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  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  Next

Comments 100401 to 100450:

  1. Lindzen and Choi find low climate sensitivity
    RW1 - Sorry, your gain makes no sense whatsoever to me. The energy trapped at the surface is a function of the insolation and the ability of the Earth/atmosphere system to radiate that heat away in a temperature dependent fashion. I think we are all much better served by using the actual relationships there rather than a non-physics based 'gain factor' that isn't actually a constant. There's no difference between insolation changes, aerosol changes, albedo changes, and CO2 changes in terms of forcing beyond their "efficacy", and the only factor with an efficacy close to 1.6 in anyone's estimation (and I consider that an outlier) is cloud albedo (Figure 2.19).
  2. Conspiracy theories
    #65: "rate of accumulation of CO2 is almost linear." Interesting; you like the simplest possible answer to science questions, but you'll find the most convoluted interpretation of events and motivations to form your conspiracy theories. That's a hallmark of skeptics: reduce complicated issues to sound-byte size chunks, then repeat the sound byte, even when they are debunked. Very productive. The annual rate of change in atmospheric CO2 concentration is increasing; it was 1 ppm/year in the early days of the MLO record, but its been over 2-2.5ppm per year for several years now. It tracks CO2 emissions from fossil fuel consumption quite well. The recent recession dropped US CO2 emissions slightly in 2009, but didn't faze China and India. Add in the Law Dome CO2 and you have a rapid rate of increase over a short period of time, and yes, that does overcome the log relationship of forcing vs. relative CO2 concentration. A graph of temperature change due to CO2 forcing vs. time is concave up, meaning it has an increasing slope. The rest is off-topic. If you want to debate changes in the Arctic, there are plenty of active threads on that topic. But if 'we had little clue' is all you've got, I wouldn't advise it.
  3. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Rob H #22 "Small unexplained elements of a theory do not undermine a theory." The three 'inconsistencies' I listed are not 'small'. They go to the heart of AGW theory. What you are suggesting is the 'its there but we just can't measure it' argument which can hardly be called scientific rigour.
    Moderator Response: [Daniel Bailey] Per Rob's comment at 22 above, in order to prove a theory wrong you need to have a competing theory that fully explains all current observations. And it needs to explain them better. You have merely pointed out three areas where the existing theory seeks more robust data, which no one denies. Conflating that into "since we can't know everything therefore we can know nothing" serves no useful purpose. Nor does it add anything to the dialogue, as has been pointed out to you repeatedly on other threads. Please come up with a viable physics-based alternative to AGW which explains what we have known about GHG's for over 150 years which also explains why anthropogenic CO2 doesn't act like the GHG that CO2 already in the carbon cycle does. That would be displaying scientific rigour. Anything less is sophistry.
  4. Do high levels of CO2 in the past contradict the warming effect of CO2?
    #14: "not with today's ocean turnover rate." Why would you use today's anything rate when talking about 450 mya? The continents were in a completely different configuration; oceanic circulation was vastly different. Here's evidence that the Ordovician ice began forming in a much lower CO2 environment: the evidence suggests that the ice began to build up some 10 million years earlier than when volcanoes began pumping the atmosphere full of the CO2 that ended the Ordovician ice age. "... sounds plausible and simpler. " The answer to this question will not be found in a simple one-size-fits-all model.
  5. Conspiracy theories
    #64 The rate of accumulation of CO2 is almost linear. http://www.woodfortrees.org/plot/esrl-co2/from:1958/to:2010/plot/esrl-co2/from:1958/to:2010/trend #Least squares trend line; slope = 1.43127 per year Admittedly there is a very slight upward trend but worldwide recessions have a way of periodically reducing CO2. Claiming this very slight upward trend offests logarithmic effects of CO2 would be counter-factual. The CRU data set is the longest one we have and arctic temperatures in 1860 are non existent on any data set. In fact until 1978 or so when satellites were launched we had little clue of temperatures up there.
  6. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Due out in print Jan 2011 How Safe Is Our Food?. An advance Epub from the CDC.
  7. Do high levels of CO2 in the past contradict the warming effect of CO2?
    muoncounter, thanks for the info. My question was narrower, I just wondered if there was a known CO2 source for the increase 445m years ago in the chart above. dhogaza, it could have come from the oceans, but not with today's ocean turnover rate. Since it took millions of years to vent out (although I'm sure the chart above is fairly crude), the ocean turnover would have to be very slow to very slowly warm and thus very slowly release its CO2. Such slow turnover may be possible with the continents arranged the way rockytom pointed out. Tom's explanation in #11 also sounds plausible and simpler.
  8. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Rob #32 I agree with the point you are making Rob. I simply wanted to point out that food safety is far less than one might expect, making it a poor example (i.e. 4 of 186 restaurants in my city passed inspection with a full 25% being red carded). Sashimi anyone?
  9. Conspiracy theories
    Of course, not only does NETDR cherry-pick his time intervals, he cherry-picks his dataset. http://www.woodfortrees.org/plot/hadcrut3gl/from:1860/to:2010/plot/hadcrut3gl/from:1880/to:1910/trend/plot/hadcrut3gl/from:1940/to:1975/trend/plot/hadcrut3gl/from:1998/to:2010/trend If you use GISTemp things look quite different. As we all know, GISTemp includes an estimate of temperature anomalies in the Arctic, which is warming faster than the rest of the planet, while HADCrut does not. And, of course, climate scienctists understand that CO2 forcing isn't the only thing that impacts temperature, but also that as CO2 forcing increases its effect on temperature is slowly becoming more important than natural variation, one reason why the last 12 years are the warmest on record despite our being in a deep solar minimum. "The rate is gentle and irregular and should slow since the effect of CO2 is logarithmic. So unless the input increases geometrically the rate will slow and it is already too slow for a catastrophe." Exponential, actually, and that happens to be what's happening. NETDR, meet the Keeling Curve
  10. Conspiracy theories
    More grasping at straws to support your conspiracy notions. The links section of this site currently shows 396 articles supporting the "it's cooling" argument. The logarithmic effect is being countered with an exponential growth in anthropogenic emissions. Any other conspiracies you want to bring out in to the light?
  11. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Ron Crouch @ 27... Likewise, there are a great many well tested aircraft that have left the ground with many souls on board not to make it safely back to earth. The point being that everything has risk. Getting out of bed in the morning carries with it risk. But we take great pains to make sure that the things we do involve acceptably low levels of risk. This is the point of the article. At this point the risk models are high and yet we proceed each day as if there were no risk at all. There is one aspect of the risks that I don't think is addressed here. Slow and fast. Eating poisonous food or a crashing airplane is an immediate catastrophe. Climate is a very slow progressing catastrophe. If you are 60 years old today you will likely not see the worst of what is to come. If you are 20 today your situation is vastly different. As well, if you live in a poor nation you are more likely to be affected than if you live in a wealthy nation. The risks involved are very unevenly distributed.
  12. Conspiracy theories
    It has warmed. Who says it hasn't . The rate is gentle and irregular and should slow since the effect of CO2 is logarithmic. So unless the input increases geometrically the rate will slow and it is already too slow for a catastrophe.
  13. Conspiracy theories
    1978 - 1998 is only 20 years. No matter how hard you insist otherwise, the world has still been warming. The hottest 12 years on the record are the past 12. Do you have a conspiracy notion about that too?
  14. Conspiracy theories
    Dhogaza #59 The point I was making is that if we have a 30 year cooing or lack of warming the catastrophe in CAGW is nonsense. Notice that it took until 1980 to get as warm as 1940. That has to hurt the overall warming. I was surprised to find that the steep 30 year period from 1978 to 1998 was only 1.2 degrees per century. That was with ocean currents very high sunspots and a monster El Nino. Mother nature was helping all she could and the rate was still low. The reason the last period is only 12 years long is obvious, I will post the rest in 18 years.
  15. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    In science you cannot "prove" anything, but you can disprove it. The onus is on the skeptics to disprove AGW. Despite having well over 100 year to do so, the "skeptics" have been unable to refute the theory of AGW/ACC, or offer a reasonable alternate theory that has withstood scrutiny.
  16. A basic overview of Antarctic ice
    Has Antarctic Ice been similiar in the recent past? Yes it has, and in fact has prob been lower. http://geology.gsapubs.org/content/38/7/635.abstract?sid=0f422966-63d5-4963-895f-b8a3935beb2d
  17. Conspiracy theories
    "Mojib Latif seems to think that in short time scales like 60 years natural variation is more important than CO2" Mojib Latif has complained loudly and visibly about his views being misconstrued by climate change denialists such as yourself. Please refrain from doing so here. He merely points out that on short time scales like a *few years* (note the lack of caps), not *60 years*, natural variability can swamp the long-term signal. He understands that over periods of two to three decades the signal expresses itself. As for your wood for trees plot, cherry-picking can get you any result you want. Yet, it's interesting that in order to get your result, your first series (1880-1910) is thirty years long and shows a fairly steep decline, your second (1940-1975) is 35 years showing a very slight decline, while your last (1998-2010) is 12 years and is essentially flat. So your own cherry-picking shows these "stalls" in warming switching from leading to a fairly steep decline before anthropogenic CO2 began to kick in in earnest, a slight decline in the 1945-1970 period, and a flat period which you could only get by cherry-picking a short 12 year period. In other words, totally consistent with increased CO2 forcing increasing warming, ...
  18. CO2 was higher in the past
    Shouldn't the title of the article read "DO high levels of CO2 in the past contradict..." (instead of does)?
  19. Lindzen and Choi find low climate sensitivity
    RW1 at 05:24 AM on 25 December, 2010
    "How do you figure we've had all the warming of a 2 C sensitivity?"
    Come on RW1, this was explained here, and here, and here. Remember we're using your own argument, (but doing it correctly). It's very straightforward (use the equation here) to determine the full warming expected at equilibrium from the rise in [CO2] between 1900 and 2000 (the dates you chose yourself). [CO2] in 1900 was 298 ppm. [CO2] in 2000 was 371 ppm. The warming at equilibrium for 3 oC climate sensitivity is 0.95 oC. The warming at equilibrium for 2 oC climate sensitivity is 0.63 oC. The actual temperature rise during this period was 0.75-0.8 oC. In other words we've had all the warming already that we expect from a climate sensitivity of 2 oC (Earth surface temperature rise per doubling of [CO2]), even though the Earth surface hasn't come to equilibrium with the enhanced greenhouse forcing during this period, and even though some of the warming has undoubtedly been countered by the large increase in made made aerosols. We know the solar contribution to warming has been small during this period (very likely less than 0.1 oC) as the very competent solar scientists inform us [see e.g. Lean and Rind (2008) and Hansen et al (2005)]... (and if were being very careful we should factor in the small contribution from man-made rises in methane and nitrous oxides atmospheric concentrations). So your assertion that 20th century warming is "in line with about a 0.6 C upper limit from a doubling of CO2" is clearly incompatible with empirical observations. That should contribute a warming of 0.19 oC at equilibrium from the 20th century rise in [CO2]. If your assertions are so wildly at odds with empirical observations RW1, then there's something very wrong with your argument.
    "How about you explain why the sensitivity numbers I've put forth fit very well with the temperatures differences at perihelion and aphelion..."
    I expect the numbers (you got them from someone's website I think) match rather by chance, unfortunately. It’s clear that you haven’t made any headway with your numerology with the set of rather bright individuals who have tried to help you out on this thread! In any case, the dominant effect on the relative hemispheric warming/cooling at aphelion and perihelion is the relative amount of land (low heat capacity) and ocean (high heat capacity) in the two hemispheres. Since the sinusoidal seasonal solar forcing is paced much faster than the Earth (and especially the oceans due to its high heat capacity) can come towards temperature equilibrium with the rapidly varying forcing, there is a strong mismatch between the rates that the hemispheres gain and lose heat. The N hemisphere (lots of land) warms more quickly than does the S hemisphere (90% ocean). Clearly, if one were able to determine climate sensitivity from analysis of the seasonal response to insolation variation there would be a nice body of scientific literature on the subject! There isn't. Unfortunately these analyses are bedevilled by difficulties in determination of the characteristic time constant of the climate system response to forcing. More importantly, the response to the very rapid (monthly) changes in insolation during the Earth's speedy passage around the sun, means that only the elements of the climate system that respond more rapidly are (partially) sampled (atmosphere and land surface). So as described in Foster et al (2008), for example, analysis of transient responses to rapid changes in forcing generally produce climate sensitivities that are biased low relative to the climate sensitivity of interest, namely the full Earth response to a strong, persistent (and progressively increasing) enhanced greenhouse gas forcing.
  20. It's Pacific Decadal Oscillation
    These subjects blend from one subject to another. How can a conversation with many elements possibly take place ? I came over to the PDO thread but the recovery from the LIA is part of the story. Carrying on a conversation with both elements is impossible and frustrating. #33 The warming may even be due to CO2 who cares ? The overall warming is about 1/2 ° C when the periodic cooling is taken into account. When the maunder minimum was over we started to measure temperature. Thinking all warming was caused by mankind seems contrary to fact. Positive feedback if it exists would multiply solar effects by 3 or more, but it might take time for them to build up. Notice the sunspots increased slowly until the late 2000's, it is an integration not an instantaneous phenomenon. http://sidc.oma.be/html/wolfaml.html
  21. Conspiracy theories
    #56 Bibliovermis To me the sine wave is clearly visible. Saying that it would be the consensus view if it were rue is meaningless. Many skeptics like Spencer have written about it also ! Here is even a paper from the University of Alaska which explains it. http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdf Here is the data, notice the cooling in 1880 - 1910, 1940 - 1978, and 2000 - present. [Actually the last is lack of warming not actual cooling yet.] Notice that the cooling cycles start about 60 years apart. Mojib Latif seems to think that in short time scales like 60 years natural variation is more important than CO2 and this graph seems to substantiate it. Over the long term there is warming, no doubt but the periodic cooling cycles make a mockery of the catastrophe in CAGW. Here is the temperature from 1860 to present. The 60 year trend is clearly visible to me. I can't understand why you can't see it. http://www.woodfortrees.org/plot/hadcrut3gl/from:1860/to:2010/plot/hadcrut3gl/from:1880/to:1910/trend/plot/hadcrut3gl/from:1940/to:1975/trend/plot/hadcrut3gl/from:1998/to:2010/trend #57 Mouncounter Notice that they all are tenured. For a young person starting out it wouldn't be a good career move. Accepting research funds from big oil would be career suicide.
  22. It's Pacific Decadal Oscillation
    #30: "ramp is because of recovery from the Little Ice Age" Even positing that's true for just a sec, what would cause such a thing? "the sine wave is caused by ocean currents. [ADO and PDO]" Which you just said, cannot cause warming. What's nice about AGW as a scientific theory, other than that it's real, is that it explains observed phenomena. Which is important in science. Otherwise, you're just making stuff up.
    Moderator Response: Everybody comment on recovery from the Liitle Ice Age on that thread, not this one.
  23. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    #21: "during a period of maximum CO2 potency, they have risen at a rate of 0.64degrees C per century, and currently show every indication of slowing down." Do try to keep your facts straight. O.14 deg C per decade on the low end; 0.4 deg C per decade may be the new norm. See Assessing global surface temperature. As for 'every indication of slowing down', look here, where the most recent 30 year trend is in excess of 0.5 deg C/decade: that isn't an indication of slowing down. Comments regarding temperature records alone -- off topic for this thread -- should go to one of those or one of the many similar threads.
  24. Lindzen and Choi find low climate sensitivity
    #218: "...a representation of how much can be expected to be added on top of natural variation from 2xCO2." There's not currently a 'natural variation' that is doubling CO2. If your model is due to the effects of CO2 only, why do you start with planetary albedo and continue with emissivity? These points of basic physics are not CO2-specific. "The amount of warming we've seen so far is perfectly in line with about a 0.6 C upper limit from a doubling of CO2." Utterly incorrect and shown a number of times in this thread. Look at hfranzen's article; he arrives at 0.14 deg C/decade, which is far more than an 0.6 C sensitivity can produce. His results come from a strictly physics-chemistry calculation. You can't both be correct -- and his work agrees with measurements of temperature increase.
  25. Conspiracy theories
    #53: "things happen so slowly that incorrect beliefs aren’t punished for 30 years" That's just ridiculous. Response to a nonsensical hypothesis is swift and sure, thanks to this very medium. Unfortunately, good people get trashed, even before their papers come out in print. "Going along with the consensus is the best career choice in climatology." Then why, according to the deniersphere, are there so many climate scientists who reject AGW? Or is that just another conspiracy? As for your 'sine and ramp theory idea, perhaps you could email it to John who could post it here.
  26. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Long before we had modern science, one of the ways we know whether food was safe was by watching what happened to our neighbour when they ate those tempting red berries. If only we had a neighbouring planet that had quickly consumed all its coal deposits; then we wouldn't need all those GCMs, we could disband the IPCC and James Hansen could spend more time with his grandchildren. Those red berries tasted nice, perhaps the fever that I'm starting to experience means that I should just eat more of them. Um, why are those alien neighbours watching me so closely?
  27. Do high levels of CO2 in the past contradict the warming effect of CO2?
    #8: "how we got out of the glacial conditions 400m years ago." #10: "where does the CO2 come from?" A large quantity of CO2 was removed from the atmosphere/oceans during this point in the geologic past. It's not a question of where it came from (may have been 'primordial'), but where it went: The widespread deposition of Ordovician marine carbonates (CaCO3) in warm shallow seas.
  28. Lindzen and Choi find low climate sensitivity
    johnkg (RE Post 219), Your maths or STILL wrong. CBDunkerson put you right on that way back in post #34. And I then clarified in Post 96 I was referring to the intrinsic response of CO2 - not any additional increase as a result of feedbacks. My statement in #218 is accurate.
  29. It's Pacific Decadal Oscillation
    Re: netdr (30) Akasofu commits many an error (multiple violations of the top 10 in the upper corner of this page). Trenberth has demolished Akasofu's credibility in the past, as shown here. You grasp at straws, as Bibliovermis details above, and as Stephen Leahy alludes to in his comment here. The Yooper
  30. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Fred Staples said: Now what will happen if the absorptivity of the atmosphere increases again? Nothing will happen. If the atmospheric temperature increased, the outgoing energy to space would be greater than the incoming energy, and it would promptly cool down again. OK, what part of the atmosphere radiates IR directly to space? And as the CO2 concentration increases, what happens to that part of the atmosphere? How will that impact the average temperature at the Earth's surface, and why? If you have even a *very basic* understanding of atmospheric physics, these should be slam-dunk easy questions for you to answer
  31. Conspiracy theories
    Positing a 60 year temperature cycle that the scientific community is either purposefully ignoring to keep their funding flowing or is too incompetent to see is a perfect example of what this entry is discussing.
  32. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    #20 Rob Maple Leaf Foods which has been in business for well over 100 years had a major problem with listeriosis in it's packaged meats in mid 2008 which led to several deaths. Any resulting deaths place such issues far from a tiny risk factor or little concern. I would submit that your food may not be as safe as you might think. Some of you that live in the U.S. might think that the USDA and FDA have your best interests at heart (and they do, but are constrained by the lack of technology). You might be surprised upon closer scrutiny as to just how much tainted stuff is let through. There is a relatively good elementary article on this subject here.
  33. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Clarification - Angstrom wasn't wrong in the context of the experiment he performed, he was wrong in his extrapolation of that experiment to the atmosphere. Here's a summary of the physics involved: http://www.realclimate.org/index.php/archives/2007/06/a-saturated-gassy-argument/
  34. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    "So, in your view of applied science we must test every bridge to destruction before we build it." Strangely enough, that's exactly what's done to bridge components, not to mention every new major airline design (the Boeing 787 project has suffered many delays, one was due to a destruction test showing that stressing the wings caused a failure in the connection to the fuselage at a level of force less than predicted by engineers). A quick read of the rest of your post shows a similar lack of understanding of stuff you talk about. Saturation doesn't not happen in the atmosphere, and the physics showing why Angstrom (who perhaps should've stuck to his unit) was wrong was figured out over FIFTY YEARS AGO.
    Moderator Response: Don't use all caps.
  35. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Vast majority of climate 'skeptism' has nothing to do with science or evidence. More information or analysis will not help. It is a culture war waged by those adopting neo-conservative values and whose very identity and world view is threatened by the reality of climate change. As Clive Hamilton puts it: "facts quail before beliefs". Everyone should consider this point he makes in his excellent essay Why We Resist the Truth About Climate Change "The evidence contradicting the information deficit model is overwhelming, so that those who continue to cleave to it, ipso facto, demonstrate its falsity. Faith in the power of information prevails over the power of information." We are not the rational creatures we'd like to think we are.
  36. It's Pacific Decadal Oscillation
    You keep insisting that there was an 70s ice age scare and that the globe has been cooling since 1998. Both of these contentions are wrong and are addressed in other areas of this site which are linked to from the top of the left column. There is no 60 year temperature cycle. Try getting your scientific knowledge from scientific sources rather than popular media like Newsweek.
  37. Lindzen and Choi find low climate sensitivity
    #218. damorbel "As stated earlier in the thread, we've already reached 75-80% of the intrinsic forcing from a doubling of CO2 and we've only seen about 0.6-0.8 C of warming." Your maths or STILL wrong. CBDunkerson put you right on that way back in post #34.
  38. It's Pacific Decadal Oscillation
    The temperature since 1860 seems to follow a 1/2 ° C per century ramp and 60 year sine wave pattern. Yes the PDO cannot cause warming but a long slow increase due to recovery from the LIA or Maunder minimum and a positive long feedback time can. It might even be because of CO2 but it is so slow that there is no catastrophe. The tops and bottoms of the sine wave causes some climate scientists to arrive at incorrect conclusions like global cooling [Newsweek 1975]. And Catastrophic Global Warming [CAGW] circa 1998. Here is a chart which shows how the temperature of the earth has varied since the beginning of records. It consists of a ½ ° C per century ramp and a sine wave with a 60 year period. The ramp is because of recovery from the Little Ice Age [or some other cause but it started before mankind emitted significant CO2] and the sine wave is caused by ocean currents. [ADO and PDO] http://wattsupwiththat.files.wordpress.com/2010/04/orssengo3.png Here is a peer reviewed study by a different author which comes to the same conclusion. http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_components_recent_climate_change.pdf There is a chart on P7 which explains a lot of “mysteries” of the temperature record much better than a CO2 based explanation does. When the sine wave went up in 1970 to 1998 the climate scientists went ballistic. They projected that to mean 3 ° C warming by 2100. When the sine wave started sideways or down in about 2000 they were shown to be wrong. To me this explains the temperature cycle far better than the "CO2 and Aerosol" theory..
    Moderator Response: Newsweek is not a scientific journal, and the article in question was not written by a scientist. There is no recovery from the Little Ice Age; see the post "We’re coming out of the Little Ice Age." This is your last warning about posting off-topic comments.
  39. Lindzen and Choi find low climate sensitivity
    chris (RE: 217), "But we've already seen that contemporary (20th century) warming is entirely consistent with a climate sensitivity in the range 2-4.5 oC. Since we've already had virtually the warming expected from a climate sensitivity of 2 oC, even without factoring in the inertia in the climate system and the counteracting effects of man made aerosols as described here, and here, and here. The empirical data are simply incompatible with your model and it surprises me that this doesn't concern you." How do you figure we've had all the warming of a 2 C sensitivity? As stated earlier in the thread, we've already reached 75-80% of the intrinsic forcing from a doubling of CO2 and we've only seen about 0.6-0.8 C of warming. Even if all of the warming was attributed to CO2, that translates to only about a 1 C sensitivity. Also, I don't think you understand the model I've laid out. It's not a representation of all the things that can affect climate and temperatures - it's just a representation of how much can be expected to be added on top of natural variation from 2xCO2. The amount of warming we've seen so far is perfectly in line with about a 0.6 C upper limit from a doubling of CO2. "That's simply not true. It's worth familiarising yourself with the large body of data that informs us about likely ranges of climate sensitivity, ranging from empirical analyses to modelling." I'm aware of it. My point was the model estimates are not derived from first principle physics or empirical observation of how the system responds to changes in radiative forcing. Also, the model estimates are way outside the bounds of how the system responds to post albedo power from the Sun. "As for the analysis of seasonal temperature variations, which seems to play a large part in your argumentation, I think it might help if you were to consider more carefully why the Earth is overall warmer at aphelion (July) and cooler at perihelion (January)." I addressed this. That the earth is cooler at perihelion despite higher insolation and warmer at aphelion despite lower insolation totally fits with the numbers I've presented for sensitivity. The reason for this is the albedo is greater in January than it is in July (*do you want me to run the numbers again?) How about you explain why the sensitivity numbers I've put forth fit very well with the temperatures differences at perihelion and aphelion and why the sensitivity numbers for a 3 C rise do not fit and are much too high?
  40. Conspiracy theories
    Re moderator response. I have rebuttals for each of the objections you raised but they are O. T. for this thread. I have never seen a thread on the sine and ramp theory as I call it and it is a fairly prevalent theory among skeptics. There is one on sine only and it points out correctly that there would be no warming overall.The ramp might be because of CO2 but at 1/2 degree per century it is manageable. I just doubt the catastrophe.
  41. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Very good article. I'd been thinking about writing one on the risk assessment perspective myself, but you beat me to it, and probably did a better job than I would have. In the environmental field, we don't mess around with risk. If there is even a chance that a chemical is carcinogenic, we regulate it. We don't say "oh well there are some uncertainties, it causes cancer at high doses in some animals, but maybe it's fine in humans, so we'll just keep releasing it into the environment and see what happens." But that is the global warming 'skeptic' approach. They want to just wait and see what happens because there is uncertainty. There will always be uncertainty, but from a risk assessment standpoint, you don't mess around with public health. You err on the side of caution every time. But that's not what we do with the climate. Rob Honeycutt @ #20 is also correct. In the USA we have the FDA which ensures that the food we consume is safe. When unsafe food gets through, it's a major scandal. Most of us don't just go out into the woods and eat whatever mushrooms or berries we find in the hopes that they won't kill us. In most cases we err on the side of caution to protect public health. On the climate, we're failing miserably to protect our health in the same manner. From a risk assessment standpoint, it's really quite appalling.
  42. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Ken Lambert @15... Regarding inconsistencies in AGW theory. Yes, there are aspects of AGW that are not yet explained. There are aspects of gravitational theory that are not explained. Vast parts of the big bang theory can not yet be explained. But each of these are accepted because the preponderance of evidence shows they are most likely accurate representations of reality. Small unexplained elements of a theory do not undermine a theory. In order to prove a theory wrong you need to have a competing theory that fully explains all current observations. And it needs to explain them BETTER.
  43. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    So, in your view of applied science we must test every bridge to destruction before we build it. We must switch from coal to nuclear, because the former may be dangerous but the latter is perfectly safe (Chernobyl, Three Mile island, irradiated fuel storage, plutonium proliferation). We must rely on renewable energy, whatever the resulting energy shortage does to the developing world. And we must stop the industrial revolutions in China and India because their cheap and abundant energy is dangerous. And we must persuade America to go back 100 years and give up air conditioning You call for a sceptical experiment. One is underway. It is universally accepted that, if increasing CO2 has any effect on climate, it is logarithmic. In other words it is the early increments that matter most. Starting at 280 ppm, 395ppm of CO2 will do more than half of whatever it is that doubling pre-industrial CO2 will do. Look at your own temperature charts. Starting from the depths of the Little Ice Age (to where they had fallen from the Medieval Warm period), temperatures peaked in 1940. From there, during a period of maximum CO2 potency, they have risen at a rate of 0.64degrees C per century, and currently show every indication of slowing down. Nothing to worry about so far. Science (and engineering) works on established theory and practice, while keeping a wary eye open for contrary indicators. Nothing is better established than basic thermodynamics. If we can clear up the confusion between heat and energy that permeates popular AGW theory we would eliminate 90% of the current theories (there are many more than one). All we need for a simple demonstration is to accept that the ability of energy to do anything – raise temperatures or produce work – depends on its surroundings. Heat is the ability to do these things. It is, by definition, the net energy transfer between regions at two different temperatures, from the higher to the lower. It is uni-directional, and depends on a function of the temperature difference, ie f(T2 –T1). For radiative energy it is actually a function of the difference between the fourth powers of the temperature, but we can ignore that qualification for the sake of this argument. Consider a bare earth heated by incoming energy from the sun and radiating W watts per square meter into space. T1 s zero, so the radiated energy, W = f(T2). Now surround the pare earth with an absorptive layer of gas which permits the incoming energy to continue to heat the earth, and which absorbs all the outgoing energy. The atmospheric layer must now radiate W to space, and must rise to a temperature T2 in order to do so. Butt he earth must radiate W to the atmosphere, and to do so its temperature must increase to T3 so that W = f(T3 – T2). Now what will happen if the absorptivity of the atmosphere increases again? Nothing will happen. If the atmospheric temperature increased, the outgoing energy to space would be greater than the incoming energy, and it would promptly cool down again. The trick here (to use a climate science term) is that once all the energy from the earth is being absorbed, further absorptivity will make no difference to the temperatures. This saturation effect was demonstrated in the laboratory by Angstrom (he of the unit) 100 years ago. You can see it again here: http://www.espere.net/Unitedkingdom/water/uk_overview.htm And for anyone who wishes to identify back energy radiation in this model from atmosphere to earth, it is the negative term in the heat transfer equation.
  44. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    cloa513 @ 1... Just last night we had a prime example of how you are wrong about food. My family went for a walk in the local park after a long week of rain. We found tons of mushrooms everywhere. A couple of large ones I picked looked particularly interesting and I thought might be edible. I came home and tried to look them up. None looked exactly like what I picked so we opted to throw them away. I also had emailed a friend who is knowledgeable. He wrote me back this morning to say they looked like they might be part of the amanita family, likely very deadly. My assumption, in the face of an unknown, absolutely HAD to be that the mushrooms were unsafe until proven safe. Your food analogy is wrong because you are comparing risk factors that are not equal. Food as you purchase it in the store has already been through a risk proposition many times over. You are not eating completely unknown foods. You are eating foods that are known to be safe. There still is a very tiny element of risk but the risk is so small as to not be of concern.
  45. Conspiracy theories
    There is no 60 year temperature cycle. The was no ice age scare in the 70s, except for a few sensationalist popular media pieces. Using the strongest El Nino event of the 20th century for the zero point of a linear analysis to declare that warming has "gone sideways" is a prime example of cherry picking. The original instance of CAGW that I know of is the Oregon Petition, which was a duplicitous sham. The global climate models are actually showing to be too conservative. Please respond to those points on their respective pages on this site. Your arguments are #5, 7 & 8, which are linked at the top of the left column. All you have to counter the published & independently validated empirical research of the past century are your beliefs based on misunderstanding and misconception. Rather than learn from what is available you resort to conspiracy notions of incompetent self interest and academic inertia. Academic inertia is overcome with new research or new interpretations of old research that provide a better fitting description. It is not countered with "you just can't admit you could be wrong and are protecting each other's funding."
  46. Miriam O'Brien (Sou) at 03:06 AM on 25 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Correction - my reference was to #14, not #15.
  47. Miriam O'Brien (Sou) at 03:01 AM on 25 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    I have to say that if getting out of bed in the morning is the most risky thing that some people do (re #15 Mizimi), it's no wonder they are so paralysed with fear of global warming that they flat out refuse to accept it :) And science can tell us in broad terms the likely effect of doubling C02 over a short period by looking at the past. It would be a hot and rocky ride! It's bad enough increasing CO2 by 44%, as everyone should have noticed by now. And there are economically viable alternatives to fossil fuel for energy. Initially some renewable energy is costing a bit more in dollar terms, but as time goes on the cost reduces so that in a short while it will cost much less than dirty energy. Certainly a lot cheaper than trying to live in a world with climate disasters. How many people only ever buy the cheapest of everything, especially when the cheapest product is so much more harmful? If that were the case we'd still be driving with leaded petrol. No-one would ever buy a car with safety features. (No-one would have a car at all - horses and buggies were cheaper.) Organic food would not be fashionable. etc etc
  48. Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    As far as the planet itself the answer is yes as the planet's relentless geological march will correct our mistakes over time (most likely long after we disappear). Whether it might be safe or not for the wellbeing of humans and other biota is another matter all together. Some here might even live long enough to witness first hand which side of the issue is correct. I know I have.
  49. Anne-Marie Blackburn at 02:55 AM on 25 December 2010
    Is it safe to double atmospheric Carbon Dioxide over a 200 year period?
    Ken Lambert @15 You're right. But contrarians need to understand that pointing out aspects which are not yet properly understood does not mean that the theory is invalid or that the scientists cannot be taken seriously. It simply means that, as in any scientific theory, more work needs to be done.
  50. Conspiracy theories
    First let me say what my beliefs are. I believe in AGW but not CAGW. The “C” sands for catastrophic. I think there is a constant ½ degree warming with a 60 year sine wave [from ocean currents] superimposed. This has recurred 3 times since 1860. There is warming but it is slow and easily managed. When the cycle is low we get predictions of an ice age [about 1978] and when it is high [about 1998] we get predictions of CAGW. Since 1998 we seem to be going sideways soon to be cooling, if the theory is right. #46 Phila. You state It's fine to talk about "self-interest" within a competitive field, but you also need to consider how rewards and credibility actually accrue to individuals within that field, because this determines which tactics are available to them. This is true in my field of electronic engineering because from conception to final test and delivery it is less than 3 years. Incorrect beliefs are punished swiftly. In climatology things happen so slowly that incorrect beliefs aren’t punished for 30 years or so and a long successful career can be had even if you are wrong. Dr Hansen’s 1988 model looked pretty good until 2007 when it departed from reality. It looked in the rear view mirror and projected the past on to the future. The sine wave went sideways and the model was wrong. You have a good point and I wish it were true. Going along with the consensus is the best career choice in climatology. In a field like Astronomy which hasn’t been heavily politicized coming up with a new theory of “dark matter” [which may not be matter and it might not be dark] would get you fame and advancement, no one would accuse you of being in the pay of big oil ! Who cares, truth is truth but could you stand your reputation being trashed for 30 years to prove it ?
    Moderator Response: You are incorrect that an ice age was predicted around 1978; see the post "Ice age predicted in the 70s." You are incorrect that warming stopped in 1998; see the post "Global warming stopped in 1998, 1995, 2002, 2007, 2010, ????." You are incorrect that Hansen's 1988 model was incorrect; see the post "Hansen’s 1988 prediction was wrong." If you wish to discuss any of those three items further, please do so on the relevant thread, not this one.

Prev  2001  2002  2003  2004  2005  2006  2007  2008  2009  2010  2011  2012  2013  2014  2015  2016  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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