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scarletrogue at 13:39 PM on 5 February 2016Medieval Warm Period was warmer
You"re kidding with the heat maps, right? Way to cherry pick a nine-year period and compare it with a 300 year period as evidence of increased global temperatures. The irony is, you can make the same argument at any time in history: Some locales are warmer, and some locales colder, just like today. While the western and southern U.S. can enjoy higher than normal temperatures, the northeast can be much colder and snowier. More than anything, it's a matter of time and location. Next thing you will tell me is, CO2 levels were not higher more than 30,000 years ago.
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wili at 04:35 AM on 5 February 2016Industrial-era ocean heat uptake has doubled since 1997
So ocean heat content doubled in the last about 20 years, and eyeballing the graph, it looks like it's quadupled in the last about 40 years.
When will this oceanic exponential rate of warming translate into similar paces of atmospheric warming?
Moderator Response:[Rob P] What do climate models project for the lower troposphere? I've had a brief look at the IPCC AR5 but have found anything yet. Interestingly, the accelerated warming of the ocean infers increased warming of the lower troposphere.
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Tom Curtis at 23:26 PM on 4 February 201610 Indicators of a Human Fingerprint on Climate Change
MA Rodger @98, The DTR data used by POJO is not from CRUTEM4, contrary to his frequent assertions. Rather it is from the CRU TS 3.23 gridded dataset, from which a timeline is produced by the KNMI Climate Explorer software. The CRU TS 3.10 dataset (updated to 2009) is described Harris, Jones, Osborne and Lister (2013). I am not aware of a paper explicitly describing version 3.23, but it is unlikely to differ significantly, except for the end date.
Harris et al write:
"The CRU TS dataset is not specifically homogeneous. Whilst many of the observations will have been homogenized (often by national meteorological agencies) prior to publication and use in the process, this is not a requirement for inclusion. With the use of climatological normals (and synthetic data in the case of secondary parameters) to supplement observations, it would be neither appropriate nor straightforward to assess homogeneity throughout the dataset. This dataset should only be used for climate trend analysis, therefore, if the results are treated cautiously, and we recommend that such analysis should be complemented by comparison with other datasets. For example, in Section 4 we compare longterm changes in CRU TS3.10 with CRUTEM3 and GPCC over world regions, and find good agreement at the chosen spatial scales. We also compare CRU TS3.10 mean temperature with CRUTEM4 at that dataset’s resolution, finding that long-term (∼50 year) and full-term trends are consistent, with only one or two exceptions where the trends are significantly different at the 95% level."
For what it is worth, here are the comparison between CRU TS3.10 and CRUTEM3. The three numbers in each category are in order, the TS3.10 trend, the CRUTEM3 trend, and the correlation of annual values in the timeseries.
Northern Hemisphere 0.10 0.09 0.97
Southern Hemisphere 0.05 0.08 0.94
Global 0.07 0.08 0.97 -
MA Rodger at 21:43 PM on 4 February 201610 Indicators of a Human Fingerprint on Climate Change
POJO @97.
The use of every day terms within science is entirely acceptable if their meaning is scientifically precise. I do not believe the two terms you used @94 in any way provide such precision.
As for you consideration of Vose et al. (2005), I would agree that "the obvious stands out" but I don't think anything is gained by stating it. You are wrong saying that Vose et al. (2005) "is the same as the IPCC in TAR." I think the reason for that is "obvious."
As for CRUTEM4 Tmax and Tmin. You suggest these data have undergone "a rigourous homeginisation process." Do you think it is adequate for your purpose? (Note that maybe "one needs a paper" to answer that.) If CRUTEM4 is accurate enough, the dramatic change in DTR estimates between Vose et al. (2005) and that afforded by CRUTEM4 would be worthy of comment, assuming your graphing is also accurate.
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David Lewis at 15:25 PM on 4 February 2016Measuring ocean heating is key to tracking global warming
This was the second sentence in the Von Schuckmann et.al. paper abstract:
"The absolute value of EEI [ Earth's Energy Imbalance ] represents the most fundamental metric defining the status of global climate change, and will be more useful than using global surface temperature. "
In debate with someone like Cruz for instance, who claims the planet is not heating up, a person could point to where physics says more than 92% of the heat would be going if the planet were heating up, the oceans, and ask him to explain, if the planet is not heating up, why are the oceans getting warmer?
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Bob Loblaw at 10:21 AM on 4 February 2016The Quest for CCS
Sharon:
When I lived in Regina, Saskatchewan, we had to replace our furnace, and looked seriously an a ground source heat pump option. At the time (about 12 years ago?), it would have cost us about $20K to install a system to heat a 1600 sq.ft. bungalow. Half of that cost would have been for the drilling; the oher half for the heating/cooling system (using existing hot air ducts in the 20-year-old house).
We also ended up opting for a high efficiency gas furnace, for several reasons:
- Cost. I did detailed calculations on our past gas consumption and anticipated heating and cooling requirements, and the payback period was very long (20 years or so). Going high efficiency basically cut our gas usage in half, compared to the old furnace.
- Saskatchewan is also a place where most electricity comes from burning coal, so GHG implications were still high.
- All that drilling in an existing yard would have meant serious replacement landscaping (costs and efforts).
It would make more sense for a new house, and would surely make a lot more sense for places where people don't have access to natural gas and use electricity to heat directly.
We also ended up opting for a wind-generated electricity supplement on our electricty bill ("green power"), to encourage SaskPower to pursue renewalbe options.
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Tom Curtis at 10:11 AM on 4 February 2016They predicted an ice age in the 70's
Moderator inline @44, I do not think the 1972 comment by Schneider and Rasool to which you link is a retraction of the 1971 paper. It is certainly not the 1974 retraction mentioned in wikipedia. However, in 2009, Schneider wrote in an email to Peter Chylek:
"all good scientists are skeptics and should be challenging every aspect
of what we do that has plausible alternative hypotheses. I personally
published what was wrong (with) my own original 1971 cooling hypothesis
a few years later when more data and better models came along and
further analysis showed [anthropogenic global warming] as the much
more likely…In fact, for me that is a very proud event—to have discovered
with colleagues why our initial assumptions were unlikely and better
ones reversed the conclusions—an early example of scientific skepticism
in action in climatology."How early Schneider discovered his 1971 paper to be in error is unclear. Certainly by 1972 he was stating that the model was inadequate, while not precluding the possibility of the accuracy of the predictions. He wrote:
"Recent numerical models studying the effect of particles on climate are often based on multiple scattering radiative transfer calculations, and use global averages for particle concentrations and optical properties. By contrasting certain existing models, some major problems in modeling studies that attempt to answer the question of the effects of increased atmospheric particles on climate can be illustrated. It will also be apparent that another uncertainty in the results of such studies arises from a lack of adequate observed input data on the geographic and vertical distributions of particle concentrations and their optical properties. Furthermore, a model that could realistically simulate the impact of increasing atmospheric particle concentration on climate must eventually include the simultaneous coupled effects of all the important atmospheric processes, such as fluid motions and cloud microphysics, in addition to the radiative transfer effects."
And by 1978, he was convinced that the warming effect of CO2 was the dominant anthropogenic influence on climate.
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Rob Honeycutt at 08:41 AM on 4 February 2016They predicted an ice age in the 70's
NicktopPC @41... Yup. And the references showing this have been offered up to you already.
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Sharon Krushel at 08:13 AM on 4 February 2016The Quest for CCS
#63 - Hello Glenn,
I addressed GHSP possibilities for our area in #59, but have since done more research. Because of our current energy mix, switching from natural gas to GHSP would acutally increase our emissions. As Alberta replaces coal with solar, wind, etc., this option will begin to make sense for more Alberta homes.
Our friend, Dr. Jim Sandercock (NAIT) has made some interesting predictions regarding the future of our alternative energy. "Geothermal is probably going to maintain its quiet majority in the alternative energy space. There are a lot of installations in the Edmonton area already – over 1,000. They’re particularly effective when they’re part of commercial buildings..."
One factor is that commercial buildings often have air conditioning (which GHSP replaces), whereas most homes here don't, so the benefit for homes is not as great.
According the Calgary Geothermal Inc., installing GSHP for our existing 1226 sq. ft. home would cost about $30,000 plus $15,000 for our detached single-car "garage" shop. This does not include travel and hotel costs. (There may be a company in Edmonton; I just haven't found one.)
One of the obstacles they often meet is that they have to be able to get a drilling rig into your yard. Unfortunately, that would be impossible for us unless we bulldoze our neighbour's garage. :(
One thing I did discover in my research is that Albertans can choose a green energy plan for electricity. I'm sure you're familiar with the concept, but...
"If you're looking to support solar power in Alberta, you need to locate a solar energy company and purchase your supply from it...it's not as though you actually have wind or solar electricity pumped directly to your outlets. Instead, the supply you purchase from renewable energy companies is simply added to the giant pot that is the energy grid. Purchasing a green energy plan means your energy use will be offset in the grand scheme of things because an equivalent to your usage was produced by a renewable energy company."
Also, if you use natural gas for heating, you can determine your carbon footprint and offset your consumption by purchasing carbon offsets or renewable energy credits (investments in renewable energy projects).
And so, Glenn, I thank you for your kind suggestion and question. I have learned a great deal in the process of answering it.
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They predicted an ice age in the 70's
NecktopPC - Wiki malfeasance? That's quite a claim, care to support it with some evidence? As a crowd-sourced reference site it's actually quite good about relying on peer-reviewed science, and the occasional mis-edit by ideologically driven or simply cranks tends to get corrected in short order.
And if you think the case for anthropologically driven global warming isn't supported, I'll point out that about 97% of the experts in the field would disagree.
You're more than welcome to rely upon a paper repudiated by one of the authors due to clear and documentable math errors, 'tho I personally would consider it completely invalidated. But I'll note that if you are reliant upon that weak a reference, one in conflict with the vast majority of work in the climate field, no one should or will take you in the least bit seriously.
Moderator Response:[PS] The published acknowledgement of the problems with the paper by the authors is here. Claiming fraud in response to information you do not like will not be tolerated here.
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NecktopPC at 07:28 AM on 4 February 2016They predicted an ice age in the 70's
KR - But is the paper, in fact, null and void?
Wikipedia however, was caught in a rather coincidental case of malfeasance, in their support for global warming.
Moderator Response:[JH] Sloganeering is prohibited by the SkS Comments Policy. Please cease and desist. If you do not, you will forfeit your privelege of posting on this website.
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They predicted an ice age in the 70's
NecktopPC - The paper wasn't retracted by the publisher (it didn't represent academic mafeasance, it was simply wrong), but from several sources:
...Schneider became aware that he had overestimated the cooling effect of aerosols, and underestimated the warming effect of CO2 by a factor of about three. He had mistakenly assumed that measurements of air particles he had taken near the source of pollution applied worldwide. He also found that much of the effect was due to natural aerosols which would not be affected by human activities, so the cooling effect of changes in industrial pollution would be much less than he had calculated. Having found that recalculation showed that global warming was the more likely outcome, he published a retraction of his earlier findings in 1974. (emphasis added)
In short, the paper was repudiated by one of the authors due to some significant math errors. I would consider that sufficient to render that paper null and void.
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NecktopPC at 06:17 AM on 4 February 2016They predicted an ice age in the 70's
Rob Honeycutt@40
Are you certain that the paper (Atmospheric Carbon Dioxide and Aerosols: Effects of Large Increases on Global Climate) from Rasool and Schneider has been retracted?
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Rob Honeycutt at 01:05 AM on 4 February 2016They predicted an ice age in the 70's
NecktopPC... It seems to me what you're doing is attempting to cherry pick aspects of various studies in order to confirm a specific conclusion you want to arrive at. There is a very broad scientific consensus on the issue of man-made global warming that is arrived at through evidence from a wide range of research spanning the past century and more.
The chances of our planet being headed into a new ice age anytime in the near future is slim to none. And none of the research you're presenting makes a case for this potential, other than a retracted paper from Rasool and Schneider.
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NecktopPC at 00:18 AM on 4 February 2016They predicted an ice age in the 70's
Glenn Tamblyn@39Well; if a statement regarding atmospheric cooling is taking place, and we know from past experience (climate history) that if this cooling continues and the build up of ice continues in Antartica like it is; then it is possible that the planet may very well be headed back into an ice age - and when this 'atmospheric cooling' trend is mentioned on the GISS [NASA] Webpage, and by one of the GISS scientists (Kate Marvel, a climatologist at GISS and the paper's lead author) then i would have to conclude that the are embracing the science revealing evidence that such mechanics are, taking place, and I view their statemnt as an endorsement and ot their recognition, of global cooling.
RE: "The definitiuon given by the moderator [PS] is appropriate."
Or as the climate changes? Like everyday; somewhere on the planet?
Moderator Response:[PS] If you think Kate Marvel thinks cooling is going to happen anytime soon, then you have either not read paper, or else wilfully misunderstood it. For discussion of paper, try here. The paper primarily reconciles various estimates of climate sensitivity.
I stick to my definition of "endorsement". If the standard you supposed applied, then these organizations would also be "endorsing" the larger no. of papers warning of CO2-induced warming. (42 to 6).
[JH] Moderation complaints and sloganeering are prohibited by the SkS Comments Policy.
Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit offensive or off-topic posts. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
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PhilippeChantreau at 00:11 AM on 4 February 2016The Quest for CCS
Sorry if I misinterpreted your meaning Sharon. I remain skeptical about CCS. It's a question of scale. Total yearly anthropogenic CO2 emissions are about 100 times that of volcanic activity. The sheer amount is staggering. Equally staggering is the scale at which CCS would have to be deployed to make a dent in it. It is a geological scale undertaking. The cost would be a significant factor, so would be the energy expenditure. I am not sure that CCS on a large scale makes sense from the thermodynamic point of view.
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SirCharles at 00:04 AM on 4 February 2016'The Blob' Disrupts What We Think We Know About Climate Change, Oceans Scientist Says
There is another "blobb" which is of concern. The animation below shows a rapidly growing cold spot in the North Atlantic in recent years:
The reason is found in the acceleration of Greenland's glacier melt due to a warming planet. More cold freshwater is remaining longer on the surface of the warmer - but denser - sea water, before getting mixed. And there are no indications of a slow-down. The opposite is the case.
=> World's oceans warming at increasingly faster rate, new study finds
Ocean water has absorbed more than 90% of the excess heat and nearly 30% of the carbon dioxide generated by human consumption of fossil fuels
=> What scientists just discovered in Greenland could be making sea-level rise even worse
=> Scientists Warn Climate Change Affecting Greenland Ice Sheet More Than Previously Thought
=> Greenland Will Lose Mass Faster due to Ice “Lid”
And this has another implication which is also worrisome => Study: Melting Greenland ice sheet is rapidly slowing the Gulf Stream
The outlook is anything but innocuous, in particular concerning the rapidly slowing golf stream.
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Tom Curtis at 16:26 PM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
Glenn Tamblyn @159, I agree. Indeed, I have been quite critical of the use of slab models to explain the greenhouse effect to the public in the past, considering their only useful application the teaching of the maths of climate models. Never-the-less, if the first law of thermodynamics were rescinded sufficiently for Postma's analysis to be correct, there would be no greenhouse effect. Therefore when discussing Postma's absurdities (and other denier critiques along the same line) we need to show where the reasoning is wrong within the context of idealized de Saussure hotboxes, and in several cases (including Postma's) that there analysis depends essentially on treating real world hotboxes as if they were perfectly insulated and the glass was perfectly transparent to visible light, even though it is well known that both assumptions are false (indeed, absurdly false).
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Tom Curtis at 16:17 PM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
JPostma @148 (2nd point):
In the PDF you show the following diagram, commenting:
"A 5-layer de Saussure IPCC greenhouse device would result in a back-surface energy flux of 6,000 W/m2, which is 5700K or 2970C or 5660F via the Stefan-Boltzmann Law. This seems to be a very practically useful result as it indicates that a primary radiant heating source (1000 W/m2 of solar energy in this case) can be concentrated or amplified to temperatures far warmer than the equivalent temperature of the primary initial radiant heat source itself. Indeed, in theory it would work better than even a magnifying glass or focusing mirror and would not be limited by the effective temperature of the source spectrum since there is no limitation in these mechanics on the thermal properties of the primary heat source. The device de Saussure used was said to have multiple panes of glass, and so the effect predicted by the modern IPCC greenhouse effect should have been readily apparent."
What is obvious from this is that you completely fail to recognize that no glass has perfect transmittance of visible light, and thatn no box is perfectly insulated. You are like some creationist pseudoscientist criticizing Newton's three laws of motions as false because (as it happens) in the real world there is friction, air resistance and uneven forces, all of which lead to divergence between experimental and predicted results in the simple models that ignore those complications.
How much of a problem these factors can actually be is seen by looking at the transmitance of modern, 1/4 inch clear glass:
(Source)
Note that while the diagram shows the example for an angle of incidence of 30 degrees, at 0 degrees (ie, perpendicular to the glass) the transmittance is not appreciably better.
Using a spreadsheet I modelled a 5 pane de Saussure Hotbox with 2% reflectance and 2% absorption. The result showed a backplate temperature of 532 K (258oC), with radiances given in the table below:
Layer SW Down SW Absorbed SW Up SW Up SW Down
5 980 20 179 801 801
4 941 19 140 1582 1582
3 904 18 103 2344 2344
2 868 17 67 3088 3088
1 834 17 33 3815 3815
0 0 801 0 4525 0(* Note that for convenience of calculation, I ignored reflected shortwave radiation going upward. Any inaccuracy of the calculation thereby introduce is more than compensated by the very low values of reflectance and transmittance relative to the actual case.)
That still ignores heat losses, the two primary sources of which will be heat loss from the backplate zone (as the hottest region of the box) and from the top pane (due to ambient airflow cooling the glass). Introducing just a 50 W/m^2 heat loss for just the second factor drops the backplate temperature to 423 K (150oC), with radiances as follows:
Level SW Down SW Absorbed SW Up SW Up SW Down
5 980 20 179 350 350
4 941 19 140 681 681
3 904 18 103 993 993
2 868 17 67 1287 1287
1 834 17 33 1563 1563
0 0 801 0 1823 0Note carefully that these results were obtained with reflectances just 29% of, and absorptions just 12% of the actual case with commercial glass. Further, the glass available in 1767 to de Saussure and in 1830 to Herschell would have been much worse than even standard glass available today.
From this analysis it is obvious that adding additonal panes of glass will suffer from a severe case of diminishing returns. With commercial grade glass, it is likely that only the first two or three panels will appreciably improve performance.It also begs the question as to what sort of "scientist" attempts analysis of experimental results by treating them as ideal cases when there are very well known inefficiencies in the actual processes? IMO only pseudoscientists are so intellectually vacuous.
If you are at all honest, you will redo your analyses including transmittance, reflectance and absorption figures for modern glass, and including reasonable estimates of heat loss other than by radiance. Alternatively you will admit your entire analysis has been specious from the get-go.
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Sharon Krushel at 16:05 PM on 3 February 2016Alberta's new carbon tax
#9 - Larry,
What a helpful, useful and encouraging post. Thank you so much! I've been trying to deal with the logistics of transitioning to renewables while living in a place where we have to deal with the life-threatening environmental problem of winter.
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Glenn Tamblyn at 15:41 PM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
Tom
It is true that GCM's treat the atmosphere as a series of slabs in terms of radiative transfer. But they are also modelling fluid flows and evaporation/condensation passing through these layers as well. Essentially mass transfers vertically, transporting energy. With a sufficiently large number of vertical layers - and you need enough layers to approximate the correct optical depth - the temperature differences between each layer are small and thus the net radiative flows low. The convective and latent heat fluxes can be substantial. So the glass box/radiation only model is severely deficient. This result was first shown by Manabe & Muller in 1961.In the context of the glass slab model Joe has used, we need to imagine that somehow the material of each of the glass layers is also merging and passing through each other - obviously a not very physical situation.
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Tom Curtis at 14:27 PM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
Glenn Tamblyn @156, the box Postma mentions is the Sudanese Solar Cooker I mentioned @152. The design is essentially the same as a de Saussure hotbox except for the addition of mirrors to compensate for the box not tracking the Sun. In the crucial experiment I discuss, the external mirror was removed, and the internal mirrors blocked so that they have no effect. What remains is a simple variant of a de Saussure hotbox.
These hotboxes are germaine to climate science in that Line by Line Radiative models and the radiation module of GCMs treat the atmosphere as a series of isothermal slabs which partially absorb outgoing shortwave radiation and then reemitt based on the temperature of the particular layer. The idealization of the de Saussure hotbox is also an idealization of that treatment of radiation. Ergo, if the treatment of radiation in the idealization of a de Saussure hotbox is fundamentally in error, so also is the treatment of radiation in Line by Line Radiation models, and the radiative modules of GCMs.
Of course, that begs the question as to why Postma tests his objections against obscure, poorly controlled experiments with hotboxes rather than the detailed comparisons of observations and the outcomes of Line By Line Radiation models, which are a far more direct and apt test:
It also begs the question as to why Postma treats the grey slab models as the IPCC model of the greenhouse effect rather than, as it is, merely a didactic model used to introduce students of atmospheric physics to the maths of radiation models.
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Glenn Tamblyn at 14:17 PM on 3 February 2016They predicted an ice age in the 70's
Is the following statement getting any colser to such an official endorsement; do you think?
Nope. Unfortunately for some reason I can't get access to the GISS website. But that text appears in many different sources. So presumably a press release perhaps or a reporter interviewed them. But look at the actual paper, here.
The authors aren't just affiliated with GISS. 3 of the 4 are also affiliated with Columbia University. So that comment could just as easily be written "In a Columbia University first, researchers accomplished such a feat ... ". Doesn't sound official then does it? Would that be an official communication from Columbia?
The definitiuon given by the moderator [PS] is appropriate. 'NASA said' means an official communication from the organisation as a whole. Individual scientific papers, even if accompanied by a press release from the research institution are just that, research papers, with no more or less standing than any other papers from a University or a private industry researcher. -
Rob Honeycutt at 12:36 PM on 3 February 2016They predicted an ice age in the 70's
NecktopPC @37... He was offering up an example of a position statement from a scientific organization, of the sort that John Cook was talking about.
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NecktopPC at 12:06 PM on 3 February 2016They predicted an ice age in the 70's
Glenn Tamblyn@33 - "So NASA, as an organisation, did not make an official endorsement of any cooling prediction."
But would they want to make an official endorsement of atmospheric cooling at this stage of the game?
Is the following statement getting any colser to such an official endorsement; do you think?
In a NASA first, researchers at GISS accomplished such a feat as they calculated the temperature impact of each of these variables — greenhouse gases, natural and manmade aerosols, ozone concentrations, and land use changes — based on historical observations from 1850 to 2005 using a massive ensemble of computer simulations. Analysis of the results showed that these climate drivers do not necessarily behave like carbon dioxide, which is uniformly spread throughout the globe and produces a consistent temperature response; rather, each climate driver has a particular set of conditions that affects the temperature response of Earth.
The new calculations reveal their complexity, said Kate Marvel, a climatologist at GISS and the paper's lead author. “Take sulfate aerosols, which are created from burning fossil fuels and contribute to atmospheric cooling,” she said. LINK
Moderator Response:[PS] This is an example of official endorsement on climate change. Similar statements can found by most of the world's academy.
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Rob Honeycutt at 12:03 PM on 3 February 2016They predicted an ice age in the 70's
NecktopPC @34... No, that is just a paper (one of a great many) listed on the NASA website. That is not a position statement made by NASA.
Moderator Response:[PS] I think some definitions would help keep this discussion focused. "Endorsement" by an organization means a position statement from that organizations governing body. (Such as a great many science organization have made about global warming). Scientific consensus is the collective judgment, position, and opinion of the community of scientists in a particular field of study. No one paper is evidence for a consensus.
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NecktopPC at 11:21 AM on 3 February 2016They predicted an ice age in the 70's
Glenn Tamblyn@33
Yes; NASA did youse those exact words. LINK
There is evidence that the Sun has had similar periods of inactivity in the more distant past. The connection between solar activity and terrestrial climate is an area of on-going research. LINK
The extra snowfall that began 10,000 years ago has been slowly accumulating on the ice sheet and compacting into solid ice over millennia, thickening the ice in East Antarctica and the interior of West Antarctica by an average of 0.7 inches (1.7 centimeters) per year. This small thickening, sustained over thousands of years and spread over the vast expanse of these sectors of Antarctica, corresponds to a very large gain of ice - enough to outweigh the losses from fast-flowing glaciers in other parts of the continent and reduce global sea level rise.
"The good news is that Antarctica is not currently contributing to sea level rise, but is taking 0.23 millimeters per year away," Zwally said. "But this is also bad news. If the 0.27 millimeters per year of sea level rise attributed to Antarctica in the IPCC report is not really coming from Antarctica, there must be some other contribution to sea level rise that is not accounted for." Read more
Can we irrefutibly say that the jury is out on this issue?
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Glenn Tamblyn at 11:14 AM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
Joe, Regarding figure 1 from your pdf.
Here is the accompanying text related to that diagram from the original source.
"A simple approachWe can get the above results directly by recognizing that the top
layer of the atmosphere must emit 239.7 W/m2 of infrared radiation
to space (same amount of solar radiation that enters the atmosphere:
what goes in must go out). The bottom layer of the atmosphere
will emit an equal amount downward to the surface of the planet.
Hence, for thermal equilibrium, the surface of the planet must emit
enough radiation to balance not only the amount it receives from the
sun (239.7 W/m2), but also what it receives in the form of downward
infrared radiation from the atmosphere 239.7 W/m2). Hence, its emission
must match 239.7+239.7 = 479.4 W/m2. Applying the Stefan-Boltzmann
law: constant x T 4 = 479.4 W/m2. We thus calculate T = 303 K.
The figure below illustrates this calculation. Contrast it to the figure
above where we assumed no atmosphere, and you will see where
the greenhouse effect comes in."
Your diagram goes here
"The effective temperature we calculate in this manner is much warmer than the actual temperature of the Earth (288 K), because we made a number of simplifying assumptions.Limitations of this calculation
1) It's assumed that the atmosphere is isothermal. The layer of the
real atmosphere that's most important in terms of the greenhouse
effect is the troposphere, where temperature decreases with height.
Because of this height dependence, the real atmosphere emits more
radiation in the downward direction than in the upward direction (88
units vs. 70 units in Fig. 3-19).2) It's assumed that the atmosphere absorbs all the outgoing
radiation at all wavelengths in the infrared part of the
electromagnetic spectrum. In reality, the absorption of radiation by
the atmosphere is highly wavelength dependent. At some wavelengths
there's very little absorption and the radiation emitted by the
earth's surface escapes to space, while at other wavelengths it gets
absorbed, reemitted, absorbed and reemitted many times before it
finally escapes. To carry out this calculation accurately it has to
be done wavelength-by wavelength... to capture the fine scale detail
in the spectrum requires literally thousands of calculations
analogous to the one we did in class.3) Radiative transfer isn't the only process by which energy escapes
from the earth's surface. Conduction of heat and evaporation of water
transfer about twice as much energy from the earth's surface to the
atmosphere as the net upward flux of infrared radiation from the
radiation does. If the temperature distribution on earth were
determined only by radiative transfer (as in this example) the Earth
would be so hot as to be uninhabitable. In this sense the true
'greenhouse effect' on Earth is much larger than the 33 K difference
between the observed surface temperature (288 K) and the effective
radiating temperature (255 K) ascribed to it in your text." (my emphasis)
This diagram is an intermediate stage as part of a teaching exercise in developing an understanding of the GH effect. It most certainly is not a definitive description of the GH effect.You have built a house of cards from extrapolating a simplification too far.
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Glenn Tamblyn at 11:06 AM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
Joe
"The temperatures where they used reflectors to increase the internal flux are not relevant to a test of the greenhouse effect."
What has anything you are talking about got to do with testing the greenhouse effect?
The box you describe is so different from the actual processes in the atmosphere that you can draw no conclusion from it. Without the ability to include convective heat transport and the vertical Lapse Rate anything you might do in such a test is rather meaningless wrt the GH Effect. -
Glenn Tamblyn at 10:57 AM on 3 February 2016They predicted an ice age in the 70's
NecktopPC
From the abstract for the Rassol and Schneider paper from 1971:
"An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 ° K. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger an ice age." (my emphasis).They certainly did not predict that an ice age would happen. Rather, to paraphrase them, 'if air pollution gets a lot worse and is sustained for some years then we think that might trigger an ice age'.
And within a few years they subsequently reversed that conclusion. Stephen Sccheider, then a young researcher, described this paper as one of the biggest mistakes of his life.
And they both worked at the Goddard Institute of Space Studies at the time. Yes a research division of NASA. But hardly NASA as a whole.
Large organisations such as NASA tend not to 'endorse' every single published paper that their scientists produce - not all of them will be correct. All science is tentative until corroborated by further research.Such organisations, when they do 'endorse' something, usually do it when a body of science has built up sufficiently on a subject. In this case the cooling paper was actually overturned several years later.
So NASA, as an organisation, did not make an official endorsement of any cooling prediction. And they did not 'endorse' the idea of warming officially till many years later. -
Daniel Bailey at 10:56 AM on 3 February 2016They predicted an ice age in the 70's
"The world could be as little as 50 or 60 years away from a disastrous new ice age"
Evidence says otherwise. No, the Sun isn't going to save us from Global Warming:
RC on 'Not even a solar minimum'."Those hoping that the sun could save us from climate change look set for disappointment. The recent lapse in solar activity is not the beginning of a decades-long absence of sunspots – a dip that might have cooled the climate. Instead, it represents a shorter, less pronounced downturn that happens every century or so."
"According to the Gleissberg cycle, the next solar maximum – in about 2024 – will probably be a dud too, but then cycles will become more energetic once again, and any cooling effect the brief downturn has had on Earth's climate will also vanish."
"Thus if the sun remains “out”, i.e., stuck for a long period in the current solar minimum, it can offset only about 7 years of CO2 increase. The human-made greenhouse gas climate forcing is now relentlessly, monotonically, increasing at a rate that overwhelms variability of natural climate forcings. Unforced variability of global temperature is great, as shown in Figure 4, but the global temperature trend on decadal and longer time scales is now determined by the larger human-made climate forcing. Speculation that we may have entered a solar-driven long-term cooling trend must be dismissed as a pipe-dream."
Basically, even a Grand Solar Minimum would barely make a dent in human-caused global warming.
Even on the regional level, the effects are very limited (per Nature):
"This offsets or delays the global warming trend by ~2 years and is small compared with the modelled global warming"
Gavin Schmidt at RC (Unforced Variations thread):
"It’s a 60% reduction in the magnitude of the solar cycle (not solar activity), and it’s not obviously terrible. It’s a statistical projection with no physics, so the extent to which it’s believable is unclear. The connection to a new ‘mini ice age’ is completely made up. That level of change in solar forcing is about -0.1W/m2, which would be made up in just 3 years of current CO2 concentration growth."
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Rob Honeycutt at 10:53 AM on 3 February 2016They predicted an ice age in the 70's
This is an article referencing a research paper that was published by Rasool and Schneider. There's an accurate accounting of this paper on wiki here.
The paper was later retracted.
But again, this was not a stated position of NASA. It was merely one paper that was quickly retracted.
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ubrew12 at 10:41 AM on 3 February 2016Climate scientists' open letter to the Wall Street Journal on its snow job
jmath@19 said: "between 0.3 and 0.6C temperature change... is the result of... 30% of... a doubling" That suggests the sensitivity to a doubling = average(0.3,0.6)/0.3 = 1.5C per doubling, which is half the generally expected sensitivity. Perhaps Earth's thermal system is not just a resistor but also a capacitor? That would explain the shortfall: you're suggesting equilibrium in a nonequilibrium system.
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NecktopPC at 10:22 AM on 3 February 2016They predicted an ice age in the 70's
U.S. Scientist Sees New Ice Age Coming
The world could be as little as 50 or 60 years away from a disastrous new ice age, a leading atmospheric scientist predicts. Dr. S. I. Rasool of the National Aeronautics and Space Administration and Columbia University. LINK
RE: "None of these bodies (at least the ones that existed back then) endorsed ice age predictions in the 70's."
Did they (NASA) not endorse Dr. Rasool?
What is NASA without its scientists, which it, hires?
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Tom Curtis at 10:07 AM on 3 February 2016Joseph E. Postma and the Greenhouse Effect
JPostma @153,
1) The temperature I quoted for the Sudanese Cooker was that achieved with the external mirror removed and the internal mirrors covered by black papers. Ergo neither contributed to the elevated temperature achieved.
2) The shape of the box is irrelevant given that, with the mirrors covered, their is not method of concentrating the heat in a particular part within the solar cooker.
3) That temperature was achieved in late April or early May. Ergo the TOA insolation at the time was not 1410 W/m^2 but 1362 W/m^2 or less. The actual surface radiation would have been significantly less than that, and probably not more than 1200 W/m^2. The TOA radiation gives a theoretical maximum temperature of 120.5 C if there is no radiative greenhouse effect as per your claims. The actual temperature achieved was 5 C above that, comfortably falsifying your claims.
@154, the temperature should have skyrocketed, as you put it, only if:
a) There was no heat loss through conduction through the sides;
b) There was no heat loss through air escaping;
c) There was no reflectance of Short Wave Radiation from the interior of the box;
d) The glass panes had zero reflectance of Long Wave Radiation; and
e) The glass panes had zero absorptivity of Long Wave Radiation.
All of these conditions are known to be false. Further, the temperature should only have skyrocketed if the actual insolation approached the theoretical maximum, which as the box was near sea level, is also known to be false.
All of this is irrelevant as to whether the Sudanese Cooker experiment (with external mirror removed and internal mirrors covered) refutes your theory, which places a clear upper limit on temperature achieved. That upper limit is exceeded despite the inefficiencies listed above.
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Andy Skuce at 09:50 AM on 3 February 2016The Quest for CCS
Sharon: It's a common argument that the upstream emissions of the oil sands amount to only 0.2% of the world's emissions, with the implication being that it is an amount that is too small to worry about.
As a rejoinder, one could argue that the proportion of the world's population that lives in Alberta is only 0.06%, so why should the rest of worry about what happens to them?
Having worked in the Alberta oil patch myself through many brutal rounds of downsizing, particularly in the 1980s, I know what a devastating effect these oil busts can have on individuals and their families. I still have many friends in the province who are watching their investments of time and expertise circle the drain, through no fault of their own. In particular, I feel bad for the many younger people who have kids, mortgages and student loans who suddenly see their futures change from one of prosperity to one of uncertainty and the fear of personal bankruptcy. It's really tough.
So, I would not be inclined to make that kind of a counter-argument since it appears indifferent to individual suffering. It's in the nature of the climate crisis that negative effects of the climate impacts and the effects of the economic disruption that mitigation will bring are not distributed fairly or evenly.
As you point out, all change brings with it winners and losers, much of it unintended. A nasty feature of the climate crisis is that those who will suffer most had the least to do with causing the problem. Also, the changes to to the climate will endure for millennia. In contrast, the damage from the worst catastophes of the past would heal in the space of a generation or two.
I would agree though that the oil sands are often demonized disproportionately. The coal industry, for example, is far worse. And the critics of oil producers are often themselves big consumers.
PS, somebody once told me that "Csikszentmihalyi" is pronounced "cheeks sent me high".
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Rob Honeycutt at 08:43 AM on 3 February 2016They predicted an ice age in the 70's
Yes, the sun could perhaps go into a low irradiance state similar to that of the Maunder Minimum. But what you have to understand is the relative radiative forcing compared to changes in CO2 and other human caused factors.
We are very fortunate to live on a planet that goes around a very stable star whose radiative output varies only a fraction of a percent. So, that change in radiative forcing of maybe -0.3W/m2 for a new Maunder Minimum is small compared to the 2.3W/m2 we see for human factors.
Moderator Response:[PS] Straying off topic again. Any further discussion should perhaps be here.
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NecktopPC at 08:23 AM on 3 February 2016They predicted an ice age in the 70's
One might assume that other scientist have been, and are continuing to follow in the footsteps of Dr. Roberts...NCAR:
There will be another Little Ice Age in 2030, according to solar scientists – the last one was 300 years ago- http://www.independent.co.uk/environment/climate-change/mini-ice-age-coming-in-next-fifteen-years-new-model-of-the-suns-cycle-shows-10382400.html
Moderator Response:[PS] Dont assume - produce evidence.
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POJO at 08:04 AM on 3 February 201610 Indicators of a Human Fingerprint on Climate Change
MA Rodger
The IPCC stance as noted on pge 9 of AR% for policy makers.
"A decrease in diurnal temperature range (DTR) was reported in the TAR, but the data available then extended only from 1950 to 1993. Updated observations reveal that DTR has not changed from 1979 to 2004 as both day- and night-time temperature have risen at about the same rate. The trends are highly variable from one region to another. {3.2}"
Backed away and OPt back in. They may not be scientific terms MA. But they very obvious to everyday meaning. I am sure you know what they mean.
In regards to Vose etal paper.
Again the obvious stands out. Back then old data was used. Since then the global data has had several changes to it via its rigourous homeginisation process.
Crutem 4 is the LATEST dataset. Analysis now is at a fingertip. Tmax - Tmin.
Voss anomalie chart is the same as the IPCC in TAR.
And here is Vose's response to the chart is below
Both maximum and minimum temperature increases from 1979-2004 whereas the DTR is basically trendless. The maximum and minimum temperature trends are nearly identical (0.287 versus 0.295°C dec-1),............
And lastly the data has moved on since way back then. Know one needs a paper to look at a chart. It is what it is.
If you have a problem with my source for the Charting best you take that up with the home of Data. It is fresh from The CLIMATE RESEARCH UNIT. This is where CRUTEM 4 comes from.
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Rob Honeycutt at 06:45 AM on 3 February 2016They predicted an ice age in the 70's
NecktopPC... I hope you are aware that Idso and Scafetta represent a very small fraction of researchers who hold such position. Both of them are very well known to all the regulars at this site. In such, you're attaching yourself to a position that is extremely unlikely to be correct.
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Rob Honeycutt at 06:39 AM on 3 February 2016They predicted an ice age in the 70's
NecktopPC @24... You can disagree all you like, the fact remains that "None of these bodies...endorsed ice age predictions in the 70's." John is referring to scientific bodies. You've yet to show us one of the bodies that endorsed that position.
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NecktopPC at 06:29 AM on 3 February 2016They predicted an ice age in the 70's
Rob Honeycutt@20
Thank you - and I'll certainly be cautious, to avoid 'running afoul of the moderation policies.
Moderator Response:[JH]
Please note that posting comments here at SkS is a privilege, not a right. This privilege can be rescinded if the posting individual treats adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
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NecktopPC at 06:16 AM on 3 February 2016They predicted an ice age in the 70's
Rob Honeycutt@18
I disagree with you on the accuracy of Mr. Cooks comment, that's all - and I have been working on providng some refrences, which are helping to substantiate the inacuracy of his statement, and or story here.
RE: "thus far you've not linked to any specific science on global cooling in the 1970's."
I am doing my best at providing information (circa 1970s) which has, included the names of scientists, and the organizations of which they were associated with, at the time, i.e. NOAA & NCAR (thus far) and the association (ice age) that have been mentioned together with global cooling.
By the way; I have read Peterson's paper, and perhaps you have read Idso's paper as well - "The Climatological Significance of a Doubling of Earth's Atmospheric Carbon Dioxide Concentration"
There is another, which is more on topic of the sun and its effects on climate, as per Dr. Roberts - the paper is by Scafetta - "Empirical evidence for a celestial origin of the climate oscillations and its implications"
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Rob Honeycutt at 06:05 AM on 3 February 2016They predicted an ice age in the 70's
No. I merely let you know how policy is applied here to everyone. I was trying to help you so that you could make your points without running afoul of moderation policy.
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NecktopPC at 06:01 AM on 3 February 2016They predicted an ice age in the 70's
Rob Honeycutt@19
I'm not "Playing the potential victom" at all. You blatantly threatened me @14 - and you speak about conduct unbecoming?
I don't know?
Moderator Response:[PS] Please stick to topic. Any discussion of moderation is offtopic. Further offtopic discussions by either of you will be deleted.
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NecktopPC at 05:58 AM on 3 February 2016They predicted an ice age in the 70's
Rob Honeycutt@14
On one hand, you asked me a couple times, what my point is, or was, and now your alluding to me 'repeatedly making the same point'.
What point is that then?
And now you seem to be adopting the stance of an adlescent, whom, when they can't have things their way, they try to break the other persons computer, or simply grab their little network and run off, with all the cords becoming unplugged (banned).
RE: "And note ahead of time that moderation complaints also get deleted."
I'll be certain not to complain about any moderation actions.
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Rob Honeycutt at 05:55 AM on 3 February 2016They predicted an ice age in the 70's
"The science was, and remains evident, regarding global cooling in that period."
And isn't it interesting that, even though we'd come through a period of cooling from 1940-1960, most scientists were more concerned about the challenges we face in relation to global warming due to emissions of greenhouse gases.
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Rob Honeycutt at 05:52 AM on 3 February 2016They predicted an ice age in the 70's
"If you wish to delete my comments, or have RobP do so, becuse it upsets the policies of your website, then that is totally up to you and your colleagues; isn't it?"
Playing the potential victom is rather unbecoming. Plenty of people come to SkS and strongly argue their points without problem at all, even when they go against the scientific consensus position, as long as they play by the rules. That's not about getting upset. It's about keeping the conversations here polite and constructive.
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Rob Honeycutt at 05:49 AM on 3 February 2016They predicted an ice age in the 70's
NecktopPC... John Cook's comment is accurate. Your references do nothing to refute that. You provided a link to a paper by Roberts that discusses agriculture and food supply in a cooling world. As I stated, Roberts worked with Sagan and others on at least two separate issues related to potential global cooling. Nuclear winter and human emissions of aerosols. Roberts was also very active, as was Sagan, in research on global warming.
You state that, "The science was, and remains evident, regarding global cooling in that period." But thus far you've not linked to any specific science on global cooling in the 1970's.
I would highly suggest you check out a paper by Peterson 2008, The Myth of the 1970s Global Cooling Scientific Consensus. PDF
Moderator Response:[PS] Yes, please do read Peterson. Note that it is incumbent on posters to produce evidence to back claims. Peterson produces strong evidence against a consensus on cooling. In my opinion, you either need to redefine consensus or find something better than Peterson that produces the opposite conclusion.
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NecktopPC at 05:49 AM on 3 February 2016They predicted an ice age in the 70's
Rob Honeycutt@11
No worries!
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