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A Glimpse at Our Possible Future Climate, Best to Worst Case Scenarios
curiousd - "Should I take these results as encouraging some optimism?"
Given that Eemian conditions included temperatures ~3°C higher than todays (in range for a 3-4°C rise if we don't change our emission practices), No, that's not encouraging.
A few papers have recently suggested that Greenland apparently did not melt as much as previously thought during the Eemian. Which indicates that Antarctica, the other major store of ice, may be more vulnerable to temperatures than we thought - that portions of the West Antarctic ice sheet (and perhaps part of East Antarctica) melted during that period - otherwise the 5-7 meter sea level rise seen during the Eemian couldn't have occurred.
Whatever the source, 5-7 meters of sea level rise is still going to have a huge impact.
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curiousd at 14:11 PM on 20 February 2013A Glimpse at Our Possible Future Climate, Best to Worst Case Scenarios
Here are a couple of interesting links to the conditions during the Eemian, after the penultimate ice age glacial minimum, I think?
http://www.sciencedaily.com/releases/2013/01/130123133428.htm
also
http://cordis.europa.eu/fetch?CALLER=EN_NEWS&ACTION=D&RCN=34734
Peer reviewed results show that during the Eemian the temperatures attained were higher than now, and the Greenland melting, though serious, was less than one would expect for those temperatures under today's conditions. (Perhaps the nature of oceanic circulation was different?)
Should I take these results as encouraging some optimism?
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calyptorhynchus at 14:02 PM on 20 February 2013In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats
About 20 years ago I picked up a copy of the Skeptical Environmentalist in a bookshop and opened it at random. My eye fell on a sentence in which Lomborg stated that we didn't need to worry about tropical deforestation because forests in the temperate latitudes were expanding.
'Nuff said.
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Bob Loblaw at 13:53 PM on 20 February 2013In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats
In my reading of Lomborg's stuff,the thing I was always bothered by was that he would compare the costs of averting global warming with the costs of achieving a reduction in one adverse factor via different methods - but he would do them one at a time. For example, if the effect of global warming was reduced crop yields, he'd compare the total cost of averting climate change with a cost of doing something like increasing agricultural productivity through breeding or irrigation, or some such. And he'd say it was cheaper to just invest in technology to maintain crop yields.
The catch was that He'd make the comparison over a number of climate-related efects, but he'd keep treating the cost of preventing climate change as if it was a new cost each time - he'd never factor in that we'd already paid that cost when we solved problem A, and we don't need to pay it again when we want to solve problems B, C, and on up to Z. Yet the alternative "solutions" never got added up to see what the total cost was. Even if preventing climate change costs Y=20*X, and you have a hundred X's that are solved with one cost Y, he'd always compare one Y to one X, not one Y to 100 X's.
Speculation as to whether he knew he was doing this falls outside the comments policy.
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Bob Loblaw at 13:34 PM on 20 February 2013Reconciling Two New Cloud Feedback Papers
Citizen 7 @ 6: "could someone explain why these trailing clouds look so different from the contrails I remember seeing in my youth"
Answering a question with several other questions:
- how long ago was it that you were a "youth"? That could be 10, 20, 30, or 70 years ago.
- where were you a "youth", and is it a different place from where you are today?
Why am I asking? Well, contrails form because aircraft engines give off water vapour (combustion byproduct). Under the right conditions (air close to saturation), the vapour will condense to liquid water or sublimate to ice crystals, forming contrails. If there is enough mixing in the air, the contrails will rapidly dissipate and be thin and short-lived. If the air is very stable and very close to saturation, the contrails may last quite a while and be quite thick.
The appearance of the contrail will depend on the amount of water vapour released, the local temperature and humidity, and the local atmospheric motions - which can depend on the height the aircraft is flying at, the current weather, and the season. The amount of water vapour released will depend on the fuel consumption, which depends on engine and aircraft design and efficiency.
When I was a "youth", there were still a lot of piston-engined aircraft around. Now, there are highly-efficient jets that often fly at higher altitudes. A lot of factors to consider, only some of which relate to the atmospheric conditions.
[...speaking as a professional atmospheric scientist and former amateur pilot...]
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DSL at 13:29 PM on 20 February 2013Reconciling Two New Cloud Feedback Papers
And yet, Sph and DB, the actual, well-documented conspiracies (reviewed in Merchants of Doubt) are simply ignored. Too much evidence, I guess. Takes all the mystery out of it.
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Miriam O'Brien (Sou) at 12:34 PM on 20 February 2013In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats
Agree with Citizen 7. I call it 'short-termism'.
I got to thinking about this issue because Lomberg et al don't factor in the medium to longer term impacts of 'waiting'. (And even then I'm only thinking medium to long term in regard to human civilisation - centuries and millennia, not to the entire earth timespan which would be hundreds of millennia to billenia.)
We've set in train long term ecological changes - loss of biodiversity, changes to waterways and long term warming. It's as if the Lomborg's, Pielke Jrs etc only see twenty or thirty years ahead (and even then are blinkered to system-wide impacts) instead of looking ahead on the century and millenia time scale.
As Citizen 7 implies, economics is not the right tool. We need to do a lot more work to develop a more holistic and far-sighted discipline to address this critical situation. This will probably mean stepping back from human-centric disciplines like economics and putting more emphasis on earth system studies, while providing some sort of 'translation' device with the human-centric disciplines for practical implementation. (Not sure where I'm heading with this one - better minds that I are undoubtedly working on it.)
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Rob Honeycutt at 12:34 PM on 20 February 2013Reconciling Two New Cloud Feedback Papers
Citizen 7... You're actually breaking the very first rule of science in saying contrails look different to you today than they did just a few years ago. That rule is: Don't trust your senses! Human perception is the worst measuring device known to man.
If you think there "might" be a difference, what you have to do is find a way to test that hypothesis. Find a way to measure the phenomenon you believe you're seeing. Find ways where you can make sure your perception is not fooling you.
This statement is immediately suspect: "...who will kind of nervously maintain that the skies have ALWAYS looked like they do now. No, they have not."
When you start from a position that you are correct before you have methodically tested that your perception you're merely listening to your need to find something there, regardless of whether something is there or not.
You state, "In some cases the "conspiracy theory" label is used to prevent people from demanding good scientific explanations for what they see..." But you do not yet know for sure that you actually see what you believe you see.
Before you test your idea you can do nothing but get into a battle of different faulty perceptions. I've been around a good number of years. I'm a GA pilot so I've long watched the sky for cloud formations and with special interest in aircraft. I have never noticed a change in contrail formations.
But I would also not rule it out until I saw strong empirical evidence one way or another.
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Citizen 7 at 12:17 PM on 20 February 2013In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats
To compare "GDP" with the physical and biological changes resulting from glbal warming is to make a serious category mistake; you're comparing two different ontological modalities, two different modes of existence, something that exists independently of our human beliefs, desires, and expectations--the biosphere, the Earth System--and something whose existence is entirely dependent on our human beliefs, the abstractions of economics, all of which will vanish when we humans no longer tread the Earth, and which may come about all the sooner if we continue to take them for concrete reality. As a professional philosopher, I am always amazed when scientists, whom one would expect to be pretty hard-nosed about what exists in the physically actual world and what doesn't, fails to mark this obvious distinction.
The important thing to understand about our socially constructed reality, our economics, politics, word-and-number games and the like, is that we humans can change these creations of ours. The physical and biological world, on the other hand, we screw around with at our peril. What is the meaning of "money," "cost," etc. when the stability of the system that supports our actual lives is at stake?
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Miriam O'Brien (Sou) at 11:49 AM on 20 February 2013In Wall Street Journal op-ed, Bjorn Lomborg urges delay with misleading stats
There seem to be a number of people saying that GDP is projected to increase faster than damage from global warming - and then say let's wait because we will be better able to pay for the damage as it happens in the future.
I don't see the analysis of the interaction between the two. It's as if the aforementioned people see GDP growth and global warming travelling on separate paths and never intersecting, which doesn't make sense to me. As adverse weather events become more common and worse, surely there will come a point where the cost of reparation and recovery starts to affect the gross domestic product, and GDP will not rise as projected and probably start declining.
What is needed is to do what we can now to avoid that situation, which can only happen if we both cut carbon emissions as well as prepare for worse droughts, floods, storm surges, fires etc.
When rebuilding after floods and cyclones in developed nations at least, building codes and planning schemes are usually altered to increase resilience for the future. During a drought desal plants and added water storage are built or planned. So that part is already happening to some degree.
I suspect that many planners/decision-makers are finding it difficult to envisage what a two degree rise will bring though. People like Lomborg (and Pielke Jr) aren't helping.
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Citizen 7 at 11:48 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
Thank you, Sphaerica, for the references; the longer Nature Climate article by Burkhardt and Karcher is especially informative. I notice that they speak of contrail cirrus as "a new cloud class," at least for their model, however, and their first set of graphics shows significant foci of young, linear contrails almost exclusively over Europe and eastern North America, something that seems to merit more explanation unless the air traffic in those areas is much, much greater than elsewhere. And I'm pretty sure I did not observe these prominent, persistent bands of clouds in the sky overhead before just a few years ago, whereas I see them regularly now--did the amount of air traffic go up suddenly? I am wondering about how new this phenomenon is, and why the geographical concentration--is there a clear correlation with the quantity of air traffic, over both time and space? Does anyone have data about this?
I also appreciate the information from Daniel Bailey that the atmosphere has "some 4% greater humidity levels" than 40 years ago--is that a direct result of global warming, or are there other factors involved? I can see how such a change might lead to a different appearance of the trails left by aircraft between now and then, though presumably such a change would have been slow and gradual. Would you say this is the primary reason they appear so prominent now?
There seems to be quite a bit of scientific uncertainty about this phenomenon, given the numerous qualifiers in the paper, but I am very glad to read a serious scientific discussion of it, rather than encountering the kind of immediate denial/debunking response I've had from some, who will kind of nervously maintain that the skies have ALWAYS looked like they do now. No, they have not. I think it's important--and surely what is required for good science--to stay with the testimony of our own eyes rather than yield quickly to "what others say," as in the Solomon Asch experiments (e.g., http://www.age-of-the-sage.org/psychology/social/asch_conformity.html). In some cases the "conspiracy theory" label is used to prevent people from demanding good scientific explanations for what they see, such as the sudden and perfectly symmetrical descent of WTC 7, when official versions seem to be lacking in explanatory power (as apparently at least one of other the posters here--funglestrumpet?--seems also to have noticed.
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Daniel Bailey at 10:56 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
I hear ya. I hear there's even a blog post on some blog somewhere detailing those kinds of conspiracies...and others...
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Bob Lacatena at 10:44 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
My goodness... there's a conspiracy for everything, isn't there?
I'll bet there's even a conspiracy to spread conspiracies (thus hiding the one, true conspiracy that they don't want us to figure out).
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Daniel Bailey at 10:37 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
As to why contrails now may appear differently than those from yesteryear, consider that the atmosphere today has some 4% greater humidity levels than that of just 40 years ago. Since contrails are essentially water vapor, that will effect dissipation and spreading.
This site is a useful reference for more information on contrails (I use it to debunk the chemtrailers):
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Bob Lacatena at 10:27 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
Citizen 7,
The exact effect is unknown. In daytime, contrails reflect sunlight and so have a cooling effect. In both daytime and nighttime, contrails also have a warming greenhouse effect.
Airplane Contrails Boost Global Warming, Study Suggests
Global radiative forcing from contrail cirrus -- Ulrike Burkhardt and Bernd Kärcher
Airplane contrails worse than CO2 emissions for global warming: study
Atmospheric science: Seeing through contrails -- Olivier Boucher
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Jsquared at 10:08 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
dana1981@5 - There has to be some good physics in that order-of-magnitude difference in the size of the responses. What could be so different in the short-term and long-term response of water vapor? All that comes to mind offhand is that aerosols don't have a chance to do their thing - nucleation - in the short-term response, or maybe it's a latitudinal effect built into the CERES and MODIS measurements? It's a little hard to give either one much credence.
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Citizen 7 at 10:03 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
I am new to this site and I hope you will forgive the naivete of this inquiry, bt I would like to know if the large, wide swaths of cloud left behind many airliners are having a negative or positive effect on global warming, or perhaps less confusingly (since a positive, feed-forward effect would be "negative" for us) are they, as per the diagram, low enough to be reflecting more sunlight or high enough to be trapping more heat? Also, could someone explain why these trailing clouds look so different from the contrails I remember seeing in my youth?
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scaddenp at 09:41 AM on 20 February 2013Geologic Time and Climate Change Science
Firstly, it takes 1000s of years to melt an icesheet. Milankovich-cycle driven climate change is very slow compared to modern climate change so the warming persisted long enough for it to happen. Maintain current temperatures and we will get there.
Second, dont assume that Roman optimum was global. If you look at say Schaefer et al 2009 you will see it was cold down here. -
dana1981 at 09:41 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
danp @2 - sorry, I don't have Dessler's paper on me, so I can't clarify. That was a comment Dessler suggested that I add when he reviewed the post, and I didn't focus on that part of the paper, so I don't recall the details.
Jsquared @4 - yes, we're talking about the cloud feedback in response to global warming here.
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william5331 at 08:50 AM on 20 February 2013Geologic Time and Climate Change Science
Slightly off topic, something (amongst a long list) that puzzles me. Are there any indications why sea level during the Eemian interglacial was about 5m above present sea level. What led to the extra melting of Greenland and, as now seems likely, the collapse of the West Antarctic Ice Sheet. How come we didn't get to these sea levels by, say, the Roman times.
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Citizen 7 at 08:11 AM on 20 February 2013Geologic Time and Climate Change Science
I question the choice of graphing geological time in a closed-circle fashion around the calendar year, as if the Earth's evolution is coming to an end, presumably with us humans writing the final chapter at the end of the Quaternary, as the Holocene becomes the Anthropocene and then, boom, it's Dec. 31st. If we do in fact push the Earth System into a "state shift" (http://www.nature.com/nature/journal/v486/n7401/abs/nature11018.html), it will not be the end of physical evolution on the Earth, nor is it likely that Life will come to an end--it will just be knocked back for some millions of years, as with other major extinction events, tho it will be too bad for us and our our own evolutionary cohorts.
Also--hope this is not too much "off topic," since i'm a new arrival here from the Climate Ethics website--what thoughts do folks here have about waking our species up to what it's doing and bringing about a change in the whole paradigm that dictates how we organize our human activities? I can envision a kind of discontinuity or "fold bifurcation" in the evolution of how we humans think coming soon too, but I believe it's something we can speed up if enough of us focus our collective intentionality on making change.
Moderator Response: [rockytom] One can think of the top of the circle as being open to the future. I guess you can show it without drawing the vertical line. The line at the top was not intended to be the end of the world as we know it and there are even more elaborate circles and spirals drawn to represent geologic time. -
Jsquared at 08:07 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
I'm a little confused about where the earlier stuff - AR4, for example, had the effect of clouds as overall fairly negative (something like 44 W/m2 SW reflected vs 31 W/m2 LW retransmitted downward - fits into this newer work.
Am I correct in saying that Dessler and Loeb and Zhou are actually looking at what happens to cloudiness and its effects on the short-term radiation balance as the climate changes ('inverse sensitivity', from the units they use), and the AR4 numbers apply to global averages over the long term? The 'inverse sensitivity' numbers don't make a lot of sense otherwise (for example the 44 W/m2 of SW reflection by clouds is supposed to cool the planet by ~12oC, giving 3.7 W/m2/K, compared to the more recent values that are about 10x smaller.
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scaddenp at 05:13 AM on 20 February 2013We're heading into an ice age
One further word. It is fortunate that this area isnt a global proxy because the authors present evidence for a temperature rise of over 2 degrees in just 59 years during 2nd century. That would have been bad on a global scale! I wonder if Kevin has actually read the paper and how he feels about the way that the paper has been represented on his "skeptic" site?
The clear link between temperature and drought in the region doesnt bode well for its residents.
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Richard Lawson at 04:54 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
If MODIS does not see clouds at night, that is pretty significant, because clouds at night have no albedo effect (=negative feedback) and so their only effect can be their insulating property (=positive feedback). So no wonder MODIS evaluations show more negative feedback.
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scaddenp at 04:35 AM on 20 February 2013We're heading into an ice age
On closer reading, the "current weather" in figure of (11degree) was chosen to be that of just the station at Mountainair, since the proxy record from C3 regression closely matched the values for that station.
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Dikran Marsupial at 04:17 AM on 20 February 2013No alternative to atmospheric CO2 draw-down
Kevin also questions the substantiation of this comment:
"This article suggests that the current atmospheric CO2 level is already triggering amplifying feedbacks from the Earth system and therefore, in themselves, efforts at reduction in atmospheric CO2-emission are no longer sufficient to prevent further global warming."
However this would seem to me as to be so basic an issue as not to really need further substantiation (i.e. it should be background knowledge). That there are positive feedback mechansims ought to be pretty well known:
- Water vapour feedback - water vapour is a GHG, and a warmer atmosphere supports a higher water vapour concentration. This is perhaps the main reason why equilibrium climate sensitivity is likely to be arounf 3 degrees per doubling od CO2, rather than the 1 degree per doubling that can be calculated as the direct effect of the CO2 emissions themselves.
- Albedo feedback - Arctic sea ice reflects much more visible light from the sun back into space than the dark sea water underneath. So as Arctic sea ice declines, in response to GHG warming, the Arctic is likely to warm faster as a result of the decreased albedo.
- Methane is a GHG, and there is a fair bit of it currently trapped in Arctic permafrost. As the permafrost melts, methane is released and we get more GHG and more warming.
So there are three positive feedback mechansims for which there is already evidence of having been triggered, that anybody interested in climate change ought to know about already. Do they really need to be pointed out every time positive feedback is mentioned?
The second part "...efforts at reduction in atmospheric CO2-emission are no longer sufficient to prevent further global warming." also seems fairly uncontraversial to me as well. The increase in greenhouse gasses has created an imbalance in the planetary energy budget, and warming will continue until the planet warms sufficiently to restore this balance (which is why there is a distinction between transient and equilibrium climate sensitivity), which will take some time due to its thermal inertia (see here for further info). So we are committed to some additional warming even if all GHG emissions were to stop immediately. If we want to avoid this warming that is in the pipeline, we need to do something else to restore the energy balance, such as increasing the albedo (space shade) or active carbon sequestration.Please take some time to read the list of "most used climate myths"; you may find that your understanding of some of the fundamental issues is not as strong as you may think it is.
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danp at 04:10 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
Thank-you for this summary of these recent papers. As one who does not have access to these paywalled documents, I really appreciate your efforts to bring the science to more people.
I am confused by one part of the post. If I understand correctly, Dessler (2010) and Dessler and Loeb (2013) both used CERES data. Zhou et al used MODIS data. The post comments on the benefits and shortcomings of both data sets.
However, the post also states: The Dessler and Loeb (2013) "paper was also intended to investigate the conclusions of Masters (2012), which argued that, using other datasets, one could get a strong negative cloud feedback. Dessler and Loeb (2013) showed that this result was due to problems in the CERES data..."
Do Dessler and Loeb (2013) show Master's (2012) results to be because of a problem in the Ceres data? Or in the manner Masters (2012) treated/handled/analyzed those data?
Thank-you.
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dana1981 at 02:15 AM on 20 February 2013A Glimpse at Our Possible Future Climate, Best to Worst Case Scenarios
Old Mole @37 - the RCP scenarios begin in 1750 (often defined as "pre-industrial"), but there wasn't much use in showing the 1750–1900 timeframe, since humans had little temperature influence prior to 1900.
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gws at 01:05 AM on 20 February 2013No alternative to atmospheric CO2 draw-down
Kevin, whether the author is right or not about
"The scale and rate of modern climate change have been greatly underestimated"
(note that this statement is not about temperature only as you seem to think)
is obviously an ongoing question. There is evidence that the IPCC has been quite conservative in its projections, so aside from the arguments made in the article itself, the claim is supported by ongoing CO2 emissions tracking the business as usual scenario (follow the link to the GCP, where they list several related peer-reviewed publications), and generally conservative scientific assumptions about the developments and changes following that scenario.
Your question
"If the temperature rise is not underestimated, and the CO2 rise rate doesn't threaten species, why is removal of CO2 required."
is puzzling. First, whether the temperature rise is underestimated or not, the rise in itself follows from first principles of planetary energy conservation and is of concernin any case, but especially at the rate it is happening. Second, the literature is full of negative effects of increasing [CO2], including "threatening species" such as those that cannot cope with decreasing ocean pH values.
Do you advocate for ignoring rising CO2 and T ?
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Dikran Marsupial at 00:16 AM on 20 February 2013No alternative to atmospheric CO2 draw-down
Kevin, if that is the problem, then why not simply ask "please can you give a reference to a paper that demonstrates that the rate of temperature increase is underestimated (or provide additional justification)"? As I said, the unnecessarily abrasive tone that you have chosen to adopt is doing you no favours here.
In response to my pointing out that many of the links refer to peer-reviewed papers, you counter with "The first link goes to the home page of the Global Cabon cyProject, not a reviewed paper.". This is just argumentative for the sake of it. Firstly I said that some of the links are to peer-reviewed papers, the obvious corrolary being that some of them are not. Secondly, the Global Carbon Project is a perfectly reasonable resource for verifying the truth or otherwise of what was being claimed, so your assertion that "backup is lacking" is absurd in this case, and you are making it look as if you are merely here for an argument, rather than for a genuine discussion of the science.
Regarding Fig.2, they give a link to the actual paper, which itself includes references to all the data sources, so again that complaint seems to me to be merely quibbling.If you read academic papers, you will find they sometimes include a degree of specilation/discussion that is not directly backed up by references, so expecting chapter and verse at the end of every single sentence is unrealistic. Do you reuire this standard from the other climate blogs you visit?
Please, if you have an issue with the science presented here, then ask questions, ask them politely in a moderate scientific manner, and don't assume that something is wrong just because it seems to disagree with what you have read elsewhere. -
meb58 at 00:06 AM on 20 February 2013Reconciling Two New Cloud Feedback Papers
But one question remains, not matter what the temperature does, more co2 in our envirnoment means that our environment must buffer this change.
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Kevin8233 at 23:51 PM on 19 February 2013No alternative to atmospheric CO2 draw-down
Actually, if you follow some of the links embedded in the article, they will take you to the supporting peer reviewed articles
There is no link provided to a peer reviewed paper which states that the rate of temperature increase is underestimated. This is a claim of this article.
The first link goes to the home page of the Global Cabon cyProject, not a reviewed paper.
While fig 1 does link to a Hansen Paper (reviewed of course), fig 2 links to a paper by Glikson, with no publishing information.
One of the main parts of the article, the link to Glikson's article on "The Conversation" about "rates to which species could not adapt", is also just a blog, not a peer reviewed paper.
These are the main problem statement aspects of the paper. If the temperature rise is not underestimated, and the CO2 rise rate doesn't threaten species, why is removal of CO2 required.
I did not state that his paper is wrong. I am just pointing out that his backup is lacking.
Note ** I did not mean to violate comment policy by using all caps on the use of the quote "suggest", I was just highlighting that that was all the article could do, was suggest. I will not all cap anything again.
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gws at 18:57 PM on 19 February 2013No alternative to atmospheric CO2 draw-down
All, there is a good review article here:
Climatic Change, December 2011, Volume 109, Issue 3-4, pp 745-790, A review of geoengineering proposals,by Naomi E. Vaughan, and Timothy M. LentonSummary:Yes, this is possible, mostly through biomass (re-)growth, use, conversion (to biochar), and combustion (plus sequestration!);yes, this will take time, andyes, an international effort is needed.An no, no fancy new technology has to be invented, just political will. -
Dikran Marsupial at 18:42 PM on 19 February 2013No alternative to atmospheric CO2 draw-down
Kevin wrote "This whole article is an opinion piece. There is no back up to it.". Actually, if you follow some of the links embedded in the article, they will take you to the supporting peer reviewed articles. It is a shame that you seem unable to restrain your hubris, as I have pointed out, you will get a far better reception if you were to make your point in a more civil manner. We are happy to discuss science here, including scientific views that go against the concensus; however few of us here want SkS to be the sort of rhetoric-laden content free waffle seen at so many climate blogs.
So state your case, calmly and without rhetoric, and you will fare much better than you are now. -
Tom Curtis at 17:27 PM on 19 February 2013We're heading into an ice age
scaddenp @305, thankyou. Allowing that the mean for a portion of the state may not match the mean of the state, but that the anomalies are likely to be close, we can shift the state anomalies down by 0.9 C to give them the same mean as the local stations. In that cast, the 21st century average to date is 0.8 C greater than the mean for July, or an estimated 0.65 C greater for the annual average. The peak July averages are 1.9 C greater than the mean, for an estimated annual average 1.6 C greater than the mean.
On these figures, peak medieval warmth in a small part of New Mexico is may be just greater than the current warmth. That is not certain, however, as the NCDC data represents only a 117 year record, and as the additional 17 years required to match are almost certainly cooler than the mean, the differentials are underestimated.
I don't think anything else in my analysis requires correction.
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scaddenp at 17:01 PM on 19 February 2013We're heading into an ice age
Tom, I have access to the paper. Let me know if interested though it doesnt seem that interesting to global temp proxies for reasons you have outlined. Their weather data is based in 34-130 year records from stations within 100km, though for that diagram, it appears to be based on closest station at Mountainair, 160m higher than the study area. I dont think the authors put much stock on the absolute values but are instead focussed on the patterns - hot/dry v cool/wet, and particularly in the speed and severity of local climate change in 2nd century.
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chriskoz at 15:49 PM on 19 February 2013Geologic Time and Climate Change Science
the first 4 billion years or so is little known compared to the last .5 billion years
I though it was typo until I spotted the dot when I pasted it here :). it'd better be "last 500 million".
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chriskoz at 13:44 PM on 19 February 2013There is no such thing as climate change denial
Well said Tom,
Consilience or convergence or concordance of evidence would all have been more precise phrases here (and would need to be used in a scientific report) but the term "climate science consensus" has been stuck for so long in popular media that we all subconciously know what it means.
It would be nice if MohamedY@18 pointed out to John that his popular term is imprecise and suggest the precise alternative from above but "I stopped reading [because this term] is BS" is not only impolite but perhaps abusive and even moderation might be in order here.
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Tom Curtis at 12:50 PM on 19 February 2013We're heading into an ice age
Kevin @302, the first thing to notice is that the modern average is not necessarilly the average over the last few decades. Indeed, by convenction, in paleographic studies the present is 1950 unless otherwise stated. The article your denier propaganda site refers to is behind a paywall, so I am unable to determine which interval was used to determine the "modern average". I am able, however, that they determine an annual average temperature as a function of the reconstructed July temperature, and that their modern annual average of 11 C corresponds to a July temperature of 22 C. Further, the warmest temperature they show for July approximately 2000 years ago (see Table 2). The NCDC shows the twentieth Century average of July temperatures in New Mexico to be just under 23 C, so it appears the "modern average" is below the average over the 20th century. For comparison, the average over the last decade to be around 23.5 C (the equivalent of a mean annual temperature of 1.25 C above the twentieth century mean). The peak modern July temperature is 25 C, the equivalent of 2.5 C above the "modern average". In other words, it appears that the reconstruction does not show temperatures higher than that of the late twentieth century at all. (Treating studies showing warming greater than 1950, or in one case 1895 as being warmer than the late twentieth century has been a common denier trick.)
Second, if you look at the following graph you will see that warm and cold periods at different locations do not coordinate in time. Ergo simply picking out a location and saying it was warmer at some time in the past, and then a different location and saying it was warmer in the past does not tell you anything about whether the global average is warmer. To do that you need a multiproxy reconstruction. Oddly deniers have been unwilling to make multiproxy reconstruction despite all the purported examples of warmer temperatures in the past they claim to have found. Note that I say purported because what deniers claim, and what was actually found in the scientific study often differ widely (as shown above). I personally suspect that this unwillingness to make reconstructions is because the deniers know that any such attempt will give the game away.
There is one exception to the rule about deniers and reconstructions. Loehle (2007), and in particular as corrected by Loehle and McCulloch 2008 (Link for both papers). There are a few oddities about that reconstruction. First, many of the proxies used had previously been used by Moberg 2005, who Loehle cites as a source. Not all of Moberg's non-treering proxies were used, however, as shown in the graph above. One wonders why Loehle found it necessary to develop a methodology that excluded the Agassiz Ice Cap and Arabian Sea proxies, for example.
Of greater concern is that Loehle simply takes the average of all proxies to determine his reconstruction. The problem with that is found in this map of the location of his proxies (from Loehle and McCulloch 2008):
A quick count shows that 10 of his 18 proxies come from around the North Atlantic; another 4 come from China, and two each from Indonesia and South Africa. That is, they are heavily localized. Simply taking a mean of the values treats the North Atlantic (including Europe and North America) as though it constituted 56% of the Earth's surface; China as though it were 22%; Indonesia and South Africa as though they were 11% each; and the entire rest of the globe as though it did not exist.
What is even odder is that reconstructions using more widely dispersed proxies have shown where was warm, and where cool in the MWP. Curiously the distribution of proxies used by Loehle gives most weight to the area that was warmest, the next most weight to the next warmest area, and zero weight to any area that was known to be cool. It is an extraordinary coincidence.
And despite all these biases, it turns out that Loehle's reconstruction still shows a RWP and MWP cooler than the late twentieth century (note the instrumental record shown as a dashed line):
It is no wonder deniers don't like reconstructions.
And it is also no wonder that people who are interested in science want to see them; because if you haven't made the effort of making a reconstruction, you have not analyzed which intervals are warmer or cooler than others. At most you have attempted to pull wool over peoples eyes with an assortment of random facts.
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scaddenp at 11:38 AM on 19 February 2013We're heading into an ice age
Your point? Global temperature reconstructions are estimated from a network of proxies from locations around the globe. If you think this one place is significant, then why do you deny the significance of other proxies, or those places where ice retreat is exposing bare rock for first time since HCO ?
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Steve8234 at 11:05 AM on 19 February 2013Geologic Time and Climate Change Science
Here is my attempt to illustrate the vast evolutionary timeline, not the geological timeline. (I know it's know outdated).
http://andabien.com/html/evolution-timeline.htm
You can find a desciption of an imaginary movie, taking one year to view, depicting evolution on earth.
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JasonB at 10:57 AM on 19 February 20132013 SkS Weekly News Roundup #7
As Chomsky has pointed out, it is illegal in America, for the CEO or other employees of a publically quoted company to do anything other than to try to maximise the stock value of their company, and thus profit to shareholders.
Sorry for being OT, but is this really true? "Illegal", to me, implies statutes to that effect. Does America really have statutes requiring CEOs to do nothing other than to try to maximise stock value, or is it in reality something taken as implied by their normal fiduciary duty, possibly coupled with some common law precedents where shareholders have sued directors?
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Tom Curtis at 10:02 AM on 19 February 2013There is no such thing as climate change denial
John Cook @20, I don't think this has anything to do with your being a physicist. People scoring merely verbal points by obtusely not recognizing a metaphore when they see one is a product of those people desperately clinging to beliefs for which they have no real evidence that they could adduce.
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scaddenp at 09:02 AM on 19 February 2013There is no such thing as climate change denial
"Consilience" is a excellent term - well defined and accurate. Perfectly applied to climate science.
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John Cook at 08:28 AM on 19 February 2013There is no such thing as climate change denial
Re "consensus of evidence", I try to be poetic and the literalists jump all over me. Maybe this is what happens when a physicist tries to get creative with language. I could've said "consilience of evidence" but most people respond "consili-whatnow?!"
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gws at 08:22 AM on 19 February 2013No alternative to atmospheric CO2 draw-down
Kevin, maybe you can enlighten us about what your actual complain is?
The author says it his first sentence, which you quoted ("This article suggests ..."), what he is going to be writing about, then makes a coherent argument with references to primay literature. You do not do anything of that kind, so why are you here?
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Andy Skuce at 07:25 AM on 19 February 2013Geologic Time and Climate Change Science
The excellent "fingernail" analogy, which rockytom uses was first used (I think) by John McPhee in his wonderful book Basin and Range, which I would recommend to everyone. Stephen Jay Gould ( no slouch himself when it came to writing on science) later used the metaphor in his book Time's Arrow, Time's Cycle. His version, as quoted on the Wikipedia article on Deep Time is as follows:
Consider the Earth's history as the old measure of the English yard, the distance from the King's nose to the tip of his outstretched hand. One stroke of a nail file on his middle finger erases human history.
I touched on the importance of understanding deep time and basic geological principles in my SkS article on my own struggle to come to terms with climate change.
More recently, Andrew Glikson has shown here how current anthropogenic processes are proceeding at a rate far faster than past natural processes.
Moderator Response: [rockytom]You are correct, Andy. It was McPhee's use of the analogy that I was thinking of when I wrote the above post. Stephen Jay Gould was one of my favorite people and he also used the analogy. I guess I don't know who first used it. I met Gould in the mid 1970s and was saddened by his untimely death. -
Kevin8233 at 07:17 AM on 19 February 2013No alternative to atmospheric CO2 draw-down
This whole article is an opinion piece. There is no back up to it.
The scale and rate of modern climate change have been greatly underestimated
The leaked AR5 shows that this statement is not true, and no, I don't think it's required to link to that, as it is in many places. There was even a discussion here on Ridley's predictions being wrong, with the IPCC's being closer - but ALL above the actual temp. So the author's statement is clearly wrong. Where is his back up? (-snip-)?
This article suggests that the current atmospheric CO2 level is already triggering amplifying feedbacks from the Earth system and therefore, in themselves, efforts at reduction in atmospheric CO2-emission are no longer sufficient to prevent further global warming.
Again, without any backup, this is just opinion. The author can (-snip-) anything he wants. Where is his proof that amplifying feedbacks are already triggerred, and more importantly, where is his proof that a reduction of CO2 is no longer sufficient.
Moderator Response:[DB] Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.
Moderating this site is a tiresome chore, particularly when commentators repeatedly submit comments in violation of this site's Comments Policy. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.
Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues will be the offing.
Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.
All-caps usage and moderation complaints snipped.
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Don9000 at 07:06 AM on 19 February 2013Geologic Time and Climate Change Science
Good work, Chris!
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Kevin8233 at 06:25 AM on 19 February 2013We're heading into an ice age
And finally, why do you regard evidence that it was warmer then than now in just one region of the world (evidence you have so far failed to produce) as proof that it was warmer than globally rather then now?
http://hockeyschtick.blogspot.com/2013/01/new-paper-finds-new-mexico-was-warmer.html
This paper shows temps from New Mexico area.
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