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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 100251 to 100300:

  1. Greenland ice mass loss after the 2010 summer
    This is interesting as the ice loss of present does not seem to be much different than the ice loss from the 30's and 40's. http://researchnews.osu.edu/archive/grnlndice.htm
  2. Lindzen and Choi find low climate sensitivity
    And 1W/m2 of forcing from whatever source will induce around 0.3C of surface temperature change without considering feedbacks. However, all forcings induce feedbacks. Feedbacks are not equal however, depending on the nature of the forcing. Thus the signature for a CO2 forcing is different from the signature of a solar forcing. This is the point of several other postings.
  3. Do high levels of CO2 in the past contradict the warming effect of CO2?
    FYI, current astrophysical models put the solar constant increase at around 7% per billion years, which works out to ~40 W/m² since the Ordovician. Meanwhile 4000 ppmv of CO2 would imply about 14 to 18 W/m² without feedbacks. This is again a pretty good indication that CO2 feedbacks are strongly positive, otherwise the entire Ordovician would have been glaciated.
  4. Lindzen and Choi find low climate sensitivity
    RW1, yes T is temperature. Each added 1 W/m^2 of power from the sun is equivalent to each added 1 W/m^2 of power from CO2. Feedback doesn't matter in the previous statement.
  5. Lindzen and Choi find low climate sensitivity
    Eric, Again, I'm talking about intrinsic forcing - meaning before any potential gain or feedback (positive or negative). I just want to make sure we agree that each 1 W/m^2 of power from the Sun is equivalent to each 1 W/m^ of power from CO2.
  6. Lindzen and Choi find low climate sensitivity
    Eric, "Not the same, although you didn't define "same". Existing power flux is in equilibrium at T, "gain" = 1.6. New power flux is added which causes an increase to T+delta, "gain" is much higher. That's because "gain" is not a constant as KR explained in 210." I'm not sure what you mean here. I know the gain is not a constant. Is the "T" you're refering to temperature or something else?
  7. Lindzen and Choi find low climate sensitivity
    RW1 asked "2 W/m^2 of power from the Sun (existing or hyothetically added) is the same as 2 W/m^2 from increased CO2?" Not the same, although you didn't define "same". Existing power flux is in equilibrium at T, "gain" = 1.6. New power flux is added which causes an increase to T+delta, "gain" is much higher. That's because "gain" is not a constant as KR explained in 210. If instead you asked "2 W/m^2 of power from the Sun (hypothetically added) is the same as 2 W/m^2 from increased CO2?", the answer is yes.
  8. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    fydijkstra @ 42... "'Is it safe to double atmospheric CO2 over a 200 year period?' We don't know. Possibly not..." Possibly not? A very, very small possibility. Virtually all the evidence coming out, and that has come out over the past 30 years, suggests that it is not safe. A very small amount of evidence suggests that it might not be a problem. Personally, in a situation like this, my inclination is to err on the side of caution. "With the present state of technology there is no way to avoid doubling CO2 in the next century." We certainly won't avoid it with the attitude that we can't avoid it. Technology is not the problem. The technology is there. It's ready. The only thing lacking is sufficient will.
  9. Lindzen and Choi find low climate sensitivity
    Eric, I mean at least as far as intrinsic forcing is concerned.
  10. Lindzen and Choi find low climate sensitivity
    Eric, BTW, I'm not trying to entrap you with that last question. I'm just attempting to establing that a W/m^2 of power is a W/m^2 of power, independent of where it originates from.
  11. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    "Why have the skeptics never developed their own climate models and performed their own model experiments? They have. See Lindzen, Spencer, Soon, Baliunas, Akasofu!" Cool. Where are their models? Can you show us the code to the GCM that, say, Soon and Baliunas wrote? Lindzen? Where's the source code to his GCM? Spencer? Same question. Oh, can't find the source ... OK, how about some model output from the GCMs these various people have written ... I'll settle for that.
  12. Lindzen and Choi find low climate sensitivity
    Eric, At last, I think you now understand what the gain is representing, and you're asking the right question - it is the basis of the argument I've put forth. Before I answer the question, do we also agree that additional forcing from CO2 is the same as solar forcing? In other words, 2 W/m^2 of power from the Sun (existing or hyothetically added) is the same as 2 W/m^2 from increased CO2?
  13. CO2 is not increasing
    #14: "we will get there... " You missed the part about 'and that rate is increasing'? So the bets are in as to when 560 ppm will happen. In the words of that great American philosopher, Dirty Harry: "You gotta ask yourself one question, do I feel lucky?"
  14. Lindzen and Choi find low climate sensitivity
    Ok, so the sun "forces" the climate. After albedo that "forcing" is 238 W/m^2. The "response" is 390 W/m^2. Therefore the "gain" is 1.6 Now add a permanent (hypothetical) 1 W/m^2 to the sun (forcing change by the consensus definition). What is the "response"? 391.6? Thus the temperature response is about 0.3 degrees higher according to your "gain" formula. Now, please show the evidence that a permanent 1W increase in effective solar forcing will only increase earth by only 0.3 degrees.
  15. Lindzen and Choi find low climate sensitivity
    Eric, The graph clearly shows the solar power fluctuting by about 20 W/m^2 from perihelion in January to aphelion in July: http://www.palisad.com/co2/eb/g/flux.png
  16. Lindzen and Choi find low climate sensitivity
    Eric, "Regardless, as I showed in 208 the "gain" term in the paper in #150 does not use the aphelion to perihelion cycle." It's included in the solar input (Psun), which varies according to perihelion/aphelion. 'Psun' is the total power from the Sun and varies - it's not a constant. "The cyclical solar change is not considered in calculating gain." This isn't correct. It's automatically considered because the post albedo power is the incoming solar power minus the albedo and each varies. The gain is based on the aggregate measure of the two, which includes the increased and decreased solar power at perihelion/aphelion, as well as the changes in the albedo. "To put it another way, the gain is not being used to calculate earth's response to the solar change that you and I call forcing." Yes it is. That is in fact precisely what the gain is calculating, albeit albedo adjusted.
  17. CO2 is not increasing
    15 dhogaza Yes I do claim it will be slow and not a problem. The maximum warming with ADO PDO and a monster El Nino and sunspots the largest in recorded history only made the 1978 to 1998 warming rate 1.2 ° C per century. I am underwhelmed. Mother nature did everything she could to help your puny CO2 and that is the best it can do ? No wonder when the ADO and PDO go negative the rate of warming goes flat or negative !
    Moderator Response: You are incorrect that solar activity since 1978 contributed to warming. See "It's the Sun" and especially "Climate Time Lag."
  18. Lindzen and Choi find low climate sensitivity
    In the absence of power from the Sun, the climate would change; therefore, by definition, power from the Sun is forcing the climate. Whether a particular forcing is constant or variable, doesn't make it any less of (or something other than) a forcing.
  19. Lindzen and Choi find low climate sensitivity
    RW1, my and your use of the term "forcing" is different from the others following us. Their definition excludes cyclical forcing like the solar aphelion to perihelion change. Regardless, as I showed in 208 the "gain" term in the paper in #150 does not use the aphelion to perihelion cycle. The gain is simply the solar power that makes it into the earth/atmosphere divided by the surface flux determine from surface temperature. The cyclical solar change is not considered in calculating gain. To put it another way, the gain is not being used to calculate earth's response to the solar change that you and I call forcing. Thus, even using our definition, the gain is not applicable to CO2 forcing or any other forcing other than the average annual solar input.
  20. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    'Is it safe to double atmospheric CO2 over a 200 year period?' We don't know. Possibly not. Is it safe to live on this planet with 6.5 billion people, who all want to have their houses heated and their food and electricity supplied? Possibly not. But do we have a choice? Possibly not! Is it safe that many millions of people live in the Ganges delta without proper protection against floods? Not at all! Is it safe that many people live in aereas threatened by earth quakes without properly constructed houses? No! Small uncertainties in the rate of future warming are irrelevant to the risk assessment. What about big uncertainties? How big is the risk of future warming? Is there a real risk of more than 50 centimeters sea level rise? Why should a civilized society not be able to cope with such a sea level rise? Why have the skeptics never developed their own climate models and performed their own model experiments? They have. See Lindzen, Spencer, Soon, Baliunas, Akasofu! Why have the skeptics never compiled their own record of surface temperature? They have! See Loehle and others. It is easy to ask questions to climate skeptics and pretend, that they have no answer wihtout presenting their arguments. It is easy to point to risks whithout showing a way to avoid them. With the present state of technology there is no way to avoid doubling CO2 in the next century. We can better be prepared to cope with the effects of that doubling - if we are able to predict those effects!
  21. CO2 is not increasing
    "The rate may be exponential but if the exponent is very small the increase in warming is itself slow and probably not a problem" The final equilibrium temperature depends on the accumulated amount of CO2 in the atmosphere, not the rate of increase. If the accumulation is fast, then equilibrium will be reached more quickly, of course. We'll be reaching a doubling of CO2 compared to pre-industrial levels this century, and at that point will be committed to about a 3C global rise in temps, with the average temperature over land in the NH being much higher than that (say, double). You claim this is "slow and probably not a problem". Many, many experts say otherwise. I'll listen to the experts rather than someone who tries to wave away exponential increases in the rate of accumulation of CO2 as being "nearly linear".
  22. CO2 is not increasing
    muoncounter(12#) 170 PPM to get to 560 ppm, so we increase around 2 PPM per year. S0 170/2=85 years give or take. We will get there near 2095-2096.
  23. CO2 is not increasing
    Tom Dayton It is no digression. The warming of CO2 is proportional to the log of the amount of CO2. By taking the log of the CO2 we see how fast the warming can take place all other things being equal. The rate may be exponential but if the exponent is very small the increase in warming is itself slow and probably not a problem. This seems to be the case. Taking the log of an exponential function shows us the exponent. The increase in value of this log is an indication of the rate of warming Now go back and read my previous post #10 again.
  24. CO2 is not increasing
    #10: "The slope should tell us how log it would take to have a doubling of effect." Yes, linear trends can be used to extrapolate forever. How's that working for you in the stock market? Bet you won't get a linear fit to these data: . We add more than 2ppm/year and that rate is increasing. Go to the MLO site and look at the annual rate of change. Then go look at an Arctic site like BRW, where the annual rate change is even larger. Look at how the fossil fuel consumption rates are rising worldwide and project forward. Look at how the oceans/biosphere aren't taking as much CO2 out of the atmosphere as they once were. Then tell us when we'll be at 560 ppm. But why do you even care about atmospheric CO2? Is that 'rampy-siney thing' not working for ya?
  25. Lindzen and Choi find low climate sensitivity
    The energy from the Sun is not a forcing agent, while a change in the rate of energy flow is. Do you understand the distinction?
  26. Lindzen and Choi find low climate sensitivity
    #225: "roughly 0.6 C sensitivity is at least as consistent with a 0.8 C rise so far," Incorrect, as shown here. That was 190 comments ago; continuing to deny/ignore the problems inherent in your hypothesis does little other than bloat this thread. As you can see from the patient explanations given above, 'forcing' has with it an inherent rate of change. Your calculated 0.6C per doubling of CO2 will neither match the current temperature change nor the rate of change of temperature change. If a model cannot match behavior that is already observed, it's time for a different model. But of course, the ready comeback will be 'it could be due to something else.' What then is the value of a model that requires an unknown or undocumented 'something else' to explain observed behavior?
  27. CO2 is not increasing
    NETDR, this thread is about the rate of increase in CO2. You had claimed on another thread that CO2 is increasing nearly linearly. I pointed you to a very thorough analysis by a professional time series statistician, showing unequivocally that the increase is exponential. You completely ignored that, instead meandering off into something about doubling the effect of CO2 and something about temperature.
  28. Lindzen and Choi find low climate sensitivity
    RW1, it is you who does not understand the terminology, specifically what is (and what isn't) a forcing. The temperature of the Earth (or the climate, if you will) is merely the sum of all inputs, some positive and some negative. Energy from the sun is one such input. If inputs are stable and there is no change, then the system is in dynamic equilibrium. Changes in inputs, positive or negative, are characterized as "forcings". Therefore forcings represent a change in the dynamic equilibrium of the Earth's energy system/climate. Constant inputs, by definition, have no forcings attached to them. It really is that simple. The Yooper
  29. Lindzen and Choi find low climate sensitivity
    Rw1, Words have meanings. If you can't understand the definition of something as basic as "forcing", then how can you possibly claim any understanding of the complexities of climate science? One more time: the definition of climate forcing is something that is changing the climate. The sun has the potential to act as a forcing, but that is not the same as saying it is a forcing at present.
  30. Lindzen and Choi find low climate sensitivity
    Bibliovermis, The sudden cessation of solar activity definitely qualifies as a change. This, by definition, makes the power from the Sun a forcing of the climate system.
  31. Lindzen and Choi find low climate sensitivity
    My, my - things are much worse that I thought. If we cannot agree that power from the Sun is forcing the climate system, then we are at an impasse. No wonder no one understands anything I've put forth. :(
  32. Lindzen and Choi find low climate sensitivity
    Change is forcing.
  33. Lindzen and Choi find low climate sensitivity
    climate forcing
  34. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Ken Lambert said, Skeptics pointing out weaknesses and inconsistencies in AGW theory does not oblige them to offer a better fit theory to the observations. But skeptics *do* have the obligation to *understand* the theory that they are criticizing. Your posts here clearly indicate that you don't, starting with your failure to understand something as basic as the time-scale difference between gaseous diffusion into surface water vs. that of deep ocean mixing.
  35. Lindzen and Choi find low climate sensitivity
    How does that not make it a forcing? I didn't say a change in forcing - just a forcing. I think you're confusing the two.
  36. Lindzen and Choi find low climate sensitivity
    Rw1, No we are saying you are misunderstanding the definition of forcing. If all you are trying to say is that the sun contributes energy to the climate, then ok yes it does, but that does not make it a "forcing".
  37. Lindzen and Choi find low climate sensitivity
    What part of change do you not understand? The sudden cessation of solar activity definitely qualifies as a change.
  38. Lindzen and Choi find low climate sensitivity
    Daniel, e, and Bibliorvermis, So you are saying the power from the Sun coming in contact with the Earth is having zero effect on the climate system - meaning if the power from the Sun suddenly stopped, the climate would remain exactly as is?
  39. The Physical Chemistry of Carbon Dioxide Absorption
    Dear Hugo. I find that the assertion in your 12 slide (the anthropogenic origin of atmospheric CO2 excess) would benefit of a mention of the Suess effect. The evolution of the isotope ratios rejects other hypotheses with more certainty than the coincidence in the increase of concentrations with anthropogenic emissions. http://en.wikipedia.org/wiki/Suess_effect See also Figure 2.3 in IPCC-AR4 http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch2s2-3.html#2-3-1 This is just a suggestion for future versions. Thanks for your work. jon
  40. Lindzen and Choi find low climate sensitivity
    Changes in irradiance are the forcing agent; solar activity, orbital parameters, etc. A constant provides no forcing. Yes, that value is always changing. The long-term trend (at least greater than the ~11 year solar cycle) is what is important.
  41. Lindzen and Choi find low climate sensitivity
    RW1, A "forcing" is by definition something that changes the climate, so no, we do not agree that the sun is currently forcing the climate.
  42. Lindzen and Choi find low climate sensitivity
    Re: rw1 (234) If energy from the sun is not changing, then there is no solar forcing, by definition. The Yooper
  43. Lindzen and Choi find low climate sensitivity
    Bibliovermis (RE: 233), I'm not talking about any changes at this point. I'm just trying to first establish that energy emitted from the Sun that travels through space and comes into contacct with the Earth is "forcing" the climate. Is that clearer?
  44. Lindzen and Choi find low climate sensitivity
    ~Changes~ in solar irradiance are a forcing. If you are making the claim that the Sun is currently providing a positive forcing, please continue at argument #1 linked from the top of the left column.
  45. Lindzen and Choi find low climate sensitivity
    Question #1: Do we all agree that power from the Sun is "forcing" the climate?
  46. Lindzen and Choi find low climate sensitivity
    I think the best approach is to take it step by step one question at a time.
  47. Lindzen and Choi find low climate sensitivity
    Eric, Also, the peri/ap is a global effect just like 2xCO2. The only reason I've separated hemispherical/seasonal from global is in regards to ocean heat content and any potential delay or inertia, etc., which the seasonal changes contradict as something taking decades to occur.
  48. Lindzen and Choi find low climate sensitivity
    Eric, I'm going to try to explain the whole thing from a different angle, as people still don't understand what the gain represents. The peri/ap forcing change is completely separate from the seasonal hemispherical responses, which are driven by the earth's tilt and have nothing to do with the distance the earth is from the Sun. The gain I've refered to is the global gain - not the hemispherical gain. 2xCO2 forcing is global - not hemispherical.
  49. Lindzen and Choi find low climate sensitivity
    RW1, the peri/ap forcing change can't be separated from the seasonal response. The seasonal earth tilt difference causes the extra forcing to be absorbed by the extra SH heat capacity (as chris said in 222). The assumption of constant gain across seasons would only be true if the heat capacity were constant across seasons.
  50. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    The validity of scientific knowledge is ~always~ decided by consensus. Just like theory, consensus has a different meaning in a scientific context. Consensus is the accumulation of empirical observation and development of validated theory. Dismissal via "fabled 'consensus'" is no different than "just a theory". It is sophistry. Scientific theories are not disproven by pointing at loose threads, but rather by presenting new hypotheses that better explain the empirical observations. Using a "reasonable doubt" standard to determine the validity of scientific theories results in events like the Scopes Trial. There is no one single observation that will cause the scientific theory of anthropogenic global warming to collapse. This philosophy of "loose thread science" explains a great deal about the process of presenting multiple, contradictory & mutually exclusive contentions. Concerning OHC, that has been discussed elsewhere on this site. Further rehashing is not relevant here. Suffice it to say, depending on a currently unknowable quantity is no different than the "god of the gaps" rhetorical tactic common in evolution discussions.

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