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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 101851 to 101900:

  1. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Climatewatcher, The effect of insolation on climate is a weak radiative forcing but just enough to cause initial changes which are amplified by greenhouse gas increases that the initial perturbations causes. The important thing that you are missing is that the Holocene Climatic Optimum occurred at different times for different places. This is largely due to the feedback mechanisms and climatic controls of the ice sheets which were still melting away. You have to also consider that sea levels were higher during the Holocene optimum and Dr. Alley suggested by as much as 0.5 m which is not an insignificant amount. Globally temperatures over that period were not much warmer than today (at most 1°C) indicating a high sensitivity from ice as most of the glaciers in the northern hemisphere disappeared at that time and greenland was smaller. Another important thing that you are missing is the rate of change being different with similar magnitudes, slow changes in temperature give the system more time to reach a new equilibrium state whereas very fast changes (such as the one we are currently causing) can cause chaotic responses.
  2. A Cloudy Outlook for Low Climate Sensitivity
    #87: "The evidence is mounting that CGR's do play a roll in climate. " What evidence? Disclose, man, we're all ears.
  3. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    #18: "Arctic summer encountered much more insolation for thousands of years" Your graphic appears to be a calculated Milankovitch graph a la Hays Imbrie and Shackelton 1976. Interesting that the graph gets prominent play at a denier site (hockeyschtick; they can't even spell shtick correctly). The time scale is in thousands of years. I'm not sure what the relevance of that is for today's situation. One should also wonder about the CO2 concentrations were at the times when arctic summer insolation was so "much more". Compare that CO2 to today. Perhaps that helps explain why "Arctic temperatures weren't much warmer, in spite of much more irradiance ... the polar bears survived". Perhaps the smaller GHE due to lower CO2 moderated that higher irradiance. Look at the whole picture: Warming, Arctic melting with comparatively low insolation and high CO2. Maybe its time to start actually watching the climate rather than the shtick.
  4. The human fingerprint in the seasons
    Just wondering. Why should this be? "Similarly, if global warming was driven by the sun, we should see the stratosphere warming as well as the troposphere." Looking into this, the major cause of warming in the stratosphere is when something gets up there that can absorb solar radiation (like particles from a volcanic eruption). Under normal conditions, Ozone levels are what cause most of the stratospheric warming (absorption of UV energy). What part of the solar spectrum would be absorbed in the stratopshere to cause it to warm?
  5. The human fingerprint in the seasons
    111 muoncounter, From looking through the graphs it seems that El Nino effect has somthing to do with the warmth of the Big Lake. Check out 1998 and you can see a comprable temp.
  6. actually thoughtful at 12:19 PM on 7 December 2010
    Renewable Baseload Energy
    Michael Sweet Here is an MIT study of Spain's wind systems circa 2008. It is fairly lightweight - nothing in there that we haven't seen in this thread. But it does have that "someone else said it" cache. Study or brochure More lightweight research, here in the American Journal of Applied Science 2009 http://www.scipub.org/fulltext/ajas/ajas62204-213.pdf The old standby isn't that bad: http://en.wikipedia.org/wiki/Wind_power_in_Spain Slightly more on grid storage: http://newenergyandfuel.com/http:/newenergyandfuel/com/2010/08/06/the-wind-power-storage-issue/ It seems that at least 20% can come from renewables without any thought of additional storage (Texas). We will eventually figure out how to price in unreliability (you can play with my power and I pay $.15/kWh - you get uninterrupted power, but pay $.20/kWh) - things of that type). There is much talk about the reliability of the grid, but every electrical device can handle a surprise power loss, brownouts and blackouts. Those sites that cannot handle that ALREADY have on-site generators. Because 99.99% reliable means a non-zero amount unreliable. Another point that people don't think about. Too stuck in the 1950s nuclear dreamscape. As I have said - the markets will make it work - we just need to stop the artificial low price of fossil fuels, so the markets get accurate information.
  7. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Well ClimateWatcher @18, I think that you could teach Dr. Alley a thing or two ;) And to think I was worried about this whole AGW/ACC "kerfuffle" ;) Sorry, try again mate-- everything is not going to be just OK. I would/could elaborate but I imagine I'd only be wasting my time. Maybe others here are more patient than I. PS: Can we here assume that you then agree with Rohrabacher's beliefs and misguided understanding of the climate science?
  8. ClimateWatcher at 11:53 AM on 7 December 2010
    How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    #13 The Arctic summer encountered much more insolation for thousands of years during the HCO: If Arctic temperatures weren't much warmer, in spite of much more irradiance, it raises some serious questions about sensitivity. But either way, the polar bears survived, the Inuit thrived, and Greenland's central ice persisted. Further, orbital variation is going impose Arctic melting greater than present for nearly all of the next hundred thousand years anyway.
  9. actually thoughtful at 11:47 AM on 7 December 2010
    Renewable Baseload Energy
    >40% is amazing for any country, anywhere, anywhen. Here is a quote that ties directly to this article: "The surge in wind power last night triggered water pumping stations which transport water into reservoirs. This store of water will then be released over the day generating electricity via water turbines at times of peak demand." short forum entry regarding wind in Spain This article is from November 09, and it references Nov 08 (same thing) - so we know they did it at least 3 times. Sigh. And in the United States we have Republicans threatening to (again) "investigate" the science - this means delay and deny.
  10. A Cloudy Outlook for Low Climate Sensitivity
    Camburn @ 87... From what I gather the evidence is mounting that GCR's play a small role in climate.
  11. Renewable Baseload Energy
    Last spring there were reports that Spain generated 40% of its electricity using wind for around 5 hours. Nameplate is about 11% and expanding at around 30% annualy. I have only seen newspaper reports (goggle "spain 40 percent electricity from wind" and lots of hits come up). Does anyone know how Spains' experience with this amount of energy from wind worked out? Problems? No problems? They are reported to still be increasing their wind capacity so it can't be all bad. Does Spains' energy relate to this thread?
  12. A Cloudy Outlook for Low Climate Sensitivity
    archiesteel@77: Hadcrut data is the source. No.....I will change my statement. Statistics are important. Either you work within the error bars or you don't. I won't go into GISSTEMP and the errors of their Arctic measurements using the 1200K radius method. Prof Hansen will be correcting this I am sure. He is an honorable man. Riccardo@85: The evidence is mounting that CGR's do play a roll in climate.
    Response: Note that the European Centre for Medium-Range Weather Forecasts (ECMWF) have independently determined that the HadCRUT record underestimates the warming record. They've created a reanalysis of Arctic temperatures using an entirely different method to GISSTemp, incorporating a range of sources including surface temperature measurements, satellites, radiosondes, ships and buoys.


  13. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    The first video was painful to watch. Rohrabacher would repeat some long-debunked skeptic myth, Alley would start to explain, then a few seconds into the explanation, Rohrabacher would interrupt him. Good job by Alley not to let Rohrabacher interrupt/talk over him every time though. Rohrabacher gives Danas from California a bad name.
  14. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Ben Santer Mangles Patrick Michaels at minute 39 (ish) at the following link. Catches him lying about indirect versus direct aerosol radiative forcing effects. http://www.c-spanvideo.org/program/ChangePa
  15. actually thoughtful at 08:57 AM on 7 December 2010
    Renewable Baseload Energy
    archiesteel all this and English as 2nd language! I am impressed. No harm, and as I said - we certainly agree that arguments should be made in good faith - and it isn't clear that everyone on this thread has done so. However - still informative. I end up being more optimistic that we can do it - get carbon out of the grid - 30% nuclear (a 50% increase for the United States) provides baseload- does what it does best - always on power) 5% hydro (because we already have it) and 65% renewables (with grid storage, which, as this post points out, is well on its way). We keep 20% of the total in gas plants that are ready to turn on. In the (near) future - electricity will be much more expensive at night, rather than in the day (hardest for renewables at night). The thing that is always missing from conversations of this type is - what will the market do? How will we react to the new reality? Probably pretty close to what we do now - by minimizing our costs. I imagine refrigerators will just turn off from 3am to 7am (by talking to the smart grid and seeing power is expensive). SOME of the necessary changes are as painless as that. Some are more intrusive - but there is nothing here that can't be done.
  16. Renewable Baseload Energy
    @actually thoughtfull: my apologies, I guess I wasn't clear enough in my original post. I was simply making the case that saying "I'm right" isn't in itself a rational argument - which is why I was suprised when you disagreed. I'm usually pretty clear in English, even though it's not my native tongue, but I still manage to be unintentionally ambiguous from time to time. Note that by "misinterpret" I do not mean "misrepresent". The latter implies malice, the former does not. Finally, I had you confused with someone else earlier, there was no prior minsinterpretation (as in misunderstanding). My bad, once more. Please accept my apologies, I'll try to be clearer in the future.
  17. A Cloudy Outlook for Low Climate Sensitivity
    @Eric: what Ricccardo said. Simply put, there is no evidence that your scenario is likely. I don't think you're looking at it skeptically enough, i.e. you seem ready to embrace a scenario which, based on the evidence we have, seems much more unlikely than the currently accepted science. I guess we'll have to agree to disagree.
  18. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    This is the same Rohrabacher that wants to lauch a crusade against science because scientists are in on the big world government conspiracy? Now, I know that this is America so that possibly sets another benchmark, but if he performed that loony act in e.g. Europe he would probably be laughed out the House. I have much respect for Alley answering in a good spirited and humorous way while being questioned by such a nutcase regarding such a serious problem. But I'll guess Rohrabacher's right about one thing though: "Wake up America (people like him are your leaders)"!
  19. A Cloudy Outlook for Low Climate Sensitivity
    Eric (skeptic) it's not that in principle the GCR-climate relation is absurd. The problems is that there has been no clear evidence of the effect, let alone the 100 Kyrs periodicity needed to explain, or even contribute to, the glacial cycles. As far as we can tell, GCR contribution is small, at best.
  20. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy - 161 I went too fast with post 171. This is what I meant to say: I think that you are suggesting that I leave the phrase "Since power is energy per unit time" out of my writeup. Am I correct? If so, I'm tending to agree with you. Bob
  21. We're heading into an ice age
    Temperature proxies for tropics - isotope data from forams in sediment core for ocean temps. (Used everywhere). Stalactites from cave systems. Lake productivity from sediment core. All proxies have problems of one sort of other usually with both temperature and age calibration so need to understand proxies in terms of constraining possible models. As coral - killing coral is easy but the carbonate skeleton is preserved. And you assume wrong about how they work. The method is based on oxygen isotopes and Sr/Ca ratios. Use google scholar for detail.
  22. Stratospheric Cooling and Tropospheric Warming
    VeryTallGuy - 161 2) From your link "Since power is energy per unit time, the energy content of IR radiation can be indicated by its IR spectrum which is a graph of power density as a function of frequency." I'd suggest the unit time bit here is unnecessary and confusing - we are not looking at dynamics. The ordinate of the graph is "watts/meter square wavenumber". I think that you are suggesting that I leave the phrase "Since power is energy per unit time". Am I correct? If so, I'm tending to agree with you. Thanks, Bob
  23. A Cloudy Outlook for Low Climate Sensitivity
    I read this "debate" with a strong sense of deja vu. It could stand for any thread on climate change on any blog anywhere in the last ten years. An accurate description and analysis of one of the many lines of science associated with global warming. All of which are dismissed, one at a time, or in various combinations by a denier. The denier wants to ignore the obvious link between the known effects of CO2 in the atmosphere; the massive increase in CO2 in the atmosphere over the last 150 years, and especially the last thirty or so, as a demonstrated consequence of burning fossil fuels; and the rapidly rising temperatures and associated ecological and geographic consequences in exactly the same period. Instead, ignoring all that, the denier has some pet theory that, by an incredible coincidence, just happens to produce exactly the same effects in precisely the same time period. I mean, it is just amazing that some other minor and hypothetical process could achieve that and give us the excuse to do nothing whatsoever about decreasing GHG emissions, isn't it?
  24. littlerobbergirl at 07:45 AM on 7 December 2010
    How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    excellent. just what we need, scientists who can communicate. shame he isnt prettier (hmph...and shame it matters) but at least our dana is prettier than theirs...
  25. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    @ClimateWacher: "Bad for ignoring the significance of the HCO." How did he ignore the significance of the HCO? Oh, right, he didn't. We know the North Hemisphere was probably a bit warmer in the HCO, however there is no evidence the entire world was - it falls within the margin of uncertainty, that old double-edged sword. :-) In any case, projected temperatures - even the more optimist scenarios - will go well above HCO temperatures. The fact temperatures are going near HCO levels at this time, while they should be well under according to natural cycles, supports AGW theory. If anything, professor Alley's responses were still too wordy (bald spot excepted). When the (very partial) congressmen started his nonsense about Mars experiencing the same climate change as we do, he should have simply said it isn't. When demagogues make statements which they can't prove, you can simply call them on it. This puts the burden of proof on them, and since they *can't* support that position (due to a lack of facts) they'll simply stop using it as an argument. Simple falsehood should be challenged simply, with the science to back it up if needed. This is why sites such as this one are so useful! :-)
  26. Eric (skeptic) at 07:15 AM on 7 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    archiesteel, can you point to some analysis that dismisses combinations of factors? Each one was dismissed in isolation in Dana's old thread, but that doesn't mean they can't combine in ways that radically change the climate. When you say "wishful thinking" are you implying that my scenario is impossible? Or just very unlikely?
  27. We're heading into an ice age
    I am curious as to how we study the impact of the 100,000 year glacial cycles in the tropics, ie - what temperature proxy data do we use? The wiki on the temperature record offers some information on other proxy data. It appears that coral growth rates are used to estimate temperatures in tropical regions? http://en.wikipedia.org/wiki/Temperature_record I assume that they are measuring coral growth rates based on calcium carbonate deposits, which will slow down as CO2 increases, and will slow down as the temperature changes, up or down. Even changes in salinity will affect their growth rate. Seems like it would be hard to get high quality temperature proxy data from coral growth rates. Given how fragile coral is, I'm amazed that they survive at all. http://en.wikipedia.org/wiki/Coral "Seaweed/Algae can destroy a coral reef. In the Caribbean and tropical Pacific, direct contact between ~40 to 70% of common seaweeds and coral cause bleaching and death to the coral via transfer of lipid–soluble metabolites.[26] Seaweed and algae proliferate given adequate nutrients and limited grazing by herbivores. Coral die if surrounding water temperature changes by more than a degree or two beyond their normal range or if water salinity drops." Chris Shaker
  28. Renewable Baseload Energy
    Scaddenp, I think your resource was useful, I read it to the end. I agree with you that it is very difficult to find unbiased data. My point to Quokka was that your source said that nuclear needed to run at high outputs to be ecomonic. Since your source is biased pronuclear I presume they are correct on this point. I think your reference helped the debate as you describe.
  29. Renewable Baseload Energy
    Providing spnning reserve for a nuclear plant of economic scale is common argument against nuclear in a small market like New Zealand. Nonetheless, my son's debating team owes this and the other solution thread, plus BNC, a big thank you for winning his high school inter-school debating competition taking the affirmative on "NZ should build nuclear power".
  30. A basic overview of Antarctic ice
    Re: 104: Typo error, the second trend estimate is for extent not area
  31. A basic overview of Antarctic ice
    # 103 Global sea ice is declining at a statistical significant rate. My results from fitting a linear trend to the data from NSIDC: Global sea ice area, linear trend: -0.0334 ± 0.0129 Global sea ice area, linear trend: -0.0367 ± 0.0112 Units are mio. square km pr year, the trend are given with AR1 corrected 95% confidence intervals. For more info check my post earlier in this thread
  32. A Cloudy Outlook for Low Climate Sensitivity
    @Eric: again, I see no compelling evidence that such mechanisms could overcome the current anthropogenic warming. It seems to me you're suffering from wishful thinking here, and are not evaluating the science in an impartial manner. "The control knob for the ice age changes is GCR" Actually, Milankovitch cycles are the main culprits for ice ages, not GCR. Sorry, but so far the evidence you've presented in favor of GCRs as a main driver of climate doesn't even come close to challenging the evidence against them.
  33. Eric (skeptic) at 06:33 AM on 7 December 2010
    A Cloudy Outlook for Low Climate Sensitivity
    #78 archiesteel, Here's one link www.utdallas.edu/nsm/physics/pdf/Tin_rev.pdf and there are many more. There are two points to consider, first that any of these factors in isolation can be "proven" to be a nonfactor over the last 30 years using linear trends. Second, combinations of these factors particularly with GCR will create enough warming and cooling to explain the paleo temperature record. The control knob for the ice age changes is GCR, with help from CO2 and solar factors. Since the solar factors are not considered in models and not part of the paleo record, they cannot be ruled out.
    Moderator Response: Link fixed
  34. A basic overview of Antarctic ice
    Philippe Chantreau at 03:45 AM on 7 December, 2010 "There is no such thing as combined polar ice, because these are asynchronous occurences. The evolution over time of the true global sea ice coverage is what matters. And can you elaborate on the year round Arctic albedo idea?" So what is your point? Global sea ice coverage is global sea ice coverage. The fact they are asynchronous doesn't seem to be making any point.
  35. We're heading into an ice age
    Mostly, I've been able to find temperature proxy data from the ice cores. I've read about temperature proxy records from tree rings. Any good pointers to background on other temperature proxy data? How do we get temperature proxy data from the tropics? Thank you, Chris Shaker
  36. Ocean acidification isn't serious
    Rob: Do we have good temperature proxy data from the tropics? Sea floor cores, or such? Do the glacial cycles show up there, too? Chris Shaker
  37. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    @ caerbannog 11 I don't know. From what I viewed Rohrabacher's attention-span was somewhat less than 15 seconds. It seemed that within 5 to 10 seconds of Alley beginning to answer one of Rohrabacher's questions, Rohrahacher begin trying to rebut him. At least Lord Christopher Monckton this time to testify. That's some progress.
  38. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    What's with this 30 second limit?! Rohrabacher offered Alley just 15 seconds, and Alley countered with 30. 15 seconds is probably more in line with Rohrabacher's attention-span, though.
  39. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    I love the part in the testimony when Pat Michaels is trying to make a response to Alley by talking about the HCO and you can get glimpses of Alley with his finger on the top of his head, nodding up and down. This entire panel discussion is well worth watching. It's about an hour and 20 mins but the whole thing is great. You can find it here on the C-Span site.
  40. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    We're doomed ... even Rohrabacher's haircut fill me with feelings of dread for the future ...
  41. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Sorry, but there's a glaring flaw in this post. Tom Lehrer's The Elements is far more nerdy than The Geoman.
  42. The human fingerprint in the seasons
    #108: My concurrence and $3.00 might get you a cup of coffee, although I make no guarantees. You did note that I concurred because I knew the Big Lake is anomalously warm. If you like spaghetti charts, look here.
  43. The human fingerprint in the seasons
    Hi Ned... Just so you know, that link you posted requires a log in.
  44. The human fingerprint in the seasons
    TOP, Lake Superior has warmed quite a bit over the past century, and ice cover is now about half what it was a century ago. A century of temperature variability in Lake Superior There has been a lot of work done on global lake ice records, e.g. by Magnuson et al. I know a bunch of the people involved; if I get a chance I'll try to write up a summary some time.
  45. actually thoughtful at 04:49 AM on 7 December 2010
    The human fingerprint in the seasons
    Hmm. Given that muoncounter concurs that Lake Superior is a good proxy for GHG (that is two votes in favor!) - take a look at the TOPs link: http://climate.umn.edu/doc/journal/superior030603.htm But look at temperature year 2006-2008 - you can actually SEE the warmer winters this post is all about. Very cool (and OK - really scary!)
  46. 2nd law of thermodynamics contradicts greenhouse theory
    Wow, Ned. That was extremely well done. Congrats.
  47. ClimateWatcher at 04:45 AM on 7 December 2010
    How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Good for the bald head analogy. Bad for ignoring the significance of the HCO.
  48. The human fingerprint in the seasons
    Re: TOP (104) Sorry, TOP, you just tripped my nonsense-meter with your whole comment:
    "So far December 2010 is running below normal temperatures. "
    Since the remainder of the comment entirely deals with Marquette and Lake Superior, let's see what 2010 looks like: Hmm, above normal Winter @ Spring temps, with the remainder of the year largely within the seasonal noise/variation. Including December.
    "In fact if you look at Marquette Michigan's temperature graph from 2008 on you will see normal to below normal temperatures dominating during the deep winter months when the jet stream prevents warmer air from the south intruding. "
    OK, let's finish this exercise, starting with 2009: and 2008 Seems to me pretty much more of the same: weather falling largely within historical norms.
    "Both freeze overs where documented in March. "
    Depends on what your definition of freeze-overs of Lake Superior is? Is it 90%+? Then I'd agree with you. By local definitions? Not since around 1980 has Lake Superior frozen over. But what do I know, I only live in Marquette. Oh, did I forget to mention that? Then I probably forgot to mention this: Lake Superior reaches record temperature by mdr on Aug. 20th, 2010. Indeed, I've commented on local warming elsewhere on this site, including here. Note: You can monitor water temps of Lake Superior here. Oh, and Lake Superior shipping usually only shuts down for winter maintenance on the Soo Locks (in January, for about 2 months, I believe). Otherwise, a year-round event with modern icebreakers. Back in the 40s and 50s, ice limited operations to an 8-month shipping season. The Yooper
  49. How to explain Milankovitch cycles to a hostile Congressman in 30 seconds
    Hi all, I agree, Rohrabacher is not interested in learning inconvenient truths. Alexandre's quote sums it up. And yes Alley is brilliant, and to say he is passionate about his work would be a gross understatement. Despite his questionable singing skills, my family (even the toddlers) really enjoyed his video: I hope that worked.
  50. The human fingerprint in the seasons
    #104: "Lake Superior is a good proxy for GHG warming" Indeed it is. See the Canada thread, where our own correspondent from the UP (aka The Yooper) confirms that the Great Lakes are anomalously warm. Please do not quote 'weather reports' from WUWT after they were caught in this fraud.

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