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  1760  1761  1762  1763  1764  1765  1766  1767  1768  1769  1770  1771  1772  1773  1774  1775  Next

Comments 88351 to 88400:

  1. What was it like the last time CO2 levels were this high?
    @11 Gilles: "Two questions : a) what is the warming rate which mankind is supposed to be unable to adapt ?" Gilles, oh Gilles. Please keep in mind that there is a difference between humanity per se and civilization. James Lovelock, author of the Gaia Hypothesis and believer in CAGW, says that as little as 100 million human beings would survive. It's even possible to say that (micro) civilizations could exist under the condition he foresees. You only need a few tens of thousands to fulfill the definition of civilization. So would you please rephrase your question based on the potential numbers of a reduced population? Even that would be a silly question to ask; a worthy one but silly nonetheless, due to the enormous difficulty (impossibility?) of calculating the techno-social effects on humanity based on X rate of warming. Human beings are much more difficult to predict than warming rates. That's due to psychology, stupidity and (panic based) ingenuity. I hope you're young. You'll get at least part of the answer to your question(s) without any math or even science. Live long and...
  2. Video on why record-breaking snow doesn't mean global warming has stopped
    batsvensson wrote : "Is that correctly understood?" Not by me, anyway. What led you to such understanding ?
  3. How I lived through a carbon tax and survived to tell the tale
    @ Gilles Please go back and re-read my comments, I never said China didn't need the power plants they are building or that there is a significant risk that we can't switch away from FF. But we are getting off topic. It seems that you have already agreed that a carbon tax can work to reduce emissions. That was the whole point of this post. Obviously selling people on short term pain for long-term gain is difficult. No argument from me there. But arguing over The exact details of how large a carbon tax should be, how fast it should ramp up are beyond both of us (neither of us have working economic models at hand). I just pointed to some research done by an economist who spends his time thinking about these issues. If you have links to research that comes to a dramatically different answer then I would be happy to look at them. Otherwise there is not much lest to discuss.
  4. What was it like the last time CO2 levels were this high?
    Spike25, I would say that the Csank article above is in the same line as earlier Tripati work, but that is not surprising since Tripati is one of the 'et al' authors. Gilles, I think you should step back and model this as a kind of multi-body problem; whenever one thing changes, all things change. The physics which are used to determine that CO2 is a GHG are well understood. More CO2 causes a warming, but it is not the only thing affecting the climate and humans are not the only thing affecting CO2. How much carbon is sequestered is partly a function of climate conditions, but also continental plate subduction plays a role, etc. However, our production of CO2 through industrial (including agriculture) processes is they only thing that has changed significantly in the last 100 years or so. We know it is getting warmer, and that it will continue to do so; the discussion is about how much and how fast. Feedbacks are everything, and the indication from the above article and others is that the feedbacks will largely amplify the base CO2 effect. Climate models predict this, but we know that climate models are incomplete. That is the nature of models. However, the article above is about the system itself, which by definition has all feedbacks in place and fully accounted for. In the Pliocene, the position of the continents, the output from the sun, and the orbital mechanics are largely the same as they are now; so, we should expect a similar thermodynamic equilibrium from a similar atmospheric composition. I also highly recommend Archer's book "Global Warming: Understanding the Forecast". It covers the basics from the interaction of IR with CO2 molecules on up, but it is not too technical for someone with the skills you have demonstrated. I suspect you are just missing a piece or two of the puzzle and that is skewing your understanding.
  5. Muller Misinformation #3: Al Gore and polar bears
    thanks for this very interesting post. it shows how denials operate. I am really surprised at how these people (also Monckton) get audience ...
  6. Christy Crock #3: Internal Variability
    Re : the NIPCC. It was set up by Fred Singer and his SEPP organisation (who also dismiss the risks of smoking and ozone delpetion), and backed by the Heartland Institute. Biased, much ? Appeals to those of a certain political persuasion, perhaps ? Trustworthy ? (The answer to the last is 'NO')
  7. Video on why record-breaking snow doesn't mean global warming has stopped
    Hence, when temperature increase snowfall will increase around the polar region causing a greater reflective surface and possible off set any further increase in temperature which in turn may trigger and ice age. Is that correctly understood?
  8. What was it like the last time CO2 levels were this high?
    "Earth's past history is sending us a strong message" The OP is claiming this as a fact while it is an interpretation of earth's history. What reason do the OP think is talking against this interpretation and why should they be ignored?
    Moderator Response: [DB] Could you rephrase your question a bit more clearly? As written, it is a bit difficult to parse.
  9. michael sweet at 03:38 AM on 17 April 2011
    Muller Misinformation #3: Al Gore and polar bears
    Dr Muller must have missed this newspaper article about a polar bear who swam hundreds of miles looking for ice, and food. The cub disappeared, presumably drowned.
  10. Clouds provide negative feedback
    RW1,
    ...if the albedo is NOT decreasing (or has even slightly increased)
    Citation please. Otherwise either case is speculation. Albedo changes due to ice cover change will be measurable and predictable (in extent and effect, if not rate of arrival). Albedo changes due to cloud cover changes to my knowledge are uncertain at best. We'd know more if certain satellites (DSCVR) hadn't been mothballed, or others lost at launch, or unbuilt satellites had been built, but barring all that... all you have is speculation. Your assumption, however, that clouds must increase albedo is false. Again, read the above post, and other material. Clouds at high altitudes, which are expected to increase with warming, are composed of ice rather than water. These clouds are virtually transparent to visible light and so do not change the earth's albedo. They do, however, absorb in the infrared and so (as does all H2O) act as powerful greenhouse gases (even though they're solid, not gaseous). Similarly, lower (non-ice) clouds at night will trap heat without changing the albedo at all, so timing of development/dissipation is a factor. Along those same lines, clouds in winter (when the angle of incidence is already low, and the surface being shielded by the clouds is likely snow covered) will have no net change (or even a positive change!) in albedo, while still exhibiting GHG effects. So the assumption that clouds will increase albedo is based on an oversimplification which requires considerably more thought, research and observation.
    ...is to become 16.6 W/m^2 largely through positive cloud feedbacks...
    Citation, please. I don't know why you say this. If by 3.7 W/m2 you mean the effect of doubling CO2, then with a climate sensitivity of 3˚C (which is the current best estimate), that would translate into 3.7*3 = 11.1 W/m2, not 16.6 W/m2.
    ...then why doesn't it take more like 1075 W/m^2 ...
    Your equations are wrong. You are comparing the wrong factors. The equilibrium temperature of a body is that at which it emits the same amount as is being absorbed. Basically, the equilibrium temperature of the earth would be that at which it emits the same amount of energy as absorbed (i.e. absorbs 239 W/m2, then emits 239 W/m2). If CO2 adds the equivalent of 3.7 W/m2, then the total amount absorbed by the climate system becomes 239 W/m2 + 3.7 W/m2 = 242.7 W/m2. With expected feedbacks, this would be 239 W/m2 + 11.1 W/m2 = 250.1 W/m2. The question is, what surface temperature (actually, combined ocean/surface/atmospheric temperatures) results in this amount of emission (radiation)? The answer is a total of 3˚C. ...where is all the energy coming from that is supposed to be causing the enhanced warming? Outside of the above discussion, I think a major mistake that you may be making (this is a guess) is to equate water vapor feedback with clouds. While increased water vapor could result in more clouds, this is not necessarily the case, and clouds are not the form in which the main feedback would occur. Increased temperatures would increase the specific humidity... the amount of moisture carried in the air not in the form of clouds (condensation). This would be a proportional increase for every cubic meter of atmosphere, and H2O is a very powerful greenhouse gas. This would be the main contributor -- water vapor -- to positive feedbacks. Other positive feedbacks would include clouds (of different sorts), reduced snow and ice, natural release of CO2 and CH4, as well as others. All total, these would result in 3˚C of warming per doubling of CO2.
  11. What was it like the last time CO2 levels were this high?
    Do you mean that there can be spontaneous variability in the CO2/temperature/oceans system even without a injection of CO2 ? interesting -I thought it was impossible. Nevertheless , unless you justify that the warm period in Pliocen was triggered by massive injection of CO2 from volcanic activity, it corresponds to what I'm saying, CO2 is a response, not a driver. The fact that it enters a feedback loop doesn't change the situation, because amplification acts on both - CO2 and temperature - and so conserve the initial ratio. { - snip - long-winded, off-topic overly mathematical derivation of feedback removed - } In other words, if the amplification factor is *not* large, the CO2 responds only linearly to the "other causes" and its relative part in the global temperature change is minor. I know perfectly that you think it is not the case - but that the amplification factor is large and that CO2 plays a major role - but I haven't seen yet a decisive evidence for that, and I like more explanations to justifiy it.
    Moderator Response: [muoncounter] Variability of atmospheric CO2 in geologic history is the subject of numerous other threads. Before you continue theorizing, please familiarize yourself with some basic tenets of geologic processes.

    Your other points(?) are addressed in several sensitivity threads. Rather than merely calling for others to bring you evidence, you might consider engaging in some actual research of your own.

  12. Muller Misinformation #3: Al Gore and polar bears
    Thank you for this post. I've enjoyed reading this site for well over a year, and have never commented. But the audacity of Muller's quotes really struck me. If any of my colleagues (at an environmental consulting firm) included obviously fabricated statements and outrageous distortions as part of a lecture or invited speech, we would likely be severely reprimanded or even fired. How does Muller get away with it? Is he emeritus?
  13. Muller Misinformation #1: confusing Mike's trick with hide the decline
    Somewhat off topic, but I just came across another scientist using "tricks" here. The point is, of course, that's us just how people discuss things.
  14. Video on why record-breaking snow doesn't mean global warming has stopped
    Or this, also from 8 years ago : Global Warming Means More Snow For Great Lakes Region From Science Daily And this from 10 years ago : Another point to note is that while continental-scale snow covered extent is expected to retreat in response to global warming, it is not so clear what other aspects of the snow cover may do. Increased precipitation may lead to increased snow accumulation in cold climate regions, while warming will be accompanied by increased frequencies of mixed precipitation and rain-on-snow events which have implications for snowmelt, snow depth and snow density. Documenting and understanding these characteristics requires monitoring with surface-based observations in addition to satellite data. Is Snow Cover Changing in Canada? It's not difficult to find...
  15. Philippe Chantreau at 02:23 AM on 17 April 2011
    Last day to vote for Climate Change Communicator of the Year
    My vote was in long ago.
  16. Video on why record-breaking snow doesn't mean global warming has stopped
    7 - JMurphy every day an education! Replies like that are what SkS is (should be) all about.
  17. Video on why record-breaking snow doesn't mean global warming has stopped
    Or how about this, more directly related, from 8 years ago : Early Warning Signs of Global Warming: Downpours, Heavy Snowfalls, and Flooding From UCSUSA
  18. Ian Forrester at 02:10 AM on 17 April 2011
    Solar Hockey Stick
    Eric, I suggest you read some of the posts at Open Mind to find out why this talk about "cycles" causing the increase in global temperatures is not valid. Global temperature increase is mostly caused by increases in CO2 resulting from the burning of fossil fuels. No matter how often you try and confuse the reality by mentioning ENSO, AMO etc, you will not convince anyone with a good scientific background that you are correct.
    Moderator Response: And everybody please keep any discussion of cycles on the appropriate threads. This thread is about the Sun, so cycling of the Sun's output could be appropriate here, but there are other threads specific to ENSO, etc.
  19. Clouds provide negative feedback
    The main point I'm getting at here is if the albedo is NOT decreasing (or has even slightly increased) and if incrementally more clouds don't trap more energy than they reflect away, where is the energy coming from that is supposed to be causing the enhanced warming? Also - if, as the AGW theory claims, an additional 3.7 W/m^2 at the surface is to become 16.6 W/m^2 largely through positive cloud feedbacks, then why doesn't it take more like 1075 W/m^2 at the surface to offset the 239 W/m^2 coming in from the Sun (16.6/3.7 = 4.5; 239 x 4.5 = 1075)?? The measured response of the system at the surface to incident energy is only about 1.6 (390 W/m^2/239 W/m^2 = 1.6). Since the atmosphere can't create any energy of its own, COE dictates the remaining difference of about 10.6 W/m^2 (3.7 x 1.6 = 6 W/m^2; 16.6 - 6 = 10.6 W/m^2) can only come from a reduced albedo (i.e. the Sun). So again, where is all the energy coming from that is supposed to be causing the enhanced warming?
  20. Video on why record-breaking snow doesn't mean global warming has stopped
    bastsvensson, that was predicted back in the 1930s at least, albeit wrongly trying to explain a different topic : In 1937 [Sir George Clarke Simpson] suggested that, paradoxically, an increase of solar radiation might bring on an ice age. His reasoning was that a rise in the Sun's radiation would warm the equator more than the poles, evaporating more water from the tropics and increasing the rate of the general circulation of the atmosphere. This would bring more snowfall in the higher latitudes, snow that would accumulate into ice sheets. According to Lamb (1977), p. 661, the first to recognize that an ice-free Arctic Ocean would lead to more snow near the ocean (based on observations of 20th century warm years) and that this could lead to onset of glaciation was O.A. Drozdov; the work was not published at once, and Lamb cites a later publication, Drozdov (1966). Also from The Discovery of Global Warming
  21. Muller Misinformation #3: Al Gore and polar bears
    Muller continues to illustrate he in not a climate change scientist. No wonder I had never heard of him until this year in my 25 years working in the field. He clearly does not reach the level of Al Gore in fact checking. Further what about consideration of other supporting lines of evidence. Say the Pacific Walrus in Alaska where indications from 2007 and 2010 are not good. This is what a scientist approaching the subject in a scientific manner would consider.
  22. Clouds provide negative feedback
    2, 3, RW1, I suggest that you read the post here before commenting further. In particular, you'll find that this statement of yours is false:
    The numbers show that clouds reflect more energy away then they trap.
  23. Clouds provide negative feedback
    These calculations are consistent with general observations - that is cloudy days are usually cooler than sunny days. The opposite would be the case if clouds blocked more energy than they reflect away (cloudy days would be warmer than sunny days). It's true that at night the net effect of clouds tends to warm or slow heat loss, but these calculations are for global averages, so the differences between night and day are already factored in. The only exception to this would be in areas that are permanently snow or ice covered, as I think the reflectivity of clouds is roughly the same as snow and ice, so in these areas the presence of clouds tend to warm by blocking what little surface emitted energy there is.
  24. Muller Misinformation #3: Al Gore and polar bears
    What's funny about this, too, is that his argument about polar bears is clearly a bait-and-switch.
    Not a single polar bear has died because of retreating ice.
    First, how could anyone possibly know this, that not a single polar bear has died because...? How could one ever attribute a single polar bear death to retreating ice? Do they have satellites in space that watch every polar bear, to see if any slip, or get trapped on ice floes? Do they have a PDMEM (Polar Bear Death Evaluation Module) which runs on a Cray supercomputer and determines the statistical probability that a satellite-detected polar bear death was, or was not, attributable to retreating ice? But more importantly (Al Gore's actual vague "That’s not good..." comment aside), no one has ever said that climate change would result in an instantaneous and immediate change in Arctic ice, which in turn would quickly devastate the polar bear population. This is a recurring theme in denial, one that bugs me, and one that people should be ready to recognize and dismiss. This is the idea that "if it hasn't happened yet, climate change is not happening, or not bad." Almost all negative effects of climate change are 20 to 50 years in the future, or even beyond that. Any argument which says "hasn't happened" is purposely ignoring the relevant time frames. Sea level discussions often take the same track, as well as effects on crop production. Sea level rises are going to accelerate dramatically. The fact that it doesn't look so bad today is ignoring the problem. Crop production is going to drop for most of the world. The fact that crop yields may temporarily improve in some regions is ignoring the problem. The problem with climate change is that it is a long term thing, with horrible, negative effects in a relatively distant future, but effects which will be impossible to avoid without action in the near future. Everyone should be on constant guard for this. "It hasn't happened" is a strawman argument against a misrepresentation of the problem, meant to distract and confuse.
  25. What was it like the last time CO2 levels were this high?
    " As I said, if you want to discuss whether temperature is the cause of the post-industrial rise in CO2," But that's not what I'm discussing - I was discussing variations of CO2 in the last millions years: if it's not temperature, what else ?
    Moderator Response: [Dikran Marsupial] On a scale of thousands of years plus, CO2 levels are largely governed by exchanges with the oceans (which depends on a number of factors, including temperature). On longer timescales by the "chemical weathering thermostat". CO2 is also produced by volcanic activity. On shorter timescales, they also vary with internal variability, e.g. ENSO etc. The book by David Archer that I mentioned earlier explains all this in some detail.
  26. HumanityRules at 01:13 AM on 17 April 2011
    Zebras? In Greenland? Really?
    9 DB Thanks for the comments. I'm not denying the basal melt occured just wondering about the mechanism involved. An ice cube in a glass will melt faster if warmer water is used but also if the water is stirred. I couldn't see in the paper where it showed the underlying mechanism for any presumed changes in the summarine melt. I just found this interesting paper from NaturePrecedings 2011 which seems to go some way to answering that question. The intro is illuminating. These authors seem to suggest that estimates of base melt in Rignot and Steffen 2008 are in fact "estimated as a residual from mass balance calculations using ice-flow and ice-thickness data", i.e. they aren't direct measurements. In fact this paper claims to be the first to make direct measurements. I'll just highlight this section towards the end which seems to suggest that it still unclear whether it's warmer waters or circulation changes that are driving changes in submarine melt. "This adds weight to the possibility that the change in Greenland glacier dynamics over the last decade was not simply a result of the warming the Atlantic waters (estimated to be roughly 1 °C10 and hence comparable to the seasonal variation) but also a consequence of the vertical displacement of the Atlantic/Arctic interface due to changes in the large scale ocean circulation." Either way this seems to be a new insight into the science and worth reading. Enjoy. (Here's another version of their work which again seems to highlight the potential role of circulation changes as an alternate (or complementary) driver of submarine warming.)
  27. How I lived through a carbon tax and survived to tell the tale
    243 Really Dan I'm surprised - why do China build more than one coal power plant per week if they don't need them ? " well yes without a carbon tax they wouldn't." and who will tax them ? It's also surprising that you reckon that there is a real risk that we couldn't replace all FF with renewables after all - which I agree with of course. But telling that, how do you compare it with the risk of CC ?
  28. Eric (skeptic) at 01:08 AM on 17 April 2011
    Solar Hockey Stick
    Ian, your definition of weather is much too narrow since ENSO is partly weather (and partly climate). It is true that ENSO is somewhat cyclical and that it mainly redistributes heat already in the system. But ENSO also changes albedo and outgoing LWR over substantial portions of the earth. The constant small CO2 warming was amplified by favorable El Nino during most of the 90's. That part of the "cycle" will not necessarily be balanced by an opposite phase of the cycle. It can't just be ignored. Another "cycle" that we "skeptics" like to point to is Arctic Oscillation and North Atlantic Oscillation, both currently more negative than positive. Those tie nicely back into this thread since they are partly solar induced. For example the current low solar UV contributes to negative NAO in general and more specific changes in blocking (chart, paper: http://www.agu.org/journals/jd/jd0814/2008JD009789/2008JD009789.pdf) It is an oversimplification to say that those solar changes are "cooling". What they do is modulate weather (to a large extent) which then affects the amplification of CO2 warming or other forcings (to a smaller extent). And again, they are only nominally cyclical (the upcoming low solar maximum may be a part of a cycle from the higher solar cycles of the late 20th century, but solar cycles of century time scales are impossible to predict)
  29. Christy Crock #3: Internal Variability
    DM : are you arguing that it's wrong to say that GCM models were easily prone to secular drifts, or did I misunderstand you ? Mucounter :"< it is a process of eliminating the improbables from consideration." Precisely - that's why you have to demonstrate carefully that the other alternatives are improbable, and that we're totally entitled to ask you the justification - do we agree that saying "I can reproduce what I see with my hypothesis" , and even "I cannot reproduce what I see with my computer simulation" is far from being sufficient to say that ?
    Moderator Response: [Dikran Marsupial] I intended to suggest you should provide evidence to back up your assertion if you want to discuss that.
  30. What was it like the last time CO2 levels were this high?
    " It is not correct that all unfalsified hypotheses are equally plausible." Maybe , but you have to prove they're not equally plausible - and there is evidence that at some times in the last million of year , a decrease of CO2 lagged a decrease of temperature. "If you are claiming that rising temperature increases CO2," well please let me know what else could increase CO2 ! and I'm precisely arguing this is relevant to this topics, because you have to disentangle which is the cause of which.
    Moderator Response: [Dikran Marsupial] As I said, if you want to discuss whether temperature is the cause of the post-industrial rise in CO2, or vice versa, please do it elsewhere, it is off-topic here. If you raise this topic again on this thread, the post will be deleted, you have been warned. This is not censorship, you are welcome to discuss it on a more appropriate thread.

    This thread would be particularly appropriate.

  31. Video on why record-breaking snow doesn't mean global warming has stopped
    Did any one propose, say, 10 years ago that snowing will increase when the climate warms up?
  32. The e-mail 'scandal' travesty in misquoting Trenberth on
    Alec Cowan #125 "The rest are your numbers, which you won't reply if contested. You still have to answer for your calculations in #116. You wouldn't answer to the obvious bait I placed in front of you, because to do so you had to admit that you were changing the black body temperature of Earth. What did you have in mind? Tunning up the Sun? Moving the Planet 2 million kilometers closer to the Sun? Growing Earth's diameter?" Alec my reply was deleted by Moderators. You have to be quick and online to see my replies these days. Offer your own calculation instead of 'baiting' us with your commentary.
    Moderator Response:

    [DB] As you well know, comments constructed to adhere to the Comments Policy which are also on-topic are never deleted. In any case, your deleted reply to Alec is here:

    Ken Lambert at 12:29 PM on 16 April 2011

    Alec Cowan #118

    "We're still talking about Earth, aren't we? Please, confirm that and your 255°K. Imagine the surprise of 15 degrees Celsius plus 240 watts per sq. meter becoming 255 degrees Kelvin and then being "remarkably close" to something slightly pertinent to the subject."

    I assume you are taking the mickey here Alec. Respond with something showing some understanding of the numbers or take your 5 year old computer and go home.

  33. It warmed just as fast in 1860-1880 and 1910-1940
    #104 - Adam My trollometer just went off the scale! Adam, you say: "I just wanted to point out to you that Phil Jones himself has confirmed that the three periods of warming were indeed exactly parallel to each other." What a world of difference there is between 'exactly parallel' and what Phil Jones actually said: "the warming rates for all 4 periods are similar and not statistically significantly different from each other." http://news.bbc.co.uk/1/hi/sci/tech/8511670.stm I find it strange that somebody would state what Phil Jones said, and then proceed to post a proof that he did not say it!
    Moderator Response: [Dikran Marsupial] Unless, like many, Adam doesn't understand what statistical (in-)significance actually means.
  34. Clouds provide negative feedback
    It was suggested I move this discussion to this thread. The numbers show that clouds reflect more energy away then they trap. Given that the albedo has not been decreasing, and if anything has even increased slightly, this is completely inconsistent with clouds operating as a net positive feedback. Here are the numbers on how much incrementally more clouds reflect, according to Trenberth et al 2009: Clouds cover about 2/3rds of the surface, so 341 W/m^2 x 0.67 = 228 W/m^2 average incident on the clouds. 79 W/m^2 divided by 228 W/m^2 = 0.34 average reflectivity of clouds. 1/3rd of the surface is cloudless, so 341 W/m^2 x 0.33 = 113 W/m^2 average incident on the cloudless surface. 23 W/m^2 divided by 113 W/m^2 = 0.20 average reflectivity of the cloudless surface. 0.34 - 0.20 = 0.14. 341 W/m^2 x 0.14 = 48 W/m^2 loss for each additional m^2 of cloud cover. Here are the numbers on how much incrementally more clouds trap: The cloudy sky has a transmittance of 30 W/m^2, and the surface emitted through the cloudy sky is about 265 W/m^2 (396 x 0.67 = 265). 265 W/m^2 - 30 W/m^2 = 235 W/m^2 absorbed by the cloudy sky. The clear sky has a transmittance of 40 W/m^2, and the surface emitted through the clear sky is 131 W/m^2 (396 x 0.33 = 131). 131 W/m^2 - 40 W/m^2 = 91 W/m^2 absorbed by the clear sky. 91 W/m^2 divided by 131 W/m^2 = 0.69; 235 W/m^2 divided by 265 W/m^2 = 0.89. 0.89 - 0.69 = 0.20 difference between the cloudy and clear sky. 0.20 x 396 W/m^2 = 79 W/m^2 additional absorbed for each additional m^2 of cloud cover. If we assume that roughly half of the absorption and re-emission is back toward the surface (Trenberth actually has this being less than half), that comes to about 39 W/m^2, or about 10 W/m^2 less than the 48 W/m^2 reflected away. *If anyone doubts my calculations, I have backed check them by assuming that if half of the absorption is directed up out to space, then the weighted average totals should correspond to a temperature of about 255K. 0.69/2 (absorbed clear sky) + 0.31 passing through the clear sky = 0.66 and 0.89/2 (absorbed cloudy sky) + 0.11 passing through the cloudy sky = 0.55; 0.66 x 0.33 (clear sky) = 0.22 and 0.55 x 0.67 (cloudy sky) = 0.37; 0.22 + 0.37 = 0.59 emitted to space from the surface; 396 W/m^2 x 0.59 = 234 W/m^2 (about 254K), which is pretty close. *The missing 5 W/m^2 is probably due to Trenberth having greater than 50% of the atmospheric absorption being emitted up out to space.
  35. It's albedo
    KR (RE: 57) "As to your El Nino event issues, keep in mind that a positive feedback is not a runaway feedback (if that is indeed what you are implying, I may have misinterpreted your post) - see the Does positive feedback necessarily mean runaway warming thread." Yes, I do understand this; however, positive feedback is also not a temporary effect either. There is no reason why it would not continue to amplify further the remaining amplified change even after the initial forcing subsided. The AGW theory claims an intrinsic rise of 1 C will become 3 C via positive feedback, so most of the change comes from the feedback - not the initial forcing.
  36. What was it like the last time CO2 levels were this high?
    Gilles#24: "for it is nowhere demonstrated that we don't see rather the effects of temperature on the CO2 level." Yet another unsubtantiated bit of hand-waving; another attempt to drag discussion off-topic. If you are claiming that rising temperature increases CO2, find the appropriate thread -- and this time, read it before offering more opinions.
  37. Muller Misinformation #1: confusing Mike's trick with hide the decline
    Ryan Starr @138, no chart is self interpreting. Consequently, any body who attempts to interpret a chart without consulting at minimum, the caption is being foolish. This point can be amply illustrated from your own words. You say "you call a proxy a proxy", but in fact no data on the WMO chart is labeled as proxy data, either on the chart or in the caption. That is because no data series on the chart is uniquely and only proxy data. You say, "You don't call an instrument record a proxy", but in fact, no instrument record is called a proxy on the WMO chart, because no series on the chart is called proxy data. Your interpretation of the charted data as a "proxy record" is your misinterpretation which is not suggested by either the chart itself, nor the caption. You are imposing your interpretation onto the chart. What is more, if you do not impose it, your whole case against Jones evaporates and you know it. The chart itself references the data source for the "paleoclimactic records" (Jones' term) of each of the three reconstructions, and the caption indicates that the three reconstructions use "paleoclimactic records ... along with historical and long instrumental records". Your misinterpretation requires that you read additional information into the chart which is not on it, and that you ignore information about the chart which is in the caption. And yet you want to blame your misinterpretation on Jones. You are therefore imposing a ridiculous standard on the chart whose only merit is that it allows you to condemn Jones. Your preference to condemn scientists rather than understand them is, however, not a great virtue; so I'm afraid I'm going to reject the totality of your nonsense as what it is.
  38. Christy Crock #3: Internal Variability
    protestant#88: "... similar warm periods like MWP and RWP in the past, ... might mean the ocean circulation patterns and internal variability could operate in not just multidecadal but also multicentennial timescales." 'It might mean' a vast number of things. 'It might mean' is hardly a scientific statement. What you lack is a credible theory, consistent with existing data and the fact that these multidecadals and their hypothetical multicentennials must be driven by something. 'It might mean' AGW. 'It might mean' Spencer's magic clouds. 'It might mean' LGM. Science has standards other than forming a list of possibles; it is a process of eliminating the improbables from consideration.
  39. What was it like the last time CO2 levels were this high?
    20 Sphaerica and 17 DM : What I'm saying is that there is a flaw in "consequently" - because it assumes that what is to be demonstrated, that we see "the effecs of raised CO2 levels" : for it is nowhere demonstrated that we don't see rather the effects of temperature on the CO2 level. DM : again I'm contesting the use of a "undismissed" theory which allows other "undismissed" theories. While you're right in your assertion about falsificationnism, you don't seem to understand its use : it's that you can gain confidence in a theory only after disproving all reasonable other explanations. What I'm saying is that nothing in what is written disproves alternative explanation - that you mainly track natural sensitivity of CO2 to external causes of temperature changes (whatever these causes are), and this is not the same that what you seem to look for - the sensitivity of temperature to CO2.
    Moderator Response: [Dikran Marsupial] No Gilles, as has already been pointed out to you, where there are multiple competing hypotheses, none of which have been excluded by the observations/experiment, then you apportion "belief" to each hypothesis according to the strength of the evidence. It is not correct that all unfalsified hypotheses are equally plausible. The "consequently" is just saying the evidence points towards a hypothesis being true, that is all. Popperians call this "corroboration", and they are happy with the idea that hypothesis become stronger the more corroborated they are.

    However the hypothesis that the post-industrial increase is due to the effects of rises in temperature, rather than the other way round, is falsified by the observations. The matter has been discussed numerous times here on SkS, so find an appropriate article where it has been discussed, read the arguments presented there, and I will be happy to discuss it with you (not as moderator) further on that thread - but not here.

  40. What was it like the last time CO2 levels were this high?
    3 degrees rise by 2050 or 60 now seems possible- 4 degrees by 2099 probable. A 4 degree rise in just over 100 years means that most species will not adapt, including us- as Alexandre said.
  41. It warmed just as fast in 1860-1880 and 1910-1940
    PS: This may not have anything to do with what we've been discussing, but I've noticed that in this article you claim to have rebutted the skeptic argument that it warmed the same rate from 1860-1880 and 1910-1940. I just wanted to point out to you that Phil Jones himself has confirmed that the three periods of warming were indeed exactly parallel to each other. So in your "rebuttal" you're actually contradicting a prominent AGW scientist, who has confirmed the skeptical argument. http://news.bbc.co.uk/1/hi/sci/tech/8511670.stm A - Do you agree that according to the global temperature record used by the IPCC, the rates of global warming from 1860-1880, 1910-1940 and 1975-1998 were identical? An initial point to make is that in the responses to these questions I've assumed that when you talk about the global temperature record, you mean the record that combines the estimates from land regions with those from the marine regions of the world. CRU produces the land component, with the Met Office Hadley Centre producing the marine component. Temperature data for the period 1860-1880 are more uncertain, because of sparser coverage, than for later periods in the 20th Century. The 1860-1880 period is also only 21 years in length. As for the two periods 1910-40 and 1975-1998 the warming rates are not statistically significantly different (see numbers below). I have also included the trend over the period 1975 to 2009, which has a very similar trend to the period 1975-1998. So, in answer to the question, the warming rates for all 4 periods are similar and not statistically significantly different from each other. Here are the trends and significances for each period: Period Length Trend (Degrees C per decade) Significance 1860-1880 21 0.163 Yes 1910-1940 31 0.15 Yes 1975-1998 24 0.166 Yes 1975-2009 35 0.161 Yes
  42. What was it like the last time CO2 levels were this high?
    MattJ Actually, the problem is the pace of the change. If the Earth warms 3 degrees in millions of years, new ecosystems will evolve, species will adapt, new species will appear. Do it in one or two centuries, and the change will be too fast for everyone. Including humans that built their whole civilization in the stable Holocene climate.
  43. Waste heat vs greenhouse warming
    RSVP#390: "not considering this minutia," If by minutiae, you mean evidence. Your statement: ... fluids such as air and water, A (the area) equals zero ... Conclusion: If A is zero, J is zero, which means energy radiated is zero ... clearly says fluids don't radiate energy. You've been shown evidence (more of that minutiae) here and here that your 'conclusion' is utterly wrong. Your continued persistence in accepting this only makes your entire argument less credible than ever.
  44. The e-mail 'scandal' travesty in misquoting Trenberth on
    "You wouldn't answer to the obvious bait I placed in front of you, because to do so you had to admit that you were changing the black body temperature of Earth." Alec and Ken, there is nothing like "THE" blackbody temperature of the Earth - it's simply not an isothermal sphere. If you ask if it is possible to change the average temperature of the Earth without changing its energy content, or the opposite, the answer is without doubt yes - and I can demonstrate it on request. It's enough to change the latitude repartition. And if you ask if the latitude repartition has changed, the answer is again yes.
  45. It warmed just as fast in 1860-1880 and 1910-1940
    First of all, I just like to make it clear that I am not poptech. We are two different people. "No, you were repeating my claim (about Greenland) and then extending it in a single leap to apply to the whole of GHG climate science." Sphaerica, so to be clear, are you saying that there isn't empirical evidence that humans are causing Greenland warming, but you believe that there is empirical evidence that humans are causing global warming? Is that what you're saying, because we seem to be going around in circles here. Muoncounter, might I remind you that it works both ways for you as well. If you believe that using less stations won't significantly affect the readings, then according to your own logic, the data would have been pretty reliable 60 years ago as well. Dikran and muoncounter, once again have you even read the paper I provided? The difference between surface and satellite data, started around 20 years ago, corresponding with the adjustments made to the global surface temp network. Here is a very detailed document, which discusses the problems with the surface temperature record: Surface Temperature Records: Policy Driven Deception? And read the following paper: 'Unresolved issues with the assessment of multidecadal global land surface temperature trends' by Roger Pielke Sr et al published in the 'Journal of Geophysical Research' (2007) ""co2 was much higher 60 years ago" That's just plain wrong. Enough said. " That was a typing mistake. I meant to say that CO2 is much higher than it was 60 years ago. Anyway, this is going nowhere. I keep having to endure cheap insults, and in this discussion, everyone just keeps going around in circles. I think that anything worth discussing on this thread has now long gone. Unless there is something worth discussing, then I don't really see any point in carrying on. This will be my last comment, unless I need to come back for any particular reason. Goodbye.
  46. Muller Misinformation #1: confusing Mike's trick with hide the decline
    139 RyanStarr - are you discussing science or marking a term paper? Do you, maybe, gave a full guide you give your students on hiw to present results?
  47. What was it like the last time CO2 levels were this high?
    Spike25 I have read Tripati's research at UCLA- I agree with her that we have not C02 levels since around 20 million years ago (see my #2 above)
  48. Debunking Economic Myths from the Climate Hearing
    Good rebuttal, Dana, as always. Sadly, I don't think many of the Republicans are likely to read it. No, no. They'll be too busy reading WUWT, or listening to the misinformation on FOX. Just in case anybody is thinking I'm being anti-American, I'm sure the Conservative Party of Canada is pretty much the same.
  49. What was it like the last time CO2 levels were this high?
    17, Gilles, For some reason you are focused on variations which are never mentioned, and the cause of the CO2 levels in the Pliocene. There were no notable variations, and the cause of the CO2 levels is not the focus of the post. Please stay on topic. From the text of the post:
    CO2 levels remained at around 365 to 410 ppm for thousands of years. Consequently, the Pliocene gives us vital clues of the long-term effects of raised CO2 levels.
    Stick to that, please.
  50. What was it like the last time CO2 levels were this high?
    How does this fit with Tripati's work suggesting we are currently higher than the Pliocene, with the last time CO2 levels being this high being 15 million years ago? http://newsroom.ucla.edu/portal/ucla/last-time-carbon-dioxide-levels-111074.aspx

Prev  1760  1761  1762  1763  1764  1765  1766  1767  1768  1769  1770  1771  1772  1773  1774  1775  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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