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David Middleton at 07:00 AM on 1 August 2010Plant stomata show higher and more variable CO2 levels
Van Hoof et al., 2005 demonstrated that the ice core CO2 data essentially represent a low-frequency, century to multi-century moving average of past atmospheric CO2 levels.
Van Hoof et al., 2005. Atmospheric CO2 during the 13th century AD: reconciliation of data from ice core measurements and stomatal frequency analysis. Tellus (2005), 57B, 351–355.
Three separate lines of scientific evidence indicate that Antarctic ice cores underestimate the average global atmospheric CO2 concentration by 20-40 ppmv:
1) GeoCarb
2) Plant stomata
3) NASA AIRS satellite measurements
See my Debunk House post for an in depth discussion.
By the way... Wagner, Van Hoof, Kouwenberg and the other botanists publishing papers on plant stomata & atmospheric CO2 are generally not "skeptics." They are looking for a pre-industrial coupling of CO2 & temperature. They aren't trying to debunk AGW.
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John Russell at 06:05 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
mspelto at 05:26 AM on 1 August, 2010 Thanks for the response. Hope you get time to answer this before you leave! The way you describe it -- and certainly the way it looks on the diagrams -- it sounds like the whole of central Greenland (where ice is a mile thick?) is an accumulation zone. Is this correct? Is, in fact, the whole of Greenland, in effect, one big glacier that radiates out in all directions? Is that a good way to visualise it? If so has anyone mapped the direction of travel of the ice around that continent? Sorry if the questions seem naive to the experts but it's important that we laypeople understand the way the mechanism works. -
Doug Bostrom at 06:03 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
Further to mspelto, key concepts: Accumulation zone, ablation zone. Easy enough, once it's pointed out. The example is helpful in determining the utility of Monckton's presentations. -
muoncounter at 05:38 AM on 1 August 201010 Indicators of a Human Fingerprint on Climate Change
#33: "The integral of [area under] this curve (divided by 4) is roughly the total Solar energy added to the Earth system since 1920." Isn't a significant fraction of TSI (30% as shown below) reflected back into space?
The papers cited at Argument #1 give significantly different conclusions from yours.
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mspelto at 05:29 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
Tomorrow I leave for the 27th consecutive glacier mass balance field monitoring season. I should note that even on small North Cascade glaciers we hope our stakes in the accumulation zone get buried and do not reappear for many years until they move down glacier. Unfortunately in 2005 and 2009 even the accumulation zone lost all of its recent snowpack. -
mspelto at 05:26 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
#14 The key is that the radar station is built in the accumulation zone where the snow pile up every year slowly burying any object place on it. Eventually this object will move into the ablation zone where melting dominates every year. If an object placed in the accumulation zone does not get buried we are in trouble. -
John Russell at 04:52 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
I'd be grateful if someone could help answer a question put to me by a denier regarding Greenland ice mass. He used an illustration from one of Monckton's lectures showing photographs of radar stations sitting on top of the ice sheet where the ice was purportedly a mile thick. The slide showed photos of the radar stations when they were first built, sitting on top of the ice, and then ten years later (and the same month of the year) buried in deep snow. Monckton -- and my denier friends's -- argument was that it was blindingly obvious proof that the ice sheet was not melting but was in fact accumulating. My counter was that A) soft snow would be removed before a structure was erected, and then re-accumulate. B) Snow packs down, so it's quite likely that the radar station would settle and soft snow would accumulate. And C) why would the ice melt from the top? Melting polar ice melts, and moves, down towards the sea and the radar stations could all now be lower than they once were -- even though snow still falls (because more snow falls as temperatures rise). Of course my response was purely conjecture -- and thus unconvincing -- but I couldn't find anything on-line that specifically addressed this anecdotal 'evidence'. Any thoughts/links/whatever, gratefully received. -
Doug Bostrom at 03:51 AM on 1 August 201010 Indicators of a Human Fingerprint on Climate Change
Worth noting, temporal changes of TOA flux could tell us something useful. The integral of a constant energy flux is a linear rise in total energy. If temperature is roughly proportional to energy input (which is so with specific heats of materials) then a rising temperature curve is no surprise. Needs to take into account radiation; for an object radiating IR temperature will not be directly proportional to energy input. So a constant energy flux will not produce a linear rise in total energy, not for Earth anyway. -
Doug Bostrom at 03:36 AM on 1 August 2010The four sides model for improving climate communication
Chiming in with dcruzuri, a thought-provoking post that causes me to scrutinize my own efforts and motivations. Thanks! John Cook caused me to reevaluate what I presume to call my "communications." I've got a proclivity toward mocking humor that may be enjoyable for some but is not at the end of the day probably very effective for communicating. On another note, this climate affair is becoming a matter of serious interest to social scientists. Lots of puzzling features to investigate. Nice to see a post looking at the scene from that perspective. -
dhogaza at 02:37 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
I have a tiny vial of water with me (Still travelling toward home) that was from ice at the bottom of the core. The water is from snow that fell in Greenland 150K years ago!
Dansat is way cooler than the rest of us put together ... What were you doing there? -
chris at 02:35 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
sorry, I mangled a sentence and didn't spot it before posting. Under (ii) it should say. "The rapid rate of warming during the 20's to 30's almost certainly had a strong contribution from the recovery following the suppression of temperatures associated with the prolonged period of high volcanic activity from the late 19th century through the first decade of the 20th century (e.g. see Figure 11 of Box et al, 2009)." -
chris at 02:25 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
angusmac at 00:24 AM on 1 August, 2010They conclude that current temperatures are, “well below” those reached in the 1930s and 1940s.
No, angusmac, that's a false précis. The term “well below” was used only once in Chylek et al. 2006, and refers specifically to the years 2004 and 2005 in one location (Ammassalik)! The passage containing “well below” is reproduced below and we can look at those two words in context [*]. It’s obvious from the Figure you reproduced that current temperatures in those coastal sites in Greenland are similar now to temperatures in the 1930’s/1940’s. [*] (my highlight) [see near start of section 5. of Chylek et al (2006)]”The year 2003 was extremely warm on the southeastern coast of Greenland. The average annual temperature and the average summer temperature for 2003 at Ammassalik was a record high since 1895. The years 2004 and 2005 were closer to normal being well below temperatures reached in 1930s and 1940s (Figure 2).
Otherwise it’s worth being a little more considered about the data on the progression of Greenland temperatures during the 20th century which indicates: (i) Current Arctic temperatures are warmer now than during the 1930's/40's, (ii) early 20th century Greenland temperature rise likely had different causes to current warming, and (iii) the evidence supports the conclusion that Greenland will continue to warm quite a bit further in the coming decades ( barring large volcanic events): (i) A recent multiproxy temperature reconstruction (Kaufmann et al, 2009) indicates that the last decade was the warmest in the Arctic for the last 2000 years, and 20th century warming has reversed a long term (and extremely slow 0.22 oC per mellenium) cooling trend. Contemporary temperature measures indicate that the Arctic as a whole is warmer now than during the mid-20th century, even if Greenland itself may be not much warmer (and accordingly Arctic sea ice retreat was likely minimal during the time of the apparent Greenland summit temperature max). (ii) The Greenland ice sheet is very sensitive to volcanic (and also solar and aerosolic) variability, with volcanic activity greatly suppressing temperature responses to global warming. A recent study of Greenland temperature (Box et al, 2009) also found that Greenland was around as warm (and possibly a tad warmer) during 1930-40 than now. The rapid rate of warming during late 20's to late 30's almost certainly had a strong contribution to the suppression of temperatures associated with the prolonged period of high volcanic activity from the late 19th century through the first decade of the 20th century (e.g. see Figure 11 of Box et al, 2009). We should also consider black carbon (BC) which has a strong warming effect when it's deposited on snow/ice; BC levels are identified in Greenland cores (McConnell et al, 2007) and were high through the period of rapid warming (they dropped in Greenland once Western industrial nations cleaned up emissions in the 50's, and BC is largely from Asia now,and mostly affecting the Himalayas). (iii) So one does need to be careful with attributing temperature variations in Greenland. These are not necessarily related to phenomena that influence Arctic temperatures overall. Obviously in the present widescale warming both Greenland and the Arctic as a whole are warming. One of the potentially concerning observations of Box et al is that Greenland tends, as a result of “polar amplification” to retain a phase relationship with overall N. hemispheric warming, such that it eventually rises to a temperature anomaly around 1.6 times that of the N. hemisphere. It’s way below that now, and if this relationship holds up Greenland has got quite a lot of warming (1-1.5 oC) just to “catch up”. Kaufman DS, et al. (2009) Recent warming reverses long-term Arctic cooling. Science 325:1236–1238. Box, J. E.et al (2009) Greenland Ice Sheet Surface Air Temperature Variability: 1840–2007. Journal of Climate, 22, 4029-4049. McConnell et al (2007) 20th-Century Industrial Black Carbon Emissions Altered Arctic Climate Forcing Science 317, 1381 - 1384 -
angusmac at 00:24 AM on 1 August 2010The Past and Future of the Greenland Ice Sheet
Perhaps your data period is too short for a reasonable comparison of recent Greenland warming? Chylek et al (2006) show that the rate of warming in, “1920-1930 was about 50% higher than that in 1995-2005.” They conclude that ,”… the current Greenland warming is not unprecedented in recent Greenland history. Temperature increases in the two warming periods are of a similar magnitude, however, the rate of warming in 1920-1930 was about 50% higher than that in 1995 - 2005.” They summarise that they, “… find no direct evidence to support the claims that the Greenland ice sheet is melting due to increased temperature caused by increased atmospheric concentration of carbon dioxide…The temperature trend during the next ten years may be a decisive factor in a possible detection of an anthropogenic part of climate signal over area of the Greenland ice sheet.”. They conclude that current temperatures are, “well below” those reached in the 1930s and 1940s. I enclose a copy of their chart of Greenland temperatures from 1900–2005 which appears to support their conclusion.
Figure 1: Comparison of Current Greenland Temperatures with Previous Temperatures (Chylek et al, 2006)
Perhaps we should wait until definitive records over a longer timescale are available before we reach unwarranted conclusions about AGW causing melting of the Greenland icecap?
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Ken Lambert at 23:57 PM on 31 July 201010 Indicators of a Human Fingerprint on Climate Change
muoncounter #31 michael sweet #30 BP is correct about the TOA imbalance not being 'measured' - but implied by models. Dr Trenberth's 0.9W/sq.m is a net of several theoretical warming and cooling forcings and feedbacks including radiative cooling from the 0.75 DegC warming of the Earth since preindustrial times when the CO2 concentration was about 280ppmv. Your Temperature vs. Solar Activity chart could be looked at this way: The integral of a constant energy flux is a linear rise in total energy. If temperature is roughly proportional to energy input (which is so with specific heats of materials) then a rising temperature curve is no surprise. Assume your baseline 11 year moving average TSI is 1365.5W/sq.m. Ignore the 11 year solar cyclic variation. It rises to about 1366W/sq.m from 1920 to 1950 and flatlines on a slightly falling trend up to date. The integral of the area under this curve (divided by 4) is roughly the total Solar energy added to the Earth system since 1920. A TSI difference of 0.5W/sq.m divided by 4 = 0.125W/sq.m which equals about 20E20Joules/year. For the 1920-1950 period this sums to about 300E20 Joules. For the 1950 - 2005 period this sums to about 1100E20 Joules. Total - roughly 1400E20 Joules. Dr Trenberth estimates that in the 2004-08 period total energy absorbed by warming land is 2E20 Joules/year, and melting total land ice is 2E20 Joules/year and Arctic Sea Ice is 1E20Joules/year. Total for all three: 5E20 Joules/year. OHC increase is highly uncertain however let's use his estimate of 20-95E20 Joules/year. Using an average of say 58E20 for OHC plus 5E20 for all other sources - we get 63E20Joules/year of energy absorbed by OHC increase and all the ice melt and land warming. We have Solar imbalance energy input since 1920 of roughly 1400E20 Joules divided by 63E20 Joules/year (at 2004-08 rates) = 22 years equivalent. The majority of the warming has occurred over the last 30 years, so 22 years equivalent solely attributable to Solar at the 2004-08 rate is highly significant. -
dcruzuri at 23:53 PM on 31 July 2010The four sides model for improving climate communication
A very insightful post. I want to contribute a different perspective, one I learned on my work trying to abolish the death penalty. This approach is designed to help you communicate better by understanding your audience and understanding what you are trying to accomplish. The theory is that anyone you are speaking to will fall somewhere on the following six point scale: 1 -- Totally committed: believes climate change is a serious issue and is committed to working in some way towards a solution. 2 -- Convinced climate change is a problem, but is less certain about how serious the problem is and/or is less engaged in dealing with it. 3 -- Somewhat uncertain on the subject of climate change, but leans toward believing it is a problem. 4 -- Uncertain about climate change, but leans towards believing it is not a problem or has been over-hyped by activists. 5 -- Does not believe climate change is a problem, or believes that proposed solutions are more destructive of society etc. than the problems they purport to fix. Believes nothing should be done. 6 -- Actively denies climate change and works to prevent the dissemination of information or the implementation of any solutions of the problem. Obviously these divisions are somewhat arbitrary, and other facets of support/opposition can be included. Think of these not as discrete boxes but markers on a spectrum. The goal of any discussion is not to move a person from where they are to #1: this simply will not happen and will often entrench the person you are speaking to more strongly in where they are, or even move them in the opposite direction. Rather, the goal is to move a person one stage up the scale: from firm opposition to uncertain, from uncertain to weak concern, from weak concern to strong concern, and finally to activism. People in #6 may be immovable, but in speaking to them you have to remember that there will be a lot of #5's and #4's listening. Our belief in using this in anti-DP work is that we will win if we can move a majority of people one step up. -
dansat at 23:25 PM on 31 July 2010The Past and Future of the Greenland Ice Sheet
Exc. post. I just returned from 9 days on the Greenland ice sheet at the NEEM drill site. They succeeded in bringing up the oldest ice ever recovered from Greenland. The Eemian and even the penultimate ice age before it is represented. There are some surprises in the ice core. There seem to be some rapid descents into colder conditions than are normally seen. The rapid (very rapid) warmups are also seen. They were able to do do 018 measurements as the core came up and the Eemian shows up very clearly. I have a tiny vial of water with me (Still travelling toward home) that was from ice at the bottom of the core. The water is from snow that fell in Greenland 150K years ago! dan -
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 winter
vs. 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.
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