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  795  796  797  798  799  800  801  802  803  804  805  806  807  808  809  810  Next

Comments 40101 to 40150:

  1. What climate denial has learnt from tobacco denial

    I had trouble with the video at the above-mentioned Merchants of Doubt website.  An alternative is Oreskes' talk at the U of Kansas, which is a 6-part video that is one of the most informative hours you'll ever spend:

    http://www.youtube.com/watch?v=fVPIA6l2OTg

  2. Cosmic rays fall cosmically behind humans in explaining global warming

    HK

    Dimetyl amine and dimethyl sulphide are two very different chemicals, but both involved in cloud condensation. The mechanism discussed in the nature paper from the CERN lab is, that dimethyl amine is stabilising clusters of sulphate ions in the atmosphere, enabling them to grow. exactly that, what Svensmark thought was an effect of cosmic rays.

    Dimetyl sulphide is mostly released by algae, dimetyl amine is released over land too and is related to huiman land use there.

  3. We're heading into an ice age

    jhnplmr wrote "trying to stabilise temperatures at their present levels in the continual changing conditions of an ice age is impractical as well as unnatural."  He also wrote "This will require enormous amounts of energy which is becoming increasingly scarce and expensive."

    No, it is not at all impractical.  Preventing cooling is trivial, as is empirically obvious.  If by magic humans stopped all increases in greenhouse gases by ceasing use of fossil fuels, ceasing landscape changes, and so on, we could prevent a glacial period with a single chlorofluorocarbon factory for the entire world, as TonyW already told you.  But as other people already have told you, our greenhouse gas increases to date with just the next couple of decades will be sufficient to prevent cooling, let alone glaciation, for thousands of years.  Hare and Meinshausen produced a graph of the temperature consequence if we magically kept the greenhouse gas forcing at its 2005 level; it does not start going down.

  4. We're heading into an ice age

    315 Roger D

    "But given this acknowlegment of AGW, how can you conclude humans have "stabilized the temperature"?

    A glance at my graph, which Rob Honeycutt has promised to link for me, would convince you.  The Vostok temperatures started to fall in line with the falling insolation 10,000 years ago but then recovered and stabilised at present levels.  This recovery and stabilisation coincided with man clearing forests, starting farming and keeping domestic animals.

    "Also, I don't think the issue is "trying to balance on the cusp".

    Yet by trying to stop change that is precisely what you are trying to achieve, whether you realise it or not.  You are trying to resist coming out of the current ice age, yet hopefully, trying not to slide into a cooling phase.  That means that you want us to balance on the cusp of the current interglacial indefinitely.

    "Finally, I'm doubtful that any/ many of those that accept AGW think it is feasible to try to control the climate as you imply they do."

    I don't think that they are trying to control the climate, I think that the "climate control" that has occurred has been accidental, although beneficial to date.

    What I am trying to do is to make you realise that trying to stabilise temperatures at their present levels in the continual changing conditions of an ice age is impractical as well as unnatural.

  5. We're heading into an ice age

    jhnplmr said: "[Global temps] then recovered and stabilised under AGW forcing."

    Um. I'm sorry but how do you come to the conclusion that global temperature has, in any way, stabilized?

  6. We're heading into an ice age

    jhnplmr (from previous thread)... "My claims are not "fantastical", they are based on many sets of published data and the resultant graphs compiled from that data."

    Your claim is that Milakovitch cycles vastly overwhelm the radiative forcing of atmospheric CO2 (100w/m^2 vs 2.3w/m^2). That is a "fantastical claim" because it clearly does not square with the vast body of research.

    HK already pointed out that you're using an inappropriate metric that is not global. That is an elemental error, and when you present elemental errors that makes you look foolish. It's not meant as an insult. I make myself look foolish sometimes too. We all do. 

    You seem like a very nice person, John. All I'm saying is, stop believing you – as a non-expert – can disprove over a century of scientific research. Instead, you'd do yourself a greater service, if you're genuinely interested in this topic, to take the time to find out the answers to the questions you have.

  7. We're heading into an ice age

    314 Barry

    "The future ice age (glacial, whatever you want to call it) is going to happen very slowly. The last one took tens of thousands of years from peak to trough, about 6 degrees average global temperature (more at the poles, less at the equator). The warm-up to the current interglacial took 5000 years."

    Well it won't happen by the next Jul 65N solar minimum in 2000 years time, but I agree with your general point that there is a slow descent into a glacial period yet a sharp rise, a sawtooth waveform.  The Vostok temperatures took about 20,000 years to fall to a minimum in the last glacial period and about 5000 years to rise as you say.

    "No one here wants to keep the global temperature constant. I think I can speak for most participants here by saying that we want change at the natural pace, not the rapid pace that may be caused by human activity."

    You look upon the contribution of AGW as completely negative, I look upon AGW as stopping global temperatures from falling over the last 10,000 years.  They started to fall in line with the falling insolation but then recovered and stabilised under AGW forcing.  If you think that the present levels of CO2 are high at 393ppm then you should consider that in the age of dinosaurs they were 3000ppm.  It is possible that the present levels will melt the ice caps and we will come out of the current ice age but I believe that AGW will dwindle as we run out of fossil fuels and then the falling insolation will cause a fall in temperatures.

    We have already avoided the "natural pace", that happened some 6000 years ago when man started farming and keeping domestic animals.  Besides, who wants to slide into a prolonged cooling period with advancing ice caps?  Man's activities have stopped that scenario.

    Moderator Response:

    [DB] "If you think that the present levels of CO2 are high at 393ppm then you should consider that in the age of dinosaurs they were 3000ppm."

    In this venue this is an example of an unsupported assertion, typically employed as a rhetorical device.  Please avoid such in the future.  If you wish to defend this rhetoric, please do so on a more appropriate thread and provide links to substantive sources published in the reputable literation which you feels support your position.

    This is an evidence-based venue.  "Beliefs" and opinions carry little weight here.

  8. Climate Bet for Charity, 2013 Update

    #60 Tom Curtis

    "And in answer to your specific question, you simply call it the Quaternary glaciation"

    If you mean the question "The problem with using "ice age" instead of "glacial period" is what do you call a succession of glacial periods interspersed with interglacial periods? " then "Quaternary glaciation" is not the answer.  That is merely the name of the current ice age.  There have been at least five major ice ages in the Earth's past (the Huronian, Cryogenian, Andean-Saharan, Karoo Ice Age and the Quaternary glaciation).  The general name is "ice age".

    Moderator Response:

    [PW] This is the *last* warning: Take any more ice age discussion to the appropriate thread. This is a thread concerning the bet for charity. Other comments here on Ice Age topics will be removed.

  9. We're heading into an ice age

    jhnplmr@313

    you acknowledge that human activiety has forced a "hockey blade" onto what would otherwise be an overal,comparatively slow decline in average global temperature: But given this acknowlegment of AGW, how can you conclude humans have "stabilized the temperature"? Also, I don't think the issue is "trying to balance on the cusp". The issue is rather that we've stopped the comparatively gradual natural cycle towards colder termperatures ("in it's tracks" as you put it) and forced a much faster rate of change in the other direction that is not, as you indicate "stabilized". Finally, I'm doubtful that any/ many of those that accept AGW think it is feasible to try to control the climate as you imply they do.

  10. We're heading into an ice age

    jhnplmr,

    I don't know why you think contributors here want to keep the planet at a constant temperature.

    The future ice age (glacial, whatever you want to call it) is going to happen very slowly. The last one took tens of thousands of years from peak to trough, about 6 degrees average global temperature (more at the poles, less at the equator). The warm-up to the current interglacial took 5000 years.

    We may achieve 6 degrees warming in as little as 200 years.

    No one here wants to keep the global temperature constant. I think I can speak for most participants here by saying that we want change at the natural pace, not the rapid pace that may be caused by human activity.

    We have geological evidence of what happens when the global temperature changes quickly, and that evidence recommends against making it happen.

  11. Climate Bet for Charity, 2013 Update

    jhnplmr @58:

    "a) ice age
    n.
    1. A cold period marked by episodes of extensive glaciation alternating with episodes of relative warmth.
    2. Ice Age The most recent glacial period, which occurred during the Pleistocene Epoch.
    The American Heritage® Dictionary of the English Language, Fourth Edition copyright ©2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

    b) ice age
    n
    (Earth Sciences / Geological Science) another name for glacial period
    Collins English Dictionary – Complete and Unabridged © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003

    c) ice′ age'
    n.
    1. (often caps.) the geologically recent Pleistocene Epoch, during which much of the Northern Hemisphere was covered by great ice sheets.
    2. any one of the Permian, Carboniferous, Cambrian, or Precambrian glaciations.
    [1870–75]
    Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
    d) ice age
    1. Any of several cold periods during which glaciers covered much of the Earth.
    2. Ice Age. The most recent glacial period, which occurred during the Pleistocene Epoch and ended about 10,000 years ago. During the Pleistocene Ice Age, great sheets of ice up to two miles thick covered most of Greenland, Canada, and the northern United States as well as northern Europe and Russia."

    (Source)

    Fairly clearly "ice age" is used in popular language to mean either "a geological epoch with ice caps at one or both poles" and "a period of greater than average glaciation within an iceage, ie, a glacial".  Yes, it can be confusing.  No it is not scientific language, but then very little is.

    Using scientific language when it differs from popular language only results in confusion.  In popular presentations, you need to either use scientific language, but explain how it relates to popular language; or use popular language, but explain how it relates to scientific language.  Neither of these choices is automatically better, and if you are explaining things to people who are unlikely to follow up in the scientific literature, the later is probably preferable.

    And in answer to your specific question, you simply call it the Quaternary glaciation.

  12. We're heading into an ice age

    312 Tom Dayton

    "So the year 0 in your NOAA data source means 1950. If you did not know that already, you would learned it if you had bothered to read the readme file that accompanies those data files."

    Which I had, I pointed out to you that I had used 1950 as my datum point for year zero. "I based my year zero on the graph on 1950 as it made it easier to transfer the data to the spreadsheet". It was you who introduced the 3950AD concept.

    "You wrote you "also don't want us to slide into another glacial period." There is no risk of that anytime soon;"

    I have pointed out this several times.  You have mentioned my comments on this point yourself.  You seem to have developed a habit of repeating my statements back to me as if I hadn't made them in the first place.

    The difference between my position and most contributors on this board is that I consider the contribution of man-made warming beneficial as it has stopped us sliding into a prolonged cooler period, we started to do this 10,000 years ago until AGW stopped it in its tracks and stabilised the temperature.  The other difference is that I consider trying to balance on the cusp of an interglacial period indefinitely is an impossible task but this is apparently what most of your contributors want!

    You call your opponents "climate change deniers" but try to keep a changing climate constant!

  13. Climate Bet for Charity, 2013 Update

    Can someone just clarify two things for me please?  I've skimmed through the comments but didn't see these questions addressed; apologies if they already have been.

     

    Firstly, the UAH data set in use at Wood for Trees is v5.5; the latest set is v5.6.  This may make minimal difference, but obviously the most recent set is the producer's 'gold standard'.

     

    Secondly, are the different base periods in use by RSS and UAH accounted for?  I see that Fig. 3 above hasn't been off-set.  It might not make any difference to the overall result, but the actual figures wouldn't be right if they aren't aligned to the same anomaly reference period. 

     

    Averaging monthly data from UAH v5.6 and RSS (offset by -0.10 to bring all the data into the 1981-2010 base period), I get an anomaly average of 0.178 for the decade Jan 2001 to Dec 2010; and an anomaly average of 0.133 for the decade started Jan 2011 (to October 2013) .

  14. Climate Bet for Charity, 2013 Update

    "Moderator Response:[TD] If you had bothered to read the first three paragraphs of the SkS post I pointed you to, you would have realized that in lay language "ice age" is a synonym for "glacial period"

     

    The problem with using "ice age" instead of "glacial period" is what do you call a succession of glacial periods interspersed with interglacial periods?  I call it an ice age, like the one we have been in for the last 2.6 million years.  I think it is important to realise that we are in an ice age and that we are trying to maintain an impossible position perched on the edge of an interglacial cusp.

    BTW, I do realise that most people do call a glacial period an ice age, I used to myself until I learnt better!  I will try to keep up with your recommended reading in future and try to stop annoying you and your fellow board members, unless the temptation gets too hard to resist!

  15. 4 Hiroshima bombs per second: a widget to raise awareness about global warming

    Anne-Marie Blackburn @41, perhaps I can be charged with focussing on a subtext. I am not sure that criticism is fair, given the focus of my first response was on the science. Nor do I think it fair given the large number or energy equivalents I have noted. But assume it is true. Is it not right, in this forum, to focus on and correct errors where they exist? I think it is, and that my focus is justified because the widget is not wrong about the absolute magnitude of the energy gain, but regarding the scientific relevance of that, and the subtext.

    And subtext there is! You quote extensively from Dawn Stover, who says, "The most common reaction to the meme is surprise, not fear". However, she also says, "The Hiroshima meme frames climate change as something catastrophic", and "the mushroom cloud has become a cliche image for conveying disaster". That is, she accepts the subtext to be there, and real (regardless of the intentions of John Cook).

    She also, the point you were trying to make, draws attention to the fact that global warming is already disasterous. The World Health Organization reports that by 2004, global warming causes 140,000 excess deaths annually. Coincidentally, that is very close to the 90-166 thousand killed at Hiroshima. Of those deaths, 85% are children, so there is no issue here of heat waves causing early deaths to the very elderly who only survived the winter because of global warming (there were 12,000 included in that category, but they are not included in the overall statistic because it is not clear that they are in fact excees deaths). Nor are they deaths from extreme weather events, as you would have*. Rather, they are the result of the estimated 3% increase in diarrhoea, the 3% increase in malaria, and the 3.8% increase in dengue fever. Further, those deaths are only 0.2% of excess deaths, well down on Urban Outdoor Pollution (2%), Unsafe water (3%), and indoor smoke from solid fuels (3.3%), leaving Global Warming tied for fifth with lead poisoning among environmental hazards, and well below the top ten risks (the 10th being indoor smoke from fuels, and the first being high blood pressure which causes 7.5 million excess deaths per annum)**.

    So in 2004 global warming was, in terms of deaths, the equivalent of the bombing of Hiroshima; albeit because the deaths were global and diffuse rather than concentrated in one city and (mostly) in one minute they appear almost invisible. It was not, however, the equivalent of 118 million Hiroshimas, ie, the equivalent energy gain relative the Little Boy bomb. OK, nobody expects an exact correspondence of mortality and loss from a simple similly, still less a subtextual one. But we expect some correlation. If we are told that global warming is like four atomic bombs per second, we do not expect mortality from global warming to be like 3 hundred millonth of an nuclear bombing per second.

    This problem can mostly be corrected by taking Stephen Schneider's advice:

    "I tried to explain to Schell how to be both effective and honest: by using metaphors that simultaneously convey both urgency and uncertainty, and also by producing supporting documents of all types and lengths (see the "scientist popularizer"). Unfortunately, this clarification is absent from the Discover article, and this omission opened the door for fifteen years of subsequent distortions and attacks."

    Schneider would in fact be proud of the simple metaphores (strictly similes) of the widget. They are effective. The convey the urgency of the issue. But they do not meet his definition of being honest*** - of backing up the metaphore by producing supporting documents that clarrify the metaphore, to what extent it applies, and which lead the reader (if they will follow the path) to a sound and well rounded understanding of the issue. At least they do not with regard to the sub-text.

    The widget would be greatly improved by adding a page to its supporting site directly addressing the issue of harm from AGW. Something, at least, that addresses it less abstractly than does its current page on "impacts".

    However, it would only be greatly improved. It still faces the fundamental problem that it is not the increase in energy stored at the surface, but the increase in temperature that represents the true threat of global warming. To see that, consider what would happen if emissions where reduced to a low enough level to keep forcing constant. Then over time the energy stored at the surface each year would decline towards zero. At the same time the danger from global warming would increase, for the temperature would increase. When the energy stored each year fell to zero, the danger from global warming would reach its peak (in this scenario). That also needs to be explained on the widget's website; and the website also needs examples of energy increase from high entropy sources as well as low to avoid the mistaken assumption that equates mere energy with danger.

    (*There is probably also an increase in deaths due to extreme weather, but again, only a percentage increase on what is a minor cause of excess deaths world wide.

    ** It is of course true that global warming will become an increasing cause of excess deaths with time, and with BAU will rise inexorably towards being the primary cause of excess deaths with time.

    *** It should be noted that Schneider's definition involves a supererogatory duty, far in excess of simple honesty; and that you can be, and Cook is, simply honest while still falling short of the standard Schneider sets. )

  16. Five Holiday Gift Ideas for the Skeptic In Your Life, with Unlimited Gift Coupon!

    Or you could donate, in their name, to "Extreme Whether", the play that tells the story of Climate Scientists battling climate deniers.  Our video is up on: http://www.indiegogo.com/projects/extreme-whether

  17. Climate Bet for Charity, 2013 Update

    jhnplmr, I have replied to you on an appropriate thread: "Are we heading into a new Ice Age?"

  18. We're heading into an ice age

    jhnplmr (on an inappropriate thread) replied to my statement "your own calculations show only a 3 W/M^2 decrease of insolation in that one tiny region from the year 1950 to the year 3950--only .7%," with "0.7% of what?" 

    Insolation in the year 3950 is predicted to be .7% less than the insolation in 1950.

    You also replied "Do you think it helpful to suddenly introduce 1950 into the discussion? I based my year zero on the graph on 1950 as it made it easier to transfer the data to the spreadsheet. You seem to want to consider a nebulous point between 1BC and 1AD as year zero. Let us call the present day 1950 and call it year zero it will save a lot of confusion. The solar minimum will occur in 2000 years time, 3950AD using your scale."  Climatologists, among other scientists, use 1950 as the standard meaning of "present."  So the year 0 in your NOAA data source means 1950. If you did not know that already, you would learned it if you had bothered to read the readme file that accompanies those data files.

    You wrote you "also don't want us to slide into another glacial period."  There is no risk of that anytime soon; see the papers I linked to in my April 26 comment. 

  19. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    Poster: suggest you read the AMS Blog: http://blog.ametsoc.org/columnists/going-to-the-source-for-accurate-information/ 

    Precisely proving the point made in the article, Heartland has sent out an email which at first glance might look like one from the AMS. The AMS response has been to point out that the 'interpretation' of the paper is basically BS.

    This is a canard which appeared last year, and in 2009. It's a regular attack, in other words, on the consensus. From familiar 'players'. Who are using familiar tactics.

  20. Climate Bet for Charity, 2013 Update

    #51 Tom Dayton

    "your own calculations show only a 3 W/M^2 decrease of insolation in that one tiny region from the year 1950 to the year 3950--only .7%."

    I might say 0.7% of what?  Do you think it helpful to suddenly introduce 1950 into the discussion?  I based my year zero on the graph on 1950 as it made it easier to transfer the data to the spreadsheet.  You seem to want to consider a nebulous point between 1BC and 1AD as year zero.  Let us call the present day 1950 and call it year zero it will save a lot of confusion.  The solar minimum will occur in 2000 years time, 3950AD using your scale.

    By my figures the present solar insolation in Jul 65N is 426.76W/m2, it will fall to 423.61W/m2 in 2000 years time, a fall of 3.15W/m2.  You say this is a fall of 0.7%, I repeat 0.7% of what?

    "You are confusing the readers of your comments, and I think yourself, by flipping between references to such small short-term changes and large (e.g., 43 W/M^2) long-term changes (over the past 10,000 years)"

    I may be confusing the readers of my comments but I am not confusing myself.  I introduced the large fall in insolation from the peak 10,000 years ago to contrast it with the rise in man-made forcing since 1750.  That fall in insolation caused a fall in the Vostok ice core temperatures for some 4000 years and then the mean temperatures started to rise.  They reached the present mean level after another 2000 years and have remained relatively constant ever since.  I put this rise down to man-made warming due to early agricultural and clearing of forests.  I looked upon this rise as beneficial as it has offset the undoubted fall in global temperatures which would have occurred otherwise.

    "You also are causing confusion by referencing glaciations and then disclaiming that you are making claims about glaciations"

     

    I am trying to clear up the confusion about where we stand at the present time.  We are in an ice age and have been for the last 2.6 million years.  Ice ages are subdivided into long cold glacial periods and brief warm interglacial periods.  We are in a warm interglacial at the moment.  It has lasted much longer than usual due to the activities of man.  I consider this beneficial as I wouldn't want us to experience a period of global cooling which would have resulted otherwise.  The people on this board seem to want the temperatures to remain constant indefinitely, they don't want us to climb out of the ice age and return to "normal temperatures" but also don't want us to slide into another glacial period.  An ice age is a period of constant climate change with ice sheets advancing from the poles and then retreating.  It is asking a lot to insist on perching on the cusp of a brief interglacial indefinitely.  We haven't got the energy resources to achieve this goal.

    "So you'll improve your argument by dropping references to glaciations."

    No I won't, these references are essential to my arguments.  They illustrate where we are and what we are trying to achieve.

    "Even that tiny geographical region's outsized decrease is nearly inconsequential in the context of the total forcings and feedbacks, as Rob Honeycutt was trying to get you to understand"

    By tiny region you mean Jul 65N insolation?  If so, a glance at a graph showing Vostok temperatures and Jul 65N solar insolation will show a very strong correlation between the two.  I suggest you plot the graphs, as I have, and look for yourself.

  21. Climate Bet for Charity, 2013 Update

    #44 Rob Honeycutt

    "I think HK has just proven my point about making elemental errors and looking foolish."

     

    I see that you descended to personal abuse.  Firstly I did not make "elemental errors" and the figures were correct to less than 1%.  I had to make a small correction to the two sets of data I used otherwise I would have had a discontinuity in the graph.  The sets of data were Orbit91 and bein11.dat.  They gave slightly different levels for Jul 65N solar insolation for the present day (year 0 on the graph).  The small correction does not affect the maximum and minimum points so my assertion that the next minimum occurs in 2000 years time is correct.

    "It's incumbent upon you to more completely do your research before making fantastical claims."

    My claims are not "fantastical", they are based on many sets of published data and the resultant graphs compiled from that data.

    I might point out that when I posted my first comment I was directed by the moderators to read an article *We're heading into an ice age".  This indicates a basic misunderstanding of our present situation.  We are in an ice age at the present time and have been for the last 2.6 million years.  An ice age is defined as a cool period with ice forming at the poles.  As we still have ice at the poles by that definition we are still in an ice age so we can't be "heading into one".  We are in a brief interglacial period within that ice age which has been artificially extended by man-made global warming.

    Moderator Response:

    [TD] If you had bothered to read the first three paragraphs of the SkS post I pointed you to, you would have realized that in lay language "ice age" is a synonym for "glacial period," and the title of that post was a response to a myth that in lay language almost always uses the term "ice age."  The SkS post makes that clear.  If you are going to participate in discussions on Skeptical Science, you need to make a reasonable effort to read, not just type.  It's fine if you don't understand something, but not fine to fail to try.

    You have now made clear that this conversation does indeed belong on that other thread.  Please post there, everybody.

  22. Climate Bet for Charity, 2013 Update

    #47 Michael Sweet

    "The link you have posted is not very helpful since it is raw data"

    Surely it is not impossible for an intelligent person such as yourself to convert that raw data to a graph as I did?  The original raw data is much more useful than derived readings from a graph.

    "It is clear from your postings that you have misread your link and think 2,000,000 years is 20,000 years"

    How can you comment on a graph you haven't seen and are apparently unable to plot for yourself?  BTW, I didn't misread the data and didn't confuse 2 million years with 20 thousand years.  Please maintain some semblance of rationality if you want to be taken seriously.

     

  23. No, Greenland Wasn't Green

    Good work. Sorry to be pedantic, but there are a couple of typos:

    Scandinavian and Icelandic exporers established two or three settlements on the south-west coast of Greenland. So what were the conditions in Greeland like 1,000 years ago?

  24. Climate Bet for Charity, 2013 Update

    This discussion should be moved to "An ice-age is coming" Most of this is well covered ground. I should also point out that the last time earth was at 450ppm, we still had Milankovitch forcings but we didnt have ice ages.

    Moderator Response:

    [TD] Agreed.  That means everybody.

  25. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    adrian smits @16

    Local CO2 concentrations aren't a strong indicator of local warming. CO2 needs to get mixed into the atmosphere and changes in concentration reach the upper atmosphere. It is changes in the upper atmosphere concentration that cause the warming. This upward mixing takes months to several years. It is then this broad change in upper level concentrations that causes the warming.

    So any effect downwind from a city due to its CO2 emissions wouldn't produce localised GH heating. That isn't to say that air masses downwind of a city may not directly carry some heat with them, although most heat transfer is via radiation. But their localised downwind CO2 won't produced localised heating.

  26. Climate's changed before

    John Wise

     

    Yes CO2 has been higher in the distant past, even much higher than 1000 ppm. Over the very longest timescales (100's of millions to billions of years) CO2 levels have been trending downwards. 400-500 million years ago CO2 levels were perhaps 4000-8000 ppm. But what we need to bear in mind is that this is actually compensating for the fact that the Sun was cooler in the past. The Sun's heat output has grown by around 40% over its 4.5 billion year history.

     

    As a rough calculation, Solar intensity today is around 341 Watts/M2 at the earth. Allow for albedo reflecting around 30% of that and the Earth absorbs around 238 Watts/M2 . If we go back 500 million years that would 230 Watts/m2. A doubling of CO2 wil produce around 3.7 Watts/M2 of warming so around 2.5 doubling of CO2 would be needed back then just to compensate for a cooler Sun. In fact the level was more like 3.5-4 doublings of current levels. And temperatures back then were warmer than now - perhaps 5-8 DegC warmer. Suggesting some of the past higher CO2 levels were compensating for a cooler Sun and some were actually producing a warmer climate.

    As for the rate of increase, yes it is currently perhaps the fatsest in Earth's history. Some numbers.

    • Current CO2 concentrations are rising at a bit over 2 ppm/yr
    • CO2 concentration over a Glacial cycle changes by around 100 ppm over perhaps 10-20,000 years. So 0.005 to 0.01 ppm/yr
    • A period around 55 million years ago called the Paleocene/Eocene Thermal Maximum (PETM) is regarded as the point in the past most analgous to today. A large, geologically rapid release of CO2 & Methane occurred and temps climbed 5-8 Deg C. Recent research by Lee Kump and colleagues has obtained a good estimate for the release of CO2 back then - it occurred over around 20,000 years. We are raising CO2 levels today 10 times faster than that. See this report http://www.sciencedaily.com/releases/2011/06/110605132433.htm
    • Much of the Coal we burn was laid down during the late Devonian and Carboniferous periods. Perhaps 60 million years. And we are burning this cola up in the space of centuries. Coal that took centuries to be laid down is burnt by us in 1 day. So yes, we are likely releasing CO2 at unprecedented rates.
  27. Climate Bet for Charity, 2013 Update

    O/T

    How did you add the pointer-magnifier?  That was slick: no user clickety-fiddlery required, it was shows up where and only where needed.

    otoh, maybe best to let plagiarizing denier sites figure it out for themselves ;-)

  28. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    I too read Murray's piece in this mornings West Australian.  Pretty disappointing.  But one should not expect too much from the West :-)

  29. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    Thanks Dana  I look forward to that.  Unfortunately however, the post on Moday won't reach more than a very few of those who read Paul Murray's piece in today's West Australian.  Consequently the vast majority may well continue to see credence in his article

  30. Climate Bet for Charity, 2013 Update

    jhnplmr, your own calculations show only a 3 W/M^2 decrease of insolation in that one tiny region from the year 1950 to the year 3950--only .7%. You are confusing the readers of your comments, and I think yourself, by flipping between references to such small short-term changes and large (e.g., 43 W/M^2) long-term changes (over the past 10,000 years). 

    You also are causing confusion by referencing glaciations and then disclaiming that you are making claims about glaciations.  Glaciations do not happen merely because of the change in insolation in that small region of the world, but because of a host of feedbacks, the conditions for which have been altered by human-created higher levels of greenhouse gases.  The next glaciation is not going to happen for many tens of thousands of years, which you seem to have acknowledged. So you'll improve your argument by dropping references to glaciations.

    As Rob Honeycutt suggested, you should get context for that size of insolation decrease.  Even that tiny geographical region's outsized decrease is nearly inconsequential in the context of the total forcings and feedbacks, as Rob Honeycutt was trying to get you to understand by pointing you to Kiehl and Evans.  For a summary you might try the SkS post by Trenberth.

    For more context, note the neglible consequences of an insolation decrease of 1 W/M^2 over the entire globe--the consequence of another Maunder Minimum.

  31. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    Poster @18 - we'll have a post on Monday about the AMS survey and the various misunderstandings and misrepresentations of it.

  32. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    Anne Marie Blackburn  I think you'll find "Big Oil" is strongly supporting the development of renewable forms of energy generation

  33. Climate's changed before

    I have read that CO2 ppm have been much higher in the distant past,as much as 1000ppm. Over what period of time did CO2 reach that level? Is the current rate of increase faster,or can we tell?

  34. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    In today's West Australian, which is the most widely newspaper in Western Australia, there is a piece by Paul Murray discussing the survey by the American Meteorological Society of the views of its members on the link between carbon emissions from human activity and global warming. This survey was carried out, so the article reports, because of the conflict among the members on this topic.  A reported key finding  is "that the society acknowledges the uncomfortable fact that political ideology influences the climate change views of scientists.  Only 52% of the members who responded "went for the full anthropogenic answer that the cause of global warming was mostly human"  Remarkably this is a lot less than the 97% that has been reported elsewhere.  However although 93% of the members who are climate scientists did support the "full anthropogenic view" 22% of the most expert group of scientists over all categories did not believe that global warming was mostly human caused.  The report also noted that "the climate debate has become increasingly polarised around political issues rather than scientific understanding".

    The article also reported on the 22 papers published by the AMS "seeking to  explain extreme global weather events from a climate perspective" of which two studied the heavy rainfall in Eastern Australia. One of the authors of these papers is David Karoly who Paul Murray notes "is the Climate Commission's prominent alarmists".  Murray goes on to say the results of the studies  " found "no apparent influence from anthropogenic climate change in the observed rainfall anaomalies"  and concludes (with reference to David Karoly) "It must be a bugger when science does that".  

    As Murray also refers to the scientific consensus as "the phoney consensus", this  article, put out in the mass circulation MSM, may well, I fear, seriously compromise the efforts to persuade West Australians that humans really do affect climate.  

  35. One Planet Only Forever at 09:50 AM on 30 November 2013
    Video: 10 climate myths debunked in under 4 minutes

    An even better response about the buring of fossil fuels would be, in addition to the damage done obtaining, transporting and burning them, they are simply non-renewable. Once they are used up they are used up. There will be no more produced for many millions of years. And Humanity should be looking forward to enjoying life on this amazing planet for a few 'billion years'. And the only way of living that can be sustained for that length of time is for humanity to be a vibrant leader of a fluorishing diverstity of life on this planet. All the attempts to artificially and unsustainably get benefit are "counter-productive". And since humanity will be striving to enjoy life for such a long time, there may actually be times in the future when readily available energy from fossil fuels would help with an actual 'short-term emergency need'.

    It is a shame that the current socioeconomic system has become so popular, but understandable. Once humans get a taste of benefits many of them develop an addiction to getting that benefit even if it is proven to be damaging or unsustainable. Those people who have become additcted and will fight the 'change of attutude' need to be stopped from succeeding at the things they will try to get away with. That is a significant challenge to solve, but there is no future for humanity if it is not solved.

  36. Climate Bet for Charity, 2013 Update

    "Moderator Response:[RH] You need to host the image somewhere and then link to that location."

    The file is on my computer, if I read your post correctly you want me to transfer it to an external web site and then use that web site URL to link it to my post.

    This seems a very cumbersome method of linking to a file.  Why can't I upload it directly from my computer?

    Moderator Response:

    [RH] SkS is a custom built site and doesn't yet have that capability. 

  37. Climate Bet for Charity, 2013 Update

    #42 HK

    "The file bein11.dat is the one you should use as it covers the next 100,000 years. Multiply the figures for 60oN or 70oN by 0.4843 to convert them from langleys/day to watt/m2 and you will find that the result supports me"

    I used orbit91 for the years BP and bein11 for the 10,000 years into the future.  I took the mean of Jul 60N and Jul 70N to get Jul 65N.  I then had to correct a zero years error between the two sets of data and multiplied by 0.479775 instead of 0.4843 to correct this error. This gives a small scaling error of < 1%.  So my figures for the next 10,000 years are less than 1% out but this doesn't affect the minimum or maximum points.

  38. Climate Bet for Charity, 2013 Update

    nzrobin @45...  Looked at your new chart. Still seems like a strange way to process the data but I think it'll all pan out in the end. Just be aware that your Y axis is probably going to change pretty dramatically as we catch some El Nino cycles in the coming years. ;-)

  39. Climate Bet for Charity, 2013 Update

    jhnplmr:

    The link you have posted is not very helpful since it is raw data . It is clear from your postings that you have misread your link and think 2,000,000 years is 20,000 years. The Wikipedia link from HK in 33 is clear and shows that you cannot read a graph.  I think you have proved my initial point that you needed to cite your links for your fantistical claims.  I am not going to post on this thread any more.

    It is typical for climate change deniers to be unable to read their own data links.  Thank you for an excellent example of this point.

  40. Climate Bet for Charity, 2013 Update

    #41 gws

     "The paper you cite only looked into the past."

    I don't recall citing any paper, which one are you referring to?

    If you are referring to the Milankovitch data then this covers 5 million yrears BP to 100,000 years into the future.

    I don't want to be forced into using the wiki graph, firstly because it is inaccurate, secondly because I didn't introduce it to back my argument.

    My initial post was:

    "From the Jul 65N Milankovitch cycle the solar insolation was 469.44W/m2 at the maximum 10,000 years ago. It is 426.76W/m2 today, a fall of 42.68W/m2."

    These figures were from the NOAA site I quoted.  I compared this fall in solar insolation with the rise in radiative forcing due to man (1.6w/m2 according to IPCC, 2.3W/m2 according to the article).  I said the man-made forcing was small compared to the change in solar insolation.

    I was then informed that the next minimum was 20,000 years into the future.  I said that the NOAA data gave it 2000 years into the future:

    +3000 424.1W/m2

    +2000 423.61W/m2

    +1000 424.61W/m2

    This shows a clear minimum in 2000 years time. After that insolation will rise.

    This change from peak (469.44W/m2) to trough (423.61W/m2), a change of 45.83W/m2, is less than that which forced us into the last glacial period, a fall from a peak of 476.59W/m2 (103,000 years ago) to a trough of 421.14W/m2 (93,000 years ago), a fall of 55.45W/m2.

     I feel much happier using my more accurate figures from the original data than trying to derive them from a published graph.

    "I do not see your argument"

    My argument is that man-made forcing is small compared to that caused by changes in solar insolation.  Furthermore, the man-made forcing has been beneficial as it has prolonged the present interglacial period without an undue rise in global temperatures.  I made the further point that trying to indefinitely prolong the present interglacial at present temperatures would require a lot of energy, which we don't have.  I then said that the fall in insolation would eventually cause a fall in global temperatures, but not a glacial period.

     I hope this makes my position clear.  It would be much clearer if I could publish my graph but this doesn't seem possible.

    Moderator Response:

    [RH] You need to host the image somewhere and then link to that location.

  41. Climate Bet for Charity, 2013 Update

    Hi Rob and John,  I like your post and feeling quite chuffed to see my graph here at Skeptical Science.  I did another view of the bet trying to eliminate the 'noisey' look at the front end.  Here's a link - http://www.kiwithinker.com/2013/11/a-decadal-global-climate-bet-a-second-view-of-the-race/.  With best regards to all from NZ, nzrobin.

  42. Climate Bet for Charity, 2013 Update

    jhnplmr...  I think HK has just proven my point about making elemental errors and looking foolish.

    It's incumbent upon you to more completely do your research before making fantastical claims.

  43. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    What a great validation of the importance of John Cook's work. Almost 200 attach articles pages or jokes.  

    It cant be denied (well of course it's done all the time but not in any way that makes any sense) that there is a political contest between science and the fossil fuel industries for control of the hearts and minds of the voting public. It's clear from the last Australian elections that climate denial and distortion of what is real can win elections.

    Politics is the world of appearances and is a kind of warfare that industries fund to a larger extent that people. I really appreciate the work of SkS to clarify the tactisc used by industry.

  44. Climate Bet for Charity, 2013 Update

    And BTW, the updated figure for man-made radiative forcing in AR5 is 2.3 watt/m2, not 1.6 watt/m2.

  45. Climate Bet for Charity, 2013 Update

    jhnplmr:

    "If you call oscillations between 560W/m2 to 460W/m2 (rises and falls of 100W/m2) very little change. IPCC gives 1.6W/m2 as the total man-made radiative forcing from 1750 to present day."

    First of all, those changes are regional, not global.

    Secondly, we are not talking about the maximum oscillations during the last 2 million years, but the next 20,000 years. That’s a big difference!

    And third, your source doesn’t agree with your claims. The file bein11.dat is the one you should use as it covers the next 100,000 years. Multiply the figures for 60oN or 70oN by 0.4843 to convert them from langleys/day to watt/m2 and you will find that the result supports me.

  46. Attacks on scientific consensus on climate change mirror tactics of tobacco industry

    Has anyone ever done a study of the downwind rural temperature records of major cities to see if there was a discernible difference in temperature from those rural areas that where not downwind? I am assuming the c02 levels would be higher downwind from the major cities and thus have higher temperatures.

    Moderator Response:

    [DB] Wind directions, no matter how prevailing, still vary.  The greenhouse gas effects of CO2, being a diffuse and well-mixed gas, manifest themselves on a global basis, rising bove ackground noise over time.  Local effeects on short timescales are lost in noisy weather effects.

  47. Debunking 97% Climate Consensus Denial

    Was Doran & Zimmerman (2009) considered peer-reviewed?  Because many denier blogs keep pionting this out as a point to their side. 

  48. Climate Bet for Charity, 2013 Update

    jhnplmr,

    The paper you cite only looked into the past. Its timeline, same like the cited wikipedia page is in thousands of years. As the wikipedia graph pointed out by HK @33 shows, in the small period past the blue dot (today), the change are going to be relatively small, much smaller than you are talking about. The larger changes (+20 W/m2), i.e. first in the positive direction, are more than 20,000 years in the future. The first negative anomaly is more than 50,000 years in the future. So unless the wikipedia graph is wrong, I do not see your argument.

  49. Attacks on scientific consensus on climate change mirror tactics of tobacco industry
    Tobacco companies are concerned about replacing users since all the serious users die out. That's why they aim a young people.Carbon fuel use will be decimating the population in the same way. Expect to see messages targeting youth - future smokers, er, carbon uses.
  50. Climate Bet for Charity, 2013 Update

    jhnplmr...  Read the Kiehl 1997 paper please. I think you'll find it informative.

Prev  795  796  797  798  799  800  801  802  803  804  805  806  807  808  809  810  Next


The Consensus Project Website

THE ESCALATOR

(free to republish)


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