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  1209  1210  1211  1212  1213  1214  1215  1216  1217  1218  1219  1220  1221  1222  1223  1224  Next

Comments 60801 to 60850:

  1. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Tony O the AAC is essentially wind driven, no major changes are projected.
  2. James Hansen's Motivation
    scaddenp @25, can I suggest as a participant (not a moderator) that all future discussion of the runaway greenhouse effect be moved to this post where it is on topic. The OP here is about Hansen's motiviation, and the TED video embedded in the OP, which contains no discussion of runaway greenhouse.
    Moderator Response: [DB] Thank you. Participants interested in discussing the "runaway greenhouse effect" please do so at the thread recommended by Tom.
  3. James Hansen's Motivation
    jzk @20, to correctly quote Hansen what you should have written is:
    "[0:10] If we allow emissions to continue at a high rate, then this century we are going to see ice sheets disintegrate [...] [1:16] On the long run, if that really happened, over the centuries we could get a run away green house effect, and then, that's it for all the species on this planet."
    (Source)
    "[2:04] [The runaway greenhouse effect] means once the planet gets warmer and warmer the oceans begin to evaporate, and water vapor is a very strong greenhouse gas - even more powerful than carbon dioxide. So you can get to a situation where it just ... the oceans will begin to boil and the planet becomes so hot that the ocean ends up in the atmosphere."
    (Same source.) In contrast, your "quote" got the wording wrong, in several places significantly wrong. What is worse, it covered up not just a change in paragraph, but a change in section by an ellipsis which indicated the continuation was part of the same sentence. (This is worse only because your changes of wording did not significantly change meaning.) Further, you did not clearly indicate either the source video, nor the times things where mentioned. More substantially, by not quoting the first part of the section from which the major part of the quote was drawn, you made it obscure that Hansen is talking about high emission rates over the centuries. From your butchered quote, it was quite possible that he was talking about high emission rates over this century only which would have unstoppable knock on effects several centuries down the track. Your immediately following comment encouraged this interpretation. You emphasize that he is puts no limitation on the prediction, and say that, "He is telling the public that if we continue business as usual (as he has said many many times in many places) that very severe things will happen like huge sea level rises, mass extinction events and boiling the water on the planet." Hansen believes that BAU over just this century, indeed, over just the next 50 years will result in huge sea level rises and major extinction events. By just tagging "boiling the water on the planet" onto the list, you implicitly suggest that the timeframe of BAU needed to boil the water is of the same order as that needed for melting most of the West Antarctic Ice Sheet and the Greenland Ice Sheet, ie, 50 to 100 years. Given the butchered nature of your quote, this constitutes a misrepresentation of Hansen. What you should have written is something like:
    "He is telling the public that if we continue business as usual (as he has said many many times in many places) that very severe things will happen like huge sea level rises, mass extinction events and, if continued over centuries, may result in boiling the water on the planet."
    (Amendments underlined, minor amendments for grammar not noted.) That then fairly represents Hansen's views by both by indicating the relevant time frame of BAU needed, and indicating that Hansen believes that the runaway greenhouse effect is a possibility, not a certainty under those conditions (as indicated by his use of the term "could"). I accept that your misrepresentation was entirely unintentional. Indeed, being fair your wording suggests the misrepresentation rather than explicitly stating it. However, I also believe my interpretation of your words to have been entirely justified given what you actually wrote. Note: I am only responding on this point because claims of misrepresentation, or actual misrepresentation must be fairly dealt with where they occurred. Any future discussion of Hansen's views on Runaway Greenhouse should be shifted to where they are on topic.
  4. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Is a breakdown, or major perturbation, of the Antarctic Circumpolar Current impossible, possible or inevitable some time in the distant future? Would this then affect circumpolar winds? (I have no idea of the answers). From the little I have seen of the outputs of climate models it would appear everyone is assuming it will remain stable. If it did change, the estimates of sea level rise would have to change too.
  5. James Hansen's Motivation
    As far as I can see, there is no consensus on runaway greenhouse to be discussed. Hansen mentions the extreme case of putting every bit of available carbon into the atmosphere,(and its a mighty distraction to real problem of what we are actually doing frankly, on which there is a consensus) and as far as I can see, there is no published science for that extreme case. He may be right (he has the wherewithall to do the maths, unlike me) but we need to see the maths to know. I think its a massive distraction because I doubt you could find an economically justifiable way to achieve it even without the downsides.
  6. michael sweet at 08:37 AM on 7 April 2012
    James Hansen's Motivation
    jzk, "The recipient of the 24th Edinburgh Medal was announced today as Dr James Hansen", see above link. If Hansen did not generally agree with the consensus he would not have received the Edinburgh Medal. Where he differs he is often correct.
  7. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    If I may be briefly grumpy about heat and human habitation. There's a big difference between can't survive anywhere, and must move somewhere. Humans live in decently warm places already, and the number of people displaced, eventually, because it gets unsurvivably hot is probably smaller than the number displaced because of high water (this is a pure SWAG on my part, but lots of people live on or near the coast in many countries).
  8. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Bernard J @8 Yes, good point. I guess I let my pessimism slip out there, since my "fortunately" applies only to the extra time we'll get for adaptation and implicitly assumes we'll blindly carry on with business-as-usual. Climate change would be an easier problem to mitigate if it were not for the fact that many of the effects are delayed. Which, as you correctly point out, is not fortunate at all.
  9. Submerged Forests off the coast of Wales: a Climate Change Snapshot
    Frank, Yes it is an approximation, but knowing this area over many years I would suggest is is pretty close. Lands you love are those you tend to know intimately. There is plenty more I could say about Borth, that would be inappropriate for SkS blogs but fine in comments: for ten years I played darts for the excellent pub, The Friendship. The local police sergeant was another member of the team but when on shift he would pop in late-on, remove the hat, plonk it atop of the piano and play beautiful ragtime and blues, as the pints lined up along the top. It is a fantastic community and place, but as several wannabee confidence-tricksters found out to their cost, Sgt John was a nice guy unless you crossed any villager, at which point the collar would be well and truly felt! How's that for a definition of Community? Glan John was a proper copper! Then there was Aran Morris, Lifeboat-skipper, and his catalogue of shouts over so many decades. These guys were all so much in touch with the environment and much they taught me, too. I owe all of them the most great debt of thanks, as someone who arrived there ca. 1982 and was so eager to learn. I think the take-home from these ramblings is: listen not to idealogues but to those who by dint of what they do have gained a deep understanding of the environment. You will not go far wrong if you follow that path. All the best - John
  10. John Russell at 05:40 AM on 7 April 2012
    Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Further to my comment @#3, Bernard's @#8 and Riccardo's @#10; incredibly, it seems like some people are ahead of us!
  11. John Russell at 02:57 AM on 7 April 2012
    James Hansen's Motivation
    The latest thoughts from Jim Hansen in the run up to him being awarded, next Tuesday, the prestigious Edinburgh Medal for his contribution to science. Quote:
    "In his lecture, Hansen will argue that the challenge facing future generations from climate change is so urgent that a flat-rate global tax is needed to force immediate cuts in fossil fuel use. The latest climate models had shown the planet was on the brink of an emergency. He said humanity faces repeated natural disasters from extreme weather events which would affect large areas of the planet. "The situation we're creating for young people and future generations is that we're handing them a climate system which is potentially out of their control," he said. "We're in an emergency: you can see what's on the horizon over the next few decades with the effects it will have on ecosystems, sea level and species extinction."
  12. An Interactive History of Climate Science
    And here is cite that does not go to a peer reviewed paper at all: http://www.c3headlines.com/peer-reviewed-studies/ Another Energy and Environment paper from 2010 listed in 2011: http://multi-science.metapress.com/content/c47t1650k0j2n047/?p=7857ae035f62422491fa3013c9897669&pi=4 And again more inappropriate year cites: http://www.mendeley.com/research/climate-change-detection-attribution-trends-longterm-geologic-data/ I will stop now but please consider that is just a perusal of the year 2011. I have not even begun to look at 2012 submissions.
  13. An Interactive History of Climate Science
    More inappropriate year papers: http://eaps.mit.edu/faculty/lindzen/cooglobwrm.pdf http://eaps.mit.edu/faculty/lindzen/dsttrotrov.pdf http://www.dvgu.ru/meteo/library/19955332865.pdf I am not being thorough here at all. I am just beginning to recognize that the multiple submissions that occurred on the same date such as 2011-9-15 warrant being clicked on.
  14. An Interactive History of Climate Science
    More evidence of shenanigans: I know that moderators on this site do not consider Energy and Environment a peer reviewed journal but yet here they are being listed: http://www.eike-klima-energie.eu/uploads/media/EE_21-4_paradigm_shift_output_limited_3_Mb.pdf Some of the papers do appear in professional journals but are opinion articles entirely unrelated to any science. For example here is a opinion piece found in a Law Review Journal: http://ojs.ubvu.vu.nl/alf/article/view/127/233 Others are double wammies of being not only decades out away from 2011 but are cited twice. I noticed that the duplicated were done within a week of each other: http://www-eaps.mit.edu/faculty/lindzen/127co2~1.pdf
  15. An Interactive History of Climate Science
    Your widget to add papers is being gamed. Take a look at the Skeptic papers for 2011. I found multiple papers that were assigned to 2011 to be years and sometimes decades earlier: http://www.sciencedirect.com/science/article/pii/S0273117797004997 http://resources.metapress.com/pdf-preview.axd?code=t341350850360302&size=largest http://ruby.fgcu.edu/courses/twimberley/EnviroPhilo/ProgressReport.pdf And that is only the first couple of dozen cites. You have others that duplicates and some that not even peer reviewed. I would like to give a more complete list but I am afraid I will get caught in the spam filter.
  16. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    chriskoz @15 - whatever his motivation, Monckton got that basic information right, so we want to give him credit for that. Denialists should be encouraged to at least get some science right! Old Mole @17 - the thin bars are larger, which is why the actual value is more likely to fall within their range than the thicker, narrower bars. To be honest, I don't pay that much attention to the state legislature. I know about my own representative, and I know the majority are Democrats, but that's about it :-)
  17. Submerged Forests off the coast of Wales: a Climate Change Snapshot
    Part of Holland, the area not ravaged by river floods or inundated by the North Sea over de last couple thousand years, stil has a layer of sand under the soil, including dune remnants inland. The map 'Land now/Land then' above shows why. It is sand blown over the country from the then dry sea bed.
  18. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    No offense to anyone involved in an otherwise excellent presentation, but could someone take a close look at Figure 2 and the legend beneath it and explain why they don't seem to coincide or make much sense? Among other things, saying that the extremes on the chart, shown by the thin bars, are more statistically likely than the thicker bars seems counter intuitive. Then again, it might just be my ignorance showing. P.S. I don't know where dana is getting his political information in part 1, but if he thinks there are any number of moderate Republicans in the California State Legislature, he has been misinformed. Moderate Republicans for local offices (as opposed to statewide offices, where one must be moderate to stand any chance) are not so much endangered as extinct.
  19. 2012 SkS Weekly Digest #13
    evolutionarymicrobiologist @ 10 - I have responded on the thread that scaddenp recommends, though I suggest you respond to his comment rather than mine.
  20. GHG emission mitigation solutions - a challenge for the Right?
    EM @ 10 -- This has nothing to do with your hypothesis on the carbon tax, but it still bears repeating: I'd be a little careful about throwing around simplistic labels like "left" and "right." I know plenty of people who call themselves "leftists" who are also in denial. I also know people on the actual left who fear the same thing you say leftists are trying to do: the removal of democratic control through fear-mongering. Any alternative energy source that could replace FF within the current economic configuration and size would necessarily deepen the crises of the current mode, easing the path toward socialism. That's how someone on the actual left would see it. The left, after all, is not interested in creating the second coming of Stalin (a dictatorship on top of a dictatorship of the representatives of the representatives of the representatives of the proletariat). They are interested in fair compensation for value created and no taxation without representation (i.e., no capitalism). As far as the right goes, the same problem applies, but much more amplified. People who call themselves "right" might be economic, social, or religious conservatives. There are reasons given by people in all three of those camps to either embrace or deny scientifically-described reality on any number of issues, and those reasons have nothing to do with the validity of the science (or, indeed, rationality, but we are human after all, in spite of my libertarian friends' attempts to deny it). Casually tossing around "left" and "right" will end up causing the thread to be five times the size that it should be, no matter what size that happens to be.
  21. Submerged Forests off the coast of Wales: a Climate Change Snapshot
    Fine article. I'm especially interested in the Tingle images.How valid are they? Do they represent a crude but suggestive approximation? yours Frank
  22. funglestrumpet at 22:13 PM on 6 April 2012
    Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    1 Bob Loblar @ 12 "I hope Monckton never gets to be powerful" He already is powerful, just look at who he gets to present his talks to. 2 Climate change has the potential to do more harm than a whole army of terrorists could ever hope to achieve, even in their wildest dreams. It may be that Monckton's misrepresentation of the science and scientists is not deliberate. But what other interpretation can there be for his refusal to defend himself against Hadfield, or respond to the repeated debunking received herein? If, as seems highly likely, it is deliberate, it is thus clearly intended to hinder or stop any action to combat climate change and one has then to conclude that he deliberately intends that climate change should be allowed to do whatever harm it can to all countries, including his own, the U.K. I sincerely hope that M.I.5 and M.I.6 are monitoring his unpatriotic behaviour (and that of other similarly minded and scientificly ignorant individuals, of course). I don't know what good, if any, it will do, but I have written to her majesty the queen in order to draw her attention to the behaviour of Viscount Monckton concerning the possible harm to the U.K. and all the countries of the Commonwealth over which she is monarch that could result from his actions. Perhaps others might consider doing likewise. I doubt it will result in his being stripped of his peerage, which would slow him down a bit, but one can hope. As Monckton flits from place to place he would do well to consider the fact that all the world's armed forces put together aren't capable of putting even the slightest scratch on Old Mother Nature. If we keep pumping out greenhouse gases into the atmosphere, she will just turn up the thermostat in response. She doesn't need us one bit, but we very much need her.
  23. michael sweet at 22:06 PM on 6 April 2012
    James Hansen's Motivation
    jzk, It is not a fair statement to suggest that Hansen is "outside the consensus". Hansen suggests that a runaway greenhouse is possible on Earth. Most of what I have seen disagrees with Hansen, see Tom's links above, but that does not mean Hansen is wrong. There does not appear to be a strong consensus on this item. Most scientists currently focus on the near term, say the next 200 years. After that there is less research. Hansen is on one extreme but that does not qualify as "outside the consensus" Re Hansen's discussion of 6C per doubling of CO2. This is the long term, not the short term sensitivity. Hansen agrees with the consensus that the Charney sensitivity is around 3C per doubling. This is the short term sensitivity. Long term, as the ice sheets melt, scientists agree that the sensitivity is greater. Hansen estimates the long term sensitivity, including albedo changes is double the Charney sensitivity. I have not seen comparable estimates from other scientists. Since scientists agree the long term sensitivity is higher than the Charney sensitivity Hansen is firmly in the consensus here. Hansen takes the view that we are responsible for our long term consequences, not just the problems predicted for the next 90 years. Do you care about the world your descendants will have to live in in 500 years? Most deniers do not even care about their children. Go to RealClimate and read their analysis of the temperature predictions Hansen made in 1981. He was 30% lower than actual increases that have been measured. Perhaps he is low here again. The main stream media gives big press to non-scientists and deniers. Hansen is closer to the consensus than Lindzen is. Uncertainty cuts both ways. Hansen's fear of runaway warming may be right, he has a long record of being correct in the past.
  24. James Hansen's Motivation
    jzk @20, Hansen does not discuss the runaway greenhouse effect in the TED video which this post is about. Therefore discussion of it is off topic on this thread, and your attempts to suggest that because John Russell (@12) agrees with what Hansen says on that video he is therefore committed to agreeing with anything Hansen has said anywhere are trolling, pure and simple. However, for the record, let me state that: 1) You are misrepresenting Hansen in that he clearly indicates that the prospect of oceans boiling only follows "in the long run" and "over centuries" of continuing high emission rates (1:15 fwd on the video to which you linked). Thus it is clearly not an imminent prospect, and is only achievable (on his opinion) by a determined, suicidal continuation of BAU as temperatures rise beyond Eocene levels. Make no mistake that such a continuation would be suicidal. Hansen is probably wrong about runaway greenhouse effect, but if we push tropical sea surface temperatures above 50 degrees C, the fact that the oceans aren't boiling will be purely academic in terms of our prospects of long term survival. 2) When NASA planned the grand tour of Voyegers 1 and 2, they used a model. That model was not evidence, but neither was it guess work. It was the prediction of a well confirmed theory. Climate models are also the predictions of well confirmed theories. Because of the complexity of the situation being modeled, they cannot be solved algebraicly, but instead must be solved numerically using approximations for some factors. That introduces uncertainty, but does not change the results into simple guess work. When you cavalierly dismiss model outcomes, you are in effect insisting that a number of well confirmed empirical theories are false. 3) Hansen's view is that the equilibrium climate sensitivity is 2.8 C per doubling of CO2. The equilibrium climate sensitivity does not include slow feed backs such as the change in albedo due to the melting of ice sheets. Hansen considers the Earth Climate Sensitivity, ie, the sensitivity including all feed backs to be around 6 degrees C. There is no contradiction between that position and that of the IPCC, and indeed, that result has been confirmed from observations by Dana Royer and his associates. 4) Hansen's position on runaway feed backs is not the consensus position. The consensus position in science is not a mandated position required as a condition of doing science, but a common position arrived at by each scientists independent assessment of the evidence. It is therefore no surprise that on some issues there is disagreement. Finally, as noted this discussion is of topic. Therefore if you care to respond, would you please do so in threads on which the response is on topic. For discussion of the the runaway greenhouse effect, I suggest the comments on the article by Chris Colose linked at 17 above. If you comments are about Hansen's views on the runaway greenhouse effect, he has no official spokesperson here so take it up with Hansen.
  25. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    Thanks Dana for nice rebuttal of new and old Monckton myths. However, regarding this comment of yours: To his credit, [...] Monckton started out his presentation by establishing that CO2 is a greenhouse gas, and the human-caused atmospheric CO2 increase has caused some warming over the past century I respectfully disagree, as follows. Not so long ago, in the middle of 2011, while touring Australia, Monckton was describing CO2 as "colourless trace gas which is food for plants". Why did he change this goalpost of his teachings so abruptly in last few months? Because he came to accept & appreciate GH effect of CO2, as your comment would suggest? I don't think so. We learned many times how he changes his goalpost on this site. Peter Sinclair calls it "Monckton maneuvres". We learned that Monckton does not care about the truthfulness or informative value of his teachings, he just cares about spreading confusion; the ridiculous nonsense of the graphic in slide 3 of his presentation is the best example. We've seen goalpost shifts in many denialist teachings. And the reason is that old myths eventually become so thoroughly debunked that they are not effective effective anymore as disinformation campagin. Then it's time to shift to other myths. The word of appology or explanation about the "change of mind" is rarely uttered. Monckton is a typical representative of such strategy. Can we assume that Monckton is accepting the fact about CO2 at stake in good faith, so as to enter a more reasonable dialog with those remaining 5 representatives who still listen to him? I still don't think so. The best characterisation of Monckton's modus operandi was given by Tom Curtis here". Please note that Monckton's description of ABC as "fasist organisation" still stands. Therefore, based on the above, I conclude Monckton's latest acceptance of CO2 as a greenhouse gas is just a big goalpost shift designed to help his evil campaign going and does not deserve any credit.
  26. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    Bob @ #12
    '...they alter the facts to fit their views ... which can be very uncomfortable if you happen to be one of the facts that needs altering.'
    But as the great Richard Feynman once remarked (my emphasis), 'For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.' What Do You Care What Other People Think, Mr Feynman Goes to Washington, Investigating the Space Shuttle Challenger Disaster, Appendix F, Conclusions. Feymnan's Challenger investigation methodology is a model of facing physical reality with its exposure of wishful thinking and humbug. If Feynam were still with us, and he is greatly missed, I think he would be very agitated about the antics of a certain other Richard. Quoting Wiki is not always a good thing but there are many lessons on this page of Feynman quotes .
  27. James Hansen's Motivation
    Tom @18, The talk starts out "what would happen if emissions continue to grow?" (-snip-) So is it then, a fair statement to say that Hansen's views are "outside the consensus?"
    Moderator Response:

    [DB] As noted earlier, and as specifically pointed out to you by Tom Curtis below, Hansen does not discuss the runaway greenhouse effect in the video linked in the OP. Your intransigent insistence that he did is therefore utter, willful falsehood.

    Please note that posting comments here at SkS is a privilege, not a right. This privilege can and will be rescinded if the posting individual continues to treat adherence to the Comments Policy as optional, rather than the mandatory condition of participating in this online forum.

    Moderating this site is a tiresome chore, particularly when commentators repeatedly submit off-topic posts and make things up. We really appreciate people's cooperation in abiding by the Comments Policy, which is largely responsible for the quality of this site.

    Finally, please understand that moderation policies are not open for discussion. If you find yourself incapable of abiding by these common set of rules that everyone else observes, then a change of venues is in the offing.

    Please take the time to review the policy and ensure future comments are in full compliance with it. Thanks for your understanding and compliance in this matter.

    Fabricated quote and trolling statements snipped.

  28. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    "Have we used the word "absurd" too many times already?" Not at all! But for a change, you could substitute 'ridiculous' - subject to ridicule - which seems very apt with regard to many of Monckton's fantasies!
  29. 2012 SkS Weekly Digest #13
    And if carbon tax was a pigovian tax, how would that doom the planet exactly? Perhaps you might like to add your thoughts to this thread. I am sure you would not regard killing subsidies on fossil fuels as socialism. How about a simple ban on new coal-fired generation and letting the market figure out the best alternative? Is that socialism?
  30. Submerged Forests off the coast of Wales: a Climate Change Snapshot
    interesting article, thanks
  31. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Adding my two cents to what John Russell and Bernard J. already said, the distribution of human population versus temperature or, better, heat index shows a long tail toward colder temperatures but a sharp cut off at high temperatures. A temperature increase of just few degrees is enough to force milions of people to move and abandon large swats of land. Adaptation is not an option in such cases. We're risking a 21st century gold rush but there's no gold anywere.
  32. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    I also enjoyed the article thanks. James Hanson has a similar discussion in his book "Storms of My Grandchildren", in Chapter 8 'Target Carbon Dioxide: Where Should Humanity Aim'. Some interesting points - . He has a good discussion on how the temperature curve is derived and does an analysis of temperature changes Vs forcings from CO2 and ice albedo changes. His starting point in this analysis was 50mya with the temp 14 and CO2 at 1400 with uncertainty of 500. . He advised Bill McKibben to set the CO2 target at 350 based on the analysis of this period. One factor was that at 34mya when Antarctica became cold enough to harbor an ice sheet the estimated CO2 was 450 with uncertainty of 100. 'This has a clear, strong implication for what constitutes a dangerous level of atmospheric carbon dioxide' . On ocean currents he mentions that 55mya at the Paleocene-Eocene thermal maximum (PETM) there was a dramatic change in ocean circulation indicating that the main location where dense surface water sank to the ocean bottom shifted from Antarctica to middle latitudes in the northern hemisphere. It is likely that this warmer water instigated the melting of methane hydrates
  33. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    John Russell pre-empted me at #3, but it's worth repeating... Mammals are not adapted to temperatures significantly higher than those of the current 'ice age'. We just aren't. In fact one reason mammality was able to evolve was because of the moderate temperatures of 'ice ages'. Any warmer, and the efficiency of the suite of counter-balancing thermoregulation adaptations starts to break down. Natural deselection... It's 'simple' thermodynamics. That the Denialati imagine that an Eocene-like climate is lovely and balmy and desirable simply shows the depth of their ignorance of mammalian physiology.
    Of course, the climate will not fully respond to this sudden shock immediately; there is inertia in the system, fortunately. It will take many hundreds of years for the oceans to heat up and many thousands for the ice caps to melt completely.
    I have one small philosophical nit-pick - it might not be "fortunate" that there is an inertia in the global climatic system. Had it been that the scale of the period of change was closer to the lifetime of a human, there might actually be more inclination to address the problem. As it is our species put its collective head in the sand, and aided and abetted by our knee-jerk response to an economic system that also ignored thermodynamics, we're already committed to a change that will likely see a human-friendly ecosystem disappear in the centuries ahead. Fortunate for us, perhaps, but not for our decendants. I've said it previously but I'll indulge again - if our decendants could manage to conquer time travel, or to reanimate the dead, they'd be post haste hunting our generation down and kicking our arses for what we're doing currently to the planet.
  34. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    The fig.2 in Micheels & al. presents a vegetation proxy of miocene times and that looks like being a much wetter period than now for some large areas. It's a preprint, and I do not know if the paper has been published yet, anyway it refers to many earlier discussions on this. Could be interesting for readers to see.
  35. James Hansen's Motivation
    Thanks Tom, Chris concludes with: " it's worth mentioning that it is virtually impossible to trigger a true runaway greenhouse in the modern day by any practical means, at least in the sense that planetary scientists use the word to describe the loss of any liquid water on a planet." Hansen is saying that with all carbon burnt and presumably with rapid clathrate melt to CH4 not CO2, then it is possible to boil the ocean. While sobering if true, I would be fairly sure his motivation are mostly based on the very considerable damage that would result from far less CO2. I think we should be mostly worrying about the damage from burning the available economic coal.
  36. James Hansen's Motivation
    I should probably add, the theory is that there is an upper limit on the greenhouse effect which represents the effect of an atmosphere with the maximum saturation with H2O. If the outgoing longwave radiation for a fully saturated atmosphere is greater than the incoming solar energy, in the Earth's case 255 W/m^2 on current albedo, then temperatures will stabilize before full saturation is reached, and hence before the oceans boil away. As it happens, the outgoing limit is significantly greater than 255 W/m^2. Nakajima et al calculated an upper limit of 385 W/m^2, which is approximately 40 W/m^2 higher than the Earth would recieve with an albedo of 0, an unlikely condition with a water saturated atmosphere to say the least. There is some doubt as to the upper limit which must be calculated using models, but it is sufficiently high that it is unlikely that the Earth could reach a runaway greenhouse effect on current solar activity. Of course, if models are as unreliable as is suggested by deniers, then we can have no confidence that a runaway greenhouse effect is impossible. The price of denying science is uncertainty, and that price is paid logically by considering even the most extreme possibilities as on the cards if we continue the grand experiment with the atmosphere. Of course, that would require consistency from the deniers, which is too much to ask.
  37. James Hansen's Motivation
    scaddenp @16: A Study on the “Runaway Greenhouse Effect” with a One-Dimensional Radiative–Convective Equilibrium Model, by Nakajima, Hayashi, and Abe. Journal of Atmospheric Sciences, 1992. And here is a popular explanation by Chris Colose.
  38. evolutionarymicrobiologist at 13:07 PM on 6 April 2012
    2012 SkS Weekly Digest #13
    I think this explains the problem to a tee. The REAL problem isn't that people are stupid, but that political agenda takes over. (-snip-), instead of just generating an alternative energy (which could have been done by now), proves my point as much as the right pretending that nothing is happening and looking for loopholes to ignore the science. I personally believe it will spell doom for our planet if we make carbon tax 1/5 or more of total government revenue. Then they will never have an incentive to find alternative energies.
    Moderator Response: [DB] Please refrain from making ideological statements (snipped) per the Comments Policy.
  39. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    The reference to Dr. Who reminded me of this old fortune quote I saved many moons ago:
    The very powerful and the very stupid have one thing in common. Instead of altering their views to fit the facts, they alter the facts to fit their views ... which can be very uncomfortable if you happen to be one of the facts that needs altering. -- Doctor Who, "Face of Evil"
    I hope Monckton never gets to be powerful.
  40. James Hansen's Motivation
    Can anyone point me to any actual paper on whether we can get runaway greenhouse if used all the carbon? I'd like to see the math.
  41. actually thoughtful at 08:06 AM on 6 April 2012
    Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Andy S - great article. I like this style of looking at the world, rather than the relentless focus on what incorrect thing so-and-so said (both are necessary). Very thought provoking. 200,000 times the natural rate - that is a number I will weave into "discussions" with deniers.
  42. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    I am fascinated by earths past climate. And this was excellent. There was something 41 million years ago called the Middle Eocene Climate Optimum Some 40 million years ago, the world experienced an extreme spike in global warming. The heat was so intense that deep sea temperatures rose by about 4 degrees Celsius. This enigmatic sultry period, known as the Middle Eocene Climatic Optimum (MECO), marked a 400,000-year-long heat wave in the midst of a long era of global cooling.
  43. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    jyyh: Thank you. No, I don't know enough about palaeo-oceanography to answer your question. Perhaps other readers do.
  44. John Russell at 04:01 AM on 6 April 2012
    Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Good article. Of course as part of our irreversible experiment to recreate the Eocene we need to start selectively breeding all current mammals to be the size of small rodents -- oh, and that includes ourselves. It seems only small mammals can handle the heat. Reptiles on the other hand... Anyone know of any small rocks to hide under?
  45. It's not bad
    Agreed, and I look forward to any further information you may be able to obtain, particularly from Barnett.
  46. keithpickering at 03:16 AM on 6 April 2012
    Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    One of the most interesting (and important) posts I've read here. Many thanks.
  47. Eocene Park: our experiment to recreate the atmosphere of an ancient hothouse climate
    Thanks, Andy. two remarks: At least the locations of continents are different today. It may take a little more rise in the concentration to melt the (whole) Antarctic ice sheet (however long it'll take). Do you know are there much differences in north Atlantic currents if one compares early Miocene (when there was a Panama Strait instead of a Channel)and Pleistocene/start of the Anthropocene? One would like to think the closing of that strait lead to cooler temps in the Arctic so it might be the concentration to melt GIS would also be higher than the last time. But by how much, I can't say. Might be even lower if the tropical Atlantic heats up by some mechanism induced by shifting atmopheric phenomena.
  48. It's not bad
    "Even if that means accepting 49.1% as meaning the same as "as much as 50%", so be it." I can accept that, too, of course. The point was the missing word "snow". You raise an excellent point, though, sources within sources. As that was original research and measurement data being reported, and there was no discussion about snow vs. glacial melt, I hadn't thought of checking further sources regarding the snow vs. glacial melt amounts, but perhaps it is in there somewhere. Then again, probably not or it would have been discussed in the original paper. I will try digging deeper into the other sources and will indeed contact Barnett if still nothing turns up to support his statement. I don't expect an answer but as you say, I've got nothing to lose. Thanks for the discussion. I believe we've come as far as we can on this one.
  49. Monckton Misleads California Lawmakers - Now It's Personal (Part 2)
    cc @7 - very nice, thanks. John Russell @9 - Monckton also apparently has time to write posts defending his nonsense California claims on WUWT (see here).
  50. Dikran Marsupial at 01:15 AM on 6 April 2012
    Murry Salby finds CO2 rise is natural
    @tompinlb That the rise in atmospheric CO2 is purely anthropogenic is easily established with a high degree of certainty. In order to put an end to this common climate myth, I wrote a paper on the subject, read about it here. I sent a pre-print of the paper to Prof. Salby, but I didn't receive a reply. Sadly Prof. Salby is simply incorrect on this one, and I strongly suspect that the journal paper he referred to in hs talk may have been withdrawn. I would be happy to go through the mass balance argument with you, it really is surprisingly very simple.

Prev  1209  1210  1211  1212  1213  1214  1215  1216  1217  1218  1219  1220  1221  1222  1223  1224  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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