produce a forward to the summary for policymakers stating a collective Mea Culpa to future human generations and a return of the Nobel prize as punishment for their fatal type I error aviodance bias.
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The Wall Street Journal downplays global warming risks once again
All,
it should also be noted here that the 100GT carbon estimate for RCP 8.5 is a middle range estimate with other studies showing an estimate as low as 25GT Carbon and as high as 500+ GT Carbon. There is over 1,600 Billion tonnes of Carbon in northern hemisphere permafrost.
In addition there is another 270-360 GT of Carbon in the sub-arctic peat, in FINLAND. http://hol.sagepub.com/content/12/1/69.short
This indicates an additional threat as the peat is already starting to burn in siberia and in the yukon territory. There is potentially more Carbon emissions potential from subarctic peat fires than there is from degrading permafrost.
I also doubt that the 55% atmospheric fraction will hold through 2100. The IPCC AR5 projects an increase to 70% for the RCP 8.5 by 2100. I expect, as with most projections from the IPCC RCP 8.5 scenario, that this is severely understated.
If the natural carbon sources above grow at significant rates, they wll overpass anthropogenic emissions by 2050 (assuming an agressive mitigation effort). -
Composer99 at 23:41 PM on 23 September 2014The Wall Street Journal downplays global warming risks once again
Ashton:
Pedantically, detailed discussions need not mean "met" in the conventional sense, in an era of long comment threads and email.
Substantially, "leading" climate scientists is a bit of weasel wording on Koonin's part. Although understandable given typical word limits (I assume the column was also published in the printed version of the Wall Street Journal) (*), the phrase could refer to climate scientists with loads of high-impact, well-cited papers published, or it could refer to S. Fred Singer, Richard Lindzen, and other contrarians with little to no recent publication and an extensive history of being wrong - or indeed, to any mish-mash of scientists Koonin personally felt were sufficiently notable to describe as "leading". This ambiguity does not resolve if we presume total sincerity on Koonin's part, since we have abundant evidence of contrarians genuinely treating contrarian scientists with extensive histories of being wrong as "leading" climate scientists.
With respect to your reference to Stern et al, I should remind you that Baron Stern, an economist, is usually referred to speaking within his domain of expertise, economics, in which case he is an expert, as is Professor Garnaut. For his part, Professor Flannery would be within his domain of expertise when discussing climate impacts on mammals (especially mammals in Australasia). I don't recall seeing Skeptical Science, or indeed any other science-based online source, rely on any of them for climate information outside their domains of expertise, although one could readily - and legitimately - include interesting or insightful things they have to say that illuminates the science. At any rate I do not see any justification for your apparent claim of tu quoque.
(*) For instance, I wouldn't want to spend substantial parts of an op-ed I wrote just naming scientists I spoke to.
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MA Rodger at 21:25 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
The zig-zagging that jwalsh continues to practice down this thread would be enough to provide an honest man with symptoms of psychiactric disorder. I am particularly impressed with his insistance that there is a significant 1200-year wobble in global climate. Thus @94 we are told:-
"That the climate has varied wildly in the past is not "out of left field". It is considered to be more established scientific fact than most IPCC statements. The Minoan, Roman, and Medieval warm periods occurred at roughly 1200 year intervals" and on this ground it is not silly to argue that "
While I assume this "established scientific fact" extends only to a significant wobble and not to a wild wobble, I was of the understanding that such "established scientific fact" would comprise some considerable evidential basis. Yet such a basis remains absent. jwalsh instead presents here argument after argument defending his thesis by asserting that the evidence which dis-establishes any 1200-year wobble is not admissible.
Marcott et al (2013), the place were such a wobble would surely feature is dismissed with an in-thread comment from Gavin Schmidt (although the comment was actually to do with MWP/modern comparisons, thus not entirely of relevance to 1200-year wobble detection).
We are emphatically assured @86 that there is other evidence but it is never advanced."Evidence of the Minoan, Roman, and Medieval warm periods from either historical records and other proxies? Hell yes."
Now, here's the thing. Both these quotes that together demonstrate a determined promotion by jwalsh of this alleged 1200-year wobble sit juxaposed to comment on Greenland ice core temperature reconstructions, things like Kobashi et al (2011) whose 4,000 temperature reconstruction from their Figure 1 is here. (Note the "Current Temperature Line" is the decadal temperature 2001-10. In a graph of the last 120-year reconstruction also within the full Figure 1, the paper puts the comparable annual temperature AD2010 at -27.3ºC.)
The reconstruction shows some pretty wild swings. But are there any wild 1200-year swings? Are there any significant 1200-year swings? Perhaps with his incomparable analytical skills jwalsh can help us out here, coz I see is a 4,000-year falling trend of 0.05ºC/century (which recent temperatures have already reversed within a single century) and a lot of wobbling but I do not see any wild or significant 1200-year wobble anywhere.
Moderator Response:[RH] This thread is turning into jwalsh's personal gishgallop. Let's try to bring it back on topic and take any splinter arguments to the proper threads. Also, one should note the full image in the Kobiashi 2011 paper where that graph comes from.
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scaddenp at 20:32 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
Jwalsh "But if you change how much warming is assessed by CO2, it follows that the relative attribution of the warming is altered."
I am not following this logic at all. If you want to change the attribution from anthropogenic factors, you have to show one of the other forcings is significant. The size of the forcings is an input to models from measurement not an output. The strength of the temperature response in the models is indeed a function of the climate sensitivity - the feedbacks - but that doesnt have anything to do with attribution. Perhaps you need to explain (and source) your comments about "downshifting estimates" and "setting temperatures"? (or was that merely rhetoric?)The importance of OHC is that you cant attribute that increasing heat to a natural cycle - it has to be attributed to net forcings. It is not as noisy as surface temperature and so a good parameter to consider for attribution. Of course it isnt as relevant as surface temperature to us, but good for checking the basic science.
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Ashton at 20:15 PM on 23 September 2014The Wall Street Journal downplays global warming risks once again
You make the comment that Steven Koonin "claims to have engaged in “Detailed technical discussions during the past year with leading climate scientists,” but who is himself not a climate scientist." Two comments on that. First and least important, I can appreciate why you use the word claims but it does, at least to me, rather imply that Koonin might not actually have met with these "leading climate scientists". The comment that Koonin is not a climate scientist suggests he is not qualified to comment om matters climatic. If that really is what is suggested, one might ask why such import is placed on the utterings of Sir Nicholas Stern, Professor Ross Garnaut, Professor Tim Flannery none of whom are climate scientists. And Tom Curtis I wonder if Steven Koonin really doesn't understand the physics of the interactions between CO2 and incoming and out going radiation. It seems very unlikely.
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ubrew12 at 16:17 PM on 23 September 2014The Wall Street Journal downplays global warming risks once again
Tom Curtis@9: Koonan is no fool. He absolutely knows that vapor is a feedback, not a forcer, in these matters. He knows it, he knows it conflicts with the doubt he's trying to cast, and so he's leaving it out. He's leaving out 80% of the actual AGW effect of raised CO2 levels, because it would work against the lie he's selling his audience. His statement "human additions to carbon dioxide... shift the atmosphere... only 1%" is a lie to anyone with a smattering of Scientific knowledge... but it is legally correct. It's written by Koonin the lawyer, not Koonin the scientist. Hopefully he was paid at least 30 pieces of silver for betraying his training.
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PhilippeChantreau at 15:38 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
Jwalsh you are showing deference for this individual by refering to him as "Lord" Monckton, a title that he has produced abundant effort to attach to his fictitious belonging to the House of Lords. The institution had to specifically address his claim, as is shown in my link. As for reading anything from him, the answer is no, that would be a complete waste of time.
And I don't find that you have appropriately addressed Tom Curtis points at 92 and 99 above. Far from it. You're long on assertions and rethoric, rather short on substance and references. The way you use references is itself quite questionable on several occasions. I understand more than I care to why you think how you think. It doesn't make it any more convincing.
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Composer99 at 15:20 PM on 23 September 2014Skeptical Science Study Finds 97% Consensus on Human-Caused Global Warming in the Peer-Reviewed Literature
jwalsh:
Cook et al 2013 are unambiguous as to why they chose to perform their review - that is, why they felt reporting on scientific consensus was necessary:
An accurate perception of the degree of scientific consensus is an essential element to public support for climate policy (Ding et al 2011). Communicating the scientific consensus also increases people's acceptance that climate change (CC) is happening (Lewandowsky et al 2012). Despite numerous indicators of a consensus, there is wide public perception that climate scientists disagree over the fundamental cause of global warming (GW; Leiserowitz et al 2012, Pew 2012).
and
Contributing to this "consensus gap" are campaigns designed to confuse the public about the level of agreement among climate scientists. In 1991, Western Fuels Association conducted a $510,000 campaign whose primary goal was to "reposition global warming as theory (not fact)". [It needs hardly be said that this is not the only expenditure by fossil fuel companies, associations, or affiliated "think tanks" to spread climate disinformation.] A key strategy involved constructing the impression of active scientific debate using dissenting scientists as spokesmen (Oreskes 2010). The situation is exacerbated by media treatment of the climate issue, where the normative practice of providing opposing sides with equal attention has allowed a vocal minority to have their views amplified (Boykoff and Boykoff 2004).
and
The narrative presented by some dissenters is that the scientific consensus is "on the point of collapse" (Oddie 2012) while "the number of scientific 'heretics' is growing with each passing year" (Allègre et al 2012). A systematic, comprehensive review of the literature provides quantitative evidence countering this assertion.
In short, if it weren't for a sustained misinformation campaign, aided and abetted by media emphasis on drama over accuracy, there would be no requirement for a study such as Cook et al 2013, just as there is no current requirement for a literature review showing, say, the level of expert consensus regarding quantum electrodynamics.
I should like to address your following comments:
The more discerning public is going to wonder similar things about this consensus claim. [...] Particularly when someone who thinks CO2 is causing 49.9% of warming is an explicit rejection, the lowest part of the scale, and a person at 50.1% is an explicit endorsement, the highest of the scale.
The "more discerning public" is going to read the IPCC reports and similar summary documents, and understand that the preponderance of evidence is what drives the expert consensus. I'm not surprised that you brought up the possibility of this hair-splittingly small distinction, which seems designed to obfuscate and muddy the waters rather than improve the paper's clarity.
There isn't any such thing as "the science" with respect to the complex and chaotic system that is our climate.
Unequivocally false. If you want to get down to brass tacks, you can sum up the basic fact of global warming with a single number:
0.6 W m-2
Everything else is commentary.
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Tom Curtis at 15:14 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
jwalsh @101:
"Taking an average as was done is of limited scientific utility. The criticism of picking one proxy over another is a valid one. I mentioned that as an issue straight away. Here's why it isn't that useful. They vary too much to do that. Say I give two people a tape measure to go measure an object, and one comes back and says it's 2.25 metres, and the second says 4.60 metres. If I actually need to know, would I take the average and proceed? No. I would know that one, or both measurements is flat-out wrong. The same is the case with data like the multi-proxies. You know one or more "must" be wrong"
Actually, with multiple proxies you do not know that any of them are wrong. What you know is that they are all regional proxies, and that regional temperatures differ from each other over time. You also know that the Global Mean Surface Temperature is the mean of all the regional temperatures across the globe.
So, the correct analogy is, suppose you send one person out to measure the height of a random individual in the city, and they tell you the height was 1.68 meters. Do you now know the average adult height? No. Suppose you send out eight people and they return with measured heights of 1.68, 1.82, 1.59, 1.76, 1.72, 1.64, 1.81, and 1.73. Do you now know that at least seven of them are wrong? Absolutely not. Do you now know that the average height is 1.719. No. But you do know that it is a much better estimate than the estimate from a single sample.
And if you take the mean of 73 samples (as with Marcott et al, without the bells and whistles), you know the result better still.
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jwalsh at 14:48 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
Tom Curtis @99
1) I criticized you for using a regional proxy (GISP2) as though it were a global proxy. You implied your use was justified on the basis that tropical ice cores did not exist "they don't last so long". You now claim that you knew about them all along, which makes your original use of GISP2 simply dishonest.
The ice at closer to the equators is much, much rarer, and incidentally only exists at extreme altitudes. Similar criticisms to regional differences apply really. However, in signal quality the arctic and antarctic cores provide much less noisy data. I honestly can't look at your 6-core data and say there was, or was not a Minoan, Roman, or MWP. It just is simply too noisy. Anyone making that claim (and the authors did not) would find it difficult to defend. Not believing in the above periods of warmth is certainly an opinion. I don't share it, and I am hardly alone. Maybe there wasn't. So the reason for the clear Greenland curves is?
We could discuss the Marcott paper all day long. But the simple fact is, it is based on very low resolution data. It is going to be significantly "smoother" by method. Useful to discuss on a centennial scale, maybe, but not decadal. Whereas ALL of the GISP2 data is high resolution. And Greenland temperatures correlate well enough today to global. To endorse the Marcott paper as telling us useful information on the LIA and MWP is not something I, and G. Schmidt it would seem, would do, for those reasons. And how is Gavin Schmidt's thoughts on using the Marcott paper for that reason "out of context"? I can't think of a way for it to be more in context.
I criticized you for (in effect) taking the average of just one proxy as an indicator of changes in global mean surface temperature. You now respond by arguing that taking the average of eight such proxies is of dubious "scientific utility" and that it is a premise that is itself " itself is too absurd to bother" checking the maths.
Taking an average as was done is of limited scientific utility. The criticism of picking one proxy over another is a valid one. I mentioned that as an issue straight away. Here's why it isn't that useful. They vary too much to do that. Say I give two people a tape measure to go measure an object, and one comes back and says it's 2.25 metres, and the second says 4.60 metres. If I actually need to know, would I take the average and proceed? No. I would know that one, or both measurements is flat-out wrong. The same is the case with data like the multi-proxies. You know one or more "must" be wrong. So you dig in a little bit to try and figure out which. Or you throw the whole mess out and start over. The use of proxies like tree-rings and such and whether they are truly accurate enough is a point of contention. There is also the issue that they yield lower resolution data.
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Tom Curtis at 14:20 PM on 23 September 2014The Wall Street Journal downplays global warming risks once again
JoeT @4, I misread what Koonin wrote and withdraw my post @8, no because it is wrong, but because it is no relevant to his claim. (There really are deniers who argue the position I rebut there, which contributed to my confusion.)
The "natural" greenhouse effect is the difference between the upward IR radiation at the Earth's surface (390 W/m^2) and the upward IR radiation to space from the top of the atmosphere (240 W/m^2). Of that 150 W/m^2 difference 27 W/m^2 is from CO2, a further 13.5 W/m^2 is from other will mixed greenhouse gases including methane and ozone. The remaining 109.5 W/m^2 comes from water vapour (61.5 W/m^2) and clouds (46.5 W/m^2).
Those values are for circa 1980 conditions, and hence include a significant portion of anthropogenic forcing already. Hence the scare quotes on "natural".
Based on RCP scenarios, by mid century greenhouse radiative forcing from anthropogenic sources is expected to increase by about 1.5 W/m^2, which is about 1% of the "natural" total greenhouse effect. However, to obtain that figure, you need to only consider the change relative to current values. If you consider the total anthropogenic forcing since 1760, that figure approximately doubles, and if you consider the business as usual forcing by the end of the century, it tripples.
Further, Koonan is carefull to only consider the "direct" effect. The effect of water vapour and clouds are actually feedbacks on temperature. If you drop temperature, they will fall, whereas if you increase it they will rise. The result is that increasing CO2 also increases the WV and cloud greenhouse forcing (but also decreases, ie, make more negative, the cloud albedo forcing). The effect is so strong that for a doubling of CO2, a 3.7 W/m^2 direct change in the total greenhouse results in a further 16.3 W/m^2 increase in water vapour and cloud greenhouse effect in feedbacks.
So, by mid century the direct increase may be only 1 or 2%, but the total increase as a result of that direct increase will be a 5 - 10% increase in the total greenhouse effect.
So, Koonan is not incorrect per se, but his claim is framed to cultivate confusion - and he fails to provide the explanation that would dissipate that confusion.
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jwalsh at 14:06 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
PhilippeChantreau @97
I find it rather amsing that you'd adopt such snark toward Wikipedia but maintain deference for a buffoon like Monckton.
I am showing "deference" to Monckton by agreeing with a single thing the man said? I simply attributed the comment to him. I've read very little about, or by him, but happened to have done so recently enough. Should I? As for Wikipedia. Surely you know what it is. Wikipedia can be convenient for some things, but you almost always better check the references. The quality of information on it varies wildly. I usually avoid it for anything other than a starting point when possible. YMMV.
Perhaps you might point us to what you are precisely what you are implying but "relevant"? It seems you are yet again confusing sensitivity with attribution. Why do you continue to ignore the points the about OHC? Attribution is about sorting which cause created a particular change. Show us your evidence for another cause or stop trolling.
I've not once confused sensitivity with attribution. But if you change how much warming is assessed by CO2, it follows that the relative attribution of the warming is altered. I mostly ignored the points on OHC, because I am trying to stay on topic (attribution). OHC seems to me to be about where the heat is going, not what is causing it in the first place. Some are speculating issues with assumptions. And these "some" are many in the IPCC. Over-estimates of CO2 sensitivity could be one of those reasons. If there's nothing wrong with the attribution percentages, but only that the heat is all going into the ocean. That's fine, then the models have to be adjusted accordingly for the policy-critical estimates of surface temperatures. But I don't think there's complete agreement that that is indeed what we are seeing.
As for trolling. I am trying not to. If you don't understand the "why's" of those thinking somewhat differently, you stand little hope of convincing them, should you think that important.
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Tom Curtis at 13:47 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
jwalsh @95:
1) I criticized you for using a regional proxy (GISP2) as though it were a global proxy. You implied your use was justified on the basis that tropical ice cores did not exist "they don't last so long". You now claim that you knew about them all along, which makes your original use of GISP2 simply dishonest.
2) I do not discuss the MWP or LIA with reference to those ice cores. Rather, I discuss the absense of evidence of evidence for a RWP or Minoan WP, which you claimed exist on the basis of GISP2. Clearly from the ice core data they were not global events - and changing the topic does not make them so.
3) From Marcott et al, we learn:
"The results suggest that at longer periods, more variability is preserved, with essentially no variability preserved at periods shorter than 300 years, ~50% preserved at 1000-year periods, and nearly all of the variability preserved for periods longer than 2000 years (figs. S17 and S18)."
If approx 50% of variability is preserved at 1000-year periods, >50% of a 1,200 year cycle would show up in the reconstruction. It is, however, not there. No amount of quoting Gavin Schmidt out of context will change that.
4) I criticized you for (in effect) taking the average of just one proxy as an indicator of changes in global mean surface temperature. You now respond by arguing that taking the average of eight such proxies is of dubious "scientific utility" and that it is a premise that is itself " itself is too absurd to bother" checking the maths. That you so argue in order to maintain that the data from the once proxy is a reliable guide to the timing and direction of trends in GMST (if not their magnitude) shows how absurd your position is, and how completely lacking in scientific merit.
As an aside, I did not credit the graph to wikipedia regardless of your misrepresentation. I sourced from wikipedia, and acknowledged the source as is required by copyright law (as they wave their copyright on condition that you credit the source). However, I cited Robert Rhode, the author of the graph. That you ignore that to play your empty rhetorical games is only to be expected from a troll.
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scaddenp at 13:29 PM on 23 September 2014The 97% v the 3% – just how much global warming are humans causing?
jwalsh - " Nothing to say about the IPCC experts on attribution downshifting estimates of future temperatures, setting aside temperatures at the mean or above from climate model projections as being unlikely? That would seem to be pretty relevant."
Perhaps you might point us to what you are precisely what you are implying but "relevant"? It seems you are yet again confusing sensitivity with attribution. Why do you continue to ignore the points the about OHC? Attribution is about sorting which cause created a particular change. Show us your evidence for another cause or stop trolling.
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