Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.

Settings

Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup

Settings

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.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe


Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...



Username
Password
New? Register here
Forgot your password?

Latest Posts

Archives

Recent Comments

Prev  2185  2186  2187  2188  2189  2190  2191  2192  2193  2194  2195  2196  2197  2198  2199  2200  Next

Comments 109601 to 109650:

  1. The contradictory nature of global warming skepticism
    JMurphy. "Irrational". The two sentences are not the same. Read them again. Re continuing warming. If you've read my posts then you'll see that I've said quite a few times that I accept bumps in temp along the way. I don't accept 10 years of flattened temps is conducive to continued global warming.
  2. A detailed look at Hansen's 1988 projections
    angusman #22, scenarios B and C and the actual temperature record are all very similar to each other through 2005. Since 2005 actual temperatures have been roughly in line with scenario C (below in some years, above in others). However, that is FAR too short a time frame on which to judge the validity of the model. If actual results continued tracking along scenario C for 15+ years then the model would be off significantly. If the warming being seen this year continued then we'd be back 'on track' closer to scenario B. That said, Hansen's 'short term' climate sensitivity factor in 1988 was definitely too high and thus his results should be expected to go further off as time goes by. Hansen 2006 essentially explained HOW the 1988 analysis got it wrong... so to say that 2006 is itself wrong... would seem to be arguing that Hansen 1988 was correct. :]
  3. The contradictory nature of global warming skepticism
    Daniel Bailey. Oh dear, you seem to have missed B in that BBC link and gone straight to C. Try again, Daniel, because YOU ARE WRONG. See MichaelM's quote above your post. MichaelM. Thanks, but I'm not confusing anything with everyday use! Prof Phil Jones states that the trend from 1995 to 2009 is not statistically significant. I didn't say it, he did.
  4. Global warming and the unstoppable 1500 year cycle
    Addressing even the most bizarre myths put forward by "skeptics" is important, and IMO, does not amount to arguing a straw man as some are suggesting here. Only the other day I was reading a CBC forum on the Arctic ice and "skeptics" were parroting Singer. How he can claim to have any credibility (and even more astounding, how people can still buy into his "science") on climate science is truly bizarre.
  5. A detailed look at Hansen's 1988 projections
    A close look at Figure 3 shows that temperatures are actually running below Scenario C - the zero-increase in CO2 from 2000. This decline has not happened. Therefore, the only conclusion that can be made from present day temperature readings is that Hansen (1988 & 2006) got it wrong.
  6. A detailed look at Hansen's 1988 projections
    Wonder if Michaels is going to retract the misleading and erroneous testimony that he gave before US House of Representatives? I mean in the spirit of accountability,transparency and rigor that he demands of the IPCC? Excellent job Dana. Am I correct in understanding that emission scenarios B and C were the same up until 2000?
  7. The contradictory nature of global warming skepticism
    @Baz: "Please retract the "liar", and I've never said I am irrational." I'm not retracting anything, as you keep repeating the same debunked fallacious statement. Oh, and you did claim to not being rational. Not rational = irrational. "Re 'Where's the heat?' So 3 years is good enough for you?" Of course not, it's not statistically significant. It should be enough for you, however, since you originally claimed a five-year period was enough for you to change your mind about the warming. I can't believe you walked right into that one, too. What are you hoping to achieve, here, exactly? Get on people's nerves until they become rude so you can then complain how AGW proponents are ill-mannered? "I say again, the last 10 years of HadCRUt is flat." And I say again, that is cherry-picking, especially since other cycles (such as the PDO and TSI) are having a cooling effect during that period. Please pick a statistically-relevant period and base your opinion on this, otherwise my choice of the last three years (which shows where the "heat" is) is just as good as your choice of five or ten years. You've been unmasked, Baz. At this point, the wise thing to do would be to just stop commenting on the science until you've shown you actually understand it. Anything else is just digging yourself deeper in your own hole. "I didn't "carefully cherry-pick" that period, it was done by Phil Jones here" Another lie? The period was picked by the BBC journalist, not Phil Jones. Jones made a point of saying the warming trend was still there during that period, though it really was at the 92% degree of confidence. Of course, this was all before 2010, one of the warmest years on record, so who knows. Again, you've exhausted everyone's patience, here. Come back when your argument is scientifically relevant.
  8. The contradictory nature of global warming skepticism
    Baz... I think you're actually not understanding the definition of "statistically significant." Statistical significance in climate is less a function of the rate of warming or cooling and more a function of the length of time. If you look at the current warming from the past couple of years it's coming at a very high rate. I don't know the figure off hand but say it's 0.45C/decade. That is still not statistically significant because it's just part of the noise. The up and down normal to the climate signal. Statistical significance is this: Confidence = signal over noise X square root of the sample size. That essentially means the climate is very noisy so in order to have confidence that you are looking at the actual "signal", and not just noise, you have to have a fairly large sample. In climate it's 20 to 30 years of data. That's why I said, when you're talking about the "flattening" temps you are talking about data that is not statistically significant.
  9. Hansen's 1988 prediction was wrong
    Hi there - I'm relatively new to commenting here so apologies if I'm missing something. I've read through dana1981's Advanced and Basic versions of this rebuttal, and something important appears to be omitted from this Basic version - namely that Pat Michaels was misleading in saying that "That model predicted that global temperature between 1988 and 1997 would rise by 0.45°C." Together with Peter Hogarth's updated chart (above), it appears that even though Hansen overestimated the sensitivity parameter, his Scenario C projection is not far off from the GISS measured temperatures. I'm not sure if it's too late to make any updates to the rebuttal, but the key conclusion here might be that Hansen's 1988 projections - even though based on far less data than we have now - were within the range of what has actually been observed. Furthermore, the measured warming provides support that Hansen had the fundamentals of climate science correct, namely that human factors are driving GHG emissions and causing global warming that is significant enough that it can be directly measured over just a few decades - not centuries from now.
  10. 2nd law of thermodynamics contradicts greenhouse theory
    KnuckleDragger, it's best to not use the term "reflect" at all, even as a convenient shorthand, because as Riccardo wrote it has a particular meaning that is different from absorption-emission. CO2 does effectively zero reflection at the wavelengths we are concerned with here, at CO2's concentrations in our atmosphere.
  11. Should The Earth Be Cooling?
    @KL: So, in other words, your entire argument rests on admittedly incomplete/imperfect ARGO readings? Given the overwhelming evidence in support of AGW theory, it seems to me this would indicate deficiencies in measure OHC, not problems with AGW theory. Unless, you know, you already have decided in your mind AGW theory is wrong, then I guess confirmation bias will cloud your judgement regarding this issue...
  12. Global warming and the unstoppable 1500 year cycle
    @Ann: you won't see this happening, because many "skeptics" change positions depending on the current argument. The goal is to keep an aura of confusion around the debate. Now, there is a small minority who holds steadfast views on AGW, but you don't often hear from them on Internet forums...
  13. A detailed look at Hansen's 1988 projections
    Scrooge, natural cooling is ignored in GCM. It happens on a time frame of millennia which usually is not considered.
  14. A detailed look at Hansen's 1988 projections
    Ken Lambert, still confusing forcings and feebacks, do you? Anyway, Hansen calculation also are "the result of ALL the forcings - both radiative and feedbacks." (sic). And within 5%.
  15. A detailed look at Hansen's 1988 projections
    First I want to say that to be able to come up with those projections in 1988 is remarkable. I think I was still using an Atari 800 at the time. Now this may be a stupid question but as discussed in a previous post, is the idea that we should be naturally cooling incorporated into the model. Of course I assume it is but just one of those nagging questions.
  16. A detailed look at Hansen's 1988 projections
    Riccardo #16 Unfortunately the measures 'air surface temperature' and GISS and HADCRUT3 temperature anomalies are the result of ALL the forcings - both radiative and feedbacks. Claiming that Hansen was out by only 5% on half the story when the feedbacks (particularly WV and CO2 interaction) are the least understood is the missing part of this article. So we are closest Scenario C with the temperature record??
  17. It's the sun
    I say the Sun is the dominant factor in climate change. If you read the new work by Frederick Bailey, on the soon to launched web site www.solarchords.com and his books, you will see the background to two discoveries, one is, what drives sunspot production, the pattern has been discovered and this led to a much greater discovery i.e. It has been cleary shown that the generally accepted value of 1AU for the Earth - Sun distance around the ecliptic plane has been found to be wrong. This work clearly shows that sunspots per se do not influence climate change but because the way they are produced, they are indicators that the AU value is changing and it is this that affects the climate. Because the two events are closely linked in time, people thought that sun spots cause climate change, they do not. This also led on to investigate why does not the TSI measurements reflect the findings made. This site clearly states here; http://www.skepticalscience.com/acrim-pmod-sun-getting-hotter.htm "There is no single continuous satellite measurement of Total Solar Irradiance" In researching the this and other sites I soon realised why the TSI variation that should be seen has not been identified, because only the variation in the output of the Sun is being measured, not the total output or TSI. The variation is then appliked to the standard figure of 1368w per Sq M and allowing for the expected orbital position. Bailey's work clearly shows the reason for the historical hot and cold periods etc.
  18. Should The Earth Be Cooling?
    Yooper #58, #61 The critical measurement is the TOA imbalance which nets all the heating and cooling forcings. Ref Fig 2.4 of AR4 which gives a total net anthropogenic forcing of +1.6W/sq.m. To this number is then added the climate responses which mainly consist of radiative cooling (from a raised Earth temperature of 0.75 degC as per S-B) of about -2.8W/sq.m and WV and Ice Albedo Feedback of about +2.1 W/sq.m. (Ref Dr Trenberth Fig 4 'Tracking the Earth's global energy) The sum is then +1.6 -2.8 +2.1 = +0.9W/sq.m All the heating and cooling forcings are acting in concert. S-B is emitting IR, Aerosols and clouds are reflecting incoming Solar heat, while CO2GHG are supposedly trapping Solar heat at lower levels (the mechanism is more correctly slowing down the transfer rather than 'trapping' heat) which tends to raise the equilibrium temperature as the analogy of a better insulator increases the T1-T2 temperature difference for a given heat flux transferred. What is certain is that CO2GHG forcing (currently claimed at about 1.6W/sq.m) is logarithmic with CO2 concentration, and S-B radiative cooling is exponential (proportional to T^4). Where these forcings and the others cross is where the forcing imbalance is zeroed and the new equilibrium temperature approached. The CO2GHG theory hangs on the interaction of WV and CO2 in the atmosphere and what will be the surface temperature rise for a unit rise in the IR emitting temperature of the Earth as seen from space. For the first law to be satisfied, most of heat flux 'imbalance' of 0.9W/sq.m should show up in the oceans due to the tiny relative storage capacity of the land and atmosphere (about 5%). OHC is proving most elusive to measure but Argo is the best we have at the present and the latest Willis analysis is not finding the 'missing heat' below 1000m. Here is the story on sea level rise: Thanks to HumanityRules nice summary: quote; "I've found 4 papers looking at closing the sea-level budget around 2003-2007. The latest is from this year. Basin patterns of global sea level changes for 2004–2007 You-Soon Chang, Anthony J. Rosati, Gabriel A. Vecchi Journal of Marine Systems 80 (2010) 115–124 Chang, like the others, calculate the steric and mass components using ARGO and GRACE and compare it to the total change calculated from altimetry. They handily summarize the 4 published attempts to close the sea-level budget in a table. Chang et al (2010) STERIC −0.11±0.22 MASS 0.70±0.34 TOT 2.67±0.52 Willis et al. (2008) STERIC −0.5±0.5 MASS 0.8±0.8 TOT 3.6±0.8 Leuliette and Miller (2009) STERIC 0.8±0.8 MASS 0.8±0.5 TOT 2.4±1.1(2.7±1.5) Cazenave et al. (2009) STERIC 0.37±0.1 MASS 1.9±0.1 TOT 2.5±0.4 Chang and Willis fail to close the budget and interestingly fail with pretty much the same numbers. Leuliette and Cazenave manage to close the budget but by very different means. Leuliette through an equal contribution from steric and mass. Cazenave primarily (80%) through mass." Note Leuliette is the only one of the 4 analyses to get equal mass and steric. Error bars are very wide on all analyses. More mass means less OHC content increase and most coming from ice melt which sinks very ittle heat compared with the claimed imbalance. Yooper - when you have supped on this - please refrain from belching on about my 'misunderstandings', Happy to debate you on any or all of the above.
  19. A detailed look at Hansen's 1988 projections
    Ken Lambert, it's way too easy to talk about apologia without even bothering to look at the details on how things work. This attitude just highlight the unwillingness to learn the science but still dismissing it. The feedbacks are, indeed, feedback, not forcings. Why should they be listed in the same table as the forcings? The albedo, water vapour feedbacks and others are the results of the full calculations and are not parametrized.
  20. The contradictory nature of global warming skepticism
    Baz, I dug around in the archives for a good writeup I remembered on statistical significance in the temperature data set. If you read the linked article you may better understand why these 'short term trends' you are relying on are not considered statistically valid trends at all. Ironically, you are dismissing a warming trend since 1995 which has greater than 90% confidence in favor of a 'flat' trend since 2001 which has much lower statistical significance.
  21. A detailed look at Hansen's 1988 projections
    Sense Seeker, #10 in this post there's a comparison of Hansen's calculation in 1988 not a thorough comparison of model results. How could he know the actual emissions in the future? Someone else could do now some new calculations with actual emissions and best available model now, but this is a different story. A good idea for a new post ;) #13 the model is not on radiative forcing alone, it's much more than this; it is called a General Circulation Model (GCM). Radiative forcings come from radiative tranfer codes that are pluged into the GCMs. I think you should dig a little bit more on GCMs; NASA GISS provide a lot of informations (and the code itself) that I'm sure you'll find intersting.
  22. The contradictory nature of global warming skepticism
    Baz #296: "Okay, there seems to be some mis-reading here again. Rob, first of all, 0.12 c per decade is NOT statistically significant - ask CBD if you don't believe me." Ask me? Ok. You appear not to know what "statistically significant" MEANS. It has nothing to do with the degree of warming, only the confidence that this warming represents a statistically valid trend rather than merely being an artifact of random fluctuations. A warming trend of 0.12 C per decade could be either statistically significant (the usual confidence level is 95%) or not depending on the data from which it is derived.
  23. A detailed look at Hansen's 1988 projections
    I clicked the link to NASA-GISS for the +1.1W/sq.m 2010 relative to 1984 forcing here: http://data.giss.nasa.gov/modelforce/RadF.txt and found data only to 2003 and nothing like +1.1. Please explain the calculation? My eyesight must be playing tricks for I see the actual temperatures running close or below Scenario C not Scenario B. Is that what you meant? And what of the climate responses - where is the estimate of WV and Ice albedo feedback and radiative cooling feedback? Seems like a contrived Hansen apologia with only half the story to me.
  24. The contradictory nature of global warming skepticism
    Spot the differences : Baz : "Please retract the "liar", and I've never said I am irrational." Baz : "Archiesteel - I never claimed to be rational!" So, if you don't claim to be rational and have never said you're irrational, what do you claim to be ? Baz : "You say, "You seem to be arguing that if AGW theory is correct then the temperature would have to increase at a near constant rate." No, I've never said that, not once." Baz : "With no volcanoes the global temp should be ramping up and away." Baz : "How so - against ever-increasing emissions of CO2 and methane? Why isn't the temperature rising Guy?" Baz "Because when warming didn't continue at the same pace (around 2005) I began to question if I was right about my beliefe in warming." So, temperatures should be "ramping up and away", "rising", continuing "at the same pace" but that doesn't mean the same as "at a near constant rate" ? I think you are getting more confused with every post and that is highlighted by this quote from your penultimate post above : "...0.12 c per decade is NOT statistically significant..." What does that mean ?
  25. The contradictory nature of global warming skepticism
    Re: Baz (296, 297)
    "CBD, Try getting your facts right if you're going to accuse others. I didn't "carefully cherry-pick" that period, it was done by Phil Jones here http://news.bbc.co.uk/1/hi/8511670.stm Happy?"
     Ok, you got my interest with your use of "cherry-pick". Let's actually look at what your cite says, shall we?
    "C - Do you agree that from January 2002 to the present there has been statistically significant global cooling? No. This period is even shorter than 1995-2009. The trend this time is negative (-0.12C per decade), but this trend is not statistically significant."
    The time period in question, 2002 to present, was actually brought into play by the commentator, BBC's environment analyst Roger Harrabin (who put questions to Professor Jones, including several gathered from climate skeptics). So you're wrong on that part. I also see that Professor Jones said the period in question was "not statistically significant". Wrong again, sir. You seem to have a severe mental block about statistical significance and trends (it must be that cherry-flavored icing on all the graphs). Dude, you seriously have to get over your trying to force the data to say what it simply doesn't say. The evidence shows you're wrong, the science shows your wrong and your own source you cite to support you shows you're wrong. If you think you're right and everyone else (including experts with lifetimes of experience in the field) say you're wrong, maybe it's because you are wrong... The Yooper
  26. The contradictory nature of global warming skepticism
    quoting Phil Jones:
    "I also calculated the trend for the period 1995 to 2009. This trend (0.12C per decade) is positive, but not significant at the 95% significance level. The positive trend is quite close to the significance level. Achieving statistical significance in scientific terms is much more likely for longer periods, and much less likely for shorter periods. "
    Baz You are confusing the statistical usage of 'significance' with its everyday use. He is not saying 0.12c/decade is unimportant, he is saying that he can only say it is 0.12C with slightly less than 95% confidence.
  27. The contradictory nature of global warming skepticism
    http://woodfortrees.org/plot/hadcrut3vgl/from:2000/plot/hadcrut3vgl/from:2000/trend http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend http://woodfortrees.org/plot/hadcrut3vgl/from:2002/plot/hadcrut3vgl/from:2002/trend Flat
  28. The contradictory nature of global warming skepticism
    Okay, there seems to be some mis-reading here again. Rob, first of all, 0.12 c per decade is NOT statistically significant - ask CBD if you don't believe me. As for flat, well that would be here then: http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend Now, you can always shoose different years and time frames if you want to! It's not exclusive. Whether it's VERY slightly up, or VERY slighty down, it's flat! CBD, Try getting your facts right if you're going to accuse others. I didn't "carefully cherry-pick" that period, it was done by Phil Jones here http://news.bbc.co.uk/1/hi/8511670.stm Happy? Re volcanoes, you know perefctly well I was talking about cooling volcanoes (the Iceland puff never did anything) as it was written clearly in 289, not any little puff (which are always happening somewhere in the world). Talk Pinotubo. As for comments, you must also see that I have taken great pains to answer genuine questions actually posed. If I missed one of your posts then it was as I was replying to others at the time. I'll leave others to judge that. You say, "You seem to be arguing that if AGW theory is correct then the temperature would have to increase at a near constant rate." No, I've never said that, not once. archiesteel: Flat? http://woodfortrees.org/plot/hadcrut3vgl/from:2001/plot/hadcrut3vgl/from:2001/trend Please retract the "liar", and I've never said I am irrational. Read back and check what I actually said on that. Re 'Where's the heat?' So 3 years is good enough for you? I say again, the last 10 years of HadCRUt is flat.
  29. A detailed look at Hansen's 1988 projections
    There is one more thing I don't understand. The calculations did not use Hansen's model, but a set of equations from a different source (Myhre et al 1998). Comparison with the forcings as established (beyond doubt, is seems) with an unexplained NASA method, and then conclude that Hansen's model was almost accurate... I am sorry, I can see Hansen got it about right, but this posting adds little to my understanding.
  30. A detailed look at Hansen's 1988 projections
    And if you want to test Hansen's scenario B as a prediction, rather than the underlying model, you needn't bother with any calculation. You can just read if from the graph.
  31. A detailed look at Hansen's 1988 projections
    Once the data for 2010 are used, his accuracy will have been prophetic.
  32. A detailed look at Hansen's 1988 projections
    Ricardo, you are mostly right but not completely. (Unless I missed something more, which is of course now a non-negligible option.) Shouldn't Table 1 give the realised Greenhouse Gas (GHG) Concentration in 1984 and 2010, rather than the one from Scenario B? The calculations seem to be based on scenario B, not the realised emissions. The real ones may be most like scenario B compared to A or C, but are unlikely to be identical. If you only want to test the model, you need to use the observed emissions as input.
  33. A detailed look at Hansen's 1988 projections
    Sense Seeker, you missed something. Two quotes from the post: "Scenario A assumed continued exponential greenhouse gas growth, which did not occur." "Hansen's Scenario B has been the closest to the actual greenhouse gas emissions changes."
  34. A detailed look at Hansen's 1988 projections
    Something here does not make sense. Nowhere do you mention what the actual emissions WERE over the intervening period. You cannot simply compare one of Hansen's scenarios with what actually happened in terms of outcomes, if you do not take into account the inputs. If the temperature curve nicely follows Hansen's scenario B, but the emissions increased exponentially (i.e., according to scenario A), Hansen's model was overestimating by a much larger margin.
  35. How we know the sun isn't causing global warming
    Dana1981, I still don't think your section on the D-O events is particularly convincing, especially with regards to the so called "timing flaw" you mention. For the sake of argument, if the LIA was the last cold phase of the D-O cycles, we could place the MWP as the peak of the last warm-phase, and subsequently the Earth should be warming now. Remember, the 1470 figure is the periodicity -- the time interval between peaks (or troughs). The Earth was in a trough several hundred years ago, and it should now be heading towards a peak (i.e. warming). So the fact that the LIA may have been the most recent cold phase of the D-O cycles does not preclude them from adding to the recent warming; quite the opposite. Please see my previous post on this thread for my reasoning on why D-O events cannot have had anything more than a negligible affect on global temps over the past few centuries.
  36. Philippe Chantreau at 18:05 PM on 20 September 2010
    Jupiter is warming
    And Bob, let's not forget that Venus is warmer than Mercury, which is closer to the Sun...
  37. Philippe Chantreau at 17:58 PM on 20 September 2010
    It's cosmic rays
    Continued from the thread mentioned above: HR, the word would be laughable but, really, what is there to hang on in the Duplissy paper itself? What paper since Duplissy has been published using CLOUD data? References? Anything yielding more conclusive results? The point was not to reveal problems in the experimental design, but the problems were uncovered nevertheless. If those ultra clean walls can release vapors susceptible of corrupting the results, I don't even want to begin imagine what happens in the real atmosphere, where CCN are already present by the hundreds per cubic cm.
  38. Philippe Chantreau at 17:41 PM on 20 September 2010
    A South American hockey stick
    HR, the word would be laughable but, really, what is there to hang on? What paper since Duplissy has been published using CLOUD data? Do you have something of any substance? The point was not to reveal problems in the epxerimental design, but the problems were uncovered nevertheless.
  39. 2nd law of thermodynamics contradicts greenhouse theory
    KnuckleDragger, to explicitly address your first question on absorption/reflection, thinking in this terms could be confusing. In everyday life we call reflection the "bouncing back" of light from a solid or liquid surface. In a gas there's no surface and it could be hard to understand how "reflection" may occur. I think it's easier to think in terms radiation absorption/emission. Quoting from the post: "Any substance that absorbs thermal radiation will also emit thermal radiation; [...]. The atmosphere absorbs thermal radiation because of the trace greenhouse gases, and also emits thermal radiation, in all directions." The backward emitted radiation is what you (and others) call reflection. So, the answer to your question is that CO2 at high concentration is a good absorber and reflector.
  40. Global warming and the unstoppable 1500 year cycle
    Here is a question to the skeptics: why don’t you provide a classification of the different climate theories held by climate skeptics ? People who don’t believe in global warming have entirely different convictions from those who do believe the earth is warming due to natural causes. In fact, these 2 points of view are as different as any skeptic theory is from the AGW theory. In order to advance the discussion, the classification “climate skeptic” is just not enough. F.i. the alternative theories could be named: NoGW, NatGW (with subclassifications: NatGW_solar, NatGW_ocean_currents, …), NonCatAGW (non-catastrophical AGW), etc. AGW is just one of the many possible climate theories – with an overwhelming amount of evidence on its side …
  41. A detailed look at Hansen's 1988 projections
    One thing that folks should keep in mind is that your typical el-cheapo Best-Buy/Walmart/whatever laptop has more computing horsepower than what Hansen had available to him to conduct his climate-modeling simulations back in 1988. This should put things in perspective here, and also give folks a fuller appreciation of Hansen's genius.
  42. Global warming and the unstoppable 1500 year cycle
    (#12)My impression actually is that most skeptics claim we are cooling, and have just entered a cooling phase that will go on for decades. Skeptics not only believe that the Earth is cooling; they also believe that the Earth is warming. They believe that the warming can be attributed to natural causes, and they believe that the warming is due to the urban heat-island effect. In addition, they believe that it's impossible to tell whether the Earth is warming or cooling because so many temperature stations are set up next to air-conditioners and bbq grills. They believe all of these things; that's how they make sure that they have all of their bases covered.
  43. A detailed look at Hansen's 1988 projections
    @paulm: That website proves nothing. Radiative forcing F is a multivariate nonlinear function. But for small variations, we can Taylor-expand and to first order it is the sum of the first derivatives. The particular objection raised is that for example d^2F/d(CO2)/d(N2O) is not zero. I agree it's not. But its contribution to dF is much smaller than the linear part. As it's unknown, it contributes to the uncertainty (error-bar) in the calculation.
  44. A detailed look at Hansen's 1988 projections
    The other thing that I think should be pointed out is that Hansen scenario B was also taking into consideration a large volcanic eruption in 1995 while Pinatubo - which can be clearly seen in the actual data - was in 1991 - once you also correct for that the scenario B already looks identical to real measured values!
  45. Why positive feedback doesn't necessarily lead to runaway warming
    Further search of previous research of the temperature limiting factors of biosphere... From http://www.dbio.uevora.pt/Micro/Brock.pdf ("Life at high temperatures", review on prior research, unfortunately it doesn't include much on terrestrial vascular plants.) "We found visible algal growth (of the unicellular blue-green Synechococcuts) at temperatures up to 73° to 75°C, but not at higher temperatures (24)" and "Quantitative studies of the algal mats along thermal gradients in hot springs have shown a definite correlation between the temperature and the algal biomass (33). In the Yellowstone hot springs, maximum algal biomass was found at albout 55°C, and it falls off sharply as the temperature increases above 55°C (34)." So one limit of inhibition for high (too hot for humans) temperatures is 55°C and photosynthesis ends at 75°C. Above this temperature all photosynthecic life will decompose and photosynthesis needs to be born or moved to the area again. Geological processes will eventually bury the decomposed carbon. further: "Thus, it is surprising that eucaryotic algae are not common at temperatures above 40°C, whereas eucaryotic fungi are found up to 60°C (14)." So 40°C is about the maximum limit when oceans will turn into carbon emitters. lastly: a point on scientific inertia... "Most of the surface of the earth has a moderate temperature, with an average of 12°C (15)." checking this up, it turns out this was an approved value in 1955: "15. H. F. Blum, Time's Arrow and Evolution (Princeton Univ. Press, Princeton, N.J., 1955)."
  46. A detailed look at Hansen's 1988 projections
    I wonder if you would consider typesetting the math with LaTeX? Would make it lots more readable. You could e.g. use http://www.codecogs.com/latex/eqneditor.php. Or if you already know LaTeX, just use TTH: http://hutchinson.belmont.ma.us/tth/
  47. A detailed look at Hansen's 1988 projections
    Heres some interesting analysis... http://residualanalysis.blogspot.com/2010/02/twin-ghgs-paradox.html The Twin GHGs Paradox The means by which a greenhouse gas (GHG) forces climate change is sometimes called radiative forcing.
    Moderator Response: Please provide more context when you post a link.
  48. actually thoughtful at 14:30 PM on 20 September 2010
    A detailed look at Hansen's 1988 projections
    It is hard to look at Hansen's 1988 work without seeing he got it right! A few quibbles, but the major mechanisms are all included, and he is off by a few tenths of a degree over 22 years! And the fix is very clear - he used 4.2 instead of 3 or 3.4 for climate sensitivity. The takehome message is climate scientists have this dialed in. With 22 years more research, current models are that much better. "Hansen got it wrong" is a lie - pure and simple.
  49. A detailed look at Hansen's 1988 projections
    Misprint on the first line. Says 1998; should be 1988.
    Response: Fixed, thanks
  50. Climate sensitivity is low
    Re: Timothy Chase (51) Thanks for taking the time to put together such a thorough comment. It's appreciated. The Yooper

Prev  2185  2186  2187  2188  2189  2190  2191  2192  2193  2194  2195  2196  2197  2198  2199  2200  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us