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Tenney Naumer at 23:05 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Sorry, forgot to say that this was a really excellent post. -
Tenney Naumer at 22:49 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
I'm pretty sure that the figures (from a 2008 pub) for the portion of mass balance loss due to melt runoff are dated. Newer studies indicate that the runoff is moving closer to half of the mass balance decline. This makes sense since the edges of the ice sheet are retreating rapidly, reducing feed to the outflow glaciers, while at the same time the melt lakes and moulins are increasing in size and quantity, and quite rapidly these days. Sorry, I don't have that study at the tip of my fingertips, it's somewhere on my blog, for sure, but others may be aware of it. -
Berényi Péter at 22:29 PM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
#30 michael sweet at 12:29 PM on 31 July, 2010 Since we measure an energy imbalance at the top of the atmosphere (TOA), this is strong evidence of global warming. Come on. We do not measure it in any meaningful sense of the word. Why disseminating misinformation? AMERICAN METEOROLOGICAL SOCIETY March 2009 BAMS | 311 EARTH’S GLOBAL ENERGY BUDGET by Kevin E. Trenberth, John T. Fasullo, and Jeffrey Kiehl "There is a TOA imbalance of 6.4 W/m2 from CERES data and this is outside of the realm of current estimates of global imbalances" That is, energy imbalance at the top of the atmosphere (TOA) is measured to be 6.4 W/m2, but that's impossible. Therefore accuracy of measurement is so low, that imbalance is not measured at all. Precision is a bit better, but that only gives temporal changes of TOA imbalance, not its absolute value. As far as radiation measurments are concerned, imbalance can even be negative, that is, Earth would lose heat instead of gaining it. It's only computational climate models that tell us otherwise, not measurements. OHC (Ocean Heat Content) measurements are also consistent with a negative energy balance. -
Doug Bostrom at 21:12 PM on 31 July 2010Waste heat vs greenhouse warming
Almost to "Music of the Spheres," as I predicted. RSVP, have you ever heard of "cosmic microwave background radiation?" -
huntjanin at 20:35 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
For Daniel (no. 5): Thanks very much. I'm writing an introductory survey on sea level rise and, being a mere generalist, need to rely on the kindness of strangers like you. Would you have any interest in reading (I can't pay you anything) my draft Preface, which describes the IPCC; draft Introduction, which tries to be a primer on global warming; and/or Chapter 1, which seeks to explain why sea level rise is important. If interested, please contact me off line at huntjanin@aol.com -
kdkd at 19:08 PM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
BP #108 I can see a significant problem with your hypothesis, to wit: CO2 fully mixes in the atmosphere, and as a result its effects are global. Black soot does not, so its primary effects are local. Do the climate models predict and observations confirm the local effects consistent with black soot playing a major role in climate change to date? Well because black soot is an indirect solar effect, we might expect it to be observed most in the day time if it was the major driver of climate change. However, instead we see more warming at night which is a signature of increased greenhouse gasses. Nice try, but it's yet more trying to chip around the edges to give an illusion of greater than justifiable uncertainty. You especially need to get rid of the emotional expressions that hint at conspiracy theory ("for God's sake, why"), and to stop presenting hypothesis as conclusion. -
muoncounter at 16:33 PM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
#30: "This heating up is Global Warming. Since we measure an energy imbalance at the top of the atmosphere (TOA), this is strong evidence of global warming." Here is additional direct evidence of global warming (and I must thank BP in the prior thread for his remarks about snow cover (comment #91) for reminding me about that dataset. Look at the NH snow cover for wintervs. the NH snow cover for spring
While I'm not a fan of straight line trends through such data, let's accept them as is for the sake of discussion. The winter snow extent is thus virtually constant; the spring decreases significantly. Hence for any given melt season, the difference (spring min areal extent - previous year's winter max areal extent) is increasingly negative from year to year. Similarly, for any given snow season, the corresponding difference (winter max areal extent - same year spring min areal extent) is increasingly positive. We have just described an oscillating system (winter max to spring min to winter max) with increasing amplitude. In such systems, increasing amplitude requires a gain in system energy. This begs the question: What supplies the additional energy, especially during a 50 year period of declining solar radiation?
This figure was discussed at length here. Answer: As less energy is available from the sun, an increasing percentage of that energy must be stored in the atmosphere/oceans from year to year and thus they are getting warmer. None of those 'questionable' temperature records needed! Oh but wait a bit, the temperatures say the same thing.
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RSVP at 16:28 PM on 31 July 2010Waste heat vs greenhouse warming
In my Universe, there are no "orphan" photons. It is a tidy Universe. If, for instance, stars radiated without a destination for each photon, there would be a photon clouds collecting in the furthest reaches of space. This of course is not the case. So as it turns out, you all live in my Universe, which from the comments is apparently quite tramatic. -
Daniel Bailey at 16:16 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Hunt: The latest paleo records indicate that the last time CO2 levels were similar to today's was about 15,000,000 years ago. Ellesmere Island in the Canadian Arctic sported boreal forests and enjoyed winters similar to parts of Southern Canada or Southern Alaska (mild winters, but still some snow). Greenland would have been largely ice-free, resulting in a nearly 6-meter sea level rise. Of course, this much of a rise from Greenland's ice loss would have already triggered a commensurate ice loss from the WAIS in Antarctica (conservatively, a composite 9 meter sea level rise - not that the extra 3 meters would matter). Remember, central Greenland is below sea level, so once the sea makes a meaningful entry through the coastal mountain ranges, it's game over for the ice sheet. With no way to reverse CO2 rises from current levels (we can't even figure out how to slow emissions, let alone how to make CCS work), the Greenland ice sheet is Dead Man Walking. How quickly? (shrugs) No one knows. The rate of mass loss is rising quickly, with no indication that it will stay uniform. Some indication in the paleo record indicates severe losses have occurred in less than a century's time (multiple-meter rises in sea level). Again, once the sea gains access through the coastal ranges, it's done. As the sheet offloads the ice, isostatic rebound of the basement rock increases (it is already doing so). Ice quakes on the sheet are recorded routinely (none significant). Possible tectonic activity could occur at some point in response to the offloading. As the Guardian link mentions, as far as sea level rise is concerned, the 1st meter of rise is the most important. If it happens too quickly, every sea level city in the world is done. Mark Lynas' 6 Degrees is a must-read (link to review provided). We are basically at 1 degree now, locked in for 2 more; the remaining debate is if it's possible to avoid the Full Monty discussed in the link. Alley's Biggest Control Knob lecture a must-see (link also provided) for an internalizing of the effects of CO2. Check out these references (not a comprehensive listing, of course, but representative of 15-minutes searching can provide): Why Greenland's ice loss matters Greenland ice sheet won't collapse Is Greenland gaining or losing ice? Greenland used to be green What links the retreat of Jakobshavn Isbrae, Wilkins Ice Shelf and the Petermann Glacier? Glaciers melting so fast, a generation will be too late Six steps to hell CO2 biggest control knob The Sermilik fjord in Greenland: a chilling view of a warming world Ice Sheets Can Retreat 'In A Geologic Instant,' Study Of Prehistoric Glacier Shows Greenland - No Ice Greenland - IPCC - Ice Melt I remember bookmarking a rotatable 3D animation someone had created of Greenland with no ice, but no luck on finding it with this tired brain tonight. Dig through this stuff for a start. Digest what you don't already know. Anything I can help you with, let me know. The Yooper -
huntjanin at 15:10 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
If you can handle a question from a real beginner, what, if anything, is the relationship between the Greenland ice sheet, carbon dioxide, plate tectonics, and sea level rise? -
jyyh at 13:33 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Is there anyway of knowing how much this stuff is in the Greenland? http://www.reuters.com/article/idUSTRE66S57H20100729 I would believe part of the meltpools drain in this kind of reservoirs, once filled, they'll burst like some subglacial volcano lake. -
michael sweet at 12:29 PM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Barry: The Earth is currently in energy imbalance. Less heat is emitted than received from the sun. To restore the balance, the Earth must heat up so that the same amount of energy is emitted as received (the Earth emits more heat when it is warmer). This heating up is Global Warming. Since we measure an energy imbalance at the top of the atmosphere (TOA), this is strong evidence of global warming. -
Eric (skeptic) at 12:13 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Has anyone figured out what temperatures were achieved in the models used by Stone 2010? Specifically I am wondering about the 400 ppm scenario and how it would get so warm as to melt a lot (or most in one particular case) of Greenland's ice by 400 years from the present. -
Berényi Péter at 12:03 PM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
#100 chris at 04:16 AM on 31 July, 2010 It's [black carbon] a significant but small fraction of the forcing from enhanced [CO2]. Consider this Hansen paper for example. doi: 10.1073/pnas.2237157100 PNAS January 13, 2004 vol. 101 no. 2 423-428 Soot climate forcing via snow and ice albedos James Hansen and Larissa Nazarenko "It seems likely that East Asia snow has large BC amounts, because China and India are now the largest sources of BC emissions, and photographs reveal a thick brown haze filled with BC that butts against the Himalayas (22), but measurements are lacking." At the same time according to the testimony of prof. Tami C. Bond before the House Committee on Energy Independence and Global Warming of the United States House of Representatives on March 16, 2010, black carbon emissions from Asia alone are larger than from the rest of the world combined.Unfortunately, as Hansen & Nazarenko states "measurements are lacking" (for God's sake, why?). Therefore it is very likely their assessment heavily underestimates the effect of black carbon on global climate, especially on NH snow cover, even if they admit "for a given forcing it [black carbon] is twice as effective as CO2 in altering global surface air temperature". The effect of that "thick brown haze" is indeed global, far from just "butting against the Himalayas".
The root cause of diminishing climatic effects of black carbon or even neglecting it entirely seems to be a preoccupation with carbon dioxide. If soot had a large effect, it would not leave enough room for CO2 in model calculations.
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David Horton at 11:55 AM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Excellent summary Ned. Do we also have a good handle on fluctuations in the more recent period? Your "around 24,000 years before present, when it covered an area 40% larger than its current extent" implies that since then it has gradually retreated to its present extent, but I assume not below? Obviously I ask because of the constant and long standing denier refrain about Greenland being "green" 400 years or so ago - the implication being that the ice sheet rebuilt to its present extent in just the last 200 or so years - an astonishing achievement! -
papertiger at 11:50 AM on 31 July 2010Mars is warming
I notice that the link to the ice core on Mars from comment 1 is defunct, so here's another. Same picture, a bit more stylishly presented. It shocks me that after close to three years, numerous rewrites, you still haven't come close to refuting my original comment. -
michael sweet at 10:26 AM on 31 July 2010Waste heat vs greenhouse warming
I agree with Doug. I find it very hard to believe that after almost 300 posts on this subject, with at least a dozen independent simple explainations, RSVP really cannot understand the basic physics of the greenhouse effect. I think he/she is having us on and seeing how long s/he can keep us going. -
Doug Bostrom at 09:29 AM on 31 July 2010Archibald’s take on world temperatures
You're articulate but incorrect, Doug Proctor. Your premise seems to hinge on the notion of a temperature rise since the 1850s but as you can see even just a few posts above (muoncounter's temperature/sunspot/C02 vs time graph) the instrumental record does not support your idea. As to correction bias, you must have missed this recent post here on Skeptical Science. -
Doug Proctor at 07:45 AM on 31 July 2010Archibald’s take on world temperatures
The planet is warming, has been since the 1850s. The warming of concern with AGW is only from about 1965, when the level of CO2 emissions (and atmospheric retention) reached the level the IPCC models said would cause significant warming, especially because, they claimed, water vapour would magnify the CO2 related temperature rise. But the temperature rise from 1850 to 1965 was "natural". No reason was given for it, but for whatever reason it happened, it was presumed to have stopped. All temperature rises since 1965 were attributed to CO2 and its multiplier. Moreover, the temperature rise seen was considered exceptional and a "runaway" issue that would have catastrophic effects for man and the biosphere. The "proof" was the approx. 0.7C* rise since the 60s. The problem with the CO2 "problem" is that ALL of the rise since the 60s has to be due to CO2 or there is no MANMADE crisis. If a portion of the pre-1960s temperature rise mechanism is still in effect - and I can think of no reason why mechanisms effect for the last 10,000 years should suddenly stop with the introduction of the miniskirt - then 0.7 becomes 0.5. And if the correction bias has some validity, and it sure looks like it does (old get colder, new gets warmer, and more corrections are for warming than for cooling, regardless what NOAA claims), then 0.5 becomes 0.4 for CO2. But 0.4 for 45 years makes only 1 degree or so per century. That is not a disaster, and even if it were added on top of "natural" rises, the disaster as such would not be anything that cap-n-trade or some such restriction on fossil fuel consumption could fix. The single villian for current climate warming is climate science's best hope for governmental green-policy implementation, but it is also its fundamental weakness. Any quarter given to "natural" forcings, or correction bias invalidates CO2's Joker-like villany. Gore, Suzuki and Hansen cannot discuss or argue the subject without leaving themselves open to admitting that natural and artefact issues have SOME bearing. Considering the +/- precision of the data, the "some" has to be significant when the temperature rise is so small. We declare War On Drugs when the Mafia or Cartels are behind what's on the street, not when it is some punk with a couple of plants hidden in his father's corn fields. If CO2 is not responsible for 90% of the claimed effect, then it is not a supervillian and CO2 suppression is not crisis-worthy. A reasonable, two-step back view, says that there is no man-responsible, CO2 based, catastrophic temperature rise. We live in a multvariant world; a single solution is simply a dream of the naive or agenda-driven. -
John Russell at 07:27 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
thingadonta at 18:07 PM on 30 July, 2010: The last link you provide (http://anhonestclimatedebate.wordpress.com/2009/05/30/scientists-blame-sun-for-global-warming/) is a 2009 blog that uses as evidence an old BBC article dragged up from Feb 1998. That article refers to 'scientists at a meeting' of the American Association for the Advancement of Science but gives no details of who they are. I think you'll have to do better than that if you want to persuade anyone. -
KR at 07:25 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy - Two additional comments/questions. El Niño/La Niña - This is a cyclic phenomena, a redistribution of energy. It doesn't create or destroy energy, just moves it around for a year or two. It also doesn't correlate temporally with the temperature increase since 1850 - we've been through a lot of cycles since then. You would need a 300+ year cycle (at least 150yrs up before reversing) to account for that increase, and there is no evidence whatsoever for such a cycle. The added global temperature (and especially the increasing ocean heat content) point to an energy accumulation, which as it so happens matches the top of atmosphere radiative imbalance. Data matches theory, oddly enough! Secondly, if you have some theory for CO2 increase that doesn't include industrial emissions from fossil fuel consumption - present it! Of course, this source will have to account for the match between fossil fuel consumption and CO2 ppm increases, ocean acidification, and provide the isotope distribution that we are currently attributing to fossil fuels. I eagerly await what you have to say on this topic. -
KR at 07:12 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy - I believe that muoncounter and in fact John Cook here on Skeptical Science have already pointed out the problems with the stomata data. It has extremely high variance, great dependence on other factors, and as an proxy for CO2, simply isn't as reliable as direct CO2 measurement from ice cores. High CO2 in the past is certainly a driver - but then there are other drivers such as solar output. The combination of the different forcings correlates quite well with temperature - it's not a single variable equation. Lastly, as to ice levels: We have continuous input (snow) and continuous output (melt and calving) from the various glaciers, ice shelves, ice caps, etc. - constant turnover. A 1 oC temperature rise can certainly change the output rate, leading to loss over time. It's not a transition temperature we're looking at, but a rate adjustment over a continuum. Although if we do reach some kind of transition point (whether albedo feedback, sufficiently reduced glacial backpressure, etc.), I expect these rates to change much faster than they have been. -
Daniel Bailey at 07:05 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Re: Geo Guy @ 102 In reference to your contention of CO2 levels in the Ordovician not corresponding to temperatures, see Skeptic Argument # 104 here for a thorough treatment. Only 15 more to the end of the list... The Yooper -
chris at 07:04 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy at 06:33 AM on 31 July, 2010 That's not correct Geo Guy. The Scotese graph has got nothing to do with fossil stomata. Since I've linked to the original paper you can see that for yourself (look at Figure 13 in the Berner paper I linked to in my post above and read how this model was constructed; you'll see it's the same as in the Scotese graph you linked to). You're also wrong about the Ordovician. I linked to a skepticalscience page that discuss Ordovician CO2/temperature relationships. Your assertion is incorrect in the light of contemporary evidence. Click on the link. Unsupported assertions about the "thermodynamics of dense glacial ice" have zero explanatory value. It seems a shame not to make use of the abundant scientific evidence that bears on these subjects...it's silly to say stuff that is obviously and demonstrably untrue! -
Geo Guy at 06:57 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
doug_bostrom # 101 - I would agree with you on your statement and I'd place myself into the first category that you list. I am there because I believe there is a fair bit of data that would suggest while man made CO2 might be contributing to global warming, there are more natural factors that a driving the process than simply greater CO2. For instance there is evidence that solar winds can be a strong indicator of variations in global temperatures. SOLAR WIND NEAR EARTH: INDICATOR OF VARIATIONS IN GLOBAL TEMPERATURE; Theodor Landscheidt; Schroeter Institute for Research in Cycles of Solar Activity; Proceedings of 1st Solar & Space Weather Euroconference, 'The Solar Cycle and Terrestrial Climate', Santa Cruz de Tenerife, Tenerife, Spain, 25-29 September 2000 (ESA SP-463, December 2000) Another contributing factor to global temperatures is the el Nino effect. While a lot of studying has been done on the phenomenon, nobody has actually come out with a reason as to why it happens. We also know that over time. when an el Nino is in effect, it has an influence on global temperatures which I believe, if taken into account, the rise in temperatures since 1900 would not be as acute. I too have my own theory that can account for the increase in atmospheric CO2, and that the theory precludes the accumulation of CO2 from ground sources. Now if this theory holds true, then the whole purpose of the IPCC is thrown "out the door" which would make a lot of third world country leaders pretty upset.Moderator Response: Geo Guy, if you want to argue with KR about El Nino, do so not on this thread but on It’s Pacific Decadal Oscillation. -
Daniel Bailey at 06:51 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Re: Barry @ 16 Yes, the radiation equation must be in balance. In the case of increasing CO2 concentrations, that balance occurs at the TOA (Top Of Atmosphere) at increasing height relative to lower concentrations. Chris Colose has many useful things to say about this at his blog Climate Change. Posts are available for varying levels of comprehension. Even I can understand some of them. :) The Yooper -
Geo Guy at 06:33 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
chris # 99 - the Scotese graph is simply a plot of results obtained by other studies involving stomata so I don't see any reason to dispute the information. The CO2 data he presented is from studies done by a variety of other scientists and contrary to your assertion that the CO2 data are based on weathering rates, they in fact are based on assessments of fossilized plant stomata. Perhaps you would do yourself a favour by spending some time to understand how stomata studies are undertaken. Certainly they cannot be any more flawed than the study of tree rings! As for the other reports, it is very likely the authors can come up with a positive relationship between atmospheric CO2 and temperature. The graph I post the link to does have periods where such a relationship appears to occur. However that in no way is definitive that if atmospheric CO2 rises so do temperatures. A case in point is the CO2 content for the Ordovician (4,00 to 5,000 ppm) while the earth experienced a well documented ice age. IF high CO2 results in higher temperatures, that relationship should appear throughout geological time. Such a relationship does not appear to exist hence the role CO2 has in rising temperatures should be questioned. As for my evidence as you requested in # 100, its simply that the thermodynamics of melting dense glacial ice cannot substantiate a 1 degree increase in local temperatures as the driving force behind the melting. It is more likely attributable to increased solar radiation combined with a weakening of the earth's magnetic field that are playing a significant role in what we are observing in our climate today. Finally as far as glaciers go, what we observe today is the result of events that happened 20 or 30 years ago and not from current temperatures etc. Regarding black carbon and its role in the melting of the ice cap on Greenland, National Geographic recently published an excellent article that goes into detail as to the role of carbon, where it originated from (China) and its effect on the Greenland ice cap. I doubt that the role has been fully integrated into scientific assessments as this information is relatively new. -
BaerbelW at 06:16 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Thanks, KR and Alexandre! I had checked the German Wikipedia-entry for Billion and it calls this term a "false friend" because it has different interpretations depending on where it is used (no mention of Australia and ambigious information for the UK). Unfortunately, there wasn't a direct link to an English article, so thanks much for your link, KR. -
Alexandre at 06:09 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
BaerbelW - 30 billion tonnes = 30*10^9 = 30 Gt = 30 milliarde Tonnen -
Alexandre at 05:56 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Great resource for a climate change presentation. Thanks John. -
Doug Bostrom at 05:42 AM on 31 July 2010Waste heat vs greenhouse warming
That microwave oven remark leads me to believe RSVP is just having us on. Specifically, RSVP knows of impedance matching but somehow cannot grasp the functional difference between thermal emissions and EM as it pertains to tuned circuits? Humoring RSVP I could ask, if a transmitter's antenna is radiating at a peak power of 100kW and the antenna of another transmitter radiating at 50kW on the same frequency is pointed at the first antenna, does the RF from the 2nd antenna "know" that it must not arrive at and resonate with the first antenna? And what's the effect if the phasing is arranged perfectly, or less so? And what's all that got to do with... hang on, -what- was the original topic here? But that's not going to work, because RSVP is going to bring up something else. Next thing I know I'll be talking about the Music of the Spheres or some such, following the Pied Piper of Prevarication. I can't even say "I'm all done with this" because if that were the case I certainly wouldn't be visiting this thread. Oh, what a sticky web RSVP weaves, heh! -
KR at 05:37 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
BaerbelW - that 30 billion should be 30*10^9. 30,000,000,000,000 would be 30*10^12, or in English/American usage 30 trillion. -
BaerbelW at 05:32 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
While working on the German translation for John's neat graphic, I became unsure of what "30 billion" stands for. Is that 30,000,000,000 (as in the US) or 30.000.000.000.000 (as in Germany)? At a guess it's the number with "only" 9 zeroes, but I'd like to make sure as it either translates to "Milliarde" or "Billion".Response: 9 zeroes -
cbrock at 05:21 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
Robert Way, the Evans paper appears to be a conference proceeding, and might be no more than an abstract. Not peer reviewed. -
Tom Dayton at 05:07 AM on 31 July 2010Waste heat vs greenhouse warming
Oh.... I can't let your contention go without response, RSVP, because it isn't even basic physics textbook material--it is microwave oven owner's guide material. An empty microwave oven does not refuse to emit microwaves. Instead, the emitted waves bounce around inside the oven and (potentially) feed back onto the emitter, creating havoc. Just Google "run microwave oven empty." Sheesh. -
Doug Bostrom at 04:26 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy, don't forget that the spectrum of skepticism (disregarding the actual definition of the term) includes both those who believe the globe is warming but don't agree with mainstream attribution of that warming as well as those who don't believe the globe is warming at all. This site deals with both issues, so some of the discussion here is going to touch on topics devoid of attribution, rather only to do with various signals indicative of warming. At some time we'll probably see the former group disavow the latter but for the time being it's rather a muddle; some people go as far as to say there's no way C02 can help warm the globe and there's no warming in any case, others say it can but not much, still others say the globe is not warming but C02 could help it do so, etc. Meanwhile there's the mainstream group who have a more coherent collection of thought, sometimes called a "theory." -
chris at 04:16 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy at 03:42 AM on 31 July, 2010 I believe that Berényi Péter's post (#91) is closer to the truth. Great, but what's your evidence? It's all very well to state that black carbon has a contribution to global warming. No one doubts that. However its influence has to be quantitated if we wish to have a reliable assesment of contributions to warming. This quantitation has been (and continues to be) done, and black carbon is incorporated into scientific assessments of the contribution to 20th century and contemporary warming (e.g. here and here). It's a significant but small fraction of the forcing from enhanced [CO2]. -
chris at 04:06 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Geo Guy at 07:22 AM on 30 July, 2010 Geo Guy at 03:17 AM on 31 July, 2010 It's hard to believe that a Geologist would consider the Scotese graph of any value in considering the relationships between Earth temperature and atmopheric [CO2] in the deep past. You must be aware, for example, that there is zero [CO2] data presented there. The apparent [CO2] data is from Berner's model of possible [CO2] based on an analysis of weathering rates and such like. Each data point is 10 million years apart. Broad swathes of vast geological time are sketched as having a single temperature...I'm sure Dr. Scotese never meant his sketch to be used in lieu of the scientific data, to assess these relationships! It should be obvious that the relationship between atmospheric CO2 levels and paleotemperature can only be assessed at those specific time points where paleotemperature and paleoCO2 data are contemporaneous. Where we have data points for paleotemperatures and paleoCO2 levels that match in time, the evidence is rather strong for a CO2/temperature coupling. Where paleo temperatures are high paleoCO2 levels are high and cold/glacial periods are associated with low CO2 levels. There's now extremely abundant information on this dating back many hundreds of millions of years. A recent review compiles much of the data and some of this has been discussed in detail elsewhere on this site. D.L. Royer (2006) "CO2-forced climate thresholds during the Phanerozoic" Geochim. Cosmochim. Acta 70, 5665-5675. a wealth of more recent data provides additional evidence for a strong relationship between [CO2] and temperature in the deep past. See for example: R.E. Carne, J.M. Eiler, J. Veizer et al (2007) "Coupling of surface temperatures and atmospheric CO2 concentrations during the Palaeozoic era" Nature 449, 198-202 W. M. Kurschner et al (2008) “The impact of Miocene atmospheric carbon dioxide fluctuations on climate and the evolution of the terrestrial ecosystem” Proc. Natl. Acad. Sci. USA 105, 499-453. D. L. Royer (2008) “Linkages between CO2, climate, and evolution in deep time” Proc. Natl Acad. Sci. USA 105, 407-408 Zachos JC (2008) “An early Cenozoic perspective on greenhouse warming and carbon-cycle dynamics” Nature 451, 279-283. Doney SC et al (2007) “Carbon and climate system coupling on timescales from the Precambrian to the Anthropocene” Ann. Rev. Environ. Resources 32, 31-66. Horton DE et al (2007) “Orbital and CO2 forcing of late Paleozoic continental ice sheets” Geophys. Res. Lett. L19708 (Oct. 11 2007). B. J. Fletcher et al. (2008) “Atmospheric carbon dioxide linked with Mesozoic and early Cenozoic climate change” Nature Geoscience 1, 43-48. And so on….. -
robert way at 04:05 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
I think it'd be great if someone could find this paper http://www.opticsinfobase.org/abstract.cfm?URI=FTS-2009-FWA4 Observations of Climate Radiative Forcing from Ground and Space Wayne F. Evans Abstract The observation and monitoring of the radiative forcing of climate from greenhouse gases at the top of the atmosphere and at the surface by FTS is presented. but my library doesn't have the rights to it. would be interesting for this sort of discussion. -
RSVP at 03:44 AM on 31 July 2010Waste heat vs greenhouse warming
Tom Dayton #154 Or write one, in which case you would probably be reading it. It would not say "by RSVP" of course. -
Geo Guy at 03:42 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
Ned # 94 - Yes, Yes, Yes...I do know that CO2 does have characteristics similar to a greenhouse. I first learned about the greenhouse gas effect nearly 40 years ago as an undergrad in geological engineering. Hence I am a believer of the greenhouse gas effect and any geologist would certainly agree. However the greenhouse gas effect is not what is at play here. From strictly a thermodynamics perspective, a single degree increase in atmospheric temperatures is not to account for the melting of the glaciers etc. I believe that Berényi Péter's post (#91) is closer to the truth. What I fail to accept is the strength many are attributing rising atmospheric CO2 has in driving climate change - that is what I am debating. Too often those on one side argue about how the planet is warming and come to the conclusion that it is man made CO2 that is driving that warming. I have yet to see any consequential evidence to support that position, particularly given that data exists to support the contention that other factors could be at play here. Many of the indicators of climate warming, as posted in this particular blog do not in any way relate to increased CO2 as being the cause. In fact the authors of the report failed to identify the cause for the warming. -
robert way at 03:40 AM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
John, this was a great post and should get more coverage. I wish there were more posts like this addressing these issues at real climate and climate progress. It would be nice for a news article to step up to the plate and really discuss each of these issues and why we know that certain things are signatures of human effects. It would also be interesting to see if there is a difference between early 20th century warming versus late in terms of days warming faster than nights in the early parts if it was indeed caused by increased solar irradience and the AMO. -
Tom Dayton at 03:36 AM on 31 July 2010Waste heat vs greenhouse warming
Okay, I give up, RSVP. You are completely, hopelessly out of touch with reality. Read a physics book, please. -
RSVP at 03:32 AM on 31 July 2010Waste heat vs greenhouse warming
If watts are consumed in the microwave, its happening in the output amp. If you leave it on too long without a load it will burn out. The waves never launch. If the Universe was only a single star, and there was absolutely nothing upon which it could shine. It could not shine. If you introduced an observer to witness this, you would no longer have a Universe with only a single star. -
Tom Dayton at 03:21 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP, the microwaves are emitted anyway. You can tell because the electricity consumed by the oven is the same as it would be if the bowl contained water. -
Geo Guy at 03:17 AM on 31 July 201010 key climate indicators all point to the same finding: global warming is unmistakable
CBDunkerson # 86 - It is hardly one dubious writeup that I posted the link to. It was an analysis of the approach and if you took the time to scroll down to the bottom to review the references and then followed up by reading some of the references, you will learn that what can be determined by stomata analysis is that the past amounts of atmospheric CO2 fluctuated a great deal more than has been proposed by groups such as the IPCC. I have always had a problem with ice core analysis because of the complex pressures and temperatures that any trapped gasses would undergo over time. There are valid critiques of ice core analysis available to read for those who are interested in doing so. My position is that when you look at both sides of the argument, you will find valid research to support both sides. This tells me the issue is more complex than many people seem to accept and therefore warrants further research by BOTH sides. In the end we need to focus on adapting to climate change as simply curtailing our carbon footprint (if we could ever achieve that) would not work if climate change is being driven primarily by factors beyond our control. -
Doug Bostrom at 03:17 AM on 31 July 2010Waste heat vs greenhouse warming
Trying to tune here, RSVP. Are you saying that because a microwave oven's frequency is tuned to dump RF energy into water that if no water is present in the oven the energy will bounce around until it finds its way back to the only thing sympathetic in the room, the magnetron? What's your point? -
RSVP at 03:11 AM on 31 July 2010Waste heat vs greenhouse warming
doug_bostrom #149 OK. I will make real simple. Put a glass bowl with no water in your microwave oven. Leave it on for 1 minute. See how hot it doesnt get. -
Doug Bostrom at 03:07 AM on 31 July 2010Waste heat vs greenhouse warming
RSVP: Photons do in a sense "know" whether they can be launched "before" leaping so to speak. Microwaves for instance require source and load impedance matching. How can it "know" this before leaving? Microwave and light and IR are of the same nature, (i.e. electromagnetic radiation). That example has nothing to do with the misunderstanding you're expressing with regard to whether radiation knows of its destination. Amplifying and then retransmitting your misunderstanding with paradoxical-seeming knowledge of microwave resonances is a strangely incoherent phenomenon of emission, a sort of epistemological transponder system with severe ringing or the like. -
Pete Ridley at 03:06 AM on 31 July 2010What do you get when you put 100 climate scientists in a room?
KR, ref. #221 (was #227), I think that we’ll have to agree to disagree on how bad scientist Hansen’s model is at forecasting global temperatures. You claim that “Luboš Motl .. posts from a clear ideological framework rather than a scientific one in the climate arena… “.Lubos has the significant advantage over us in that he does at least have a track record in one of the numerous scientific disciplines involved in improving our poor understanding of global climate processes and drivers. I place you in that “ideological framework” category and have no reason to believe that you have any scientific expertise whatsoever. If I am mistaken on that then perhaps you’d like to Ref. #228 (was #234), thanks for identifying what you consider to be three independent data sets that scientists use to estimate mean global temperatures (note that I am talking about near-surface temperature estimates such as those used by The Hadley Centre scientists, - see comment #207/217 (were #213/223). I have no disagreement about the satellite data being independent (although I understand that that those data do not refer to near-surface but to lower troposphere which may or may not be comparable). It is interesting to see what those expert climate scientists Dr. Roy Spencer and Professor John Chrisy have to say. According to their assessment of global temperatures at June 2010 (2) see http://www.drroyspencer.com/latest-global-temperatures/) there has been something like 0.13C per decade increase during the past 30 years, which, if continued (and that’s a big IF), would give a mere 1.6C increase in mean global lower atmospheric temperature by 2100, not the 6-7C forecast by some scientists. Of course we mustn’t overlook the fact that this is all pure speculation, since we (including the scientists) have no idea what global mean temperatures will be in 2100. I am not convinced about the independence those GHCN and GSOD data bases from each other so will try to make time to take a closer look at them before commenting further. Meanwhile you may like to read what the Climate Sceptic said in its 2008 “Temperature Measurement” article (http://www.climate-skeptic.com/temperature_measurement/). As I’m off on a week’s holiday with my lovely grand children you’ll have to wait for my next set of comments until I’m back, around 7th August.
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