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keithpickering at 02:42 AM on 2 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
I think it may be a problem for the GWPF when their scientist-for-hire produces the required drivel at such a level of detail that it is instantly falsifiable.
My climate prediction: Expect GWPF to hire someone less verbose, and more opaque, in the future.
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MA Rodger at 19:13 PM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
Tom Curtis @5.
The ridicule I present @3 is indeed unscientific but when a paper is as you say "not worth the paper it's written on," that paper hangs on to the very edge of science by its fingertips. Add to that the comments by McKitrick in the GWPF's forward (saying how important this paper is for policy makers) and Mills' no-temperature-increase-this century prediction reported in the press: given such a situation, for an academic to remain silent and not set out where he stands - that is unforgivable in science. The paper could just as as well be written in crayon in the kindergarden.
And do note that this particular set of GWPF are the Global Warming Policy Foundation. This part of the GWPF is a registered charity (an educational charity no less, so that'll learn you!!) and being a charity that £3,000 paid to Mills was part funded by the UK taxpayer. Yet again the Gentlemen Who Prefer Fantasy bring legitimate UK charities into disrepute.
Resorting to ridicule may not be entirely appropriate within an SkS comment thread where scientific analysis should not be drowned out by laddish invective but on the interweb generally I do consider ridicule an effective response to these GWPF jokers.
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sidd at 14:42 PM on 1 March 2016Antarctica is gaining ice
That should read "Table 5" not "Table 10"
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Tom Curtis at 14:14 PM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
MA Rodger @3, your are correct about crudeness and inappropriateness of using cherry picked break points in this sort of study, although the references to 'kindergarden' are uncalled for. Also uncalled for are suggestions elsewhere that Mills is only publishing a report of this nature because of the fee he recieved from the GWPF. He has taken a similar line in the (dubious) Journal of Cosmology, although at least avoiding the fraudulent practise of cherry picking in that paper.
What is interesting is that in 2009 in Climactic Change, Mills performed an analysis showing that:
"Using an updated data set of global temperature and radiative forcings, it has been shown that temperature and total radiative forcing cointegrate and that this relationship is stable across the period from 1850 to 2000. A robust estimate of the temperature sensitivity to a doubling of radiative forcing is calculated to be in the range of 1–3◦C, with a point estimate of just over 2◦C. Since we cannot reject the hypothesis that the different radiative forcings have an identical impact on temperature, this result can also be interpreted as providing the temperature sensitivity to a doubling of atmospheric CO2 concentration."
(Note that the "temperature sensitivity" discussed is the Transient Climate Response.)
Thus, Mills has shown that total radiative forcing is a robust predictor of meant global temperature.
Mills also analysed NH trends in 2006 using a variety of methods, concluding that:
"In summary, then, although the techniques investigated here display certain idiosyncrasies, they share the common feature of a ‘long wave’ in trend NH temperatures with a pronounced warming trend since 1970. The range of trend functions provided by these techniques should, however, temper the enthusiasm of anyone tempted to use them for extrapolating trend temperatures far into the future."
That last caution is wise given the limitations of purely statistical techniques. Had Mills taken it at face value, he would never have published his latest excrescence for the GWPF. Needless to say, if purely statistical trend prediction are dubious for predicting the future, purely statistical trend prediction based on cherry picked break points is not worth the paper it is printed on.
Further, in a peer reviewed trend analysis in 2009, he wrote:
"As can also be seen from Figure 2, the trend slopes are all approximately constant, at around 0.03oC per annum. This implies that, at this current rate of trend increase, Northern Hemisphere temperatures will be some 3oC higher by this time next century. Being parametric, the stochastic trend model provides a standard error for both the current trend level and slope: these are 0.05 and 0.01 respectively. Forecasted trends will also have standard errors. Although the forecasted trend in 2105 will be around 3.6oC (above the 1961-1990 mean), it will have a standard error of 2.3oC attached to it, indicating the imprecision with which such long run forecasts are necessarily accompanied by: a 70% prediction interval runs approximately from 1.3 to 5.9oC. This long-range trend forecast is very much in line with the projections made by the Met Office’s Hadley Centre coupled atmospheric-ocean general circulation models, HadCM2 and HadCM3, using a ’business as usual’ scenario that assumes mid-range economic growth but no measures to reduce greenhouse-gas emissions."
That paper also analysed the Central England Temperature series (CET), in which he found two short term trends of similar magnitude to the late twentieth century trend, but that is to be expected when that series represents temperatures over a small region. Hemispheric and global series, in contrast, will show the average over many regional trends and consequently be far less variable. Consequently, we need not expect temperatures of 14.08 C by 2005 (as predicted from the CET trend), and contrary to Mills assertion, that temperature is not inline with model predictions.
Taking the three papers together, Mills own work has shown that radiative forcings are a robust predictor of temperature, while statistical patterns in temperature patterns alone are not a robust predictor of gobal temperature. Further, purely statistical predictions are downgraded by cherry picking trend periods. Therefore, to treat projected trends based on cherry picked data as refuting climate models, whose results are consistent with the robust predictions of temperature from radiative forcing directly contradicts Mills' own work. In short, not only does he know that is work in the GWPF report is of poor quality - not only does he know that it is not robust - but Mills knows the conclusions drawn for him by McKittrick in the introduction are directly contradicted by Mills actually peer reviewed work.
It is no wonder that he refuses to confirm that he considers his result to be credible.
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sidd at 12:23 PM on 1 March 2016Antarctica is gaining ice
That Zwally paper is interesting. Set aside the matter of the total mass change for a moment, and look at the changes between 1992-2001 and 2003-2008, the delta column in Table 10 or by eyeball from Fig 9. Mass waste in PIG, Thwaites and neighbours had doubled in the periods covered in the paper, the you can see the hole burning toward Ross, Ronne and the Transantarctic mountains. Recall that we are now in 2016. So apart from an overall constant, the trends agree. Fig 9 indicates that Totten is another place to watch, and I am glad the Amery doesn't seem to be waking up, at least in this data. -
Glenn Tamblyn at 08:40 AM on 1 March 2016Antarctica is gaining ice
Iceman
Here is the latest sea ice extent for Antarctica.
Fairly low for this time of year.
Yes there has been some increase in the maximum in recent years. But we will have to wait and see as to whether that is an ongoing increase or not.
And Rob is right, The Zwally paper is new and is an outlier result compared to other studies. Too early to assess whether it will stand or not. -
KR at 07:51 AM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
Mills' paper starts with the assumption that climate temperature changes are a non-stationary process, which is to say a random walk.
Unfortunately for his hypotheses, a physical system cannot exhibit a random walk without violating the Conservation of Energy - it must be trend-stationary to forcings, potentially varying around that trend but with an ever-increasing returning tendency when it does. A random walk, on the other hand, can accumulate variations either + or - from the forcing levels, leading to a situation where the climate would either gain or lose energy forever; that is just physically absurd.
Note that trend-stationary behavior is clearly demonstrated from a proper application of test for random-walk behavior (which the climate doesn't exhibit), see here and here for some very clear analysis by Tamino.
Given that bit of nonsense as a starting point, nothing else in Mills paper physically follows, including his 'eyecrometer' picks of breakpoints. If someone ever tells you that climate exhibits 'non-stationary' behavior or is a random walk, you can assume that they don't know physics, and you can ignore the rest of their spiel.
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scaddenp at 05:54 AM on 1 March 2016Earth is warming 50x faster than when it comes out of an ice age
We are likely to be in a La Nina by year end and even if not, another La Nina will come and with it, a redistribution of water onto land. Just as surely will be deniers cries that "sealevel is falling". It makes no sense to be concerned about short term trends. With his "just saying", I am pretty sure Gingerbaker is aware of that too.
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MA Rodger at 04:32 AM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
The technical basis of this GWPF Technical Paper No1 actually rests on a method that is well known here at SkS. The result rests wholly on the method employed to identify the break-points in the HadCRUT4 & RSS TLT data series. This method is not without its critics so GWPF Technical Paper No1 presents the reasons for employing this method in Note 9. And these reasons are that the 'author' (posh word for kid with crayon) Terence C. Mills of Loughborough University (likely attached to the university's kindergarden) feels he can argue that (firstly) alternative methods are less well developed that his chosen approach and (secondly) break-points can be identified over the full length of the data series when using his chosen method.
This chosen method thus allows him a level of flexibility unavailable with any of the alternatives.
The method utilises a very powerful piece of equipment call a Mk1 Eyeball. Yes, you have it right. The kid with the crayon is cherry-picking his breakpoints visually. Note 9 does make plain that other break-points can still be considered but the kid with the crayon is happy to ignore any of that and go with his prediction for temperatures out to 2020. And I note there is some press coverage showing that the kid with the crayon has got his hands on a longer ruler than the one used in GWPF Technical Paper No1. He is reported predicting global tempertatures out to 2100(And they are talking years not hours!!) based solely on the data 2002-2014. The kid may well know that short sets of noisy data (less than 18 years or so) give statistically unsound results but he probably hasn't learnt to count up to eighteen yet.
9. The break-points were determined ‘exogenously’, in other words by visual examination of a plot of the series. This was done for two related reasons. First, methods for determining breaks endogenously remain in a relatively early stage of development (see Bai, 1997; Bai and Perron, 1998, 2003,McKitrick and Vogelsang 2014) and their properties in dynamic regression models have not been completely established. Second, these methods require observations to be ‘trimmed’ from the beginning and end of the sample to ensure that the tests have reasonable properties: any trimming at the end of the sample will make it almost impossible to find a break that occurs near the end of the sample, as may well have happened in this series, this being the well documented ‘pause’ or ‘hiatus’ in temperatures. Consequently, other researchers may wish to explore alternative break points: certainly bringing the last break point forwards from December 2001 will begin to produce a significant positive trend for the fifth regime.
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Rob Painting at 04:28 AM on 1 March 2016Antarctica is gaining ice
There are a whole bunch of studies that show the Antarctic (land-based) ice sheet is losing mass versus Zwally's study that claims otherwise. Zwally's work is currently incompatible with Holocene sea level history and recent assessments of the sea level budget.
So there's a considerable volume of scientific work arguing against it. We'll just have to wait and see if Zwally's work stands up to scrutiny. If it does, we will change the text accordingly. Changing it now would be premature.
As for Antarctic sea ice, that's very interesting and very likely related to the wind trends and their effect on the polar gyres. SkS will have a new post on that in a few weeks.
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scttharding5 at 04:26 AM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
It's like saying that the burner on my stove isn't going to heat up based on past patterns, and ignoring the fact that I just lit the gas.
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Iceman at 04:00 AM on 1 March 2016Antarctica is gaining ice
"Update Nov. 7 2015
A study published by Jay Zwally and his team on Oct. 30 (Zwally et al. 2015) has suggested that until 2008 there might have been a bigger increase in ice on East Antarctica than there is a decrease in the west, meaning that total Antarctic land ice is increasing."
There is nothing in that study to suggest that he ice gain that has been occurring for 10,000 years has stopped.
The Science has shown that Antarctica is gaining ice. Clinging to this false claim that the "science says" Antarctica is losing land ice shows poor alligiance to science. -
Iceman at 03:54 AM on 1 March 2016Antarctica is gaining ice
"Satellites measure Antarctica is gaining sea ice but losing land ice at an accelerating rate which has implications for sea level rise."
This "argument" is clearly wrong. Antartica is gaining land ice mass and sea Ice. This should be corrected if this site claims to offer science as answers.
http://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses -
Jim Hunt at 02:33 AM on 1 March 2016GWPF throws out centuries of physics, climate scientists laugh, conservative media fawns
Note also that the Global Warming Policy Forum is attempting to pull the same stunt with a porky pie production line of Arctic sea ice misinformation. For all the gory details of this long running saga please see:
The Great Global Warming Policy Forum Con
Dear Benny,
I note that the GWPF webmaster has still not taken on board any of the helpful [Arctic sea ice] advice I have proffered over the last few weeks, and has now posted some inaccurate information about “global warming”. Will he or she never learn?
Apparently not!
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wili at 01:53 AM on 1 March 2016Earth is warming 50x faster than when it comes out of an ice age
Thanks, ms and noa. Looking at earlier years, one might assume that this most recent divergence from the linear trend is just that--a temporary blip. But of course, it could be the beginning of a new, steeper linear, or the beginning of an exponential trend. If the latter, the question is what the doubling time will be.
As with many things, we won't know for sure till it's in the rearview mirror. -
noa at 22:50 PM on 29 February 2016Earth is warming 50x faster than when it comes out of an ice age
He might be refering to this graph from AVISO Data. If you look only at the data from Jason-2 you get a SLR rate of 4.31 mm/yr. Of course this is a very short time span, so I do not thin it has any significance as of yet.
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scaddenp at 11:54 AM on 29 February 2016Volcanoes emit more CO2 than humans
Clapper, large volcanoes in this era mostly cool the earth temporarily thanks to aerosols which persist for a few years. In the distant past, gigantic volcanic eruptions sustained for a long time (Large Igneous Provences) are associated with mass extinctions. See here (and the other part) for more detail. Short answer is that you need volcanic activity like hasnt been experienced for 100s of million years to get something comparable to human FF emission rates.
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michael sweet at 11:27 AM on 29 February 2016Earth is warming 50x faster than when it comes out of an ice age
Wili,
Here is a link to the Colorado data.
I am not sure what the last entered date is. Perhaps Gingerb has a better graph. 2015 goes way up, but 1997 did also. 2014 does not look bad to me. It looks like the data was close to the long term line until the start of 2015. We can hope that the data will return to the long term mean like it did in 1998.
Moderator Response:[PS] Please try again. You cant insert a PDF as an image.
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Clapper55 at 11:14 AM on 29 February 2016Volcanoes emit more CO2 than humans
I would like to see more about what would have to occur in order for volcanic activity to make humans decreasing carbon emissions not effective. I also want know how much if any volcanic activity has on global warming and compared to humans effects.
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wili at 10:03 AM on 29 February 2016Earth is warming 50x faster than when it comes out of an ice age
Gingerb, could you share your source on those figures?
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Tom Curtis at 07:36 AM on 29 February 2016Breathing contributes to CO2 buildup
hydman1 @58, in all photosynthesis in plants, molecules of CO2 combine with molecules of water to produce sugar and oxygen. This is the general formula:
There are different pathways to achieve this reaction, but the initial and final reaction products are the same for all pathways. Therefore there is no difference in the efficiency of plants in converting CO2 (plus H2O) to O2 (plus C6H12O6).
What there is is a difference in is the biomass of different ecosystemts and/or crops per hectare; and hence a difference in the amount of carbon stored per hectare. That difference, however, is accounted for under the rubric of Land Use Change (LUC).
Building CO2 converters, ie, machinery that takes CO2 and seperates the oxygen from the carbon cannot (due to conservation of energy) use less energy than is produced by burning coal, and due to inefficiencies, will likely use substantially more. Any such solution, therefore, cannot work without the majority of the economy being sustained by non-fossil fuel energy. At that point, it would be simpler, and much cheaper to simply substitute the non-fossil fuel energy for the current fossil fuel energy use.
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hydman1 at 06:25 AM on 29 February 2016Breathing contributes to CO2 buildup
The notion that there is an eco balance to cancel respirated co2 and only co2 emissions from other sources should be considered is rediculous. There is no proof that the crops that replaced other disiduous plants that were growning on the ground before the crops were planted were or are any more efficient at converting co2 to o2. The real fact is that the yield of crops have largley been increased by improved germination, resistance to disease, irragation, and the control of pests as much as the number of acres dedicated to agriculture over the last 50 years. Those changes do little or nothing to affect the co2 consumption by crops. In the US farmland was allowed to remain unplanted in order to reduce food surplus and increase crop futures. The reason that we contiune to hear the bable from environmentalist groups about carbon emmissions is that they are more about self preservation. The notion that population control is the real answer to all these issues is unthinkable to them because for many of the leaders of this cause, that is where there power base comes from. The earth has a finite capacity for filtering out co2 strictly based on vegetation. Maybe we should be building co2 converters instead or shutting down coal if favor of nuclear power or trying to convert to wind which can only work if it was a globally connected power grid. That is decades or centuries away.
Moderator Response:Thank you for taking the time to share with us. Skeptical Science is a user forum wherein the science of climate change can be discussed from the standpoint of the science itself. Ideology and politics get checked at the keyboard.
Please take the time to review the Comments Policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
In particular, please note the "No inflammatory statement and accusations of fraud".
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There's no correlation between CO2 and temperature
SOMMERSWERD - ...And your question is in fact a query about CO2 absorption saturation, which is more appropriately dealt with on the appropriate thread.
Moderator Response:[PS] Fixed link
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There's no correlation between CO2 and temperature
SOMMERSWERD - Actually, I did answer your question. Atmospheric absorption is concentration and hence pressure/altitude dependent, with sea level pressure and concentrations of CO2 absorbing all CO2 frequencies in a matter of meters.
What matters for the greenhouse effect is at what temperature (and hence rate) IR is emitted to space - that occurs at altitude, when there is insufficient CO2 above the effective emission altitude to absorb the majority of the outgoing IR.
Increasing CO2 simply raises the effective emission altitude - and there is in fact solid data showing that over the last 50 years the tropopause where the effective emission occurs has risen a few hundred meters. Given the lapse rate relationship, that altitude change accounts for the observed rise in temps over that period.
So in detail the answer is "it depends on what you're asking". All CO2 frequencies get fully absorbed at the surface (with corresponding thermal emission), the strongest absorption lines continue to absorb a majority of the IR at those frequencies until pressure drops enough to allow >50% through to space, and changes in CO2 concentration simply change that altitude - where again >50% of the emitted IR at those wavelengths escapes the atmosphere. Your question "...how much energy remains to be affected?" is therefore somewhat meaningless without more context.
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SOMMERSWERD at 05:42 AM on 29 February 2016There's no correlation between CO2 and temperature
KR
My question was simple but you have not responded. No discussion; just a question that you do not respond directly.
Moderator Response:[PS] KR pointed you to a more appropriate thread for discussion of question. It is off-topic here. Please take the discussion there. Offtopic discussion will be deleted from this thread.
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Glenn Tamblyn at 04:43 AM on 29 February 2016Earth is warming 50x faster than when it comes out of an ice age
sidd
Sounds like this is new findings from including the fracture mechanics of ice cliffs.Assentially it seems to be saying that an ice edge more than 1000 meters high, so 100 above the water, 900 below, in water 900 meters deep or more is unstable. So a sheet 200, 500, 800 meters thick at it's edge is stable, whether it is floating or not.
The ice in the WAIS is largely over 1000 meters thick then tapers to less than that at places like the Thwaites. So the edge of the Thwaites doesn't suffer from this instability. But if it retreats back into deeper water, where the ice is thicker, it can become unstable. -
There's no correlation between CO2 and temperature
SOMMERSWERD - See CO2 is saturated for a discussion of this. The real effects of greenhouse gases take place in the upper atmosphere when the concentrations drop to the level that IR can escape to space, and increased levels of CO2 just raise that altitude. There is no 'saturation' issue.
Moderator Response:[PS] Fixed link
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SOMMERSWERD at 01:25 AM on 29 February 2016There's no correlation between CO2 and temperature
Hi from Spain. I have a question:
"How much of the thermal radiation energy from the Earth in the band centered on the 14.77micron wavelength that is resonant with the vibrational mode of CO2 has already been affected by the current atmospheric CO2 concentration, and how much energy remains to be affected?”
A greeting and thanks in advance
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tcflood at 15:48 PM on 28 February 2016How Exxon Overstates the Uncertainty in Climate Science
It seems to me that the main problem is that the graph (at least at the scale in the online postings) is illegible for *anyone* and so it invites misrepresentation. It would best be presented as a set of five graphs: four that show all the model results for a each of the four RCPs so as to give a good impression of the scatter of the models; then one graph that shows four *averages* of all the results for each of the RCPs. Such a presentation would be much harder to misinterpret and misrepresent.
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sidd at 14:07 PM on 28 February 2016Earth is warming 50x faster than when it comes out of an ice age
Interesting. Alley says "decades" for Thwaites ... possibly. First time i heard him say decades. -
Gingerbaker at 07:41 AM on 28 February 2016Earth is warming 50x faster than when it comes out of an ice age
"... a doubling time from a 1mm per year ice sheet contribution to sea level in the decade 2005-2015 would lead to a cumulative 5 meter rise by 2095.""
SLR doubled in 2015 from 4.1mm/year in 2014 to 10mm in 2015. Just sayin'.
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swampfoxh at 06:58 AM on 28 February 2016How Exxon Overstates the Uncertainty in Climate Science
Up is still up. All of the RCP are "up". I think some of the problem has to do with a person's perception of the impact of a "couple degrees of temperature. With respect to the climate in the dining room on the night your boss is coming over for dinner, a couple of degrees means nothing. Climate scientists know that a, "couple of degrees of global averaged higher temperatures is a "big deal"". So, let us not fret much about the Exxon folks or anyone else that doesn't get it. Keep plugging away at the scientific efforts and the peer-reviewed results and more people will "sign on" to solutions, even if we "extinct-ify most of the human race before we "get there". After all, the globe could use a drastic population reduction...think how much CO2 we wouldn't be pumping into the atmosphere? (There, I've said it) Sorry.
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Glenn Tamblyn at 15:27 PM on 27 February 2016Earth is warming 50x faster than when it comes out of an ice age
wili
Roughly yes. He did think there was still some uncertainty about whether Thwaites is committed to going, and he also thought that it was possibly a century or 2 before is really ramps up, but then it is a multi-decadal rather than multicentury process for the WAIS.
The description of including the fracture mechanics of high ice-cliffs and how that can drive retreat was fascinating/horrifying. And that including that into the ice models 'solved' the Plioscene was telling.Like the best discoveries, once the original realisation that a mechanism needs to be included has been made, in hindsight it can seem like 'well, of course'. But in reality those are important advances in understanding.
It is probably one of those things a layman doesn't question when they see that land terminating glaciers taper down to their end while sea terminating glaciers end in ice cliffs. But when you think it through and realise the implications a lightbulb moment happens. -
michael sweet at 12:36 PM on 27 February 2016Earth is warming 50x faster than when it comes out of an ice age
Why leave out the Arctic Sea ice which is also setting a new record every day for lowest sea ice ? Alan Motorman is using last year's denier meme, there is a reason the deniers are not using it this year.
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Tom Curtis at 10:47 AM on 27 February 2016Earth is warming 50x faster than when it comes out of an ice age
KR @10, you forgot the Antarctic Sea Ice area, which is currently below the 1979-2008 mean:
And global sea ice area which is currently setting a record minimum area in absolute terms, and one of the lowest anomalies on record:
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Earth is warming 50x faster than when it comes out of an ice age
Alan_Motorman - What do you mean, the arctic ice caps are increasing? Antarctic land ice is decreasing at ~134 billion tons per year:
[Source]
(see GRACE data up through this year here, only one paper in disagreement, Zwally et al, and there are potential issues with that methodology), Greenland ice decreasing at 287 billion tons per year, Arctic ice is on a steep downward trend (albeit with yearly variations that do not reach statistical significance):
[Source]
There is no way anyone can seriously assert that the ice caps are increasing.
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Alan_Motorman at 05:03 AM on 27 February 2016Earth is warming 50x faster than when it comes out of an ice age
The artic ice caps are increasing. Water levels will stabilize or even get lower over the next 50 years.
What can offset this trend of cooling is volcanic or methane gas leading to greenhouse affects.
I'm particularly concerned with methane gas pockets under the oceans. Slight temperature variations or earthquakes can lead to these "bubbles" releasing into the atmosphere.
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wili at 02:31 AM on 27 February 2016Earth is warming 50x faster than when it comes out of an ice age
Thanks for that link, Glenn.
As I understand it, he's saying that Thwaites could destabilize at any time, and whenever it does, it is most likely to go in a matter of decades, leading to a rather abrupt sea level rise of about a 4 meters in the northern hemisphere. That is pretty shocking. Is that your understanding of the message?
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sailingfree at 02:16 AM on 27 February 2016There's no empirical evidence
We have direct evidence, as the following news article and original paper show.
http://newscenter.lbl.gov/2015/02/25/co2-greenhouse-effect-increase/
http://www.nature.com/nature/journal/v519/n7543/full/nature14240.html
The above describe direct measurement of the incoming and outgoing radiation of the Globe at various wavelengths over a decade, and show that it is directly due to more CO2. -
scaddenp at 12:24 PM on 26 February 2016Human CO2 is a tiny % of CO2 emissions
Can you be more specific about you want? The gory detail can be found in Chapter 6 of the IPCC AR5 WG1 report.
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Clapper55 at 11:37 AM on 26 February 2016Human CO2 is a tiny % of CO2 emissions
this article is very informative showing how humans are contributing to carbon emissions in to our atmosphere. I would be interested in seeing a more complex version of this showing exactly where natural emissions and man made go.
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Glenn Tamblyn at 09:59 AM on 26 February 2016Earth is warming 50x faster than when it comes out of an ice age
wili
You might find this talk by Richard Alley interesting. Particularly later in the talk where he discusses the Thwaites Glacier. -
John Hartz at 06:19 AM on 26 February 2016Models are unreliable
Tom Curtis: I have neither the time nor inclination to get into a protracted discussion about the details of Frank Shann's posts. Having said that, I believe that the word "simulate" would have been a better choice than "predict" in Dana's OP. "Predict" connotes to the average person the foretelling of something that is likely to happen in the future.
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Tom Curtis at 01:39 AM on 26 February 2016Models are unreliable
John Harz @981, Frank Shann's premise of (not argument for) the need for effective communication is valid (and well known, and acknowledged). His belief that using only archetypal meanings represents effective communication is just false, something he conceals from himself by not asking the crucial question - what is misunderstood as a result of the use of the word 'predict' by Dana. The answer is nothing - something his survey does not address and he does not address in counter argument.
In constrast, his preferred word, 'describe' would introduce genuine misunderstanding, and has it happens is also not an archetypal use of the term.
Your link supports his premise - ie, that effective communication is important, but has only one bearing on his argument about whether a particular example of communication was more or less effective than alternatives. In fact, it only has one bearing on the topic. Specifically, he is a scientist, as were (in all probability) his colleagues who he surveyed. From your link we learn that scientists are poor judges of effective communication. That is, the linked article undermines his claim to relevant expertise on this issue.
I was prepared to allow his courtious granting of himself the last word @967 to stand, but not if you are going to step in and misrepresent the discussion in his favour.
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John Hartz at 00:21 AM on 26 February 2016Models are unreliable
Framk Shann has, in my opinion, made a sound argument for improving the way SkS and others communicate the science of climate change. His central point is butressed by a just published editorial by Nature Climate Change, Reading science.
The tease-line of the editorial is:
Scientists are often accused of poorly communicating their findings, but improving scientific literacy is everyone's responsibility.
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wili at 23:38 PM on 25 February 2016Earth is warming 50x faster than when it comes out of an ice age
Thanks for the clarification, KR. IRRC, Hansen somewhere also said we couldn't competely rule out a doubling time of 5 years. But I don't have the source at my fingertips, so maybe that's my memory playing tricks on me.
I still wonder why one shouldn't just multiply 50 (or 20, or whatever) to the rates given in #s 1 and 2 in my first post to get an approximation of the rates we should expect going forward. I know that there was a lot more ice then in the northern hemisphere, but as I understand it, the Antarctic ice sheet wasn't really in play then. And in any case, wouldn't a lower starting point just be another element to put into the same equation?
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mwsmith12 at 23:19 PM on 25 February 2016Earth is warming 50x faster than when it comes out of an ice age
The title says "Earth is warming 50x faster than when it comes out of an ice age," but the article says "We’re already warming the Earth about 20 times faster than during the ice age transition, and over the next century that rate could increase to 50 times faster or more."
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scaddenp at 12:45 PM on 25 February 2016Models are unreliable
I just had a quick look at Mann 2015 where this all started and at CMIP5 website. According to website, the runs were originally done in 2011. The CMIP5 graph is Mann, is the model ensemble but run with updated forcings. To my mind, this is indeed the correct way to evaluate the predictive power of a model, though the internal variability makes difference fom 2011 to 2015 insignificant. The continued predictive accuracy of even primitive models like Manabe and Weatherall, and FAR suggests to me that climate models are a very long way ahead of reading entrails as means of predicting future climate.
I wonder if Sks should publish a big list of the performance of the alternative "skeptic" models like David Evans, Scafetta, :"the Stadium wave" and other cycle-fitting exercises for comparison.
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FrankShann at 11:53 AM on 25 February 2016Models are unreliable
scaddenp: thanks for taking the trouble to reply, and for the very useful link.
Despite the difficulties, it would be great to have a Skeptical Science resource page that was kept up to date with previous IPCC models (or even just two or three of them) and their forecasts (given the forcings that actually occurred), which would show that the models are accurate. I accept that's very easy for me to suggest, but a lot of work for someone else to do.
I agree about the wilfully ignorant, but surely we need to keep trying. It's one of the important functions of Skeptical Science. Most deniers don't read Skeptical Science, but it's a very useful resource for people trying to persuade the deniers and (more realistically) the undecided. Climate scientists will win in the end - because they're right. Let's hope they win soon enough to prevent catastrophe.
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scaddenp at 11:06 AM on 25 February 2016Models are unreliable
Rerunning the actual climate models is not a trivial process. Serious computer time for version 4 and 5 models. Hassles with code for pre-CMIP days. However, outputs can be scaled for actual forcings. "Lessons for past climate predictions" series do this. Eg for the FAR models, see http://www.skepticalscience.com/lessons-from-past-climate-predictions-ipcc-far.html
However, I am very doubtful about the possibility of changing the minds of the wilfully ignorant. It seems to outsider, that in USA in particular, climate denial is part of right-wing political identity.
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