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Comments 131551 to 131600:

131551. Quietman at 13:14 PM on 30 June 2008
        Climate's changed before
        A change or two in climate history has recently been revealed indicating change happens faster than thought: Fossils Found In Tibet Revise History Of Elevation, Climate ScienceDaily (June 12, 2008) — About 15,000 feet up on Tibet's desolate Himalayan-Tibetan Plateau, an international research team led by Florida State University geologist Yang Wang was surprised to find thick layers of ancient lake sediment filled with plant, fish and animal fossils typical of far lower elevations and warmer, wetter climates. Greenland Ice Core Analysis Shows Drastic Climate Change Near End Of Last Ice Age ScienceDaily (June 19, 2008) — Information gleaned from a Greenland ice core by an international science team shows that two huge Northern Hemisphere temperature spikes prior to the close of the last ice age some 11,500 years ago were tied to fundamental shifts in atmospheric circulation.
        Response: This would indicate that climate is more sensitive than realised which means the climate response to CO2 forcing will be greater than current estimations.
131552. Quietman at 04:53 AM on 30 June 2008
        Arctic sea ice melt - natural or man-made?
        As for evidence of increased vulcanism that are causing hot spots and more active El Ninos, etc. Surprisingly Rapid Changes In Earth’s Core Discovered - ScienceDaily (June 20, 2008) — The movements in the liquid part of the Earth’s core are changing surprisingly quickly, and this affects the Earth’s magnetic field, according to new research from DTU Space. Olsen et al. Rapidly changing flows in the Earth's core (I have posted the abstract in the volcano thread).
131553. Quietman at 04:22 AM on 30 June 2008
        Volcanoes emit more CO2 than humans
        The current work on vulcanism in the south Pacific: Olsen et al. Rapidly changing flows in the Earth’s core. Nature Geoscience 1, 390 - 394 (2008) Published online: 18 May 2008 | doi:10.1038/ngeo203 Subject Category: Geomagnetism, palaeomagnetism and core processes Rapidly changing flows in the Earth's core Nils Olsen & Mioara Mandea A large part of the Earth's magnetic field is generated by fluid motion in the molten outer core. As a result of continuous satellite measurements since 1999, the core magnetic field and its recent variations can now be described with a high resolution in space and time. These data have recently been used to investigate small-scale core flow, but no advantage has yet been taken of the improved temporal resolution, partly because the filtering effect of the electrically conducting mantle was assumed to mask short-period magnetic variations.. Here we show that changes in the magnetic field occurring over only a few months, indicative of fluid flow at the top of the core, can in fact be resolved. Using nine years of magnetic field data obtained by satellites as well as Earth-based observatories, we determine the temporal changes in the core magnetic field and flow in the core. We find that the core flow is spatially localized and involves rapid variations over a few months, with surprisingly large local accelerations. Our results suggest that short-term fluctuations of the core magnetic field are robust features of rapid core dynamics and should be considered in the development of future numerical models of the geodynamo. Danish National Space Center/DTU and Niels Bohr Institute at Copenhagen University, Juliane Maries Vej 30, 2100 Copenhagen, Denmark GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany Correspondence to: Nils Olsen1 e-mail: nio@space.dtu.dk
131554. Quietman at 04:02 AM on 30 June 2008
        Arctic sea ice melt - natural or man-made?
        "Resonant interactions between solar activity and climate" Tobias, S.M.; Weiss, N.O. Journal of Climate. Vol. 13, no. 21, pp. 3745-3759. Nov. 2000 Solar magnetic activity exhibits chaotically modulated cycles with a mean period of 11 yr, which are responsible for slight variations in solar luminosity and modulation of the solar wind, while the earth’s atmosphere and oceans support oscillations with many different frequencies. Although there are several mechanisms that might couple solar variability with climate, there is, as yet, no compelling evidence that a direct forcing is sufficiently effective to drive climatic change. In many nonlinear systems resonant coupling allows weak forcing to have a dramatic effect. An idealized model is considered, in which the solar dynamo and the climate are represented by low-order systems, each of which in isolation supports chaotic oscillations. The climate is represented by the Lorenz equations: solutions oscillate about either of two fixed points, representing warm and cold states, flipping sporadically between them. The effect of a weak nonlinear input from the dynamo to the climate that tends to push it toward the warm state is computed. This input has a significant effect when the ‘typical frequencies’ of each system are in resonance. The solution is now asymmetric, with the warm state preferred. The degree of asymmetry is less than might be anticipated, because resonant forcing extends the duration of oscillations about either state, and so increases the timescale for flipping. The presence of grand minima in the solar output leads to complicated intermittent behaviour in the climate. Consequently, the results of frequency analysis are sensitive to the duration of time series that is used. It is clear that the resonance provides a powerful mechanism for amplifying climate forcing by solar activity. Surface warming by the solar cycle as revealed by the composite mean difference projection Charles D. Camp and Ka Kit Tung Received 29 March 2007; revised 15 May 2007; accepted 14 June 2007; published 18 July 2007. Geophys. Res. Lett., 34, L14703, doi:10.1029/2007GL030207. ABSTRACT [1] By projecting surface temperature data (1959?2004) onto the spatial structure obtained objectively from the composite mean difference between solar max and solar min years, we obtain a global warming signal of almost 0.2_K attributable to the 11-year solar cycle. The statistical significance of such a globally coherent solar response at the surface is established for the first time. Citation: Camp, C. D., and K. K. Tung (2007), Surface warming by the solar cycle as revealed by the composite mean difference projection, Geophys. Res. Lett., 34, L14703, doi:10.1029/2007GL030207. Conclusion [11] We propose that spatial information be used to filter the surface-temperature data to obtain a cleaner solar-cycle response. At the global scales, an objectively determined spatial filter can be constructed using the composite difference between the solar-max years and the solar-min years. This filter effectively removes the shorter interannual variations, such as from ENSO. We obtained a globally averaged warming of almost 0.2_K during solar max as compared to solar min, somewhat larger than previously reported. More importantly, we have established that the global-temperature response to the solar cycle is statistically significant at over 95% confidence level. The spatial pattern of the warming is also of interest, and shows the polar amplification expected also for the greenhouse-warming problem. The method used here, the CMD Projection, is one of two methods we have tried that take advantage of the spatial information, the other method being the LDA method. Although not as optimal as the LDA method, the CMD Projection possesses most of the advantages of the former while being much simpler to understand and implement. As it turns out, the spatial patterns deduced by the two different methods are very close to each other. However, the LDA method yields a more accurate estimate of the solar-cycle response in the sense that its error bar is only half as large. [12] We will argue in a separate paper that the observed warming is caused mostly by the radiative heating (TSI minus the 15% absorbed by ozone in the stratosphere), when taking into account the positive climate feedbacks (a factor of 2?3) also expected for the greenhouse warming problem. Solar-Cycle Warming at the Earth?s Surface and an Observational Determination of Climate Sensitivity. By Ka-Kit Tung and Charles D. Camp Department of Applied Mathematics, University of Washington, Seattle Washington, USA Journal of Geophysical Research, submitted. ABSTRACT The total solar irradiance (TSI) has been measured by orbiting satellites since 1978 to vary on an 11-year cycle by about 0.07%. From solar min to solar max, the TSI reaching the earth?s surface increases at a rate comparable to the radiative heating due to a 1% per year increase in greenhouse gases, and will probably add, during the next five to six years in the advancing phase of Solar Cycle 24, almost 0.2 ?K to the globally-averaged temperature, thus doubling the amount of transient global warming expected from greenhouse warming alone. Deducing the resulting pattern of warming at the earth?s surface promises insights into how our climate reacts to known radiative forcing, and yields an independent measure of climate sensitivity based on instrumental records. This model-independent, observationally-obtained climate sensitivity is equivalent to a global double-CO2 warming of 2.3 -4.1 ?K at equilibrium, at 95% confidence level. The problem of solar-cycle response is interesting in its own right, for it is one of the rare natural global phenomena that have not yet been successfully explained. 7. Conclusion Using NCEP reanalysis data that span four and a half solar cycles, we have obtained the spatial pattern over the globe which best separates the solar-max years from the solar-min years, and established that this coherent global pattern is statistically significant using a Monte-Carlo test. The pattern shows a global warming of the Earth?s surface of about 0.2 ?K, with larger warming over the polar regions than over the tropics, and larger over continents than over the oceans. It is also established that the global warming of the surface is related to the 11-year solar cycle, in particular to its TSI, at over 95% confidence level. Since the solar-forcing variability has been measured by satellites, we therefore now know both the forcing and the response (assuming cause and effect). This information is then used to deduce the climate sensitivity. Since the equilibrium response should be larger than the periodic response measured, the periodic solar-cycle response measurements yields a lower bound on the equilibrium climate sensitivity that is equivalent to a global warming of 2.3 ?K at doubled CO2. A 95% confidence interval is estimated to be 2.3-4.1 ?K. This range is established independent of models. 11-Year solar cycle in the stratosphere extracted by the empirical mode decomposition method K.T. Coughlin, K.K. Tung University of Washington, Box 352420, Seattle, WA 98195, USA Received 19 October 2002; received in revised form 26 February 2003; accepted 26 February 2003 Advances in Space Research 34 (2004) 323?329 Abstract We apply a novel method to extract the solar cycle signal from stratospheric data. An alternative to traditional analysis is a nonlinear empirical mode decomposition (EMD) method. This method is adaptive and therefore highly efficient at identifying embedded structures, even those with small amplitudes. Using this analysis, the geopotential height in the Northern Hemisphere can be completely decomposed into five non-stationary temporal modes including an annual cycle, a QBO signal, an ENSO-like mode, a solar cycle signal and a trend. High correlations with the sunspot cycle unambiguously establish that the fourth mode is an 11-year solar cycle signal. 5. Conclusion A clear solar cycle signal is observed in the 30 mb geopotential height using the nonlinear, non-stationary EMD method. The total geopotential height at 30 mb is spatially averaged over all longitudes and from 20N to 90N. No specific grouping of the data is used in this analysis. The entire timeseries is completely decomposed into five modes and a trend. Using a Monte-Carlo simulation, the power in each mode is compared to the power in 500 decompositions of random noise. The fourth mode is found to have an average power far above the noise level and therefore is a significant signal. The correlation between this signal and the solar cycle proxy is 0.70 which is also significant given our estimation of the degrees of freedom in the mode. Using a regression with AR errors, the significance of the correlation is verified. The result is both a statistically and visually convincing solar cycle signal in the total 30 mb geopotential height. Further analysis at lower levels and with latitudinal variations will be presented in our forthcoming paper.
131555. Quietman at 03:05 AM on 30 June 2008
        Arctic sea ice melt - natural or man-made?
        And yes Philippe, I have very little respect for the post JFK education standards in the U.S. with the "no one left behind" concept used to reduce the passing average to the lowest common denominator. On the other hand I have the greatest respect for those who have overcome this handicap.
131556. Quietman at 02:50 AM on 30 June 2008
        Arctic sea ice melt - natural or man-made?
        Philippe Sorry, I was under the impression that you understood the sarcasm. My issue is back to a previously discussed point: why is it that Fairbridge "hypothesis" has not been thoroughly investigated by planetary and solar scentists?
131557. Philippe Chantreau at 09:00 AM on 29 June 2008
        Arctic sea ice melt - natural or man-made?
        Your condescending tone was ill-used against me, I did not direct anything of the sort a you. You bring us back to a previously discussed point: why is it that Fairbridge "hypothesis" has not been thoroughly investigated by planetary and solar scentists? As for your post #103, it's your opinion. Everybody has one. Many of these scientists are as old or older than you. It now sounds like you're being condescending toward an entire scientific and academic community.
131558. Quietman at 04:29 AM on 29 June 2008
        Arctic sea ice melt - natural or man-made?
        p.s. Nothing about this planet is well understood, despite claims to the contrary. Our young scientists have much to learn.
131559. Quietman at 04:26 AM on 29 June 2008
        Arctic sea ice melt - natural or man-made?
        Philippe Thank you, I am quite pleased that you recognized my complaint. Just because I am retired does not mean that I have time on my hands, albeit more than I had as an engineer. In an agrarian community winters are slow but this is planting and pest control season. If you are interested I have posts with links under the volcano thread. While vulcanism is still discounted by many scientists, more is discovered every day, and if Dr. Fairbridge was correct in his solar hypothesis, more evidence will be found soon, thanks to modern satellites. The most recent two are in the south Pacific.
131560. chris at 23:43 PM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Shawnet, re: "Since there is the same amount of CO2 in the SH as the NH, CO2 cant explain the state of the cryosphere in toto." O.K., but nobody says that CO2 can explain the state of the cryosphere in toto! Two points: (A) As well as CO2, there are the other man-made greenhouse gases (methane, nitrous oxides, CFC's, tropospheric ozone), there are man-made aerosols, there are variations in solar outputs, volcanic eruptions.... (B) One then has to consider how various wind and ocean currents distribute thermal energy around the world. The net thermal imbalance (that gives us global-scale warming or cooling) is a summation of all of (A): -CO2 dominates -other greenhouse gases make a significant contribution -aerosols are nett cooling -solar variation has made no significant contribution since the late 50's (perhaps a slight cooling one overall) -volcanic eruptions make sporadic cooling "pulses" etc. (the numbers for many of these contributions are in the Ramanathan and Carmichael paper leebert cited - see posts #39/#48) So global warming IS largely about greenhouse gases, the full effects of which are attenuated by our aerosol emissions. (B) relates to the manner in which this excess thermal energy is distributed around the world. It doesn't depend on the location of CO2, and the fact that the CO2 concentrations are the same in the Nrthn. and Srthn. hemisphere, is a red-herring with respect to the distribution of thermal energy (excess heat) measured at the Earth's surface. After all, land warms faster than the oceans since the oceans provide a massive sink which buffers surface warming. So obviously the Nrthn. hemisphere warms faster than the Srthn. Major ocean currents carry heat from the low latitudes to the high Nrthn latitudes (Arctic!), whereas ocean currents in the deep Srthn. hemisphere "insulate" the Antarctic from heat absorbed in the low latitudes….. That's all pretty well understood (see post #66). Since the time of detailed satellite observation the Antarctic sea ice hasn't changed very much at all: a small trend of around +12,000 km2 per year for the summer sea ice extent: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.south.jpg ...whereas during the same period, the Arctic summer sea ice trend is around -85,000 km2 per year (more like -131,000 km2 per year since 2000-ish). http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg Note that the data presented at the site you linked to in post #59 is a little bit misleading, since, first, it's considering only a single year, secondly it gives the sea ice extent at one particular snapshot in time (Jan 31st 2008!), and thirdly it doesn't really compare like with like. For example the concern is for SUMMER ice extent since this is the period in which solar irradiation directly affects surface warming through albedo effects from sea ice melting (and black carbon too!). Thus it's more appropriate to compare sea ice extent in late summer in the Arctic (Aug-Sept) with sea ice extent in late summer in the Antarctic (Feb-March). Note btw, that the Antarctic sea ice extent was apparently larger in the period 1900-1960 than now[*], so it too has undergone some attenuation, but in the last 20-ish years it's been pretty steady. But that's not unexpected given our understanding of the manner in which thermal energy from low latitudes distributes to higher latitudes. [*] N. A. Rayner et al. (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century; Journal Of Geophysical Research, 108, NO. D14, 4407.
131561. Philippe Chantreau at 12:14 PM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Shawnet, the Tale of the Tape at Cryosphere Today seems to disagree with you: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg The magnifying function helps to see that the current level is significantly lower than any in 01-02. What data are you using?
131562. Philippe Chantreau at 11:51 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Quietman, thank you for the condescending tone. It is a good reminder of what we all should try to avoid, I will be more watchful to not reproduce anything like it. Shawnet, the comparison I was concerned about on that graph was between this year and last year. The current extent does not bode well for what Sep minimum will be, but time will tell.
131563. shawnhet at 08:20 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Chris, "Question (a) has an explanation that is well-supported by the scientific evidence: massive enhancement of the Earth's greenhouse effect. The warming in the arctic is pretty much as expected from supplementing the Earth's greenhouse gases with extra CO2, methane, nitrous oxides, tropospheric ozone and CFC's. There may well be a significant contribution from BC although we've had pretty much all the forcing from that source already according to Hansen and Nazarenko, and it's not clear that the warming effect of BC has been greater than the cooling effect of other manmade aerosols. Certainly according to Hansen, and Ramanathan and Carmichael, the total worldwide aerosol effect (BC et al) is a cooling one. It may be net warming in the arctic 'though. One would have to look at the numbers carefully, if the appropriate one's are available." Chris, the point about the SH and NH is that the GE can't explain the loss of ice in the SH, *because there isn't one*. There's a gain(and one reasonably close to the loss in the NH). Since there is the same amount of CO2 in the SH as the NH, CO2 cant explain the state of the cryosphere in toto. Phillippe:"Shawnet, the ice area is actually very close to what it was last year, due to a period of fast melting in the spring: http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png" I don't think that what I said and what you said really disagree. It is just a question of what you are comparing it to. I was comparing it to the early part of this century, while your link compares it to the 1979-2000 mean. Cheers, :)
131564. chris at 07:03 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Quietman, If you consider that "undersea vulcanism" is contributing to global (or regional) warming, then you need to give us some evidence. Remember that: (i) the mid-ocean plates have been slowly ripping themselves apart for countless (almost!) millenia. Has this process suddenly intensified since the middle of the 20th century? Evidence please. (ii) one of the more active mid ocean plate-separations lies towards and then in Iceland, as the plates carrying America and Europe rip apart at the mid-Atlantic ridge. This is a region with massive "vulcanism" (undersea and above sea). However, this region is one of the rare locations on earth that has actually cooled since the middle of the 20th century. How can "vulcanism" provide an explanation for warming (global or regional) if one of, if not the most active, region "vulcanism"-wise has actually cooled a tad since the mid 20th century? Explanation please. (iii) Science progresses on the basis of evidence. If you'd like to pursue "vulcanism" as a contributory factor in local or global warming, you'll need to find some evidence. You can't keep ducking these straightforward requests and expect to be taken seriously. Evidence please. Otherwise we're likely to be skeptical of your unsupported claims! Note btw: (a) that greenhouse-gas induced warming (resulting largely from massive enhancement of the atmospheric carbon dioxide concentration) is hardly a "myth". One of the very papers that you cited in support of something or other, concludes with a determination of the earth's climate sensitivity to doubling atmospheric [CO2]: 2.3 °K< ΔT2xCO2 <4.1 °K . (“2xCO2” is subscripted)[***] Which say's: “2.3 degrees Kelvin is less than the change in temperature from doubling [CO2], which is less than 4.1 degrees Kelvin” (Tung and Camp consider that the climate sensitivty is around 3 oC (+/- a bit). [***]Tung and Camp: http://www.amath.washington.edu/research/articles/Tung/journals/solar-jgr.pdf Clearly Tung and Camp don't consider man-made enhancement of the earth's greenhouse effect via massive enhancement of the atmospheric CO2 concentration "a myth". (b)that science doesn't progress on the basis of "blogs" and "columns"! (c) that unsubstantiated denigration of scientists (your unsubstantiated comments re Hansen) doesn't constitute skepticism! I hope you're not one of those " ...closed minds that will not even look at a paper if they don't like the author". (d) It's not only science that is all about the evidence. Skepticism too is all about the evidence!
131565. Quietman at 05:57 AM on 28 June 2008
        Volcanoes emit more CO2 than humans
        John A little more detail here. "A major part of Earth's volcanism happens at the so-called mid-ocean ridges and, therefore, completely undetected on the seafloor." Bathymetric chart of the Gakkel Ridge (Nice photo and charts)
131566. Quietman at 05:40 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Philippe Yes I could but there are too many. I did my homework, now you can google it just as easily. I have better things to do at this time of year. The weather is quite pleasant, low 70's with a cool canadian breeze and I have several acres to take care of. I have to restrict my on-line time to coffee breaks so I really do not have the time to look up the links for my paper collection which is a few hundred megabytes at this time. You and chris can continue believing in the CO2 induced AGW myth if you want to, otherwise investigate like I did.
131567. Quietman at 05:32 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Undersea vulcanism - more than just eruptions and those eruptions do not cause cooling, they cause warming. This is not atmospheric ejecta. You have done your CO2 homework, not study up on vulcanism and plate tectonics, geomagnetism and ocean forcings.
131568. Quietman at 05:28 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        chris "This notion seems to be creeping in, in an unsubstantiated manner!" It is unsubstantiated only to a few deniers. At all the other columns and blogs I have read, it is acknowledged. The world around you sees the increased vulcanism, why don't you? Or are you confusing vulcanism with eruptions? And don't bother to quote Hansen, he has too much to lose by admitting that he started this whole thing in error, rendering his work useless.
131569. chris at 05:09 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Re "vulcanism" This notion seems to be creeping in, in an unsubstantiated manner! So it's worth pointing out that volcanic eruptions generally result in short periods of cooling due to the release into the high atmosphere of volcanic aerosols that are relatively quickly washed out of the skies. This is an obvious and well-documented effect of volcanos. Thus the eruption of Pinatubo and the subsequent trosposphere and ocean surface cooling "pulse" was useful in analysing the response of the Earth to reduced forcing and the rate of recovery after superficial cooling, and so on: e.g.: Soden BJ et al (2002) Global cooling after the eruption of Mount Pinatubo: A test of climate feedback by water vapor, Science 296, 727-730. And very large volcanic eruptions are well known for their rather unpleasant cooling effects (e.g. Tambora and the subsequent "year without a summer"). We've had quite a few volcanic eruptions since the middle of the last century, and so the global temperature rise has been periodically "knocked back" by these cooling "pulses": e.g. see Figure 1 of: http://pubs.giss.nasa.gov/docs/2005/2005_Hansen_etal_1.pdf So if someone has a notion that "vulcanism" is contributing to global (or regional) warming, then a little bit of substantiation with some scientific evidence would be nice!
131570. Philippe Chantreau at 04:01 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Shawnet, the ice area is actually very close to what it was last year, due to a period of fast melting in the spring: http://nsidc.org/data/seaice_index/images/daily_images/N_timeseries.png Quietman, you say " have seen evidence cropping up everywhere for increased worldwide vulcanism since 1976." Can you point to papers where that evidence is compiled and (better) analyzed?
131571. Quietman at 03:27 AM on 28 June 2008
        Volcanoes emit more CO2 than humans
        Some evidence: "Healy Researchers Make A Series Of Striking Discoveries About Arctic Ocean" — Contrary to their expectations, scientists on a research cruise to the Arctic Ocean have found evidence that the Gakkel Ridge, the world's slowest spreading mid-ocean ridge, may be very volcanically active. They also believe that conditions in a field of undersea vents, known as "black smokers," could support previously unknown species of marine life ScienceDaily (Nov. 29, 2001) "Fire Under Arctic Ice: Volcanoes Have Been Blowing Their Tops In The Deep Ocean" — A research team led by the Woods Hole Oceanographic Institution (WHOI) has uncovered evidence of explosive volcanic eruptions deep beneath the ice-covered surface of the Arctic Ocean. Such violent eruptions of splintered, fragmented rock--known as pyroclastic deposits -- were not thought possible at great ocean depths because of the intense weight and pressure of water and because of the composition of seafloor magma and rock. ScienceDaily (June 26, 2008) I would think that this is an indication of increased vulcanism.
131572. Quietman at 02:54 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Philippe No more than AGW did, neither is about 2007. Both are about recent warming. I have seen evidence cropping up everywhere for increased worldwide vulcanism since 1976 but it has been steadily ignored. Am I the only one making the solar connection? Gravitational stress stronh enough to effect the sun has to also be more than strong enough to effect the earth's inner circulation.
131573. chris at 02:43 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Shawnet, There are two questions aren't there! (a) What's caused the remorseless attenuation of arctic sea ice since the 1960's? (b) What's caused the massive excess summer melt in 2007? and you also asked again: (c) why the difference betwen the Nrthn. and Srthn. hemisphere? Question (b) has been more or less answered (see the excellent summary of the science by John Cook at the top of the page). It seems that the remorseless attenuation of arctic sea ice since the 1960's has made the ice sheet very vulnerable to short term summer "weather" conditions. Note that while the winter arctic sea ice extent has recovered a tad, it's the summer sea-ice extent that is the critical factor, and so we'll have to wait to see to what extent 2007 was a recoverable blip. Question (c) has been answered pretty much (see posts #66/#69) The differences in the effects of global warming on Antarctic and Arctic are reasonably well defined. It's largely a question of sea and ocean currents and the way that excess heat is distributed from the lower latitudes to the higher. There may be some BC contribution. After all there is little BC found in the Antarctic (on the other hand the cooling aerosols also predominate in the Arctic cf the Antarctic). Vulcanism is a red herring I suspect [for (a), (b) and (c)]. It doesn't make a lot of sense at all. One needs to make a clear cut explanation of how this "vulcanism" works. At the very least one needs to address the facts that: (i) the most volcanically-active region in the the Arctic or Antarctic is the area in and around Iceland (an eruption every 5 years on average; 1/3'd of all lava expelled in the last 500 years is in Iceland which not only sits astride the opening of the plates running along the opening Atlantic basin, but also above a "mantle plume")... ...however the region around Iceland and S. Greenland is the one area of the Arctic that has actually cooled a tad since the 1960's. How can "vulcanism" be an explanation for marked warming when the most volcanically-active region has cooled??? (ii) The vulcanism in the Arctic (and Antarctic) is of long-long-standing (millions of years). Without some evidence that this vulcanism has (a) all of a sudden increased markedly in the relevant regions and periods, (b) that any thermal energy is of a magnitude and appropriately distributed to contribute to the observed melt, and so on....one should remain rather skeptical of such a notion. Question (a) has an explanation that is well-supported by the scientific evidence: massive enhancement of the Earth's greenhouse effect. The warming in the arctic is pretty much as expected from supplementing the Earth's greenhouse gases with extra CO2, methane, nitrous oxides, tropospheric ozone and CFC's. There may well be a significant contribution from BC although we've had pretty much all the forcing from that source already according to Hansen and Nazarenko, and it's not clear that the warming effect of BC has been greater than the cooling effect of other manmade aerosols. Certainly according to Hansen, and Ramanathan and Carmichael, the total worldwide aerosol effect (BC et al) is a cooling one. It may be net warming in the arctic 'though. One would have to look at the numbers carefully, if the appropriate one's are available.
131574. shawnhet at 01:12 AM on 28 June 2008
        Arctic sea ice melt - natural or man-made?
        Chris, "Hansen and Nazarenko point out that the BC emissions that affect the arctic (mostly from Eurasia) dropped sharply in the 1990's due to the breakup of the former Soviet Union. So, again, that tends to argue against the contribution from BC as a major contributor to the acceleration of artic sea ice recession since around 2000, let alone the very dramatic anomalous drop of summer sea ice last year. Presumably the reduction in total aerosol load from Eurasia will have both "cooling" effects (reduction of BC component) and "warming" effects (reduction of aerosol screening of surface solar irradiation), so things are unlikely to be straightforward!" I agree that BC is unlikely to be a major contributor in the last year. This is likely the result of a natural confluence of factors, especially considering that the sea ice extent has already rebounded to around the 2001-2002 levels.(http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg). Much more interesting IMO is why the Antarctic and Arctic changes are in opposite directions for the last while. BC may go part of the way to explaining this though it probably can't explain the whole thing. I wouldn't be surprised if the trend is the result of many things, possibly including ocean currents, BC and vulcanism. Cheers, :)
131575. Philippe Chantreau at 16:36 PM on 27 June 2008
        Arctic sea ice melt - natural or man-made?
        Are you suggesting that the 1999-2001 events melted the ice in 2007?
131576. Quietman at 15:20 PM on 27 June 2008
        Arctic sea ice melt - natural or man-made?
        John I think we are finding a little more evidence of my vulcanism hypothesis: "International expedition discovers gigantic volcanic eruption in the Arctic Ocean" Please read Fire under the ice Public release date: 25-Jun-2008, (natural causes).
131577. Renfield at 13:25 PM on 27 June 2008
        There is no consensus
        If the Caribbean Academy of Sciences and the Royal Irish Academy endorse man made global warming can any person with a conscience still doubt? Mr Hansen from NASA's Goddard Institute thinks the doubters should be punished. Shouldn't they be given the opportunity to recant? Water boarding causes no lasting damage and requires no carbon use whatsoever, unlike burning at the stake, etc. Mr. Hansen let slip a prediction for the future. "All the Arctic sea ice will be gone in five to ten years." Going out on a limb, isn't he. He might be alive to reap the ricicule. I've marked my calendar: "Look for hell fire and inundation". For now, I'll keep the beach property.
131578. Quietman at 12:02 PM on 27 June 2008
        Can animals and plants adapt to global warming?
        Looks like we did it again" "'Unintended Consequence' The decision to place polar bears under the protection of the Endangered Species Act came in response to the continued "loss of sea ice," the bear's natural habitat, that would put them "at risk of becoming endangered in the foreseeable future," according to a statement by the Department of the Interior on May 14. There is no mention that the danger to polar bears stems from hunting. In the same statement, Secretary of the Interior Dirk Kempthorne specifically noted that "limiting the unintended harm to the society and economy of the United States" was a concern. What did not seem to be a priority, however, was the harm to the economy in Arctic Canada, home to about two-thirds of the world's polar bear population, which is estimated at 20,000 to 25,000." [ABC (US) News]
131579. chris at 08:29 AM on 26 June 2008
        Arctic sea ice melt - natural or man-made?
        Yes, fair enough...notice however that Hansen and Nazarenko: (i) conclude their abstract with ["However, soot contributions to climate change do not alter the conclusion that anthropogenic greenhouse gases have been the main cause of recent global warming and will be the predominant climate forcing in the future"] and: (ii) have, in their more recent work downgraded the role of black carbon/snow/ice albedo effects. The paper you cited is here: J. Hansen and L. Nazarenko (2004) Soot climate forcing via snow and ice albedos; Proc. Natl. Acad. Sci 101 423-428 (abstract below [*]) The paper can be downloaded from NASA/GISS: http://pubs.giss.nasa.gov/docs/2004/2004_Hansen_Nazarenko.pdf Note that Hansen and Nazarenko assign a total black ice/albedo forcing of 0.15 W/m2 and a total contribution to global warming since 1880 of 0.17 oC. However they later reassess this and downgrade the contribution of black ice/albedo forcing to 0.05 W/m2 (and total contribution to global warming of 0.065 oC) in their more recent study: Hansen, J. et al (2007) Climate simulations for 1880-2003 with GISS modelE. Clim. Dynam., 29, 661-696. (see Appendix A5) This can also be downloaded from NASA/GISS: http://pubs.giss.nasa.gov/docs/2007/2007_Hansen_etal_3_small.pdf A recent study by Flanner et al (2007), concludes that the BC effect in the arctic has been quite significant too [**]. Hansen and Nazarenko point out that the BC emissions that affect the arctic (mostly from Eurasia) dropped sharply in the 1990's due to the breakup of the former Soviet Union. So, again, that tends to argue against the contribution from BC as a major contributor to the acceleration of artic sea ice recession since around 2000, let alone the very dramatic anomalous drop of summer sea ice last year. Presumably the reduction in total aerosol load from Eurasia will have both "cooling" effects (reduction of BC component) and "warming" effects (reduction of aerosol screening of surface solar irradiation), so things are unlikely to be straightforward! e.g. Hansen and Nazarenko (2004) say: ["Snow samples in the 1980s (6), including sites in Alaska, Canada, Greenland, Sweden, and Spitzbergen, and on sea ice in the central Arctic, yielded typical BC amounts of 10–50 ppbw (excluding Greenland). "Arctic haze" studies (19) showed that most of the aerosols originated in Europe and the Former Soviet Union (FSU) in winter/spring driven by circulation around the Icelandic Low and Siberian High. BC emissions from Eurasia probably declined sharply in the 1990s as, e.g., FSU BC emissions fell by a factor of four with the collapse of the FSU economy (20). Reduced BC emissions are not necessarily permanent in the face of possible economic recovery, increased shipping in the opening Northwest and Northeast Passages, regional hydrocarbon resource development, and increased use of diesel-powered vehicles."] Hansen and Nazarenko (2004) abstract [*] "Plausible estimates for the effect of soot on snow and ice albedos (1.5% in the Arctic and 3% in Northern Hemisphere land areas) yield a climate forcing of +0.3 W/m2 in the Northern Hemisphere. The "efficacy" of this forcing is 2, i.e., for a given forcing it is twice as effective as CO2 in altering global surface air temperature. This indirect soot forcing may have contributed to global warming of the past century, including the trend toward early springs in the Northern Hemisphere, thinning Arctic sea ice, and melting land ice and permafrost. If, as we suggest, melting ice and sea level rise define the level of dangerous anthropogenic interference with the climate system, then reducing soot emissions, thus restoring snow albedos to pristine high values, would have the double benefit of reducing global warming and raising the global temperature level at which dangerous anthropogenic interference occurs. However, soot contributions to climate change do not alter the conclusion that anthropogenic greenhouse gases have been the main cause of recent global warming and will be the predominant climate forcing in the future." [**]M. G. Flanner et al (2007) Present-day climate forcing and response from black carbon in snow, J. Geophys. Res. 112, D11202
131580. shawnhet at 06:00 AM on 26 June 2008
        Arctic sea ice melt - natural or man-made?
        Here's an alternative POV, "Fig. 6 shows the change in surface albedo in our transient climate simulation for 1880–2002 for March to April and May to June. The specified spectral-mean snow albedo changes were 0.83 × 1.5% ~ 1.25% for snow/ice in the Arctic Ocean and 0.83 × 3% ~ 2.5% for snow over Northern Hemisphere land. The surface albedo changes are diminished over land by vegetation masking of the snow (14), which is very effective in forested areas but ineffective in tundra regions with little vegetation. The warming of the surface and air due to the soot albedo effect enhances the surface albedo changes over both land and ocean because of enhanced snow aging (increased grain size) and especially because of the earlier onset of spring melt. Thus, the soot-lowered albedo and increased temperatures initiate positive feedbacks via earlier snowmelt and rainfall. Fig. 5 shows the change in the net short-wave heating of the surface for the same periods as in Fig. 6. Note that the regional flux changes at the surface are as much as 10 W/m2 and more. This compares with a typical annual-mean forcing of <1 W/m2 (Fig. 1). Clarke and Noone (2) calculated a maximum May-to-June surface flux perturbation of ≈6 W/m2 for an assumed snow albedo perturbation of 2%. Given that our soot-imposed albedo change for the period 1880-2002 was only ≈1.25% (over sea ice), this means that we find a surface heating about twice as large as that calculated by Clarke and Noone (2). The cause of this difference is the positive feedbacks in our climate model that reduce the albedo further, especially the acceleration of the summer melt season. Our results are not in disagreement with those of Clarke and Noone (2), because they mentioned in their concluding remarks the likelihood that such positive feedbacks would enhance the soot albedo effect. These positive feedbacks, especially the acceleration of the melt season, have practical implications. The perturbations of surface fluxes are largest in the regions of sea ice, permafrost, glaciers, and the low altitude portion of the Greenland ice sheet that is subject to summer melt. This suggests that soot may contribute to thinning of sea ice (16), melting permafrost, glacier retreat, and accelerating movement of Greenland ice (17)." http://www.pnas.org/cgi/content/full/2237157100/DC1/2 Soot climate forcing via snow and ice albedos James Hansen * , and Larissa Nazarenko * Cheers, :)
131581. chris at 04:40 AM on 26 June 2008
        Arctic sea ice melt - natural or man-made?
        shawnet, It's a reasonable possibility for a contribution....particles of soot lying on the ice might have a significant effect. You can see a similar effect walking in the mountains in the spring...where snow has melted back enough that rocks are poking out of the snow, there's usually a clear melt zone (like an empty "moat") around each rock, due to the absorbance of solar heat by the rock and the radiation of that warmth to the surrounding snow. According to one of the scientists that leebert referred to, and work published in Science last year [*], that might have had a significant effect in the arctic. However, according to a detailed analysis of black carbon found directly in Greenland ice cores [*], the largest deposition of "soot" (black carbon) was in the early to mid 20th century. The estimated early summer surface forcing was ~ 0.42 W/m2 before 1850, 1.13 W/m2 in 1850-1951 (and as high as 3.2 Wm2 in the early 20th century). It’s been around 0.59 W/m2 since 1951 to present. So at least by that analysis, soot on arctic ice (at least to the extent that Greenland ice cores are relevant) may not be having much more of an effect now than it was before 1850, although it may well have contributed to the attenuation of sea ice in the early part of the 20th century, when there was quite a sharp rise in arctic temperatures too... [*] J. R. McConnell et al (2007) 20th-century industrial black carbon emissions altered arctic climate forcing; Science 317, 1381-1384.
131582. shawnhet at 01:52 AM on 26 June 2008
        Arctic sea ice melt - natural or man-made?
        Just spitballing here, but mightn't a possible explanation be that the cooling aerosols affect temperature generally (ie all the air) whereas soot has a highly concentrated effect. A particle of soot lying on an ice sheet will heat up directly on that ice sheet and will only affect the air temperature after that heat radiates out. Thus, soot could have a small overall heating(air temperature) affect and a large *melting* effect. Cheers, :)
131583. chris at 20:41 PM on 25 June 2008
        Arctic sea ice melt - natural or man-made?
        Quietman, Tung and Camp are pretty clear about their meaning in relation to climate sensitivity. You've done what you did with the Stjern paper, and are constructing you’re entire “argument” around extraordinary selective précis based on selective quoting. That’s not science and it ain’t skepticism either! Notice that the bit you’ve just reproduced (in your post #79) from Tung and Camp’s conclusion leaves out completely the second element of Tung and Camp’s analysis which is to use their analysis to calculate a value for the climate sensitivity. Let’s look carefully at Tung and Camp. (here’s the url:) http://www.amath.washington.edu/research/articles/Tung/journals/solar-jgr.pdf We are concerned here with what Tung and Camp mean when they refer to the “climate sensitivity” and whether this calculated “climate sensitivity” is in accord with the large number of independent studies that have been compiled by the IPCC to yield a “climate sensitivity”, which in standard usage, refers to the Earth’s equilibrium temperature response to a doubling of atmospheric [CO2]. Since doubling of atmospheric CO2 results in an enhanced radiative forcing of around 3.7 W/m2, one could also express the “climate sensitivity” in terms of the Earth’s equilibrium warming response to an enhanced radiative forcing of 3.7 W/m2. The mainstream scientific data compiled by the IPCC indicates that the Earth’s “climate sensitivity” is equivalent to a warming of 3 oC, plus/minus a bit at 95% confidence of warming due to doubled atmospheric [CO2]. Explicitly the 96% confidence range is 1.5-4.5 oC of warming per doubling of atmospheric [CO2] – this is the “climate sensitivity”. Tung and Camp’s manuscript (urled above) is numbered line by line throughout, so we can indicate clearly to what we are referring. Note that at this point we’re not interested in whether Tung and Camp is wrong or right - we’re taking their paper and its analysis at face value, and trying to make a clear interpretation of what they mean: (i) Clearly Tung and Camp’s measure of climate sensitivity is very similar to that of other mainstream science. It’s near 3 oC plus/minus a bit at 95% confidence level. The range is a bit tighter that that complied by the IPCC. That’s obvious from what they say in reference to their calculated climate sensitivity (see lines 16-18 in the abstract): [“This model-independent, observationally-obtained climate sensitivity is equivalent to a global double-CO2 warming of 2.3 -4.1 °K at equilibrium, at 95% confidence level.”] (ii) Do Tung and Camp mean by “climate sensitivity” what everyone else means by “climate sensitivity”. In other words are they referring to the forcing resulting from a doubling of atmospheric [CO2]? Yes. In lines 32/33 they say (referring to their estimate of the forcing from the solar cycle minimum to the maximum) : [“This solar radiative forcing is about 1/20 that for doubling CO2 (δQ~3.7 Wm-2).”] So they are in accord with the straightforward analysis that doubling [CO2] yields a radiative forcing of 3.7 W/m2 (iii) Do Tung and Camp agree that the IPCC complied data yields a 95% confidence range of “climate sensitivity” of 1.4 – 4.5 oC per doubling of atmospheric [CO2]? Yes. In lines 46-49, they say: [“Confidence in these models would be greatly increased if their climate sensitivity---currently with a factor of three uncertainty, yielding 1.5 °K to 4.5 °K equilibrium warming (ΔT2xCO2) due to a doubling of CO2 in the atmosphere [Houghton and et al., 2001]---can be calibrated against nature’s.”] (iv) Does the climate sensitivity calculated by Tung and Camp refer to the equilibrium warming resulting from a radiative forcing from doubling atmospheric [CO2]? Yes. In lines 51-55, they indicate that their method of determining the climate sensitivity will allow information about future CO2 forcing: [“Since the forcing is known, contrasting solar-max and solar-min years over multiple periods yields a pattern of earth’s forced response, which is better than previous attempts of using “warm-year analogs in recent century”--- some of which may be due to unforced variability --- to infer information relevant to future CO2 forcing.”] (see vi) and (vii) too! (v) Do Tung and Camp think that their “best value” of the climate sensitivity is nearer 2.3 oC rather than 3 oC? No. Tung and Camp’s value of 2.3 oC per doubling of atmospheric [CO2] (or per radiative forcing of 3.7 W/m2) is a lower bound: lines 373-377: [“Fortunately, a period of 11years is long enough to yield a useful lower bound. We can combine our lower bound, obtained completely independent of models, with the upper bound obtained also in a model-independent way by Forster and Gregory [2006] (subject to the assumption of priors mentioned above) to yield the following 95% confidence interval:”] and: lines 382-383: [“The lower bound of 2.3 °K happens to be the same as the model-derived value (2.4 °K) of Murphy et al [2004] after converting it into the 5-95% range of the latter; it is ~1 °K higher than the previous IPCC lower bound.”] and Tung and Camp explicitly state that they consider that the climate sensitivity is near 3 oC lines 364-366: [“Nevertheless, since the observed time lag in the solar-cycle response is small (see Appendix), our best guess is that the equilibrium climate sensitivity should not be too different from 3.0 °K.”] (vi) are Tung and Camp really talking about a climate sensitivity that is equivalent to the earth’s equilibrium surface warming due to a doubling of atmospheric [CO2}? Yes. The entire discussion leading up to their determination of climate sensitivity is done within the framework of previous determinations of values for the climate sensitivity, which is the Earth’s surface temperature warming at equilibrium in response to doubling atmospheric [CO2] (see lines 287-355) (vii) are we absolutely sure?! Yes. Tung and Camp express their climate sensitivity value explicitly in terms of a temperature range encompassing the 95% confidence levels that result from a doubling of atmospheric [CO2]: See their equation 2 (line 379) in which their climate sensitivity value is expressed as its range at 95% confidence: 2.3 °K< ΔT2xCO2 <4.1 °K . (“2xCO2” is subscripted) This can be stated verbally as: “2.3 degrees Kelvin is less than the change in temperature from doubling [CO2], which is less than 4.1 degrees Kelvin” And they’ve already assured us [see point (iii) above] that “deltaT2xCO2” means “equilibrium warming due to a doubling of CO2 in the atmosphere”.
131584. chris at 20:35 PM on 25 June 2008
        Arctic sea ice melt - natural or man-made?
        (i) Quietman, science has its basis in straightforward presentation of data and honest discussion of that data and its interpretations. Skepticism is not about using semantic confusion and misrepresentation to attempt to make things appear other than they are [In this case your assertion that Stjern et al (1980) and my comments are not consistent!]. And one should read papers carefully and look at the data presented. It would be a wonderful piece of work that didn’t contain one or two sentences that, taken in isolation, could be construed to mean something that wasn’t quite consistent with the data and interpretation presented. But one shouldn’t hunt out these sentences/phrases, and attempt to construct an “argument” on them! See paragraph (iii) below. (ii) The bottom line is that (as John Cook outlines clearly in his top article, as does Kay et al, 2008, and so on), the evidence indicates that the anomalous arctic sea ice melt last summer is a consequence of a long term (30-40 years) persistent attenuation of arctic sea ice due to global warming and albedo feedbacks, on which a hardly-anomalous “weather” occurrence acted on an already-denuded and thinned ice sheet. (iii) Since the total solar irradiance measured at the surface has diminished during this long period according to the manuscript that you highlighted [down from 115 W/m2 around 1960, to a low near 103 W/m2 in the late 1980’s to a partial recovery to around 106/7 W/m2 now – see Figure 3 of Stjern et al (2008)], one can conclude that the nett contribution of aerosols in the arctic during the long period of attenuation of sea ice since the 1960’s has been a cooling one. In other words aerosols have protected the arctic sea ice from the full effects of enhanced-greenhouse-induced warming. The paper that leebert brought to our attention (Ramanathan and Carmichael; e.g. see posts #39, #48), makes a similar conclusion for the total aerosol contribution on a worldwide basis, which of course indirectly affects the arctic since it’s the transfer of excess thermal energy to the high northern latitudes that is a major contributor to the marked warming there. Might the apparent reduction in the aerosol effect in the arctic in the last 10 years have contributed to the more rapid attenuation of sea ice since the turn of the century? Yes of course (see post #78). However the aerosol “dimming” effect is (according to Stjern et al, 2008) still larger than in the 1960’s. In any case a reduction of “dimming” is not something we take much comfort from. As Ramanathan and Carmichael point out, clearing the skies of our aerosols will have the effect of further enhancing the warming resulting from our large enhancement of the earth’s greenhouse effect. And of course the aerosol effect, whether it’s increasing or decreasing, is another man-made contribution to the earth’s energy “budget”. That’s clear again I hope. I've repeatedly reiterated my meaning (in posts #19, #76, #78, and now here)..I'm not sure I can say it more clearly!
131585. BARRYBEAR at 15:54 PM on 25 June 2008
        Arctic sea ice melt - natural or man-made?
        I have been telling people for years that there is a huge difference between natural warming and Human related warming. One big problem with most Environmental scientists is that they apparently have never studied other sciences, and for the most part know which side of the warming "bread" holds the butter. By which I mean that there is little or no research money for scientists who don't toe the Warming line. Take polar ice melting for example. I can name some people who are quite glad, even if they don't know it, that the poles are melting. The people of the state of Texas. Remember Glaciers once covered most of what we now call North America. These glaciers have been receeding for thousands of years. We human types have only been measuring these changes for a few hundred years at best and tend to think that the Earth is a static place. It is not static. Here is a great example of what I mean. According to www.glacierbay.org when George Vancouver first sailed into Icy Strait in 1794 Glacier Bay was but a dent in a "Grand Pacific Glacier" some 4000 feet thick in places and some 20 miles wide. By 1879 when John Muir explored the bay the glacier had receeded some 30 miles, all without the help of humans, their cars and coal fired power plants. Lets face it the poles have been melting for a long time. Does that mean we should continue to burn fossil fuels at today's alarming rate? Hell no. Even if those fuels didn't pollute the Earth it would make best sense to use solar, wind and other renewable sources. Will we end up like Venus or Mars? Hell no. Venus is just too close to the sun and Mars lost it's atmosphere because it's core cooled and the magnetic field that protects a planet's atmosphere was lost. Are we destroying the Earth? Again no. We may not be able to live here anymore, but the Earth will be just fine.
131586. Quietman at 15:13 PM on 25 June 2008
        Arctic sea ice melt - natural or man-made?
        chris at 01:33 AM on 19 June 2008 (#76) "re #75: That's a tad dishonest Quietman" Re: (ii) "solar brightening from lack of aerosols". Nope. The atmospheric aerosol load has increased rather significantly since the 1960's. Thus enhanced Arctic sea ice melt has increased despite the overall decreased solar irradiation reaching the surface. Rather than "solar brightening" we've actually had a bit of "solar dimming". This is consistent with the paper that you cited (Stjern et al (2008); urled below[***], in which solar irradiation reaching the surface is averaged over 11 high Northern latitude stations as an indication of "dimming"/"brightening". IN Global dimming and global brightening - an analysis of surface radiation and cloud cover data in northern Europe BY Camilla W. Stjern1,2 , Jón Egill Kristjánsson1 and Aksel Walløe Hansen3 IT CLEARLY STATES IN QUITE PLAIN ENGLISH THE FOLLOWING: "In the more recent decades, most of our stations show a turn to brightening, which agrees with the new global trend described by Wild et al.(2005)." "While Stanhill (1995) reported of widespread dimming in the Arctic up to the mid-1990s, the present study shows a turn to brightening also here." We are not talking about 1995 - this is about an event in summer 2007. That is what I mean when I say something is dated. Things have changed in the last few years. "Using NCEP reanalysis data that span four and a half solar cycles, we have obtained the spatial pattern over the globe which best separates the solar-max years from the solar-min years, and established that this coherent global pattern is statistically significant using a Monte-Carlo test. The pattern shows a global warming of the Earth’s surface of about 0.2 °K, with larger warming over the polar regions than over the tropics, and larger over continents than over the oceans. It is also established that the global warming of the surface is related to the 11-year solar cycle, in particular to its TSI, at over 95% confidence level." From the Conclusion: Solar-Cycle Warming at the Earth’s Surface and an Observational Determination of Climate Sensitivity. By Ka-Kit Tung and Charles D. Camp This is compared (equated) EQUIVALENT TO CO2 MODELING - NOT CAUSED BY CO2. THIS ALSO IS PLAIN ENGLISH. You can not expect someone to reply to arguments based on interpretations of papers that only support their own view rather than the authors conclusions.
131587. Quietman at 04:52 AM on 25 June 2008
        There is no consensus
        RobetS Re: "-2004 Volcanology (you can argue here if you want)" Probably the best of all sources listed. They have a better understanding of internal forcing than anyone else other than these groups: -4736 Hydrology -2326 Ocean sciences But where are the astronomers?
131588. Quietman at 04:44 AM on 25 June 2008
        Global warming stopped in 1998, 1995, 2002, 2007, 2010, ????
        Lee Logical assumption. The upwelling flow, warm or cold, effects ENSO and the Air currents, hence weather and climate. The resulting flows within the ocean I have not looked into but it would be interesting to know. Anyone?
131589. Quietman at 03:33 AM on 25 June 2008
        It's the sun
        TruthSeeker Recent attention has been on "Arctic sea ice melt - natural or man-made?" if you feel up to beating your head against a wall.
131590. Quietman at 03:28 AM on 25 June 2008
        April update on global cooling 2008
        Addendum to post 11 No records set and we are back to temps below to about historic average. WA may have been right on this prediction, at least in the NE U.S.
131591. Second order skeptic at 22:45 PM on 24 June 2008
        Antarctica is gaining ice
        AnthonySG1: Your images are concerned with the ice _area_ . Ice _mass_ on the other hand is shrinking. http://www.jpl.nasa.gov/news/news.cfm?release=2008-010
131592. TruthSeeker at 03:56 AM on 24 June 2008
        It's the sun
        Wow, my post has been up for 12 days, with no responses refuting the challenges to the theory of global warming that I posted? Does this mean that there is no credible scientific evidence to support the theory of global warming when it is confronted with these challenges?
131593. TruthSeeker at 22:41 PM on 23 June 2008
        It's the sun
        Wow, my post has been up for 12 days, with no responses refuting the challenges to the theory of global warming that I posted? Does this mean that there is no credible scientific evidence to support the theory of global warming when it is confronted with these challenges?
131594. chris at 22:47 PM on 21 June 2008
        A new twist on mid-century cooling
        This is a bit "storm in a teacup"-ish. It doesn't really change anything but does help to understand the anomalous "warm then cool" bump in the 1940's which seems to be asociated with sea surface temperatures as John Cook's article describes. Another odd observation that isn't often discussed is the apparent levelling off of atmospheric [CO2] between 1940-1955. This has been described in the original Antarctic Law Dome ice-core high resolution atmospheric [CO2] record, and in the updated version (extended back to 2000 years BP) it's still there [***]. i.e between 1940 and 1955 atmospheric [CO2] rose only by 2 ppm (from 310 ppm to 312 ppm). The authors propose an enhanced ocean uptake during this period. Like BrettC one wonders whether the war had anything to with this! [***]Meure, CM et al. (2006) Law Dome CO2, CH4 and N2O ice core records extended to 2000 years BP Geophys. Res. Lett., 33 L14810. Abstract: New measurements of atmospheric greenhouse gas concentrations in ice from Law Dome, Antarctica reproduce published Law Dome CO2 and CH4 records, extend them back to 2000 years BP, and include N2O. They have very high air age resolution, data density and measurement precision. Firn air measurements span the past 65 years and overlap with the ice core and direct atmospheric observations. Major increases in CO2, CH4 and N2O concentrations during the past 200 years followed a period of relative stability beforehand. Decadal variations during the industrial period include the stabilization of CO2 and slowing of CH4 and N2O growth in the 1940s and 1950s. Variations of up to 10 ppm CO2, 40 ppb CH4 and 10 ppb N2O occurred throughout the preindustrial period. Methane concentrations grew by 100 ppb from AD 0 to 1800, possibly due to early anthropogenic emissions.
131595. Quietman at 05:16 AM on 21 June 2008
        There is no consensus
        Apparently the number has increased for this new petition. In an article dated Monday, May 19, 2008 it says 31,000 Scientists Debunk Al Gore and Global Warming. Anyone know about this one?
131596. Austerlitz at 00:59 AM on 21 June 2008
        CO2 lags temperature
        If the following assertion is true: "The CO2 record confirms both the amplifying effect of atmospheric CO2 and how sensitive climate is to change." Then how can the downturns of the cycle, cooling, be explained in the presence of the elevated and lagging CO2? The hypothesis: Milankovitch cycles warm the oceans, and release C02 which amplifies the warming. That explains why C02 lags initial warming, and also causes the overall increase. However, this does nothing to explain the temperature decrease. With so much C02 driven temperature increase, how could temperature possibly decrease in the cycle? What is the feedback mechanism? The arguments above explain only half the model, and describe a system that would spiral to out of control heating until leveling. These arguments fail to explain the cycle's cooling phase. Without a convincing answer to that, the assertion that C02 has a causal relationship to temperature is false.
131597. Brian H at 09:03 AM on 20 June 2008
        CO2 lags temperature
        Errata: Nordhaus. And a comment: I think what falls out of this is that CO2 is simply irrelevant, except insofar as it supports increased plant growth, and costs resources in a futile attempt to control it. If it made any difference, maximizing it to prevent Global Cooling would be a good idea, but ...
131598. Brian H at 08:57 AM on 20 June 2008
        CO2 lags temperature
        Icebert; You will be fascinated to read Freeman Dyson's review of Norhaus' economic model of the next century of consequences to various GW solutions, taking GW as given. Among other intriguing findings: Kyoto makes little net difference; Gore's solutions are the Full Monte disaster; and the optimum is a "low-impact backstop" alternate carbon-free technology. Enjoy! http://www.nybooks.com/articles/21494
131599. chris at 07:08 AM on 20 June 2008
        The Mystery of the Vanishing Ocean Heat
        "flipping to the last page"? Perhaps not, but a report in Nature today goes at least some way to sorting out the inconsistencies between apparent ocean cooling and continued sea level rise in recent years: C.M. Domingues et al (2008) Improved estimates of upper-ocean warming and multi-decadal sea-level rise, Nature 453, 1090-1093 (19 June issue) http://www.nature.com/nature/journal/v453/n7198/abs/nature07080.html The paper describes corrections to ocean heat content measures with various independently identified biases [ARGO as described in the top article, and XBT's (expendable bathy-thermographs which had various ocean depth calibration errors]. The rise in ocean heat content is now rather more "regular" without the very large apparent decrease in heat content in the early 80's (see Fig 3 in John Cook's top article), matches pretty well the expected sea level rise expected from ocean thermal expansion, and the variability seems to have a signature of the various volcanic eruptions of the last 50 years....
131600. LAI at 05:34 AM on 19 June 2008
        Cartoon about global warming alarmism
        frankbi/Quietman I'd suggest reading Walter Williams, Henry Hazlitt or others on this idea before you write it off as completely "looney." I find it hard to disagree with anything "green" these days, but his logic is sound. Trashing a conservationist idea because it violates sound economic principle might well be missing the bigger issue, but attacking the logical economic theory doesn't make sense either. We need to find the common ground that everyone can buy into. Good article by Williams here: http://tinyurl.com/4oeufl and for Hazlitt I'd point you to this book: http://tinyurl.com/529bop.

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