Arguments
Recent Comments
Prev 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 Next
Comments 126201 to 126250:
-
smarkit at 04:41 AM on 9 December 2009The hockey stick divergence problem
One consequence of the divergence is to call into question the assertion continuouly made that this is the warmest period in centuries. One potential consequence of the divergence is that it is due NOT to anthropogenic causes, but in fact is due to a misunderstanding of tree's response to climate factors. If so, this would, for example, lead one to conclude that the Medieval Warm Period is not well represented in the proxy data. And if the MWP is underestimated in the proxy data, well, the hockey stick disappears. This is one of the reasons the proxy data was adopted in the first place.Response: The "take home points" re the divergence problem are as follows:- The divergence problem doesn't occur with all tree-ring proxies but mostly in higher latitude sites with low latitude sites showing less or no divergence
- When you compare high latitude tree-ring proxies that show divergence to the low latitude tree-ring proxies that have no divergence, the two track each other back to the Medieval Warm Period. This indicates the divergence problem is unique to recent decades.
- Most importantly, when you exclude tree-rings and only use other proxies, the same result is found - that the last few decades are warmer than any period over the past 1300 years.
-
Ian Forrester at 02:36 AM on 9 December 2009What happened to the evidence for man-made global warming?
Here is another: "Historical Changes in Lake Ice-Out Dates as Indicators of Climate Change in New England, 1850-2000" http://pubs.usgs.gov/fs/2005/3002/ H/T to Douglas Watts over at Tamino's.Response: Thanks for the link - I've added the reference above and also added it to the It's Not Happening page. -
Tom Dayton at 02:12 AM on 9 December 2009Measuring Earth's energy imbalance
guinganbresil, An improved but still imperfect insulator will let out a smaller proportion of the energy that is trying to escape. Not necessarily a smaller absolute amount of energy, because the amount of energy trying to escape is increasing. The balance between those two phenomena--more trying to escape, less proportion escaping--is what determines the absolute amount that escapes. But the analogy is not working well, because a boiler is not the same as a blackbody that gets all its energy from outside of itself. -
SNRatio at 00:41 AM on 9 December 2009What happened to the evidence for man-made global warming?
I feel a bit uneasy about the methodology when counting record highs and (in particular) record lows (Meehle 2009). I think a more robust statistic could be both less controversial and more informative. -
guinganbresil at 00:38 AM on 9 December 2009Measuring Earth's energy imbalance
Tom, as the insolating capability of the 'imperfect insulator' is increased it should let less heat out - not more. Also pretty plain and fundamental. -
pdt at 23:16 PM on 8 December 2009What happened to the evidence for man-made global warming?
""For 25years a very large number of scientists with vast amounts of funding have been trying to develop an AIDS vaccine and have so far failed on this single question." This argument is as false analogy." I agree. A more apt analogy is identifying HIV as being the cause of AIDS. I think there are even some people out there still denying that too. -
batsvensson at 18:05 PM on 8 December 2009What happened to the evidence for man-made global warming?
"For 25years a very large number of scientists with vast amounts of funding have been trying to develop an AIDS vaccine and have so far failed on this single question." This argument is as false analogy. The money spent on HIV control is not about quantifying measurement and establishing a new science but engineering a decease control. The problem space is well understood from a scientific point of view. HIV has two strands a slow mutating and fast mutating. It is the fast mutating strand that has not been controlled successfully yet. However, this is not a scientific problem but a social problem. (This problem can be solved if we want to, but we are not willing to use such methods as they are inhuman.) But in principle I agree with the line of thought; counting time and money spent as a measure on success isnt really the best measure stick, however it is indicative. -
batsvensson at 17:40 PM on 8 December 2009What happened to the evidence for man-made global warming?
As an added note to my previous post – contrary to what many may believe; to include 'god' as a factor in a theory isnt a violation of the scientific method, nor does it necessarily make a theory non-refutable. The reason god isnt included in modern scientific theories is because currently god doesnt add anything extra of interest to theory building. This is simply Occam's razor in action. -
batsvensson at 17:33 PM on 8 December 2009What happened to the evidence for man-made global warming?
Steven Sullivan wrote, "And btw, how would one show 'God did it' to be a false antithesis, by experiment?" It all depends on what criteria you assume as valid observation and the restriction you put on the observational data. Some people may claim "it" as new born infants. Do you consider this "it" to be non-refutable? As to address the main point of your post: The choice of a particular theory is not of importance, it is how the theory is formulated that matters. -
SuperD at 16:49 PM on 8 December 2009Climategate CRU emails suggest conspiracy
Whenever scientists fight disclosure - as is evident in the emails - everyone should be concerned. As for it being a couple of scientists, given they control the main temperature history used by the IPCC the fact that they are few in number is somewhat less relevant than the position they hold. I'm no scientist but it seems to me that in the CO2 caused global warming debate the temperature record is of a certain significance. I don't see why the temperature record including unadjusted data and methodologies should not be publicly available. After all we wouldn't trust a government to run an election, count the votes and then tell us who won. The main thing that the emails demonstrate is that the politics and science are very tightly intertwined. This serves politicians more than scientists. -
HumanityRules at 15:31 PM on 8 December 2009What happened to the evidence for man-made global warming?
Back to the science. Going down your bullet points, permafrost papers. Both papers you cited are modelling rather than measuring permafrost breakdown. Both papers identify precipitation rather than air temperature as possibly the most crucial factor. And if you read the abstracts both end with similar sentance, to paraphrase - much more work is required. In fact very little actual measurement has been done, given that this is 25% of the NH it seems amazing. One site that has tried to co-ordinate work is http://www.udel.edu/Geography/calm/index.html . They even have downloadable data sets. A very quick look at them shows no worrying trend, in many cases the trend is the opposite. I'd like to see this data analysed properly in a paper or if anybody here has the brains to do something. I get repetitive but the study of climate change amd permfrost seems at an extremely early stage.Response: Thanks for the feedback. Probably a better resource for permafrost temperature trends is Walsh 2009 which includes a handy table that summarizes recent permafrost temperature trends in various Arctic regions (Table 6.8). For a synthesis of studies on permafrost degradation, the best resource I've found so far is section 4.7.2.3 of the IPCC AR4. Kudos for following up the links, you must get less sleep than I do :-) -
HumanityRules at 10:15 AM on 8 December 2009What happened to the evidence for man-made global warming?
#25 ProfMandia Copenhaen Diagnosis is a prime example on when scientists flirt with politics. The preface is shameless about this being a propaganda piece "The report has been purposefully written with a target readership of policy-makers, stakeholders, the media and the broader public." It reports only one side of the debate. For example in the section "Carbon Sinks and Future Vulnerabilities" while mentioning the high uncertainty of this work it continues on as if this is a known fact and certainly in the bullet point summaries states this as if it is a fact. It does not attempt to present opposing views in perfectly respectable journals such as Knorr, W. (2009), Is the airborne fraction of anthropogenic CO2 emissions increasing?, Geophys. Res. Lett., 36, L21710, doi:10.1029/2009GL040613. Knorr suggest there is no evidence that this process is occuring an important consideration you would think. At what point does "carbon sinks are absorbing less CO2" becomes one of those 'known knowns' which can no longer be questioned. For 25years a very large number of scientists with vast amounts of funding have been trying to develop an AIDS vaccine and have so far failed on this single question. Yet in a similar time we are expected to believe that a whole body of science has been resolved. Abandoning uncertainty is a very dangerous process it leads to dogma. I don't wish to throw away the science but equally we should be aware that emotion and politics are driving this science as much as rational thought. -
ProfMandia at 08:53 AM on 8 December 2009What happened to the evidence for man-made global warming?
Discussions about the few details of AGW that are not well-understood take place in journals, conferences, and some blogs (Realclimate, especially). This site is the single best place to get the misinformation debunked. Do not forget the purpose of this site. John does a superb job of summarizing what the experts are saying - he is not doing the research himself. The IPCC AR4 reports, the Synthesis Report from Copenhagen, and the Copenhagen Diagnosis Report all summarize what has happened, what is happening now and why certain aspects are happening faster than expected. http://www.copenhagendiagnosis.org/ The main tenets of AGW are very "settled" just as those of evolution are. The forecast is much less certain but still certain enough and scarey enough to take action now. Debating the causes of global warming just delays the cure. -
Lee Grable at 08:34 AM on 8 December 2009What happened to the evidence for man-made global warming?
NewYorkJ,,,, Well said. kudos. -
NewYorkJ at 08:27 AM on 8 December 2009What happened to the evidence for man-made global warming?
Can anyone honestly say with a straight face that if their personal emails from the last 10 years were stolen, printed everywhere, and parsed by those looking for something bad, that there wouldn't be anything at all that might be easily misconstrued? How about if such emails were of discussions of scientific issues that require further expertise, context, and knowledge of the topic being discussed? Emails inherently are informal and lack context, and as we've seen from this incident, they've been very much abused and distorted for political gain. While John's broader point is more relevant, it's also not a good idea to ignore the above and simply concede the massive amount of distortion and slander that is being leveled at individual scientists. As the decade comes to a close, it would be nice to have a long post summarizing the evidence that has accumulated over the past decade, everything from resolving the surface to lower tropospheric satellite discrepancy, to Antarctic observations and deep ocean heat context. I think this post is an excellent starting point. -
Steven Sullivan at 08:13 AM on 8 December 2009What happened to the evidence for man-made global warming?
batvensson wrote: "A thesis (or intepretation) in science must be inferred with the excluded third: the interpretation will be held as true only after an experiment been conducted that shows that the antithesis is false. And the antithesis in this case is "global warming is due to natural variations". A thesis can also be inferred as likely to be the best current model when no credible competing model has been proffered to explain the data. In particular, no credible model based only on natural causes has passed muster to explain the observed trends in climate change. And btw, how would one show 'God did it' to be a false antithesis, by experiment? -
ProfMandia at 07:58 AM on 8 December 2009What happened to the evidence for man-made global warming?
Here is a strong right-hook back at 'em: http://www.youtube.com/user/greenman3610#p/u/0/P70SlEqX7oY Keep in mind that Europeans are far more knowledgeable about AGW than Americans, Canadians, and Autralians. The governments that were in power during the past decade have a lot to do with this. Here in the US, the Bush Administration was OPENLY anti-science. As Dylan says, "The times they are a-changin'." -
Blessthefall at 07:53 AM on 8 December 2009What happened to the evidence for man-made global warming?
"How can one be skeptical about man-made global warming when there is so much empirical evidence?" Considering this website is about as one-sided as one can be, this quote amazes me. This website makes a few assumptions that are flat out wrong: 1) The only studies that exist are the studies that show that man is contributing to climate change 2) Even if studies that refuted AGW do exist, they are wrong These are a few of the major flaws of this website, among many others. Also, people seem to be downplaying the CRU e-mail event. If a skeptical scientist had manipulated and thrown out data and refused to share data, I guarantee that the AGW crowd would be all over it. It really is astonishing that people are literally shrugging at the fact that some scientists have fudged the data. I would say more, but I don't want my dissenting comments to get deleted again. -
Mizimi at 06:54 AM on 8 December 2009Climategate CRU emails suggest conspiracy
Nicely put Riccardo, but unfortunately the few scientists involved were in positions of high authority which changes the dynamic somewhat. Public confidence will take a dive regardless, boosted by those who have opted out because their work has been (so they say) misrepresented/misused. -
Lee Grable at 06:02 AM on 8 December 2009What happened to the evidence for man-made global warming?
One other thought, since the actual science of global warming is settled, or as settled as science can be, there's a natural tendency among climate scientists to think that there's no debate. and thus to act accordingly. But there is a global warming debate. However one sided it is. The debate exists with the public, which is the only debate that matters. Nothing happens without public support. Or at least public apathy. Facism, communisism, Tyranny, dictatorships, slavery, you name it. None of it could have happened unless the public allowed it. Think about that. -
Lupine at 05:50 AM on 8 December 2009What happened to the evidence for man-made global warming?
This has been a PR disaster. I've been watching this unfold for some time, having started in our local paper (which has touting global warming conspiracy theories for years) and the problem with so-called "climategate" is that climatologists are letting the Denial community totally dominate the news. I hear talk of leaked e-mails, faked and/or altered/hidden data, politicians calling for investigations and claiming hoaxes. Honestly to the casual layman this looks really bad. Climatologists have to make the public understand, in simple terms, what's in these e-mails exactly, how many researchers are involved, what exactly the research they're talking about is, what it means, what it doesn't mean, and most importantly all the other evidence pointing to climate change. Otherwise the public is going to buy into the conspiracy theories and nothing will get done. -
Lee Grable at 05:26 AM on 8 December 2009What happened to the evidence for man-made global warming?
"This attack on an entire field of science is unprecedented". That's true, it's never happened before. What it also means is that the climate science community has no idea how to fight back. You've allowed yourselves to be backed into a corner, while the deniersphere is pummeling you, and all you can do is cower there, covering your heads,crying and whining cuz people are being mean to you. Now I don't know about anybody else, but I'm reluctent to come to the defence of someone who isn't willing to defend themselves. Even though I have, along with a lot of other people on other websites. Then I come here and find out that I'm being lazy cuz I'm not offering an explanation with the link to this site I'm providing. I can't repeat the first thought I had when I read that,but I think you get my drift. But back to my point, you've got to start fighting back. It's not like the deniersphere isn't handing you ammo. The "hide the decline" email is a perfect example. Ann Coulter in her latest op-ed, "quoted" the email thus,"I used a trick to 'hide the decline' in global temperatures since the 1960s". This is a LIE. Why aren't ya'll screaming that at the top of your media lungs?!?!?!? This is what's out in the media, this is what regular people, people who are too concerned with how they're going to feed and house themselves and their CHILDREN, are reading. People who are looking for any reason to have one less thing to worry about. And they'll stop worrying about the things that they can't see. Like global warming. So, either start fighting back, or shut up, cuz your losing the public. -
batsvensson at 03:43 AM on 8 December 2009What happened to the evidence for man-made global warming?
Imo, the CRU email has little or no bearing at all for the scientifically based critics. It does not add anything of interest and it doesnt withdraw anything of interest. It's just a curious side note in the protocol. However I can understand why some get upset about it, and this is the reason why they should be upset then: A thesis (or intepretation) in science must be inferred with the excluded third: the interpretation will be held as true only after an experiment been conducted that shows that the antithesis is false. And the antithesis in this case is "global warming is due to natural variations". Such experiment has been conducted – namely in simulated climate models. These models shows only a warming trend when human released CO2 is added to the model. I have no objection against accepting the simulation results, but then it should also be made clear that the conclusion is not based on an empirical evidence but a theoretical argument. Not every scientist, in particular experimentalist and field researches, is convinced about this theoretical predictions reliability and/or want to see empirical evidence supporting the theoretical predictions. But no such empirical experiment has been made so far. This is what the scientific criticism is (or should be) about The "broad view" argument, pointing at a long list of experiment showing global temperature increases, CO2 is an greenhouse gas and CO2 level increases etc etc, is nothing else than a long list of positive confirmations to the prediction made by models. From an epistemological point of view it adds nothing weather we have one(1) or one thousand experiment if they only are positive confirmation of this prediction, there is still the possibility of something else to be the cause, unless the antitheses can be experimental established. -
Alexandre at 00:16 AM on 8 December 2009What happened to the evidence for man-made global warming?
Here´s another paper, based on tropical glaciers, that already shows a reconstruction remarkably similar to the multi-proxy papers (see graphs on page 15): Thomson et al 2003 TROPICAL GLACIER AND ICE CORE EVIDENCE OF CLIMATE CHANGE ON ANNUAL TO MILLENNIAL TIME SCALES http://bprc.osu.edu/Icecore/Thompsonetal-climatic-change-2003.pdf -
Norman Wells at 21:34 PM on 7 December 2009Comparing CO2 emissions to CO2 levels
Norman wells I imagine my thinking is over simplified but it seems to me that when all fossil fuels have been exhausted,and the carbon therein released ,the Earth's atmosphere should contain approximately as much Co2 as it held when vegetable life began.Since plants were able to grow in those conditions,Earth's temperature could not have been so high that life could not be supported .Why then is there such great concern over the future effects of global warming ?Response: Because back when the Earth's CO2 levels were much higher than today, the solar output was also around 5% less than current levels. More on higher CO2 levels in the past... -
HumanityRules at 19:44 PM on 7 December 2009What happened to the evidence for man-made global warming?
#2 response In many ways there should be no boundaries to where these discussions should go. Although I can understand your impatience at the distrust shown by your mystery emailer. Do you want a discussion of the papers in your article? As a biologist, Parmesan 2003 interested me. Unfortunately it's a review which means the data is actually spread over dozens of other papers. So a quick look at them shows that most of the data is generated in Europe (in many cases naturalists in the UK), a little is in N America, I have found only one reference with data in the tropics (Costa Rica). This might put a big question mark over the "global" nature of the data. Having read a couple of papers throughout and a few abstracts I note several omissions from the review. ( numbers are Parmeson's references) 36 - equates most changes with nutrient/toxin (sulphates) changes rather than temperature (can only correlate with temperature over a five year period). 40 - shows flucuations in species correlated with changes in the NAO rather than a linear change to AGW. 22 - showed only 60 (rather than 279) plants flowered significantly earlier in recent times. While this paper showed greatest correlatiopn with temperature it also noted a correlation with NAO. 43 - The Costa Rica paper, this paper spend the whole time relating species change to precipitation (mist). But I do concede, and it is this sort of thing that baffles me the most, then relates this to temperature change. Unfortunately I don't have time to look at any others but I looked at these because they represented large numbers in Table 1 or were referred to multiple times. The case that this review is "global" or that it shows the fingerprint of AGW can be questioned. Personnally I don't distrust scientists. But I'm well aware they love to extract the maximum significance from their limited data. It helps to secure journals with a higher impact factor, very important to scientists. -
Tom Dayton at 18:05 PM on 7 December 2009CO2 effect is saturated
NkThrasher, that has been done. A long time ago, and repeated with increasing precision and thoroughness right up to currently. See the post How do we know CO2 is causing warming?; in that post, look in the green "Acknowledgements" box just above the start of the Comments section. Click on the link "laboratory measurements...". -
HumanityRules at 17:50 PM on 7 December 2009What happened to the evidence for man-made global warming?
It seems equally unfair to equate the rantings of one crazy rightwing senator with all those people who want a critical/depolitisized debate on the science. As it is unfair to say one email from one scientist represents the views/morals of the whole body of scientists. There's plenty to read here, I'm going to have to give up my day job!!! (the Hansen 2005 link seems broken)Response: I'll concede that Inhofe is one of the more extreme cases of global warming skepticism but he's certainly not alone in dismissing climate science. There are many examples in the media and blogosphere. One personal anecdote: I've been corresponding by email with one skeptic, having a constructive, reasonable discussion of the science. However, Climategate has him distrusting all climate scientists, effectively making any further discussion of peer reviewed science impossible.
Thanks for the tip re Hansen 2005 - I've fixed that link. -
NkThrasher at 17:41 PM on 7 December 2009CO2 effect is saturated
Wouldn't a much more useful test of a saturation point be, testing for a saturation point? This only seems to directly indicate that if there is such a saturation point, we haven't hit it yet, not that there is no saturation point to hit. I haven't been able to find anything to this effect, but a test in a laboratory using a similar method to observe the absorption rate of the same wavelengths passing through a chamber with various concentrations of the gasses we would expect to see in the upper atmosphere could show whether it does have an asymptotic behavior and thus 'saturates'? Just seems somewhat fishy that the logic goes "It could reach a saturation point!" "But it's still increasing as we increase the CO2, so there is no saturation point!", analogous to "If you eat too much candy you get sick!" "But I've been eating candy for the last 20 minutes and I continue to feel fine!" -
HumanityRules at 17:22 PM on 7 December 2009What happened to the evidence for man-made global warming?
Congratulations on getting on the BBC's list of recommended blogs.Response: Thanks for the link, I didn't know about that page, must be hot off the press (will "hot off the server" be a phrase used by future generations?). That page is a useful resource. -
bigdaddy at 14:58 PM on 7 December 2009An overview of glacier trends
Data: current North American Glacial Area 13080.6 sq.Km Overview of current North american Glaciation: Source: http://www.ccin.ca/cms/en/socc/currentGlaciers.aspx -
Tom Dayton at 13:30 PM on 7 December 2009What do the hacked CRU emails tell us?
And now greenman3610 has posted a video with a bit more technical detail (though with a bit less humor, unless you're a Beevis and Butthead fan). -
foram at 13:13 PM on 7 December 2009Al Gore got it wrong
I am astounded to see point 8 ("that coral reefs were bleaching because of global warming") included as an 'error'. I'd suggest you could safely add that one to the list of what Al got right. Yes, there are other factors that cause corals to bleach, but mass coral bleaching is accepted to occur as a result of higher-than-normal sea temperatures resulting from global warming. Leaving it to the experts: "The primary cause of mass coral bleaching is increased sea temperatures. At a local scale, many stressors including disease, sedimentation, cyanide fishing, pollutants and changes in salinity may cause corals to bleach. Mass bleaching, however, affects reefs at regional to global scales and cannot be explained solely by localised stressors operating at small scales. Rather, a ontinuously expanding body of scientific evidence indicates that such mass bleaching events are closely associated with large-scale, anomalously high sea surface temperatures. Temperature increases of only 1-2ºC can trigger mass bleaching events because corals already live close to their maximum thermal limits." (Marshall and Schuttenberg, 2006) Re: bleaching, climate change and temperature, the Australian Institute of Marine Science simply states: What is known: - Global climate is changing rapidly due to human activities and will result in continued rising temperatures both on land and in the sea. - Climate change due to the enhanced greenhouse effect has significant consequences for coral reefs. There is a direct link between unusually warm seawater temperature and bleaching of reef-building corals around the world. (http://www.aims.gov.au/pages/search/search-coral-bleaching.html) Some overviews of bleaching science containing dozens of references to the primary literature: Johnson JE and Marshall PA (editors) (2007) Climate Change and the Great Barrier Reef LINK In particular, see Chapter 10: Hoegh-Guldberg O, Anthony K, Berkelmans R, Dove S, Fabricus K, Lough J, Marshall P, van Oppen MJH, Negri A and Willis B (2007) Chapter 10 Vulnerability of reef-building corals on the Great Barrier Reef to Climate Change. In Climate Change and the Great Barrier Reef, eds. Johnson JE and Marshall PA. Great Barrier Reef Marine Park Authority and Australian Greenhouse Office, Australia Marshall and Schuttenberg (2006) "A Reef Manager's Guide to Coral Bleaching", Great Barrier Reef Marine Park Authority. LINK A few useful links: Great Barrier Reef Marine Park Authority (what is coral bleaching) LINK NOAA Coral Reef Watch (satellite based sea temperature monitoring for coral bleaching prediction) http://coralreefwatch.noaa.gov/satellite/index.html Status of Coral Reefs of the World http://www.aims.gov.au/pages/research/coral-bleaching/scr2004/
-
bigdaddy at 11:49 AM on 7 December 2009An overview of glacier trends
I have found an estimate of the North american Continental Ice sheet at the LGM,as measured in area, just in case any others might find this information usefull. " an area of about 15 million square kilometres (17.4 million, including Greenland ice)." For a full description here is the source: http://ess.nrcan.gc.ca/ercc-rrcc/proj4/theme1/deglac_e.php -
Tom Dayton at 05:58 AM on 7 December 2009What do the hacked CRU emails tell us?
Fantastic video on the hack! Posted on deSmogBlog.Response: Thanks for the link - have added it to the Climategate page (and what the hey, have embedded it here for ease of viewing). -
Mizimi at 05:55 AM on 7 December 2009What do the hacked CRU emails tell us?
Actually Chris, my original source was the BBC news - it has also been reported in the paper press as a resignation, but I accept that UEA press statement says he has stood aside as Director "until the completion of the Independent Review to ensure that CRU can continue to operate normally and the Independent Review can conduct its work into the allegations" -
chris at 04:44 AM on 7 December 2009What do the hacked CRU emails tell us?
no he hasn't Mizimi. He's stepped aside temporarily while the review takes place. That's pretty standard practice in this sort of circumstance. http://www.uea.ac.uk/mac/comm/media/press/2009/dec/homepagenews/CRUreview what strange places you go to, to source your "information"! -
Tom Dayton at 04:25 AM on 7 December 2009Measuring Earth's energy imbalance
guinganbresil, I think maybe your (admirably!) deeply detailed and technical thinking on this topic has distracted you away from the more plain and fundamental physical fact that an imperfect insulator will continue to let out a portion of energy that is accumulating. -
guinganbresil at 02:17 AM on 7 December 2009Measuring Earth's energy imbalance
Tom, I hate to be in a position of defending an analogy, but it does get to the root of my point. The OLR spectrum covers more than just the CO2 band. The total OLR (integrated over the spectrum) is the term that will affect the radiative balance - not just the CO2 band. If CO2 is the causative factor in radiative imbalance, it will need to dominate the overall OLR behavior. If the CO2 is not dominating the behavior of the total OLR then it could/would be an aggravating factor to other causative factors. This is CRITICAL to evaluating the applicability of predictions made by climate models. The figure 1C (Harries 2001) shown in "How do we know CO2 is causing warming?" is only showing the effect of trace gases. It gives the false impression that total OLR is going down. If you look at Harries figure 1B, it shows an increase in the range 750-1000 cm^-1 that clearly exceeds the decrease in the CO2 band. That is the "Non-CO2 hole" in the bucket. Harries explains the increase in this range as due to the effects of ice crystals not completely removed from the data set due to the differences in FOV between the IRIS and IMG detectors. This does not explain how the same effect is seen by Griggs 2004 and Chen 2007 with the addition of AIRS and TES data with different FOV's. Chen asserts that the behavior in the window region is not due to cloud contamination. Satellite measurements of total OLR also indicate an upward trend. To boil it down - looking at only the decrease in the CO2 15 um band and concluding that the overall energy balance of the Earth is controlled by that decrease neglects the effect of the non-CO2 regions of the OLR spectrum. The argument that the decrease in CO2 warms the Earth which causes the other regions of the spectrum to increase even more does not conserve energy. To go back to the dreaded analogies it is like saying that you wrap a space heater in insulation and the heater inside heats up (I agree) and the room outside of the insulation also heats up (I disagree.) I would agree with CO2 being the causative factor if the increase in the window region was less than the decrease in the CO2 band - that would make sense both with increased blackbody from a warmer Earth and still conserve energy. If more IR is being trapped by GHG's then the total OLR must decrease - this should be basic stuff - I am missing something? Look at Venus, OLR is ~150 W/m^2 compared to Earth's ~235 W/m^2... Riccardo mentioned an observed increase in OLR due to the recovery from a past transient and referenced Murphy (seen in response to #1 above). I am not aware of any historical records (Vostok etc.) indicating that we should be recovering from a large transient. The step response in Murphy shows an increase in OLR but ONLY AFTER the increase in CO2 stops. The OLR should be decreasing while CO2 increases if the CO2 is the causative factor. -
SNRatio at 00:15 AM on 7 December 2009Can you make a hockey stick without tree rings?
@leto, 42 My very personal opinion: Gather trustwothy anectdotal data, and proceed from there in whatever manner you have statistical justification for. If there were one proxy series of the type you are asking for, we would have known by now, I think. I can give you a couple of examples from Norway. In Halvdan Svartes saga, it is told that he drowned (about 880 CE) in Røykensvik in late winter when the ice broke under horse and sledge because of cattle being watered out on the ice and their droppings making the ice rotten. That means it can not have been much warmer than now, but not much colder either. In Eigils saga (ca 950 CE), Eigil Skallagrimson is ordered by king Håkon to take a trip to Vermland (now Sweden) to collect taxes. It seems to be about this time of year, and the saga tells us that the winter roads are cleared ('breyttir vegar'). Well, I can tell you, they are not frozen, so there is no way you can use those tracks right now, I happen to live along them. That piece of information indicates temperatures around or slightly below the 2000-2009 mean. This is all in line with the present consensus in Norway, that medieval temperatures were 0.5-1 oC higher than the 1961-1990 mean, which means about what we experience now. No amount of proxy reconstructions is going to change the historical record, and I guess quite a lot of good information is still to be gathered from careful analysis of anecdotal evidence. And the 'precision' you get from proxy reconstructions is most often illusionary. Just compare the different reconstructions. -
Leto at 23:20 PM on 6 December 2009Can you make a hockey stick without tree rings?
DeNihilist, Thanks for the response. I will look at the material in more detail, but I have already heard a lot from the anti-AGW (skeptical) camp. I am familar with the whole Yamal saga, which is part of the reason I do not trust tree rings. I am somewhat surprised I have not had any reply from the pro-AGW camp pointing me to one unambiguous non-tree proxy that fits the 'global hockey stick with local European MWP' pattern. This is, after all, supposed to be the scientific consensus, or so I'd been told. Is there such a proxy? I would have thought, from the title of this thread, that such proxies did exist. Reconstructions based on combined data don't carry the same evidential weight for me, I'm afraid. I'm not saying data can't be combined but there is always room for human subjectivity and confirmation bias to creep into the combination process. I repeat, I am not not trolling to make a point here. I would just like to know if there is any firm ground to stand on before launching into my own analysis of the more complex statistical methods. Leto. -
bigdaddy at 21:12 PM on 6 December 2009An overview of glacier trends
An excellent read, Thanks for the suggestion.However, not much information of the sort i am seeking. -
bigdaddy at 19:30 PM on 6 December 2009An overview of glacier trends
well, perhaps, I have other use for this data than the current climate change issue, wich i do.Thats why i was hoping someone could help me.I am specifically looking for North American continiental deglacition rates from the point in time of its southern most advance to the present day.estimated original mass,percentage of the original mass that exist today.wether it be tables, graphs etc. Im not sure that such estimates even exist.However, you have knowledge i dont wich points that its far far greater than it was in time frames of geologic scale. perhaps you could provide those geologic time frames you work with ? I have to start somewhereResponse: I don't know of tables or downloadable data but one paper How sensitive is the world's climate? (Hansen 1993) examines the period when the Earth fell into the last major ice age, calculating the change in Earth's albedo due to growing ice sheets. Should be worth a read - a good introduction to the concept of climate sensitivity also. -
Tom Dayton at 19:01 PM on 6 December 2009An overview of glacier trends
bigdaddy, the point is that the changes we are experiencing now are far, far faster than those in more geologic time frames. That's the point, and that's the problem. -
Leo G at 18:51 PM on 6 December 2009Can you make a hockey stick without tree rings?
how about isotopes from tree rings? http://www.arctic.ucalgary.ca/main/documents/media_release_pdfs/Analysis%20of%20isotopes%20in%20tree%20rings%20can%20reveal%20past%20climate%20events.pdfResponse: This seems to be a developing technology (or to be more precise, an existing technology that has become more affordable) so hopefully this will provide a lot more proxy information in upcoming years. -
Leo G at 18:37 PM on 6 December 2009Was there a Medieval Warm Period?
Anyone know if there has ever been a search through the monastic enclaves of europe/middle east, etc. for any kind of climate/temperature data from before instrument period? -
Philippe Chantreau at 18:24 PM on 6 December 2009Can you make a hockey stick without tree rings?
Blair, watch that program again and read some books. You are extremely confused. Levels of CO2 "hundreds" of time higher than preindustrial would be at or above 56000ppm; care to point when exactly was that happening? And look at that word again from a good source. It's Neanderthal. -
bigdaddy at 18:12 PM on 6 December 2009An overview of glacier trends
Additionally, if any could resolve Mr.Lindzens concerns about climate modeling,as expressed in this article. http://online.wsj.com/article/SB10001424052748703939404574567423917025400.html?mod=googlenews_wsj -
bigdaddy at 17:55 PM on 6 December 2009An overview of glacier trends
Pardon me gentlmen,Its my initial observation that your discussion is based on relatively short spans of time. Could any point me in the direction to obtain graphs of N.A.contitnental ice sheet deglaciation rates in more geologic time frames? -
blair at 17:44 PM on 6 December 2009Can you make a hockey stick without tree rings?
As far as I can see, from my perspective, the issue is not the rise in temperature, rather, what is its cause. Now, I haven't gone through all of the postings above, but it appears that little, if anything, is said about the CO2 levels. There was a program on PBS regarding mankind and our evolution. To summarize, our precursor was nethanderals. The great ice age gradually forced the nethanderals further south as a consequence of impact of great droughts. Further, statements (not in this program) have been made to effect, the CO2 levels during this period were 100s of times greater than the CO2 level today. (One wonders what brand of SUVs the nethanderals were driving?) Yet, there was an ice age. Anyhow, the survivors ended up on eastern mid-Africa. Out of the survivors, came us, the homosapiens (shades of Darwin). Indeed, our genes have nethanderal traces. The next item that is relevant to this issue of warming is the reaction time of influences. Just because you give your car gas, it doesn't mean that in 1 second you will be going 60 mph. Likewise, how long does it take for a car going 60 mph to stop. Let alone the other issue of relaxation time. i.e., once the influence is removed, how long does it take to go back to the previous level. To continue, I think that the next few winters are going to be interesting regarding the CO2 hypothesis. So far, this winter is starting up as a cold one, even though there have been forecasts of a warmer NE. To summarize, I think that that the CO2 people still have to make their argument. Certainly, their postings and data manipulations have not given a lot of people the feeling that their science is objective.Response: "the issue is not the rise in temperature, rather, what is its cause. Now, I haven't gone through all of the postings above, but it appears that little, if anything, is said about the CO2 levels"
This is because proxy records tell us what temperature has been in the past, not what's causing the temperature changes. But as you say, attribution is indeed the central issue of global warming - I would go so far as to say the hockey stick controversy serves as a distraction from the more crucial observations that rising CO2 levels are causing an enhanced greenhouse effect which is the main contributor to global warming.
The issue of relaxation time is also an important point that is rarely discussed. In an earlier post, we examined the whole concept of climate time lag and "warming in the pipeline".
There is also a detailed examination of the argument that CO2 has been higher in the past.
Prev 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 Next
