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billthefrog at 07:22 AM on 29 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
@ Joel
Oops! I discovered the Snowball Earth site a few years back, but hadn't noticed that it had gone inactive. Mea culpa
NOAA has an interesting palaeoclimatology portal that you might find useful.
Examples of teaching resources covering this material can be found here and here.
A far more detailed description of the first (?) of these events way back in the Palaeoproterozoic Era, the Huronian glaciation, was given in the Proceedings of the National Academy of Sciences.
Hope that helps.
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Chris Snow at 07:14 AM on 29 May 2014The Wall Street Journal denies the 97% scientific consensus on human-caused global warming
Anything that references the Oregon Petition, which claims that 31,000 scientists deny AGW can safely be dismissed as a load of old tosh. As you say, anyone with a college degree can sign the petition. Still, 31,000 sounds a lot until you realise that around a quarter of the US adult population have college degrees. Taking a fairly conservative estimate of 40 million potential signatories since 1998, we get 31,000 / 40,000,000 = 0.0775%. So the 31,000 scientists deny AGW claim is more accurately stated as fewer than 0.0775% of US college graduates since 1998 can be bothered to sign a petition denying AGW, which doesn't sound quite so impressive.
Regarding the 97% consensus, I reckon that here in the UK it's closer to 100%. I can't actually think of a British climate scientist who is a sceptic. Which is why we often end up with someone like Nigel Lawson in the media arguing the sceptic case.
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Alpinist at 06:59 AM on 29 May 2014The Wall Street Journal denies the 97% scientific consensus on human-caused global warming
Another stupid WSJ editorial about climate change. What a surprise. Here's something I posted at RC a couple years ago:
"Sigh, another day, another stupid WSJ editorial…it’s almost as predictable as high temperature records. You might think that the WSJ would be interested in a fact based reality. You would be wrong."
Some things just never go out of style.
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BojanD at 06:11 AM on 29 May 2014John Oliver's viral video: the best climate debate you'll ever see
Not sure I'm following you. I've read the guidelines on rating abstracts and they don't align well with what you're saying here. Just consider that a lot of papers are from the 90s and if the paper from that period explicitly endorses IPCC view (see 3.6), than they endorse the view of the FAR and SAR report and the SAR found discernable influence, not main one. Of course I'm aware that was the state of the climatology of that period, but we're not discussing the evidence here, but the consensus.
I've rated some abstracts myself and there were a lot from the third category implicit endorsement that I've rated as fourth (no position) when the main cause was the issue. If I read "one of the sources of CO(2) and other greenhouse gases (GHG) that influence global climate change", I can't possibly know if this influence is the main one. So Cook et al correctly worded the main findings, but Bedford and Cook didn't, which is surprising, but not that terribly important. -
Joel_Huberman at 02:44 AM on 29 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
@billthefrog - Thanks for letting us know about the interesting Snowball Earth web site. So far as I can tell, though, the last news postings at that site were in 2006. Is there a reason why the site hasn't been kept up? Are there any other sites dealing with the Snowball Earth hypothesis that might provide more current information?
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howardlee at 00:13 AM on 29 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
billthefrog - I think most workers in the field accept the end cretaceous was a "double whammy" - LIP-generated global warming triggering a significant extinction, with the impact dealing a final blow. It's interesting to note that the pendulum is definitely swinging back to emphasize the role of the Deccan Traps LIP as originally highlighted by Gerta Keller.
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howardlee at 00:06 AM on 29 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
Climatelurker - It''s clear that some LIP events have been associated with severe extinctions and others have had more mild extinctions. The Emeishan LIP that occurred just before the Siberian Traps generated global warming and an extinction event much less severe than the Siberian Traps did.
That some LIPs have more severe effects on life than others is a puzzle. It probably relates to eruption rate, presence/absence of organics in the sediments at the LIP location, and other random things. As the authors of one paper noted: "...larger eruptions of flood basalts which clearly had no effect on global ecosystems (e.g. Tarim). The reason why some LIPs are contemporaneous with mass extinctions could be related to random conditions which cannot easily be predicted such as: parental magma composition, geographic location, composition of country rock, or vulnerability of species."
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howardlee at 23:49 PM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
Villabolo - you are correct for the Kalkarindji LIP - the authors mention oil specifically. In the Permian Siberian Traps LIP it looks like it was mainly coal. In this generalized figure I used "fossil fuels" as a collective noun and to make clear the parallels between the past and today's climate change. In all cases the heat from the magma baked the organic-rich sediments converting them to methane and CO2 (with a host of other nasties mixed in).
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billthefrog at 22:28 PM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
@ climatelurker
As scaddenp rightly states, rate of change is absolutely critical in terms of extinction potential. In the case of both bolides and mega-volcanism, there is a double whammy. The initial spectacular aerosol cooling is likely to be pretty short-lived, as these particles will not have a long atmospheric residence time. On the otherhand, so-called greenhouse gases have this habit of lingering on, and on, and on...
One of the fingerprints of massive CO2 build up is the presence of cap carbonate deposits, as discussed in this piece from the Snowball Earth site.
Also, the following from the BBC describing some of the dramatic events on the planet's timeline might be of more than passing interest. Scroll down to the bottom of that screen and there are links to various extinction theories (incl climate change) as well as the varying habitats that would have been extant at different times.
Incidentally, I've just noticed that one of the scientists appearing in the BBC video clips (Paul Hoffman, from the Earth and Planetary Sciences Dept at Harvard) is also involved with the Snowball Earth project.
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BC at 13:54 PM on 28 May 20142014 SkS Weekly Digest #21
I couldn't access the first link under El Nino Watch
Moderator Response:[PS] I notice that it is not actually a link. Till author fixes it, try this:
"How El Niño Might Alter the Political Climate"
[JH] The link has been inserted into the OP. Thank you for bringing this glitch to my attention.
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DSL at 13:28 PM on 28 May 2014Antarctica is gaining ice
Anthony, check out the sea level rise explorers here and here to see what a few meters or a few dozen meters of SLR mean for agricultural and infrastructural destruction, and population displacement.
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Daniel Bailey at 13:00 PM on 28 May 2014Antarctica is gaining ice
http://pubs.usgs.gov/fs/fs2-00/
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michael sweet at 12:10 PM on 28 May 2014Antarctica is gaining ice
Anthony,
This SkS thread says tht if Geenland melted it would raise sea level 6 meters. You would expect at least the same amount from Antarctica. Here in Florida a 12 meter sea level rise would inundate 3/4 of the state, home to about 15 million people. Bangladesh would be long gone. That seems like a lot to me. How much is a lot to you?
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Charliec65 at 07:43 AM on 28 May 2014Looking for connections
I agree with placing the growth of the human population into the essay. We're living in a "life bubble" much like our recent financial bubble. We unfortunately don't have a central bank to come to the rescue. The correction will likely be as hard as the beneficial rise as we've experienced over the past 300 years.
Broadly living processes have little capability to control their growth rates. There isn't one life form that fails to over-exploit its environment. We have been shaped by evolution to reproduce, expand into environments, and wage war from verbal to physical when necessary or possible to sustain our groups. Humans like to think of themselves as separated from nature by nurture, but that's a tenuous connection in the best of times.
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scaddenp at 07:29 AM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
climatelurker - what is important is the rate of change. A rapid change over 3C may have more effect than a very slow change over say 6C. The initial cooling by aerosols and then rapid warming by GHG are probably both important. I think the most useful numbers would be rate of change in forcing (W/m2/century) which is much more informative than % concentration. However, for paleoevents, it is very difficult to get high precision both dating and forcing. CO2 is only indirectly measured by change in a proxy for pH which in itself must have a large time-constant for ocean mixing. Estimating the forcing from aerosols on a volcanic eruption that has never been observed is even more complex. We struggle to measure aerosols even today.
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villabolo at 06:09 AM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
On the volcanic diagram, in the white box at the lower left, it says "fossil fuels". Shouldn't that read fossil oil instead? It became a fuel from our modern persapective.
Moderator Response:[JH] Nope. Natural gas is a fossil fuel. It is not fossil oil.
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climatelurker at 05:33 AM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
I'm curious what the differential is between pre and post extinction events, if there's a threshold beyond which massive die-off's are (or appear to be) set in motion. Maybe as a percentage of current atmospheric levels, or an absolute change? I've seen there are links to how fast the changes occur, but how much isn't clear (at least not to me). Would love to see an article about CO2 levels at different times, and what they were before and after these events. I imagine such a discussion would have to take into account feedbacks and absorption saturations, et cetera... I can hear the deniers already, "CO2 is already almost saturated! Adding more won't do anything!"
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Anthony10658 at 05:24 AM on 28 May 2014Antarctica is gaining ice
The Vice news program on HBO had an interesting story of how the Glacial land ice is melting in Greenland at a rapid rate. If Greenland becomes green, and all the land ice melts, can we really expect the sea level to rise by that much?
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Anthony10658 at 05:20 AM on 28 May 2014Animals and plants can adapt
Speaking of migrations, over the past few years, there has been a increase of Canadian Geese who have taken up permanent residence in the San Francisco South Bay Area. The strange part about it is that the weather here is actually warm, not cold. The birds used to be seen here for the winter months, now they are here all year round, hanging at public parks, golf courses, and school fields.
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billthefrog at 04:07 AM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
In 2013, the eminent palaeontologist, Steven Stanley was bestowed the Penrose Medal, the top honour awarded by the Geological Society of America. Prof Stanley has long been a proponent of the idea of punctuated evolution, as opposed to the classical, more gradual evolutionary pressures first suggested by Darwin and Wallace.
Stanley's proposed mechanism for these evolutionary spurts is by extinctions (mass and otherwise) either freeing up niches or increasing the competion therein. His suggested mechanism for these extinction events? You guessed it - climate change. Interestingly, Stanley feels that climate change in either direction can be equally efficacious as an extinction mechanism.
Being a thicko engineer, I never covered any of this stuff during either of my degrees. I only have a vague grasp through a general interest in science and wanting to learn more about our planet's history. (And hence getting some insight into its future.)
The OP mentions that "most scientists agree a giant asteroid impact wiped out the dinosaurs". This is obviously out of my field, but I had discussed the K/T (I'll never get used to calling it the K/Pg) on many occasions with one of my neighbours - sadly no longer with us. The gentleman in question however, was a Fellow of the Geological Society of London and was keen to disabuse me of the idea that this was a settled issue.
According to Myles, there were (are?) two diametrically opposed camps in the debate. (Sound familar?) There are those who are convinced by the arguments put forward by the Alvarez/Alvarez/Asaro/Michel camp relating to the Chicxulub bolide as the Deus ex Machina. However, as indeed mentioned in the OP, others look towards the massive basaltic eruptions that spewed forth from the Deccan Traps.
By amazing coincidence, my current bedtime reading is a book called "The Sixth Extinction", by Richard Leakey and Roger Lewin. They also view climate change as a very likely vector for the many of the extinctions the planet has experienced - and continues to experience to this day.
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WheelsOC at 02:36 AM on 28 May 2014Rapid climate changes more deadly than asteroid impacts in Earth’s past – study shows.
A couple of years ago there was a paper that compared modern rates of CO2 emissions/ocean acidification to geologically significant changes and mass extinction events over the last ~300 million years. It turns out that even The Great Dying happened with atmospheric CO2 increasing at rates 1-2 orders of magnitude slower than what we're causing today.
The paper is here (paywalled), and there's a good write-up summarizing it here.
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Rob Honeycutt at 01:22 AM on 28 May 2014Sea level rise due to floating ice?
This whole discussion is perfect example of what seems to go on with climate change denial, on a larger level.
One side is trying to point out how the science works. The other side starts with a presumption of fact, rejects known physics, does incorrect experiments/analysis, claims those doing the science are politically motivated when the results conflict with their expected outcomes, and in the end storms off unable to process the fact that they are wrong on the science.
It's hard to be the person proven wrong. It takes a strong person to look at evidence and admit an error. All too often I see people double down on their error and run away rather than facing hard facts, as thorconstr has done.
Moderator Response:[Dikran Marsupial] Please can we restrict the discussion to the science.
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Tom Curtis at 01:03 AM on 28 May 2014John Oliver's viral video: the best climate debate you'll ever see
BojanD @6, a paper assessed as reporting that 45% of global warming was anthropogenic, with the rest being natural would have been rated as rejecting the consensus on global warming. That is made explicit by rating category 7. As categories 5-7 do not differ on whether they endorse or reject the consensus, but only the quality of the evidence as to whether they endorse or reject the consensus, what applies to category 7 also applies to categories 5 and 6. Similar reasoning applies in reverse for endorsement. Consequently, I do not think it was Bedford and Cook who made the mistake in this instance.
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BojanD at 00:47 AM on 28 May 2014John Oliver's viral video: the best climate debate you'll ever see
@localis, you're right, it won't do anything to change the denier's attitude. Recently I was involved in a discussion where somebody proudly proclaimed that Bedford & Cook were wrong in asserting that Cook et al. found 97% consensus that humans were the main cause. I agree, since it found 'only' the consensus on AGW (which means they are a cause and not necessarily the main one), but this person blew this lapse out of proportion. It was a typical penny-wise, pound-foolish attitude that you encounter in individuals that pretend to introduce rationality in the discourse.
It makes me wonder, however, how Bedford & Cook could make such an obvious mistake. -
wili at 00:05 AM on 28 May 20142014 SkS Weekly Digest #21
Thanks for the highlights. If I may be so bold, it would be great to have an update on slr estimates in light of the recent news about GIS and WAIS melt dynamics. What do these studies mean for long and short term melt rates. The MSM coverage seems to include estimates that seem to go far beyond what the science is saying and estimates that seem far to conservative given, especially given the recent developments. ANy clarification you folks could throw on this jumble about these important issues would be greatly appreciated.
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John Hartz at 21:57 PM on 27 May 2014Sea level rise due to floating ice?
Could it be that thorconstr's ultimate goal was to provke regular SkS commenters in order to "proove" that SkS is ideologically biased? If so, the ice-in-glass-of-water "experiment" was just a ruse.
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Tom Curtis at 21:34 PM on 27 May 2014Sea level rise due to floating ice?
chriskoz @53, thanks for picking up, and correcting the errors.
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chriskoz at 20:54 PM on 27 May 20142014 SkS Weekly News Roundup #21B
wili@1,
Usually, Al Jazeera reports quite accurate and complete climate science news but this time, i'm a bit disappointed because your link does not provide good info, not even a pointer to the study itself... I found somewhat better report in SA here, with the link to the actual study therein.
I don't have access to the study so I cannot be sure what it is about. But I suspect they talk only about the topography of Greenland coastal rockbed, as reported in SA. I.e.: the volume of fjords below sea-level, currently filled with ice, is 3 times bigger than assumed in current iceflow models. Likely they don't make any inference about how much iceflow model output changes if the model bedrock topography is altered accordingly. So we need to wait for that conclusion.
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chriskoz at 19:19 PM on 27 May 2014Sea level rise due to floating ice?
Tom@47,
the ice in fresh water ill have only 0.042 m^3 above the surface, but 0.044[0.054] m^3 above the surface if floating in fresh [salt] water[...] 0.002 m^2 more volume than it displaced in sea water
You made a slight arithmetic mistake, corrected above. Consequenttly, the difference in displaced water is: 0.458 - 0.446 = 0.012m^2 (rather than your incorrect 0.002 m^2 result). So, after that correction we conclude that the perceived increase of volume of seawater (dV) in your setup increased by 0.8% (0.012m^3 out of 1.446m^3).
So, in Thor's setup, where the proportion of ice is much less, say some 50ml in 250ml (he didn't give me the number because he wants to discuss his rhetorics rather than science), I estimate dV would be some 3-4 times smaller (per my quess of his proportions), therefore dV in his experiment was some 0.3%, which translates to dh of 0.3mm over 10cm high glass. Or even less: some 0.2mm, because his glass has signifficantly higher crosss section where dh is measured.
In conclusion, such small dh (0.2mm) is undistinguishable by eye and within the menisk shape uncertainty, as pointed earlier by DM. Therefore, Thor's experiment cannot be used to confirm this simple science herein. We know, that Thor set it up not for confirming science but for his baseless rhetorics.
On the other hand, an original experiment as setup by MartinS confirms the science: I estimate his dh should be about 1mm (because the ice chunk proportion looks as big as Toms') which looks about right on his picture.
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Tom Curtis at 19:16 PM on 27 May 2014Sea level rise due to floating ice?
Thankyou Dikran, for reminding me of thorcontr's empty challenge about blowing up the images to show the lips of the glass:
Close examination on the left of the glass shows the water level not up to the lip in either photo, ie, either with ice present (upper image) of melted (lower image). If, however, you look to the right hand side (under the yellow arrows), in the upper image the inside of the lip is clearly visible. In constrast, in the lower image the lip is obscured from vision by the meniscus. Clearly the meniscus must have risen higher than the lip to obscure it from vision, and hence has shown an increase in level. Indeed, the difference in camera angles tends to obscure this fact.
Clearly the surface of the glass slopes downward from left to right, resulting in the meniscus being above the lip on the right, but below it on the left. Also, if you look closely, this is obscured in the first image by the surface of an ice cube partially concealing the lip on the left, giving an apparent slope in the other direction to casual observation.
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Dikran Marsupial at 19:04 PM on 27 May 2014Sea level rise due to floating ice?
Just to add, Wikipedia has a nice brief explanation about how liquid volumes should be measured to take the meniscus into account. Note in particular observations should be made with the top of the liquid at eye level to avoid parallax errors. Compare this with MatrinS's experiment and with thorconstr's. I knew this already because I did chemistry at school. It is alright not to know this, but it is not alright to repeatedly ignore this sort of knowledge when problems with experiments are pointed out to you by those who do.
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Dikran Marsupial at 18:35 PM on 27 May 2014Sea level rise due to floating ice?
thorconstr wrote "I can't believe you ask this, no matter what the surface, when things rub they cause friction which would affect the experiment."
O.K. so the question is how much friction would there be, and would it be enough to materially affect the outcome of the experiment. I would say that the friction involved would be negligible as ice and glass, both lubricated by a film of water, are both extremely slippery materials. Note that as the ice is melting there won't be much of a connection between the solid surfaces as the surface of the ice will be constantly melting. Note the reason that ice skating is possible is that a thin film of water removes what little friction there was between the ice and the blade of the skate.
"Everyone here accepted the first experiment without question, the experiment is far from professional yet you accept it like the "Holy Grail", "
This is hyperbole. It is a simple experiment that verifies something we already know from very basic theory (as Tom pointed out to you). If you get the science right, you don't need this sort of rhetoric.
"Mine wasn't intended as a professional experiment."
neither was MartinS's, I suspect, and yet you chose to question the honesty of his experiment, when it was actually performed rather more professionally than yours - at least the meniscus could be measured properly in his.
" If I found that I was wrong I would have said so. "
We try running the experiment again, using the suggestions I gave.
"If I blow the pictures up to show only the glass rim the water level is the same, whether you believe it or not."
How many times do I have to say that you can't accurately measure the meniscus this way by eye. Blowing up the pictures doesn't change this fact.
"In retrospect, posting on a such a totally left leaning sight was a mistake."
Physics is independent of political orientation. Try doing the experiment properly.
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Tom Curtis at 11:38 AM on 27 May 2014Sea level rise due to floating ice?
thorconstr @48, what I (and I suspect nearly everyone) accepted was not the "first experiment", but the analysis based on a detailed knowledge of the relevant scientific principles and values by two experts in the field as detailed in the paper found by following the first link in the article. Some of us may also have done analyses similar to mine @47 to test that the result genuinely followed from known scientific principles (or used an alternate method based on calculating the new salt concentration after melting of the ice, and determining the difference in density that results). I (and I suspect nearly everyone) considered the illustrations to be merely a usefull illustration, not explained in sufficient detail for anything but illustrative purposes.
Your "experiment", in contrast, lacks relevant details, is poorly constructed and gives results constrary to what you claim. It is certainly an inadequate basis for over turning a basic scientific principle (which is what you are attempting to do, though you do not recognize the fact).
<snip> I am only interested in one response from you. Does ice floating in sea water float higher, lower, or the same as ice floating in fresh water?
Moderator Response:[PS] A reasoned debate is more likely without implied derogatory observations. This applies to everyone.
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Tom Curtis at 11:19 AM on 27 May 2014Record growth of atmospheric CO2 in 2013
Yves @10, I certainly don't want to claim that 12 month increases in CO2 concentration of 2.95 ppmv or above have not occurred. Only that such increases do not represent a record. As it happens, the top ten 12 month increases in CO2 concentration for the global data are:
Rank Value
1_____ 3.6
2_____ 3.47
3_____ 3.42
4_____ 3.41
5_____ 3.32
6_____ 3.21
7______3.03
8______3
9_____3
10____2.99Of those, the bolded values have terminated within the last twelve months. The underlined values terminated in late 1998/ early 1999. The tenth ranked increase terminated in early 1988 (an El Nino year based on Fig 3 in the OP).
With regards to the specific points you make:
1) If the result was from January to January (as indicated by the adjusted value you quote), then the provisional result was 2.63 ppmv. The adjusted value may, however, have been for 2.47 (December to December), for which I can find no archive values.
2) The trend shown above is about correct, with the current trend value being 2.2 ppmv per twelve month period, incrementing at 0.03 ppmv per annum. That value is far more significant than individual monthly values.
3) You are probably correct with regard to differences in trend for different ENSO state. However, using rolling twelve month differences may give enough data to give a significant result (I have not tested).
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One Planet Only Forever at 10:18 AM on 27 May 2014Looking for connections
John Hartz @22.
A very good read indeed.
Of course, since the people benefiting from creating the harm of this weapon of mass destruction can easily believe they will not suffer more cosequences than the benefit they hope to get, future generations will suffer and have no means of getting even, it is easy to get popular support for this unacceptable behaviour among those who clearly see themselves benefiting from it and don't care how they benefit.
Even better questions:
"Is it a crime against humanity for someone who has the ability to be well informed and understand the unacceptability of pursuing benefit from burning fossil fuels to deliberately not understand things and instead pursue benefit from unacceptable activity?"
"Is it worse than a crime against humanity for a wealthy and successful person to try to mislead or misinform others about the unacceptability of benefiting from burning fossil fuels?"
If either of the above is true then: Anyone who is actually well informed and should appreciate and understand the unacceptability of already fortunate people trying to benefit from the unsustainable and damaging burning of fossil fuels but deliberately participates in the misleading or misinforming of others on this issue is "Aiding and abetting criminal behaviour".
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thorconstr at 09:23 AM on 27 May 2014Sea level rise due to floating ice?
"I've asked this before thorconstr, but exactly how can a vertical glass wall support a block of melting ice, both substances notable for their slipperyness?"
I can't believe you ask this, no matter what the surface, when things rub they cause friction which would affect the experiment. My background is as a high voltage lineman 15 years, high end home builder 18 years, private pilot, and building high end cars for fun. I don't profess to be a scientist, I do have a lot of "real world" knowledge. Everyone here accepted the first experiment without question, the experiment is far from professional yet you accept it like the "Holy Grail", not a negative response, and you all have problems with mine. Mine wasn't intended as a professional experiment. If I found that I was wrong I would have said so. If I blow the pictures up to show only the glass rim the water level is the same, whether you believe it or not. In retrospect, posting on a such a totally left leaning sight was a mistake. And I unlike most on this site do have an "open mind".<Snip>
Moderator Response:[PS] Commentators have pointed out problems with your experiment and reasonable improvements, as well as detailed explanations of the principle at work here (Tom). Responding to these comments would be better than throwing insults. Your conjecture that no rise in water level is what is expected overthrows a few thousand years of knowledge so the onus lies with you.
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Tom Curtis at 00:10 AM on 27 May 2014Sea level rise due to floating ice?
Despite the triviality of the topic, I'll have one more go.
Suppose you have two large tubs of water at 0 degrees C, one containing a cubic meter of fresh water, and the second containing a cubic meter of sea water (salt content = 35 g per liter). The density of the water in the first case is 999.868 Kg/m^3. In the second it is 1028.131 Kg/m^3. In both tubs you place half a cubic meter of ice, also at 0 degrees C.
The first question I have for those doubting the science (such at thorconstr), is in which tub does the ice ride highest? That is, in which tub is the greatest volume of ice above the level of the water?
As it happens, the density of ice at 0 degrees C is 916.2 Kg/m^3. Hence 0.5 cubic meters of ice has a mass of 458.1 Kg. By Archimedes Principle, we know that the weight of the displaced water equals the weight of the floating object. Thus the block of ice will displace 458.1 Kg of sea water, and the same mass of fresh water. Because of their different densities, however, that means it will displace 0.458 m^3 of fresh water, but only 0.446 m^3 of sea water. That is, the ice in fresh water ill have only 0.042 m^3 above the surface, but 0.044 m^3 above the surface if floating in fresh water. It floats higher in sea water.
We can carry that one step further. If the ice melts it will occupy a volume of 0.458 m^3. That is, it will occupy the same volume as was displaced by it in fresh water, but 0.002 m^2 more volume than it displaced in sea water. That excess volume must result in a rise in the water level. To deny that fact requires us to insist that the displacement of a body is the same regardless of the density of the fluid in which it floats.
The science involved in this case is not that difficult. It is as simple as realizing that ice will float higher in a denser fluid. It is even simple enough to be taught in high school chemistry (in the UK). The problem is that having got a fixed and inaccurate view of that Archimede's Principle states, thorconstr's mind is not open to subtleties that follow from the actual principle.
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Dikran Marsupial at 22:10 PM on 26 May 2014Sea level rise due to floating ice?
thorconstr wrote "I find it amusing that you are sceptical about my experiment where the level remains constant from picture to picture",
The amusing thing is thorconstr utter lack of self-skepticism about his own experiment, which is sad because self-skepticim lies at the heart of science.
The level does not remain constant from picture to picture. In the picture with the ice the meniscus is clearly concave around the rim of the glass, in the picture without the ice it looks to be convex around the rim. The lack of a constant camera angle (poor scientific practice) makes it difficult to be absolutely sure of this. Thorconst should reat his experiment properly, and use a glass with vertical sides, not fill it to the brim and mark the bottom of the meniscus as MartinS did as that is the only sensible way of performing the experiment. Also thorconstr should use a larger ratio of ice to water to make any change in volume as large and easy to measure as possible (as MartinS sensibly did). Of course thorconstr wont actually do this, because there is a limit to most skeptics sckepticism - it doesn't extent to themselves.
"but a huge chink of ice leaning top and bottom against the container and not freely floating does not concern you."
I've asked this before thorconstr, but exactly how can a vertical glass wall support a block of melting ice, both substances notable for their slipperyness?
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Yves at 21:31 PM on 26 May 2014Record growth of atmospheric CO2 in 2013
Tom@9,
AFAIK I've truly seen the 2.95 ppm figure in the NOAA website, as a global mean for 2013 ... but 2 months ago. It was a preliminary result, now corrected as 2.48 ppm. There is an extensive explanation of the data treatment in http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html
This alters the somewhat emotional title, but not the trend, well described in Figure 3. The preliminary value was at the upper limit of the interannual variability for a neutral year (grey points), the corrected value is still above the expected mean values but well within the variability range.
OTOH, I think that the sentence following Fig.3 "If we look in more detail at Fig. 3, we can see that the slope for La Niña years is slightly lower than during neutral years, and the slope for El Niño is slightly higher than during neutral years." is overstated, since we lack enough El Niño or La Niña points (only 8 red and 7 blue points) for inferring robust - statistically significant - statements. -
chriskoz at 20:50 PM on 26 May 2014Sea level rise due to floating ice?
[PS]@43,
That's exactly what I was hoping to show @39 if thorconstr had given me the parameters needed to calculate the expected outcome. Depending of the results of the calculations, say if dh more than 0.5mm, then we would be able to confirm or bust this science. Otherwise (more likely IMO) we would conclude the experiment requires refining because it was impossible to tell. So the experiment would be useful & we would end up wiser.
Sadly, Thor chose to decline my friendly and open minded invitation, instead accusing people of some imaginary "agenda" when they saw something he didn't like. Why so? This piece is AGW-neutral, therefore there should be no "controversy" here... All I can say is: that's typical behaviour of a science denier in general.
As unimportant this piece in the big picture of climate science is, it shows the classic example of science denial represented by Thor here. I was hoping that Thor's experiment shows inquisitiveness of mind (I agree with the appraisal by Tom@36) but in the end, Thor disappointed me big time showing the attitude that has nothing to do with typical constructive skepticism, as his user name would suggest...
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One Planet Only Forever at 14:36 PM on 26 May 2014Looking for connections
My version of “Think Global act Local” has become “Think Globally about all life and the Future - Act Locally Now and Forever”.
I recommend adding a global population line to fig 3 and fig 4. Actually, a more interesting presentation would be to add figures showing the consumptions and GDP as “Per person” so that the per person rate of growth of these items can be more clearly seen.
The total population has not grown as rapidly as consumption, which is clearly not sustainable growth on a finite world. Yet, even with these indicators of success growing faster than the population, many people still suffer horribly through no real fault of their own. They suffer because of the success of people who do not care how they personally succeed. Even very few humans benefiting from burning up non-renewable resources, or consuming other non-renewable resources without full recycling, is fundamentally unsustainable.
This article is in line with my best understanding of what is going on. It, and the comments so far, have prompted me to re-visit my thoughts and present them in a slightly different way. I have submitted all of my related thoughts one comment....
This article is a great summation of what has been going on and continues to go on. And there are even more unacceptable consequences from the burning of fossil fuels, such as the horrible conflicts between people who have been able to get away with benefiting more than others. They fight each other to remain the most wealthy and the most powerful from the unsustainable damaging limited opportunities they strive to benefit from. They also fight against developing groups who desire to become the most powerful, aspiring to be like the current most powerful through similar unsustainable unacceptable activities.
The constant development of the best understanding of what is going on, particularly understanding what is unacceptable, in spite of its potential popularity or profitability, is key to all of humanity succeeding at becoming a sustainable part of life on this amazing planet (the only viable future for humanity)....
I appreciate the many different groups that investigate and develop better understanding of things related to sustainable human activity. And I am beginning to appreciate that using terms like sustainability without fully describing what they are intended to mean provides more opportunity for people to interpret things as they wish. The definition of sustain had a “permanence” to it. However, some groups now use the word in ways that do not actually suit its meaning. The Alberta Government refers to efforts to sustainably extract the oil sands. They should be referring to prolonging or extending the opportunity to get away with it, since extraction of any non-renewable resource cannot be sustained it can only be prolonged.
One thing I have recently learned is that electricity generation in Alberta is so horrible that, from a CO2 emissions impact perspective, in Alberta it is currently better to drive a car with a gasoline fuel efficiency of 11 litres/100 km than an all electric car (based on 2.3 kg of CO2/litre of gasoline burned, and electric car performance of 20 to 25 kWh/100 km). Alberta's electricity generation produces over 1.0 kg of CO2/kWh. That is 4 times the Canadian average of 0.25 kg/kWh. Alberta's electricity generation is also worse than China's current national average of 0.75 kg/kWh. Alberta is even worse than the highest level China had of nearly 0.9 kg/kWh in 2003....
It is very important to better understand the impacts of the CO2 emissions aspect of unsustainable pursuits of benefit from burning fossil fuels. However, it is also important to understand the bigger picture. There are many other harmful unacceptable consequences of trying to benefit from burning fossil fuels. And there are many other aspects of the current global socioeconomic system that are similarly unacceptable, having no real future and creating harmful impacts on the future.
Some believe that GDP growth can be counted on into the future. So any “future costs” of the impacts of today's benefits can be discounted because the future will be better. That is essentially saying that benefits by today's most fortunate are acceptable as long as the created future consequences, as figured out by the most fortunate today, are larger but not significantly larger than the benefit today's most fortunate figure they would be giving up not to create those future problems. That is like one person justifying their bad behaviour by claiming that the problems they cause other people are only a little bit more than the benefit they thought they would be giving up by behaving decently, an absurd justification since the creation of problems others will face is never justifiable....
This amazing planet is expected to be habitable for several hundred million years. Humanity needs to be focused on constantly developing better ways to sustainable be a part of a robust diversity of life on this amazing planet, including a diversity of sustainable ways of living. Science and politics should both be focused on that clearly essential objective. Instead we see scientific pursuits wasted on developing unsustainable ways of gaining or prolonging benefit for a few through unacceptable actions. And we see political leaders beholden to people who became wealthy and powerful through their willingness to benefit from unacceptable unsustainable actions.
When humanity has figured out how to be a sustainable be a part of a robust diversity of life it will have developed a gift worthy of spreading beyond this planet. And one key thing to be figured out is how to keep the few among humanity who will try to benefit from unacceptable actions from ever succeeding. Those trouble-makers spoil things for everyone else. They think life is a competition with the winner having the most stuff, no matter how they got it (like sports cheaters). And they believe that everyone else deserves what they end up with. They particularly enjoy “beating” caring and considerate people who are at a competitive disadvantage to a callous and cruel-hearted pursuer of personal benefit who can get away with the unacceptable things they are more than willing to try to benefit from regardless of the amount of evidence showing how unacceptable their desires are. And those are the kind of people who will persist at attempting to discredit and dismiss any evidence of how unacceptable they are. Those type of people want to enjoy their life as much as possible for as long as possible. Any delay of effective restriction on their unacceptable activities is a “win” for them. And they have been building many ways to keep their undeserved benefits after restrictions get imposed, their “safety-net”. And even if they can't keep all the undeserved benefits they know they enjoyed an undeserved better time for as long as they could get away with, which is really appealing to many people, should be appalling to everyone else.
Those “successful” industrial powers were always fundamentally unsustainable. They all needed external resources to stay the power they were. And they all did unacceptable things to get control of those external resources for “their own maximum benefit”.
And because the “basis of success” in the model has been getting away with success through unacceptable actions, those who are more than willing to behave unacceptably have been increasing in numbers among the successful and powerful, which is only accelerating the unsustainability towards its inevitable dead end.
Some among the few who are more fortunate because of the over-consumption “their group” have been able to control and benefit from, are proposing going beyond the planet as the answer for their voracious unsustainable desires. That is the same as the unacceptable unsustainable way the British Empire prolonged its power, and that America did as well (after the unsustainable natural resource advantage America had was used up). The control of access to limited opportunity has also been the basis for prolonging the “superiority” of the wealthy powerful European nations. And Brazil, China, Russia, and India are following the same pattern, aspiring to be the most successful through similar unsustainable pursuits.
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Bob Loblaw at 13:00 PM on 26 May 2014Sea level rise due to floating ice?
"the camera angle was different."
The camera angle sucks. Why did you take the pictures at an angle that makes it so hard to see the level? The last picture is obviously much closer to horizontal than any of the others. Even with the poor camera angle, put me in the group that says the water level looks higher in the last picture.
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wili at 09:51 AM on 26 May 20142014 SkS Weekly News Roundup #21B
Thanks for the link to the article on WAIS melt. But I am wondering if there is anyone who has put together the new information on accelerated estimations of rates of glacier retreat from both WAIS and GIS to come up with new predictions of total slr by 2100 or earlier. This is the closest I have come to finding anything:http://america.aljazeera.com/articles/2014/5/18/greenland-ice-melt.html
"The Intergovernmental Panel on Climate Change in August warned of a three-foot sea level rise by 2100. But with new insight into melting glaciers in West Antarctica, that increase must be revised to at least seven feet."
But this does not include slr from the new understanding of GIS dynamics. Would that add another two feet or so? So are we talking 3 meters or more by century end? How much of that would come in the next couple decades?Moderator Response:[PS] Fixed link
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thorconstr at 08:55 AM on 26 May 2014Sea level rise due to floating ice?
The glass was never moved, the camera angle was different. No.
Moderator Response:[PS] While trying to rewrite Archimedes principles with poorly controlled experiments might be entertaining, I would ask all concerned to note from the original article.
"They further conclude that 1.6% of current sea level rise (about 3.1 mm per year) is caused by loss of sea ice." (emphasis mine)
and wonder if there are more important parts of the science to discuss?
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saileshrao at 07:18 AM on 26 May 2014Looking for connections
will@27,
"The earth does foster its 'children' for a while...until it suddently flies into a rage periodically and slaughters (almost) all of them in a mass extinction event."
Not to pick on will, but the language here is very interesting and speaks to the hubristic source of our collective predicament: the Earth is an "it," while the Earth's children contain billions of "he"s and billions of "she"s, along with thousands of "Your Highness"es, "Your Lordship"s, "Your Holiness"es and such. -
DSL at 04:47 AM on 26 May 2014Sea level rise due to floating ice?
thorconstr, why did you move the glass mid-experiment? Also, are you going to answer chriskoz?
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thorconstr at 04:28 AM on 26 May 2014Sea level rise due to floating ice?
I find it amusing that you are sceptical about my experiment where the level remains constant from picture to picture, but a huge chink of ice leaning top and bottom against the container and not freely floating does not concern you. I have better things to do than cheat to prove a point. An now I'm going to do them. Adious.
Moderator Response:[JH] Parlor tricks are rarely well received on this website.
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Jutland at 02:44 AM on 26 May 2014Climate sensitivity is low
Tom @314 and Chriskoz @ 315Thank you both for your helpful and swift replies. I had suspected something must be awry as he had published it online rather than in a peer-reviewed journal, but I am not a scientist, so could not work out what it might be. Incidentally, as this is the first day I've posted may I say what a valuable resource this site is, I very much appreciate it. For many years I *thought* I understood the greenhouse effect, because I understood those simple diagrams which show a single-layer atmosphere with equivalent arrows emerging out, one into space and one back to the ground. Then I read a piece by John Houghton which talked about the adiabatic lapse rate and how the greenhouse effect would be impossible if the lapse rate didn't exist. And I realised that I didn't really understand the greenhouse effect at all, because the lapse rate wasn't on those over-simple diagrams. This site was one of the ones I used to read up on it to improve my understanding, and it was the first place I thought of for help when I was reading Wasdell's paper, so thank you very much. -
Dikran Marsupial at 01:24 AM on 26 May 2014Sea level rise due to floating ice?
Incidentally, there is a well known trick that is often used in the classroom to demonstrate surface tension. You fill a glass to the brim with water, and then float pins on the surface, and surface tension is enough to support the pin. The pin still displaces water in accordance with Archimedes principle, but the water doesn't overflow the glass as the surface tension at the edge of the glass is surprisingly strong. All that happens is that the meniscus rises slightly. You can't get the meniscus that high by pouring the water into the glass because the drops don't drop in gently enough and the waves mean that the surface tension can be overcome.
Now thorconst says that the meniscus hasn't changed, but you can't measure it accurately by eye. Thorconsts response is a demonstration that (as usual) the skepticism of the skeptics is rather one sided, so the talk of an agenda is rather ironic.
If he/she were really a skeptic they would repeat the experiment using a flask that wasn't filled to the brim and mark the bottom of the meniscus as martinS did as this is the only way that you can measure it accurately. He/she would also use a larger ratio of ice to water to make the effect as large as possible to make it as easily measurable as possible (which he/she clearly didn't the first time, but MartinS quite sensibly did). Lastly having a better intuition for physics might help, it is hard to see how much support vertical glass can have on melting ice (both notably slippery substances).
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Klapper at 23:26 PM on 25 May 2014Sense and climate sensitivity – more evidence we're in for a hot future
@Chriskoz #44:
I think what you are saying is that there are confounding factors to the cooling forcing of anthropogenic aerosols. You gave the example of changes in precipitation in turn causing local warming in Beijing, undoing the normal cooling effect of aerosols.
What about Chengdu then. My analysis of a 10 x 10 degree box around Chengdu shows the same warming rate over 30 years as the global rate for land. Is this area also effected by the same drying by sulphates as Being?
If there is a sulphates drying effect then perhaps this effect is also occurred historically in other areas meaning our current estimates for net aerosol forcing are too high.
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