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Rob Honeycutt at 03:27 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
Here's a question. Sorry if someone else brought this up already. So, part of the idea here is whether or not there could be spikes in global temperature over the course of the holocene, somewhat proportionate to what we see in the 20th c, that do not show up in the Marcott graphs due to methodology. Right?
If there were such spikes, would that not be an indication of extremely high climate sensitivity?
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KR at 03:00 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
Tom Curtis - I see a single 0.45C spike at ~5.75 Kya, a few more at ~7 Kya; a Monte Carlo perturbation of proxies with an embedded spike of 0.45C would show (in the space of all possible realizations) a distribution of realizations with spikes at (nominal unperturbed realization), below (blurred by perturbations that reduced overlay) and above (where unrelated short term spikes get perturbed under the larger one) that value.
Hence I would consider that a single realization at that point represents a value that is too high for the data, an outlier, that consists of perturbations that happen to overlay variations in a reinforcing fashion at that point.
A more interesting period IMO is the range of ~1.8-0.2 Kya; showing a distribution of realizations that result in an approximately 0.15 C rise and a following drop. That is the kind of blurred pattern (although rather small) I would expect from previous Holocene reconstructions indicating a variation of ~0.3 C at that point - encampassing the MWP and LIA.
Again: In perturbed Monte Carlo reconstructions the possible space of realizations must include original level excursions, plus realizations below (many of these due to blurring) and above (a few due to stacking, which in fact permits full level realization in the presence of date errors) - a distribution. Again, I do not see any possible century-level 0.9 C spikes in the Marcott realization set.
The only possible way for such a spike to be missed is if it wasn't in the data at all - and given the data (proxy sampling minima: 20 years, maxima: 530, median: 120) a two century excursion would have been sampled.
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But this is all really a side-show. We have proxies down to decadal and near-annual resolution (ice cores and speleotherms, in particular), and none of them show a global 'spike' signal of this nature. The only reason the question was raised in the first place, IMO and as noted here, is as obfuscation regarding global warming. Current warming is unprecedented in the Holocene, and it is due to our actions - it's not a 'natural cycle'.
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Tom Curtis at 02:16 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
KR @39, I can accept your first point. However, consider the spike above the cloud at about 5.75 Kya on the 1000 realization spaghetti graph. Just what were the mean values for the thousand years before and after that spike in that realization? Clearly you cannot say as its hidden in the spaghetti. So, for all we know it could be a spike of about 0.45 C that would be all that is shown of a 0.9 C spike based on Tamino's analysis. Indeed, given the attenuation of the spike simply from the low resolution of some proxies, if that spike is a fluctuation from the mean of the series, it reproduces Tamino's "uperturbed" example.
That is the problem.
Unfortunately, I still do not know why Tamino's examples produce greater variability than do Marcott et al's actual reconstruction; and not knowing that, I do not know that the difference which causes it would not also smooth away a brief, high amplitude spike.
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KR at 01:31 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
MrPete - The fact that our current temperature rise will take thousands of years to reset is not from the Marcott et al paper, but rather from basic physics and the atmospheric concentration lifetime of CO2 (Archer 2005, as but one resource). Even once the atmosphere and oceans equilibrate in CO2, it will take thousands of years for CaCO3 reactions and silicate weathering to draw down the excess.
The only circular arguments being made in regards to this paper are those claiming that short-term spikes could have been missed by the Marcott analysis (despite there being no physical basis for such up/down spikes, nor evidence for them, and despite high-resolution proxy evidence against such spikes), and that therefore current warming is natural and nothing to worry about. That's entirely circular, unsupported, and nonsensical.
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MrPete at 01:14 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
CBDunkerson, you wrote:
Rather, temperatures will continue their precipitous rise until we get greenhouse gas emissions under control and then they will stay at that high temperature, decreasing only very slowly, for thousands of years.
This statement is not so easily proven. The fact that it is not proven is why so much is being invested to discover the answer. We certainly can't make that assumption in a paper that's supposed to help us understand whether that statement is true or not... that would be presuming the conclusion, ie circular logic.
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KR at 00:38 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
Tom Curtis - Tamino added the spike to a single instance of the dates (best estimate, I expect), then the Monte Carlo procedure perturbed those dates causing the smearing he saw in his analysis. If the time of the spike in each proxy did not change then neither would the spikes change from the shape initially introduced - the +/- uncertainties in the data would average out entirely. He did not add the spike after perturbations.
One very important point about the Marcott et al discussion on resolution is that they calculated that resolution from a frequency point of view - evaluating power spectra at various frequencies.
The gain function is near 1 above ~2000-year periods, suggesting that multi-millennial variability in the Holocene stack may be almost fully recorded. Below ~300-year periods, in contrast, the gain is near-zero, implying proxy record uncertainties completely, remove centennial variability in the stack. Between these two periods, the gain function exhibits a steady ramp and crosses 0.5 at a period of ~1000 years.
[Marcott et al 2013 supplemental]
This does mean that a frequency-limited signal such as a 300-yr sinusoidal variation would be removed entirely. However, a spike of 200 years duration (0.9 C in the Tamino analysis) contains many frequencies - from the 0 frequency average value added to the full signal by the spike, down to the ~decadal sharp edge transitions that are completely lost. Their Monte Carlo analysis is in effect a low-pass filter, which would not have removed that large a spike - just blurred it. In that regard I feel the authors are under-rating their own procedures; a spike like modern warming, even if reversed by non-physical gremlins, would still show in their final data.
What's more - given the nature of Monte Carlo analysis, some of the perturbed realizations would include such a spike in full (if it existed), others would not, resulting in blurring. Some peturbations, by shifting unrelated data under the spike, would actually increase it in that realization.
But if you examine the full 1000 realizations that Marcott et al ran:
There are no such spikes visible in any realization. It is my opinion that Marcott et al have down-played their own work - that a warming like the one we are currently experiencing, if it had occurred in the Holocene, would have shown up in this analysis.
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CBDunkerson at 00:16 AM on 6 April 2013The two epochs of Marcott and the Wheelchair
Tom Curtis, while obviously it would be nice to be able to 'conclusively prove' that there were no brief temperature spikes, comparable to the current rate of warming, over the entire period of the Marcott study... but I have to ask whether that is really even necessary?
I think you would agree that both of the following are easily proven;
1: The recent warming will not be a brief spike. Rather, temperatures will continue their precipitous rise until we get greenhouse gas emissions under control and then they will stay at that high temperature, decreasing only very slowly, for thousands of years.
2: The Marcott data does provide enough detail to conclude that there has been no similar 'new high temperature plateau' over the period of the study.
Who cares if it is theoretically possible that some never observed or imagined phenomena could have caused a temperature spike comparable to current warming, which then immediately reversed back down to roughly the pre-warming temperature such that the change could be undetected by the Marcott study? Aside from being rampant speculation with absolutely no basis in evidence and seeming highly unlikely to even be possible... whatever might cause such a brief spike would also be completely irrelevant to what is happening today.
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Tom Curtis at 23:35 PM on 5 April 2013The two epochs of Marcott and the Wheelchair
Further to Tamino's attempt to show that spikes in temperature would show up in Marcott et al's reconstruction, it turns out that high energy physicist, Clive Best has attempted to refute Tamino. He introduces Tamino like spikes into his own replication of Marcott et al, and finds a detectible but small responce:
He writes:
"The peaks are indeed visible although smaller than those claimed by Tamino. In addition, I believe we have been too generous by displacing the proxy data linearly upwards since the measurement standard deviation should be properly folded in. I estimate this would reduce the peaks by ~30%.
What I find very interesting is that there actually do appear to be smaller but similar peaks in the real data (blue arrows), one of which corresponds to the Medieval Warm Period !"
Unfortunately is his over optimistic. HIs replication of Marcott et al procedes converting ally proxie data to anomallies, and then dividing the time span into 50 year bins. Then for each bin, if a proxy date falls in that bin, it is included but excluded otherwise. The anomaly temperature for each 50 year interval is found by taking the "geographic average" by which he possibly means an area weighted average for 5x5 cells. Crucially, he does not introduce any interpolation between data points. Thus, proxies with 300 year time resolution will only be found, on average, in every sixth bin. That is, the number of proxies in each successive bin varies considerably. As he takes a (possibly area weighted) mean of each bin rather than using the mothod of differences, the result is that the average jumps around a lot every fifty years, introducing a large amount of spurious short term variability.
Because he introduces so much spurious short term variability by his method, he is certainly mistaken to claim examples of that variability as possible large spikes in the temperature data as smoothed by Marcott et al.
Importantly, the failure to linearly interpolate is not the cause of Best's reduced spike. Had his bins included linearly interpolated values of proxies that did not have a date within the bin range (and included a mean of the data of poxies with multiple data points in the bin range, instead of all data points), the result would be to introduce additional data that was unperturbed by the spike, thereby reducing even the small spike he shows.
Best's method will also include some proxies with high resolution multiple times in each bin. In his first attempt at this method he used 100 year bins, which would have included some proxies five times in each bin, and others only once every fifth bin. The inclusion of multiple data points from a single proxy in the bin has the effect of giving that proxy additional weight. This probably accounts for the slight difference in the overall shape of his reconstruction when compared to that of Marcott et al, and is definitely inferior to Marcott et al in that regard. His crude method does confirm, however, that the overall shape of the Marcott et al reconstruction is a product of the data, not an artifact:
Returning to the issue at hand, what of Best's reduced peak? I believe that is because he did not add the full spike to each data point in the relevant bins. Specifically, he "simply increased all proxy temperatures within 100 years of a peak by DT = 0.009*DY, where DY=(100-ABS(peak year-proxy year))". That is a reasonable proceedure. I have asked Tamino whether he did the same in a comment; but as he declined to post that comment or an answer I do not know whether he did likewise, or added the full value to each proxy within the timespan.
Assuming Tamino did not make so egregious an error (a wise assumption), the second relevant factor is the temporal perturbing of proxy dates. If Tamino added a spike linearly adjusted by year to each proxy within 100 years of the peak of the spike, and then temporally perturbed the proxies before linearly interopotating etc, that would tend to smear the spike out. If instead he temporally perturbed the proxy dates, then introduced the spike based on linear interpolation he would produce a very distinct spike. That is because the time of the spike would remain fixed across all temporal perturbations. After taking the mean, a strong signal would emerge. Indeed, if this is indeed what he has done, the method is analogous to a process used by amateur astronomers to take pictures with much finer resolution then the cameras they use to take the pictures.
If this is his procedure, it is, however, a mistake. We are not in the position of amateur astronomeurs who can take a 1000 photo stack and convert it into a single high resolution photograph. Rather, we have a single low resolution photo (the 73 proxies) and cannot get a greater resolution than provided by those 73 proxies.
The correct method to test whether a short, high amplitude spike would be detectable is to first perturb the proxies temporally once, then introduced the linearly extrapolated spike to perturbed proxies what fall within the 200 year history of the spike. Then, taking the resulting pseudoproxies, apply the full Marcott procedure to them. That is, for each pseudoproxy, make one thousand perturbed proxies, perturbed both in date and anomaly temperature. From these thousand realizations of each proxy, create a thousand reconstructions, then take the mean of those thousand reconstructions. Only if the introduced spike is visible and distinct at the end of that process have you proved that a large short term spike would be visible in the Marcott et al reconstruction.
Moderator Response:[RH] Fixed image width.
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CBDunkerson at 23:15 PM on 5 April 2013The Fool's Gold of Current Climate
The article Andy Skuce linked to also includes a bit about the fact that we know from fossil remains that polar bears used to live in the Baltic sea off Sweden and Finland... but now they don't. Still plenty of ringed seals there, but no polar bears. Why? Because there is no longer sea ice in that region for polar bears to hunt from. The presence of their prey doesn't mean a thing if they can't catch it.
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climatelurker at 22:54 PM on 5 April 2013The Fool's Gold of Current Climate
As someone else suggested, it seems likely that polar bears will continue only as a hybrid species crossbred with other bears if they lose their habitat. I'm not sure how a polar bear could 're-emerge' as a distinct species during ice ages, though. Once the DNA has been mixed, it can't exactly be un-mixed.
However, there are a lot more animals in the crosshairs of climate change than polar bears and penguins. How is climate change going to alter disease trajectories in different species, for example the white nose fungus that's decimating bat populations (is it possible even if not yet evident that it's linked to climate change?), or if climate change has a hand in the bee colony collapse (aside from the neonicotinoid pesticide link). What will climate change do with bird or swine flu? E-Bola? Rabies? Strep Throat? Are fish and cetacean populations experiencing mass die-offs as a result of climate change already? What if previous mass extinctions from climate change had disease explosions as their vectors? Is that possible to study in the fossil records?
To try to tie this back to the blog topic, it seems like these underlying things may already be happening, hardly what I would call benign or beneficial (not even bringing the physical effects of rising water and weather pattern changes into the discussion).
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bouke at 19:46 PM on 5 April 2013Klotzbach Revisited and John Christy's response, part 2
I started reading the Klotzbach paper and notice they reference surfacestations.org several times, which is maintained by Anthony Watts. It reminded me of this sad exchange: Watts uses a picture to 'prove' that antarctic surface stations are influenced by urban heat island. The picture turns out to be from the wrong end of the continent, and the weather station on the picture isn't even used for climate data. And Watts never acknowledges his errors.
Why anyone even wants to associate with that guy is beyond me, but if they do that's an instant mark against their credibility.
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scaddenp at 17:27 PM on 5 April 2013CO2 limits will hurt the poor
Apologies Ray - your comment was clearly engendered by my comments are whether you were in the ideological camp or not. It is my response to you that would have been off topic and so I have brought it here.
Ray, the climate negotiations go nowhere because US in particular dont commit to reductions. Without that happening (and Europe) obviously no progress is made, but the intent of Doha is reductions by rich nations without restricting the growth of poorer nations. Not even the US denies this aim. And Kyoto clearly gives lie to your ascertain that idea that western powers are trying to restrict the growth of the poor. Rehman statement says that is it the failure by the west to reduce their emissions (and thus inflicting climate change on the poor) that is the problem.
However, I now I might have misread you. Your statement was "my political views are that I find it difficult to accept that the major western powers are trying to enforce, on countries which are much poorer than they are, actiions that will disadvantage the citizens of those countries in their efforts to attain the standards of living approaching those of the developed world."
By this I understood you mean that thought the west was trying to restict growth of emissions in the 3rd world (actions that will disadvantage), where as I realise that you might have meant that they are forced to accept inaction by the west and thus limited by climate change in trying to improve their standard of living. If this was your meaning, then I apologise.
If you agree that western powers need to drastically reduce emissions so that poor nations can grow without harming their climate, then we have no disagreement.
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Dissident at 17:20 PM on 5 April 2013The two epochs of Marcott and the Wheelchair
many thanks for the explanations CBDunkerson, Tom Curtis and Tom Drayton. I thought random spikes would have made a visible trace in the record of past temperature, but didn't know how it could be shown.
Philip Shehan, why bother going on WUWT? Except perhaps as a comedy venue...
Moderator Response:[JH] Phillip Shehan's most recent comment was deemed to be "off topic" and hence was deleted.
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Andy Skuce at 16:09 PM on 5 April 2013The Fool's Gold of Current Climate
There's a useful article here:
8 Tips From Scientists On Covering Polar Bears
It deals, among other things, with the myth that Polar Bears will just adapt to an ice-free Arctic, since ice is part of the ecosystem, like soil is in a forest and we would not expect trees to just adapt to a soil-free forest.
The climate conditions that Polar Bears will face by the end of this century with unmitigated warming will be unprecedented in the entire existence of the species over the last ~600,000 years since they split from brown bears. I hope I am wrong, but there seems every reason to doubt that they will be able to adapt to this very rapid change over just a few generations.
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Ray at 15:44 PM on 5 April 2013The Scientific Method
scaddenp I posted a comment on the political aspect as you directed. Not sure why this was necessary as you brought politics into the discussion with your initial comment "because mitigation actions proposed so far are discordant with your politics?" That you now deem my reply as "off topic" seems unusual but I have done as requested to avoid any problems with irrelevance
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Ray at 15:37 PM on 5 April 2013CO2 limits will hurt the poor
scaddenp. Have you actually looked at the takeup of the Doha meeting? The major polluters are noticable by their absence. US, Canada, China, India. 37 countries signed onto the Doha agreement. These countries are responsible for 15% of the global emissions. Not exactly a stunning result by our leaders in view of the stated seriousness of climate change. But what was the opinion of concerned groups?
Asad Rehman head of climate and energy at Friends of the Earth had this to say "A weak and dangerously ineffectual agreement is nothing but a polluters charter – it legitimises a do-nothing approach whilst creating a mirage that governments are acting in the interests of the planet and its people," "Doha was a disaster zone where poor developing countries were forced to capitulate to the interests of wealthy countries, effectively condemning their own citizens to the climate crisis. The blame for the disaster in Doha can be laid squarely at the foot of countries like the USA who have blocked and bullied those who are serious about tackling climate change. His sentiments encapsulate my own thinking
Kumi Naidoo, executive director of Greenpeace International accused delegate as being out of touch. He said " "We ask the negotiators in Doha: Which planet are you on? Clearly not the planet where people are dying from storms, floods and droughts. Nor the planet where renewable energy is growing rapidly and increasing constraints are being placed on the use of dirty fuels such as coal. The politicians and negotiators have lost touch with climate reality – sadly their failure will be paid for in lives and livelihoods,"
As is apparent these guys, who are a lot closer to the action than either of us, are a lot less enamoured of Doha than you seem to be.
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Michael Whittemore at 15:30 PM on 5 April 2013The Fool's Gold of Current Climate
@mandas (22)
The point Terranova makes about "population size of prey species" also does not explain the availability of prey. Regards to polar bears there may be lots of seals but little ice for the bears to be able to access them. I also think an early breakup of the ice could cause the deaths of bears trapped out in the ocean.
Of cause the polar bears could just change their source of prey (-snip-)
Moderator Response:(Rob P) -Inappropriate content snipped
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mandas at 15:06 PM on 5 April 2013The Fool's Gold of Current Climate
Terranova
I am also a wildlife scientist, and I have to say that I am flabbergasted by your statements at post #9. You can't seriously be trying to tell us that the only factor which affects polar bear populations is the population size of their prey species. Perhaps I misread you, and the moderators cut off some of your explanation.
But then, your statements that:... I don't doubt they will survive the next 100,000 years now that overharvesting of both species has been controlled.... is the sort of statement that only someone would make if they were completely unfamilar with wildlife, and who was putting forward an ideological statement rather than a scientific one. So on that basis alone I have to wonder what you are trying to suggest - and if you really have the qualifications necessary to suggest it.
You do know that one of the most important factors influencing the population size of any species is habitat, right? So what do you think will happen to polar bears if their habitat is degraded?
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jbyrd at 14:36 PM on 5 April 2013The Scientific Method
The basic concept, precept 'Scientific Method" should, for any reasoning entity, (joke)
throw up question marks. I propose that, for now at least, we forget Linneaus (or however you spell it) and rename us Homo Experiri, with Homo Sapiens being reserved for a yet to be observed, but hoped for, truly wise Man.
The point is that we (homo sapiens) are born performing the scientific method. The difference between a 2 year old and a 40 year old, or a Neandertal, or a pine tree , is qualitative.
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scaddenp at 13:58 PM on 5 April 2013CO2 limits will hurt the poor
One other thought from discussions with rabid libertarians that objected to any kind of international agreement on grounds that it was one set of nations interfering with liberty of another. The usual addendum to complete freedom of action is the assumption of full responsibility for the consequences of action. I have no problem with this. So if we scrapped any international negotiation, how happy would you be with apportioning the full costs of adaptation whereever they occur (since you cant keep you emissions within your boundaries) on the basis of accumulative emissions that caused the problem? That would include countries taking their share of refugees?
On that basis, USA, UK and Germany would bear the brute of adaptation costs. Since studies show adaptation more expensive than mitigation, I woiuld mitigate real fast to avoid the liability.
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Michael Whittemore at 13:26 PM on 5 April 2013The Fool's Gold of Current Climate
It still amazes me that professional people can slander their name so much by twisting the findings in climate science so they can try and go against the consensus. They may have their moment in the spot light, but it’s a stain they are never going to get off them. I have to agree that a little warming from induced CO2 could be a good thing, which Dana also seems to suggest. Terra forming is an important process that we are going to have to better understand if we plan to live in this universe. I for one do not want to see the likes of an ice age in the future (be that if I find a way to keep myself a live for thousands of years).
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Bob Loblaw at 13:00 PM on 5 April 2013The Fool's Gold of Current Climate
Glenn: "whatever numbers of Polar bears survive will be as a result of switching their hunting patterns to more land based prey."
In the Churchill area, this probably means eating tourists instead of seals.... I'm sure the tourists will be glad the bears found an alternate food source. Working in the Churchill area was one of the few times in my life where I felt the need to own a gun, and carry it with me all the time. If the bears weren't on the ice, they were hungry. -
dhogaza at 11:38 AM on 5 April 2013The Fool's Gold of Current Climate
"I don't think that short winters and long summers with nothing to eat would be good for polar bear health in that area."
Just found this, a layman's summary of a very recent study on hudson's bay polar bears:
http://www.csmonitor.com/Environment/2013/0320/Warming-Arctic-Receding-ice-leaves-Hudson-Bay-polar-bears-less-time-to-eat
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Glenn Tamblyn at 11:34 AM on 5 April 2013The Fool's Gold of Current Climate
Terranova
How does the ringed seal breeding cycle work? They have nests under the ice so heavy ice winters are easy to understand as being bad - maybe colder, harder to maintain air pockets, keep breathing holes open, whatever. What the graphic you show doesn't indicate is what they will do during extremely low ice winters, levels of ice unseen in historical times.
What is the minimum ice thickness they need to produce a den in the ice? How long does the ice need to be there for their breeding cycle? Can they delay their breeding pattern if the ice is late in forming?
On current trends the Arctic will be virtually ice free in September within 2-3 years. Ice free from August to October a couple of years later. Maybe ice free for 6 months a year within 1 - 2 decades. And all the ice that forms each winter will be first year ice - no more than 2+ meters thick, perhaps not as folded and misshapen as older ice and thus with worse conditions for creating dens.
What will the impact on the seals be then?
It's more likely that whatever numbers of Polar bears survive will be as a result of switching their hunting patterns to more land based prey.
An interesting study a year or so ago looked at the genetics of Polar Bears. Prior to this the conventional understanding seems to have been that the Polar Bear was only around 120-150,000 years old as a species, having emerged from a sub-population of Brown Bears near the previous inter-glacial.
This study puts them at around 3 million years old. However, what seems to happen is that the Polar Bear population declines hugely over the glacial cycle, effectively breeding back into the Brown Bear population (Brown & Polar Bears have been observed mating) then reappears as a distinctive population when temperatures turn colder again.
Perhaps they should be called The Great White Brown Bear.
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dhogaza at 11:30 AM on 5 April 2013The Fool's Gold of Current Climate
Bob Loblaw:
"I don't think that short winters and long summers with nothing to eat would be good for polar bear health in that area."
Polar bear numbers in the hudson's bay population have dropped 22% from the 1980s, and is attributed to changes in sea ice coverage there.
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Bob Loblaw at 11:28 AM on 5 April 2013The Fool's Gold of Current Climate
Glenn@6, Victor@1:
When I first read Victor's coment, I thought about nutrients limiting plant growth, but on more detailed reading, I realized Victor was asking about the nutrients available in the plants, after they grow to the point where we can eat them. Even if plants grow bigger, are they better for us? Or does a faster-growing plant provide little or no additional nutrients to us when we consume them?
An interesting question, for which I have no answer or knowledge on how to figure out an answer. Perhaps there is something in the plant breeding literature that discusses selective breeding for increased growth and evaluates the effect on nutrient levels in the resulting product.
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dhogaza at 11:27 AM on 5 April 2013The Fool's Gold of Current Climate
Also, terranova:
1. your graph discusses a study in one region, the beaufort sea.
2. the study is old, there's almost no data on the effect of the population resulting from changed sea ice conditions in the last couple of decades, and none for the last 15 years. If the winter ice were to disappear entirely from the region, so would polar bears.
Fortunately, scientists have continued studying polar bears in the Beaufort Sea. When working on your masters, I suggest you not restrict your literature search on past research on predator/prey relationships between wolves, bison and elk in Yellowstone to studies done before 1995. You'd miss an important event, the reintroduction of wolves in 1995 ... likewise, focusing on a study done in the arctic in the 1990s that concentrates on data from the 1960s-1980s misses significant changes in the arctic since then.
Here's a piece that came out in 2006, noting changes in population structure in polar bears of the southern beaufort sea that are similar to those seen in the hudson's bay population before their numbers started declining significantly:
http://pubs.usgs.gov/of/2006/1337/
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Bob Loblaw at 11:19 AM on 5 April 2013The Fool's Gold of Current Climate
Terranova:
Only anecdotal evidence, but I spent several summers in the Churchill area. The polar bears do little eating in the summer, on land. They fatten up on the ice, eating seals in the winter, and after the summer they are pretty hungry by the time the ice starts to form again in the fall. Although I can appreciate that in the past a heavy ice winter could lead to fewer seals and less to eat, I don't think that short winters and long summers with nothing to eat would be good for polar bear health in that area.
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dhogaza at 11:11 AM on 5 April 2013The Fool's Gold of Current Climate
"The polar bears success is predicated by the population size of its prey species, and one of their favorites is the ringed seal. Seal numbers drop during heavy ice winters and the polar bear numbers fall in response. The mothers and young are especially hard hit."
My guess is that you're going to be very surprised next year when you start your masters program in predator/prey relationships. Let's just say that the model you present is ... overly simplistic.
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Riduna at 10:43 AM on 5 April 2013The Fool's Gold of Current Climate
Scaddenp … Quite right! There is a tendency to forget that plant (and animal) life is temperature sensitive and can only function within a limited range. That range is moving further north and south of the equator and plants will either do the same or adapt to higher surface temperatures. The problem is that the speed of temperature rise is too rapid for most plants to either adapt or move.
As Dana points out, even if Ridley is not concerned by present climate conditions produced by a surface temperature rise of 0.8°C since 1750, he – and we – should be very alarmed at the effects of a further increase of 2°C by 2100. Why should we be alarmed? Because the effects on climate are likely to be so severe that the ability of our own species to adapt and survive may well be compromised.
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Bob Lacatena at 10:23 AM on 5 April 2013The Fool's Gold of Current Climate
Terranova,
I don't doubt they will survive the next 100,000 years now that overharvesting of both species has been controlled.
I'm not dismissing your comment, but have you really considered how the Arctic ecosystems are likely to change, given the rate of warming and change that we currently see, which is only a fraction of what is inevitably in store?
As a trained biologist, do you think that you can really, rationally support the position that "you don't doubt" that polar bears will survive a change to their ecosystem that may well be more dramatic than anything experienced in the past half a million years?
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Terranova at 10:10 AM on 5 April 2013The Fool's Gold of Current Climate
I am not a chemist, physicist, geologist, or any other science directly related to the climate and climate change (which is one reason I am here to educate myself). But, I am a practicing biologist/naturalist that already holds an MS degree in Fisheries and Wildlife and will be starting another Master's program this year in Biological Sciences focusing on predator/prey relationships (wolves, bison and elk in Yellowstone).
Polar bears and their prey have survived both short term climate oscillations and long term glacial/interglacial periods over the last 100,000 years. I don't doubt they will survive the next 100,000 years now that overharvesting of both species has been controlled.
The polar bears success is predicated by the population size of its prey species, and one of their favorites is the ringed seal. Seal numbers drop during heavy ice winters and the polar bear numbers fall in response. The mothers and young are especially hard hit.
The graphic below shows this relationship.
Moderator Response:[Sph] Image width reduced to fit in page.
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Glenn Tamblyn at 09:20 AM on 5 April 2013The Scientific Method
Ray
"I'm a molecular biologist not a climate scientist so I'm looking for debate on Climate Change conducted by those who have different views"
As a molecular biologist, you would have a good knowledge from your field of what areas of study are well established, which areas are still being researched and explored. So if you were looking for a debate on Molecular Biology, surely you would expect that debate to be around those areas being researched and not those areas considered well established.
So if you saw the 'debate' going back to question the well established stuff, just rehashing old disproven arguments etc, and many people refusing to accept the old disproofs, you would rightly be rather leary of it wouldn't you? I am a Mechanical Engineer by training so my background in Thermodynamics etc gives me some insight into Climate Science. But in Molecular Biology my knowledge ends at High School Chemistry and Biology.
If I were to listen to the debate on Molecular Biology, how would I be able to judge whether all those arguments put forward rejecting the established view are reasonable or not? I could very easily be led to believe that their is a real dispute; that the 'science isn't settled', with many reasonable protagonists on all sides. Whereas you know that there is well established science in those areas of Microbiology, and that those putting forward the counter views are actually ignorant or cranks.
So how does one tell that the 'debate' is real rather than a platform for the cranks?
And given my previous comment to you, could a reluctance to accept AGW because of the magnitude of the implications be influencing your willingness to listen to the counter views?
Surely the best answer to this is to do one of two things. A, get really knowledgeable about the science yourself so you don't need to rely on a debate. Or B, investigate deeply whether the debate is real or actually reality vs the Cranks.
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Tom Curtis at 09:07 AM on 5 April 2013The two epochs of Marcott and the Wheelchair
Dissident @ 31, the issue of whether or not Marcott et al's reconstruction could detect large short term temperature spikes, or whether or not it did detect the modern spike is completely irrelevant to their paper.
The crucial part of their paper is where they jitter the age and temperature data of their proxies based on the known errors in both, and produced 1000 reconstructions from the jittered proxies:
They then plotted the distribution of all temperatures within the Holocene for all 1000 reconstructions (see their figure 3 reproduced in my post 8 above). The distribution then shown is not actually the distribution of Holocene temperatures, but rather the distribution of possible Holocene temperatures given the data from Marcott et al. The plotted distribution is then a Probability Density Function (PDF) of Holocene temperatures. When compared to that PDF with modern temperatures as determined by the instrumental record, it turns out that less than 5% of potential Holocene temperatures are as low as those found at the start of the 20th century (1900-1909), whereas 82% of potential Holocene temperatures are less than temperatures at the start of the 21st century (2000-2009). If they introduce additional variability to allow for variability lost by their method of reconstruction, that figure falls to 72% (Figure S22 in the supplementary material).
That 72% figure is not very remarkable by itself, but it is when considered against the very low temperatures at the start of twentieth century. In one century, temperatures have increased by 67% of the full range of temperatures possibly achieved over the last ten thousand years. That is disturbing.
Even worse, IPCC projected temperatures for the end of the twentieth century are likely to be "... 5 to 12 standard deviations above the Holocene temperature mean"! That is, they will be well oustide anything humans have ever experienced. That also is remarkable, and very concerning. That is the very robust finding from Marcott et al that the usual suspects wish to distract you from.
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Glenn Tamblyn at 09:02 AM on 5 April 2013The Scientific Method
Ray
Consider the possibility that Climate Change is real and that failure to act on it will cause real suffering to many people including, perhaps even especially, those in the developing world. And that the actions we need to take to prevent it, certainly if carried out using 'conventional' economics will, or at least may, have the negative impacts you are concerned about.This is where the implications of AGW can really mess our heads around, creating a harsh cognitive dissonance between competing needs.
Humanity is in a really, really bad place. Right now! And it can stretch us all to try and accept that fact. So, depending on our differing personalities and where our focus lies we can easily slip into two mindsets.
- AGW is real and is the most serious issue and must be tackled urgently.
Or
- All those other demands are real, the needs of the developing world are real etc. The things needed to tackle AGW will have negative consequences for these issues, so negative that they can't be countenanced.
The truely hard thing for people to do is to replace my 'Or' with 'And'.
Then we need to confront that harsh reality that humanity is facing a deep crisis, perhaps the greatest crisis in human history. Out response to AGW so far suggests that the severity of the situation hasn't impinged on most people yet. That it just seems to big to get our heads around.
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mandas at 09:02 AM on 5 April 2013The Fool's Gold of Current Climate
Hi Guys,
I believe there is an error in your article. In the paragraph under the cartoon of the falling Venture Banker, you say this:
Of course, Ridley isn't the only climate contrarian to make the mistake of focusing on current impacts while ignoring those to come in the future.
A 'mistake' suggest that Ridley makes an error of oversight. I would like to suggest that this is far from the truth. It is not a 'mistake' it is a deliberate distortion, and as such the sentence should read:
Of course, Ridley isn't the only climate contrarian to deliberately misinform the public by focusing on current impacts while ignoring those to come in the future.
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scaddenp at 08:54 AM on 5 April 2013CO2 limits will hurt the poor
For a look at historical emissions and what would be an equitable distribution, look at the opening of MacKay's "Sustainable energy without the hot air", specifically here.
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scaddenp at 08:51 AM on 5 April 2013The Fool's Gold of Current Climate
Hmm, doesnt photosynthesis stop about 38C and slow down beyond 30? That cant be good for the tropics.
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scaddenp at 08:43 AM on 5 April 2013The Scientific Method
Ray, I agree on reading widely. Just not so wide as to bother with WUWT or CO2Science. That way I dont miss papers of potential interest (and since I work in petroleum and to lesser extent coal, finding AGW isnt real would be particularly welcome). However, I have no time for blog "science". Publish it or shut up. Your reading of published paper on alternative hypotheses for climate change wouldnt take up of your time.
Your other comment is totally off topic here. I have responded to it here.
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scaddenp at 08:43 AM on 5 April 2013CO2 limits will hurt the poor
Ray, (replying from here) Your characteriztion of "western powers" seems seriously at odds with what I see. If you dont mitigate emissions, then the studies show climate change will affect the poorer countries much harder than the west. Kyoto didnt apply to undeveloped nations. Negotiation have focussed on reduction of emissions in west so poorer nations can grow and on the west (who are historically responsible for almost all of the extra GHG currently in atmosphere) funding ways for growth in these countries in ways that doesnt damage the climate. Can you interpret Doha in any other way??
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Tom Curtis at 08:41 AM on 5 April 2013The two epochs of Marcott and the Wheelchair
Tom Dayton @33, Tamino has not shown what he claims.
Specifically, if you look at Tamino's reconstruction of Marcott et al, whether by averaging or by the difference method, it shows far greater short term variation than does Marcott et al:
It follows that his method preserves far more short term information than does Marcott et al's. That by itself is sufficient to show that his experiment is not directly comparable. However, we can go further than that. Look at the sharp downtick at approximately 6.25 thousand years ago (Kya) on Tamino's reproduction of the Marcott reconstruction, we can use it to see how well adding temporal jittering reduces it:
By my eyeball estimate, with taking the mean of 100 reconstructions temporally perturbed proxies, the 6.25 Kya downtick is about halved, ie, about the same reduction as the artificially introduced upticks. Even taking the mean of 1000 reconstructions with temporally perturbed proxies scarcely reduces it further:
Clearly there remains something different about Tamino's method that better preserves short term variation than does Marcott et al's.
If we extrapolate the additional reduction in short term structure reqired for Tamino's reconstruction to match Marcott et al at 6.25 Kya, it probably requires a further quartering of the perturbations. The problem is that a further quartering of Tamino's introduced spikes would leave them with about the same amplitude as the "spikes" at about 1.1 and 7 Kya on Marcott's reconstruction. That is, extrapolating the necessary reduction in short term variation shows that Marcott's reconstruction may contain the remnants of spiked of similar amplitude to those that would be produced by his artificial spikes. I don't think such spikes exist, but Tamino has not shown it.
One key difference between Tamino and Marcott's reconstruction is that Marcott et al not only perturbe the proxies temporally, but also in terms of amplitude. That difference may be the difference in the respective ability to reproduce short term variation. If so, then Tamino's artificial spikes may not be detectible in a full Marcott et al reconstruction. So while an interesting attempt, Tamino has not shown that such spikes would be detectable.
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Glenn Tamblyn at 08:11 AM on 5 April 2013The Fool's Gold of Current Climate
VictorVenema
There is a principle in agronomy called Liebig's Law of the Minimum. Essentially that growth of a plant is constrained by whichever resource is in shortest supply. Greenhouses manage what is happening so that everything is optimised so there is a benefit from extra CO2.
A CO2 fertilisation effect is real and is considered models of the Carbon Cycle. But it isn't nearly as simple as the 'CO2 is plant food' meme would paint it. And the higher temperatures that go along with the extra CO2 aren't good. For a range of major crops, yields increase slightly for modets temp increases. Beyond that they start to plummet.
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MA Rodger at 08:04 AM on 5 April 2013Klotzbach Revisited and John Christy's response, part 2
In my view, the John Christy post on Wattsupia shows pretty dire scholoarship. Additional to the comment within the post here, I am left wondering about the likes of his comment "As noted however, several additional calculations confirm the value of 1.1 utilized by Klotzbach et al. 2010" when I spy not one "additional calcualtion" being "noted."
Or "hence closer agreement of absolute trends can imply greater disagreement with model results" which in some circumstances will be true but strangely not in this case. Indeed, in this case it is the exact opposite.
And his little table is hardly a useful way of comparing the trends and if he insists on its use it would perhaps also help if he learnt his 1.1 and 1.2 times tables.
Myself, I interpret his final statements (in which he turns his message into a comment on climate sensitivity and un-named negative feedbacks) as showing that Christy is simply unable to make sensible comment about the actual issue under discussion.
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Kevin C at 08:01 AM on 5 April 2013Klotzbach Revisited and John Christy's response, part 1
Thanks, I've got gridded data for all of them as part of another project. I'll add it to my to-do list.
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shoyemore at 07:47 AM on 5 April 2013The Fool's Gold of Current Climate
So "Let's have a little bit of global warming"
is much like
"Let's get a little bit pregnant"?
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John Fisher at 07:10 AM on 5 April 2013The Fool's Gold of Current Climate
Anthony Watts made the same mistake 3 years ago, commenting
"Actually a warmer planet with more C02 will in fact improve growing conditions, which is why that exact growing environment is created in production greenhouses."
Conditions in production greenhouses are monitored and modulated (drip lines, drainage, ventilation, etc). We can't simply open a 'space window' to let more heat escape!
Matt Ridley's talk reminds me of the Swedish politician who remarked--from his perspective--that a little global warming would be a good thing. He was later berated by an Israeli minister who called him self-interested twit.
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vrooomie at 06:55 AM on 5 April 2013The Fool's Gold of Current Climate
VictorVenema, I do not have close at hand links to help you get your ansewers but, free-air CO2 enrichment (FACE) studies have been done for a number of decades. I was involved a small bit in such studies at Biosphere II in the late 90s. Plant physiology is a well-known area, and there are thousands of papers on the subject.
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Tom Dayton at 06:52 AM on 5 April 2013The two epochs of Marcott and the Wheelchair
Tamino has evidence that if there were any spikes in the Marcott original data, they almost certainly would have been visible even after Marcott's processing: http://tamino.wordpress.com/2013/04/03/smearing-climate-data/
So much for the fake skeptic argument that the recent warming spike seen in the instrumental record might merely match or be less than spikes in that older record.
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bjchip at 06:50 AM on 5 April 2013The Fool's Gold of Current Climate
In a nation where half the population has a religious aversion to simple evolution, the conversions when Mother Nature actually starts hitting us with the consequences are going to be extreme.
We will go from their climate disbelief to a climate inquisition... the religion they accuse us of having will finally exist... in them.
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CBDunkerson at 01:27 AM on 5 April 2013The two epochs of Marcott and the Wheelchair
Dissident, the link you provide goes to the usual nonsense from Pielke and Lomborg. McIntyre has been pushing the same denials and sadly Revkin continues to give undue credence to the deniers.
Essentially, they are playing the same old 'data resolution' game that they do with every proxy study. The proxies used to generate the data in the Marcott study cannot give us temperature values in each and every year. There are gaps. Thus, it is theoretically possible that during one of those gaps there could have been a massive temperature increase, similar to the one we are currently experiencing, which then immediately reversed course and dropped back down to 'normal' in time for the next available data point. Note that they don't even try to provide an explanation of what could cause such a massive warming spike and then immediate cooling back to the prior temperature... because it is ridiculous. Nothing remotely like that has ever been seen or imagined. Further, they know full well that the warming spike we are currently experiencing will not be quickly reversed... rather, the temperature will rocket up and then stay there.
This boils down to one of the most common fictions of the deceivers... 'we do not know everything, therefor we are free to continue believing things we do know to be false'. We don't know exactly what the temperatures were in the 'gaps', so we can pretend that massive brief warming spikes happen all the time for no apparent reason and the current warming will quickly reverse... even though we know from basic physics that it won't.
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