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All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

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Comments 42801 to 42850:

  1. How much will sea levels rise in the 21st Century?

    Thank several of you for correcting my misunderstanding of the aggregate production of CO2 by China, for the actual annual production by 2100.

    I personally appreciate jja @ 16, interspersing his comments with "magical  thinking" perjoratives.

    It's one thing to be a chicken little "The sky is falling" alarmist:  it's another to actually have the equivalent becoming manifest.

    In regard to 

    " If global temperatures rise, the warmer world will radiate more energy back out into space and the energy imbalance will reduce"

    being a salient response to a "+7C"  increase by 2100...:   well, I am speechless.

    We must derive a doable "Direct Air Capture" technology.

  2. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth - I would agree with Tom Curtis - claiming that the uncertainty of multiple measurements from almost 4000 ARGO floats is identical to the error of a single measurement is absurd, and anyone with science or engineering background (which you claim) should be well aware of this aspect of signal averaging, right along with the Central Limit Theorem

    OHC is an anomaly measure, not an absolute measure, and hence the link you provided regarding absolute measures is wholly irrelevant. Use of anomalies also removes any potential systemic bias in those measurements. 

    Your last few comments appear to be (IMO) increasingly disingenuous.

  3. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth, to follow up on Tom Curtis's reply to you, read about the Law of Large Numbers.

  4. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth @17, as I understand it, the uncertainty of the mean of n values, each with uncertainty x equals x/(n^0.5).  Your claim that the increase of OHC in within the error bars presumes either that there was just one measurement (for the whole ocean), or that the error of measurement is entirely composed of a systematic bias.  Please put forward your evidence of either proposition.

    Absent that evidence, you appear to be guilty of deliberate obscuring of the evidence (assuming that, as a scientist, you know the basic mathematics of uncertainties).

  5. StealthAircraftSoftwareModeler at 02:05 AM on 23 August 2013
    A grand solar minimum would barely make a dent in human-caused global warming

    KR @14: Minnett 2000 and the A High-Accuracy, Seagoing Infrared Spectroradiometer paper (http://journals.ametsoc.org/doi/pdf/10.1175/1520-0426%282001%29018%3C0994%3ATMAERI%3E2.0.CO%3B2) point out that their “high accuracy equipment” has stated accuracies of 0.1K. The entire OHC content anomaly when converted from Joules back to temperature in the ocean is on the order of 0.09C (I assume you can do the math and conversion, but if not let me know and I’ll show my work). Clearly, OHC is within the error bars of the measurement system, unless Argo can measure more accurately (unlikely). It could be there or it might not be – it simply is too small to measure. Then, when combined with the number of measurements and uncertainties induces by thermal eddies and ocean mixture, it is seems unlikely to me that measurements can tease out the true OHC.

    Finally, I believe OHC from NOAA suffers from modeling artifacts like surface air temperature (SAT). Please see Dr. Schmidt’s discussion of SAT at NASA GISS: http://data.giss.nasa.gov/gistemp/abs_temp.html

  6. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth:

    I would have thought your misconception regarding TOA vs surface energy balance and their respective significance with regards to global warming has been previously addressed, so I confess I am surprised to see you re-state it here.

    I should also add that you appear to engage in cherry-picking. Stephens et al 2012 has to be considered in context with other papers of the same nature. As far as I have seen you have provided no analysis doing so. At the very least if you feel Stephens et al by itself outweighs any (or indeed every) other similar paper, it is down to you to show your working.

    Finally, with respect to your assertions about NOAA vs ARGO, unless you yourself provide evidence (*) to support your claim, no one has any obligation to accept it as correct.

    On that note, the opening paragraph of Levitus et al 2012 states:

    We provide updated estimates of the change of ocean heat content and the thermosteric component of sea level change of the 0–700 and 0–2000 m layers of the World Ocean for 1955–2010. Our estimates are based on historical data not previously available, additional modern data, and bathythermograph data corrected for instrumental biases. We have also used Argo data corrected by the Argo DAC if available and used uncorrected Argo data if no corrections were available at the time we downloaded the Argo data. [Emphasis mine.]

    So the data you deride uses the very same floats that Svensmark claims "have not registered any increase in temperature" and finds... that they have.

    ----------

    (*) Evidence other than an appeal to your qualifications, I might add.

  7. StealthAircraftSoftwareModeler at 01:47 AM on 23 August 2013
    A grand solar minimum would barely make a dent in human-caused global warming

    Sphaerica @ 13: I followed your link and “read more”, but the link seems to support my statements @12. You may not like the information because it doesn’t support a CAGW position, or it shows that Dana is incorrect, but that doesn’t mean I am “preaching.” I fully admit I may be incorrect in my statements or have misunderstood something, and if so, please correct me. What in my statements @12 are wrong?

  8. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth - Svensmark is in fact flatly wrong in claiming the ARGO probes "...have not registered any temperature rise", and you are equally off-base in claiming "...Heat Content is some output from a software model, not direct measurements...".

    Temperatures measured by the ARGO floats and the XBTs before them are rising in the raw data, and the ocean heat content (OHC) is simply observed temperature change scaled by the thermal mass of the ocean layer in question - not some kind of complex model. OHC cannot be dismissed by appealing to model complexities. 

    ---

    OHC may be one of the best measures of the top of atmosphere imbalance available - averaged over long time periods, global, representing (for the full depth of the oceans) ~93% of the energy changes. And it is consistent with satellite observations of TOA flux (Loeb et al 2012). Adding up components of the Earth energy budget (evaporation, thermals, clouds, albedo, etc) sums estimate uncertainties - but OHC is a direct measure of TOA imbalance. 

    In addition to Sphaericas link on ocean warming/IR, I would also point out a RealClimate discussion of the same work. 

  9. 2013 SkS Weekly News Roundup #34A

    John Chapman - That's mm/yr, not cm/yr. 3.2mm/yr * 10 is 32 mm, or 3.2cm, or about an inch and a half per decade. 

    3.2mm plus 0.013mm/yr acceleration (Church and White 2006) leads to a total of about 33-34cm by 2100. That, however, doesn't figure in temperatures - semi-empirical modeling of temperature versus sea level (Vermeer and Rahmstorf 2009 for one example) predicts 90-170cm for middle-range temperature scenarios. 

  10. 2013 SkS Weekly News Roundup #34A

    Roger Pielke's dissent represents 7% of the 14 AGU members, so that's consitent with the 95% consensus figure!

    I note tow of the articles mention sea level rises.  One at 8 inches by 2050 and the other 3 feet by 2100.  Recent rates of rise have been reported at near 3 mm per year, which equates to almost a foot per decade indicating rises of 3.5 feet by 2050 and over 8 feet by 2100, and that's without an acceleration of the rise.  Why are those projections inconsistent with recent measurements?

  11. How much will sea levels rise in the 21st Century?

    jja @39.

    The 5ZJ for 50mm SLR was calculated @30 to be 5.5ZJ (rather than approximated @19). Of course this exrtra 10% energy requirement is minor but I mention it here for the sake of correctness.

    I'm on board with your estimates down to the paragraph beginning "If Atmospheric temperature is increased to +7C by 2100..." Here we hit a profound problem. If global temperatures rise, the warmer world will radiate more energy back out into space and the energy imbalance will reduce. The larger that temperature increase, the greater the reduction in (inward) energy imbalance, this being accentuated if ECS is small (a situation that is quite fun when denialists try picking up on energy fluxes to support their fantasies). So to achieve 2,494 - 3,483 ZJ global energy flux to 2100 would require all surface warming to stop over that period.

    A +7⁰C global temperature rise (above pre-industrial values) with ECS=4.3 would result in increased outward radiation of 5.3 W/m^2 or 86 ZJ pa. Subtracting  this would make your 58 to 81.2 ZJ pa negative, although I would assume your +7⁰C was assuming long term positive feedbacks which are usually considered additonal to ECS.

    Your final estimated values assume that energy imbalance will increase as additional RF accumulates. That is a big assumption. I would suggest that taking the rate of change of RF (ie ∆RF) as a proxy for energy imbalance may be a useful first assumption. Present levels of net RF are difficult to quantify but positive RF are better quantified with ∆RF = 0.043 W/m^2 pa over recent decades. Continuing at that rate would give an additional 3.7 W/m^2 by 2100. This does not provide a basis for projecting a significantly larger ∆RF over the coming century and thus no large increase in future energy imbalance can be inferred from such a consideration.

  12. A grand solar minimum would barely make a dent in human-caused global warming

    Stealth,

    Preach less, read more. Your understanding of ocean warming is wrong.

  13. Coumou & Robinson on Extreme Heat: Choose Your Own Adventure

    Tom@1,

    I would not be so sure that "observations overshoot the model projections" for the event shown on figure 2. You cannot say that unless you have and compare the actual data. Eyeballing may be very subjective. For example, having downloaded the high quality picture, my eyeballs concentrated on large swathes of dark blue coloured 1-SIGMA observations in NAmerica, Siberuia and WAus, whereas the models paint it light blue or green, thus models overshoot the observations there.

    Your question:

    is the percentage of land area shown represent the percentage of total land area or the percentage of actually observed land area?

    can only be answered the the authors. But I think it should the the latter (of actually observed land area), if they did not interpolated the grids with no data; otherwise it would not make sense in the context of comparing the observations with the model predictions.

  14. StealthAircraftSoftwareModeler at 13:24 PM on 22 August 2013
    A grand solar minimum would barely make a dent in human-caused global warming

    Solar Output is Stable

    Solar Output may be fairly stable at the top of the atmosphere, but solar radiation reaching the earth’s surface varies significantly. See: Wild 2009 in JoGR (http://www.leif.org/EOS/2008JD011470.pdf) and Wild 2012 in the AMS (http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-11-00074.1).

    Additionally, the uncertainty in the observations in the earth’s energy balance is significant. See: Stephens et al 2012 in Nature (http://www.nature.com/ngeo/journal/v5/n10/full/ngeo1580.html). A direct quote is:

    “This lack of precise knowledge of surface energy fluxes profoundly affects our ability to understand how Earth’s climate responds to increasing concentrations of greenhouse gases.” – Graeme Stephens et al.

    A quick look at Kiehl and Trenberth’s energy budget shows the surface imbalance is 0.6 +/- 17 W/m^2. Yes, that is plus/minus 17 W/m^2, which is an error bar that is 34 W/m^2 wide. The reduced IR flux from 1950 to today due to CO2 is on the order of only 1 W/m^2. The uncertainty in the earth’s surface energy balance is at least 30 times larger than the forcing effect of CO2.

    Heating of the Deep Oceans

    The ocean is warmed almost exclusively by short wave solar radiation. IR radiation from CO2 or the aerosphere does not, and cannot penetrate liquid water (not more than a few millimeters). Since the ocean surface is has also paused in warming, either short wave solar radiation is warming the ocean, or the deep ocean is not warming. Converting from heat content to degrees C, the ocean warming over the last 30 years is less than 0.1 degrees C, which is probably well within the error bars or the Argo float’s measurement ability.

    Svensmark Gets Ocean Warming Wrong

    Svensmark statement is not refuted by the NOAA Heat Content chart. Svenmark states the Argo floats have not registered any increase in temperature. The NOAA Heat Content is some output from a software model, not direct measurements like the Argo floats. Unless you can prove that Argo does show an increase in temperature, the NOAA Heat Content is a non sequitur to Svenmark’s claim.

    Human Influence on Climate Change is Bigger than the Sun's

    This may be true if you meant the change in the solar output at the top of the atmosphere -- since that varies by about 1 W/m^2,and the effect of CO2 is on the order of 1 W/m^2. But at the earth’s surface, the +/- 17 W/m^2 uncertainty completely swamps the effect of CO2.

  15. Andrew Dessler on Why It's Stupid not to Act on Climate Change

     

    No, I'm saying that Andrew Dessler's statement that "97% of scientists think global warming may be severe" means precisely nothing without further defining:

    1) What "may" means...a 50 percent probability? 10 percent? 1 percent? 0.1 percent?

    2) What "severe" means...how much global temperature rise, how much sea level rise, what will it do to global GDP, what will it do to life expectancy, and so on.

     

    Moderator Response:

    [PW} Mark, you have been given incisive and complete answers to this, on this forum and in Dessler's video. It's clear you do not like the answers and are now on *extremely* thin ice, wrt to sloganeering. Further sloganeering ~will~ be removed.

  16. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    Old Mole - Quite true, quite true. 

    It's just that "We are that particular tiny fraction of the 3%", although accurate, isn't a very catchy slogan for denialists. It might make a good T-shirt, though.

  17. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    I cannot personally understand why people seem so intent on attacking the 97% figure as unrealistic when clearly it is the 3% figure that really deserves scrutiny, since it really is not 3% at all, but over a dozen fractions of a percentage point combined without any real reason for doing so.

     

    Take for example the Lu study blaming CFCs by blatant curve fitting. Do you imagine for one moment that any survey of climate scientists asked the question "Are you convinced that CFC'c are responsible for climate change?" (although that would, technically constitute AGW, since there are no naturally occuring CFCs) that over 99% of those expressing an opinion would disagree? Wouldn't that hold equally true of theories about solar fluctuation, cosmic rays, or the intervention of the Flying Spaghetti Monster?

    Calling it 3% vastly inflates the credibility of AGW opponents, and hides what they really are ... cranks at the fringes of scientific thought.

  18. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Mark Harrigan @33, your point (1) is clearly addressed by Dessler in his video, as shown in the transcript @37.  The "hole in the logic" is, it turns out, simply a matter of your not paying attention to what was said.

  19. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Mark Bahner @35, you are angling to suggest that Andrew Dessler does not adress the issue as to which has the greatest net cost, switching to renewable energy or maintaining business as usual.  That, however, is not the case.  He adresses the issue very specifically from 4:38 in the video.  He says:

    "There are several reasons to think that switching to renewable energy, even if climate change turns out to not be a very serious problem, is not a terribly bad action.  There are co-benefits, such as cleaner air and political benefits of not using fossil fuels.  In addition, its a reversible decision.  If we choose not to burn coal now, we can always burn it later.  And finally, it is inevitable.  We're going to run out of fossil fuel, and we're going to have to make the switch; and in general the earlier you start making these changes, the cheaper they are - so starting now has that advantage.

    It is also worth pointing out that climate change is, at a very fundamental level, irreversible.  Every cubic kilometer of ice we loose, every centimeter of sea level rise that occurs - those are not going to be reversed on any timescale that we care about.  Those are irreversible changes so far as I'm concerned.  And irreversibility means that you have to be very certain of the costs and benefits before you take an irreversible action.

    And so when you put all this together, it seems very clear to me that the worse error is not taking action on climate change, and having it turn out to be severe.  And I think that if you want to argue that we should listen to the 3% of dissident scientists, then you have to make the argument that that is not the case - that switching to renewable energy is the worse mistake.  I think that that's an extremely difficult argument to make."

    I would add to that that:

    1)  BAU will result in a change in global means surface temperature as great as the difference between the last glacial maximum and the preindustrial average; and the assumption that such a large change can be made without major disruption of agriculture is fanciful;

    2)  Global warming has a high probability of completely or partially destroying major ecosystems including all arctic and subarctic ecosystems, the Amazonian rainforest, and the Great Barrier Reef (which is an almost certain casualty of ocean acidification alone, let alone the additional impacts of global warming) and the idea that humanity can swan along unharmed amidst such wide spread ecological catastrophes is again, fanciful; and

    3)  The most detailed economic analyses of the issue, as represented in IPCC WG 2 and 3 show the economic cost of BAU to be greater than that of taking action to prevent climate change, even though they make the absurd assumption that no matter how great the impact of climate change, it will never slow economic growth.

    Thus, Dessler adresses the issue you raise and your complaint appears to boil down to that he does not do so in the same detail as WG 2 & 3 within the scope of a six minute video.  

  20. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Mark harrigan - you argument would be better if you could cite some credible science supporting a climate sensitivity of less than 2. Hoping it will be low without also doing any kind of risk assessment for it being greater than 3 doesnt sound like sensible strategy to me. Words like "severe" or "mild" arent really that useful. Better is to look at what the projected climatic effects will be for a sensitivity of 2 and compare those impacts with costs of mitigation now.

  21. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    Sphaerica @26, there is one instance in the self rated papers of a paper rated by abstract as explicitly endorsing with quantification (1) being self rated as explicitly rejecting with quantification (7), ie, a difference of -6, which is not shown on the graph.  That represents the same percentage of papers as that shown for differences of -4 and 4.  It is, therefore, not consequential, but should be shown for accuracy.

    It is very amusing to see Joeygoze trying to suggest that the data has been hidden, when it is freely available for download.

  22. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze,

    In case you don't find it in there (although you really should read the post to which I linked -- you seem to be suffering from a lot of misconceptions based on "yeah, but what if..." thinking), the self rating data is here.

  23. Toward Improved Discussions of Methane & Climate

    Apparently, according to the IMPACTS group modeling, the sea of Okhotsk may be very important to the U.S. Their modeling shows a severe anoxic region in the northern Pacific, originating in the sea of Okhotsk, after 30 years of methane hydrate release, according to their conservative modeling. The figures in their Powerpoint slide show illustrate this anoxic region extending across to Alaska, down the west coast of Canada, and all the way down the California coast to around Baja California, wandering out into the Pacific near the equator, then continuing in diluted form along the west coast of South America.

    Will there be hydrogen sulfide clouds rolling in from the Pacific into northern California within my lifetime?

    A lot of that probably depends on the global methane hydrate inventory, and whether hydrate dissociation will be a top down, orderly process.

    Is the real global hydrate inventory 80,000 (or more) cubic kilometers of hydrate or around 4000 cubic kilometers?

    Whatever the methane hydrate inventory is, Dickens says that under projected warming conditions, the methane hydrate stability zone will shrink by about 50 percent. So, whatever is down there, maybe half of it is likely coming out, over the next decades or centuries.

    Does the IMPACTS modeling take into account gas driven pumping of sea water through the hydrate deposits, for example? Wouldn't gas release into methane chimneys make the seawater in that chimney less dense, pumping upward flow? Would warm water flow down an adjacent channel, to fill that chimney? Could a sort of chaotic or oscillating flow driven by gas pumping and alternating chilling of water in adjacent channels result?

    How sure are we that gas pumping will not lead to pumping of sea water through the hydrate deposits, when gas releases by the hydrate deposits increase by tens or hundreds of times?

    Here's a paper that talks about very slow flow, driven by gas pumping, tidal pumping and various other forces through a normal hydrate deposit, not yet much affected by global warming:

    Fluid and chemical £ux in and out of sediments hosting methane hydrate deposits on Hydrate Ridge, OR, II:Hydrological processes

    How much will gas driven pumping increase when methane gas emission from shallow hydrate deposits increases by tens or hundreds of times?

    All of this would seem to make the slab models used by the IMPACTS team at least questionable, and possibly actively misleading.

    If scientific conservatism is helping to kill the biosphere, maybe it's time to try something else.

  24. How much will sea levels rise in the 21st Century?

    MA Roger @37

    you said, "I have yet to see anyone describe how an energy flux can be created large enough to melt enough ice for anything like 5M SLR."

    You have also said (@19) that "To melt enough ice to achieve 50mm SLR p.a. would require roughly 5 ZJ p.a"

    1.  If 11/5 of total SLR is due to thermal expansion and not ice melt (probably closer to 1/3 ) and

    2.  We want to find how much ice would be needed to melt to raise sea level by 5M

    and we use your assumptions then

    5 ZJ (ice melt) = 5 CM sea level rise, 100ZJ (ice melt) = 1 M sea level rise,  Target Sea Level rise = 4 M = 400 CM = 400ZJ (ice melt)

    Current Energy imbalance according to Hansen and Soto is 11.6 ZJ per year


    Total Energy imbalance from today to 2100 = current energy imbalance + Increased RF between now and 2100 = (11.6 ZJ per year (corresponding to .75W/m^2) + 46.4 ZJ per year to 69.6 ZJ per year) , (corresponing increased RF from now to 2100 of between 3 to 4.5 W/M^2 additional forcing)

    Therefore the total energy imbalance at 2100 compared to today will be between 58ZJ per year and 81.2 ZJ per year.

    These total energy imbalance values will yeild an average imbalance between now and 2100 of (approximately) 29 and 40.5 ZJ per year.

    So, over an 86 year period, the total period extra energy absorbed by planet earth is between 2,494ZJ and 3,483 ZJ between now and 2100.

     

    If Atmospheric temperature is increased to +7C by 2100 and Arctic amplification due to early summer sea ice loss occurs then the deposition of 400ZJ (conservative estimate) is certainly plausible.

     

    compare with alternative calculation below, the

     

    The value I used was indeed RF values not energy imbalance. If I use your math and Hansen & Sotos value of .75 (they adjust for the solar minimum) I get a value of (7.5 * .75/.58) * 1.2 which is equal to 11.6 ZJ p.a. this will make a total earth cumulative energy imbalance of 1,000 ZJ by 2100 (86 years) If even a few of the non-linear feedbacks are taken into account and a higher (more realistic) emission scenario is used then the value of energy imbalance by 2100 could easily be 4-6X the current value. Therefore the total cumulative energy by 2100 will be closer to 3,000 +2,000/-1,000 ZJ . This will increase if I used the slightly higher values of Balmaseda, Trenberth & Kallen
    In addition, if the ECS value is 4.3 then surface warming will be greater and the proportion of heat transferred by convection to land-based ice will increase.

  25. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze #24,

    That information is available, and in fact has already been published here, at SkS, along with the following histogram:

  26. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze,

    See "Table 5. Comparison of our abstract rating to self-rating for papers that received self-ratings."

    Useful would be to read the full study, the supplementary material, the FAQ, and examine the full list of papers and authors yourself, and as a learning exercise, doing your own ratings.  Most of the criticism tends to be from individuals who do not have a good understanding of the study, or hope their target audience doesn't.

  27. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    NewYorkJ - So can you point me to the following data? From the article in your link.

    "We invited the scientific authors to categorize their own papers, so if they responded, their 'correct' classifications of the full papers are included in our database. As illustrated in the graphic below, we found the same 97% consensus in both the abstracts-only and author self-rating methods."  I see the graph below the text but it is expressed in %s, want to see the number of papers in which authors also gave a response and agree with the classification, is that available?

  28. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze,

    Mr. poptech's argument has been addressed.

    www.theguardian.com/environment/climate-consensus-97-per-cent/2013/may/28/global-warming-consensus-climate-denialism-characteristics

    Remember there were 12,000 papers surveyed.  What percentage are then under dispute by those carefully-selected skeptical authors?

  29. Where SkS-Material gets used - Coursera's Climate Literacy Course

    Just wanted to say I use SkS material all the time in my teaching at UNC and also in various outreach endeavors (blogs, talks to the public, etc).  I even have an SkS graphic in a new book chapter coming out. It is all so invaluable!  

    One tip though: the axis and tic labels on SkS graphs are often way to small.  Please start making with much larger font:)  

    Thanks Gang!!!

  30. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Tom Curtis,

    You're right. Here is what Andrew Dessler said, "Future warming may be severe."

    Here's a comparable statement, "An asteroid may hit the earth in the next century. The effects may be severe."

    Neither statement is scientifically actionable, because there is no further explanation for either the phrase "may be" or "severe" in either statement.

    Here's information that Andrew Dessler could have provided to assess the need for action:

    1) What 97% of scientists think is the most likely global average surface temperature increase, in the absence of action, and with action.

    2) What 97% of scientists think is the most likely global average sea level rise from 2013 to 2100, in the absence of action, and with action.

    3) What 97% of scientists think the most likely worldwide average life expectancy at birth will be for someone in 2100 without action and with action.

    4) What 97% of scientists think the most likely worldwide average per-capita GDP will be for 2100, with and without action.

    5) What 97% of scientists think the most likely number of malaria deaths will be, with and without action.

  31. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    mark,

    I directly addressed your comments.  You claim (without any support) that renewables are more expensive.  I referred you to another thread where that was discussed and the conclusion was that renewables are not more expensive.  Because you did not read the link you do not realize why you are wrong.  Recently I linked to a peer reviewed study where they calculated the cost of using renewables compared to fossil fuels in the New York area.  They built three times as much nameplate wind as you point out above (natural gas also only produces 30% of nameplate, does that bother you?).  The renewables were cheaper than the fossil fuels.  I cannot find the link because it was not on the correct thread (it is on one of the weekly review threads, why don't you find it since you like to post on unrelated threads).  Since you have provided no links to support your wild claims and do not bother to read links I give you, I do not need to provide links here.  Peer reviewed data shows that you are incorrect in your claim that renewables are more expensive.  Post on the correct thread if you want more information.

    You also claim incorrectly that it might not be too bad.  There is a thread for that argument also.  If you do not follow the organization plan the arguments become too repetitive, because everyone thinks they have a new argument.  Your argument is not new and has already been addressed on the appropriate thread.

    Your point three is obviously wrong.  It is rude to come to a site and tell the moderators how to run their site when we have developed rules over several years.  If you posted to the correct thread, and cited your claims, I will provide the information you claim you want.  Read the background information you have already been linked to.

    Your conclusion was refuted on the link I gave you.  Read the links.  It is not my responsibility to spoon feed you everything you want.  You are required to do your homework and read the background information.

  32. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    OK, so even if I accept the "standard practice" of throwing out papers that do not take a position and look at 3,870 papers in which 97% of them support human driven AGW, let's look at that set more deeply from Cook et al. 

    http://www.populartechnology.net/2013/05/97-study-falsely-classifies-scientists.html#Update2

    Many scientists, when spoken to about their papers and how they were classified in the Cook et al. paper claim that their paper was not classified correctly. One scientist makes the same point that I made earlier, "Science is not a democracy, even if the majority of scientists think one thing (and it translates to more papers saying so), they aren't necessarily correct. Moreover, as you can see from the above example, the analysis (in Cook et al.) itself is faulty, namely, it doesn't even quantify correctly the number of scientists or the number of papers which endorse or diminish the importance of AGW." (quote from Dr. Shariv, Astrophysics, Univ. of Jerusalem)

     

    Phil Cohen - On your statement, " if you have evidence against AGW, that's new and important, and why in the world wouldn't you put it in your summary?"  Maybe because Cook et al. recruited a bunch of die hard AGW believers to help conduct the study and any work that contradicts the faith may have been ignored?  I would rather see a study to proove consensus would be a survey study sent to scientists to answer straight forward questions thus you eliminate the entire difficult process of analyzing the words of a paper and subjectively determine what the authors meant.

  33. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    (-snip-)

    Point 1 - There IS a hole in the logic.  I am not saying it cannot be filled.  But it IS necessary to address the issue of what the are costs of mitigation (via renewables, reduction in consumption and efficiiency).  It needs to be shown that these are less than the costs of the damge that climate change will produce

    Point 2 - To have some say (as they did) that the chance of warming turning out to be mild (i.e. at the low end of the climate sensitivity arguments) is zero is just as egregious and scientifically ignorant as the deniers who refuse to acknowledge that it might be much worse.  The fact is we do not know.  There is non- negligible risk climate sensitivity is high and the damage function similarly high - but it also may turn out not to be so/  (-snip-).

    Point 3 - (-snip-)

    Moderator Response:

    [JH] You are skating on the thin ice of excessive repetition and sloganeering, both of which are prohibited by the site's Comment Policy. Please cease and desist, or face the consequences.


    [DB] Off-topic snipped.  The next off-topic comment will be deleted in its entirety.

  34. Coumou & Robinson on Extreme Heat: Choose Your Own Adventure

    Thanks Byron. I was wondering why the change appeared most clearly near the equator when the poles have seen the most rapid warming. Your comments about regional variation provide a logical explanation.

    The way this study looks at the data should also correlate well with what the average person thinks of as 'extreme heat'. That is, there is often a disconnect when you tell people that the Arctic has undergone 'massive warming'... because even after that warming the temperatures there are still 'cold' by the standards of most people (who live in warmer climes). On the other hand, areas which will experience 'extreme heat' as identified by this study should correlate well to what most people think of as extreme.

  35. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    "For example, is a scientific paper that is peer reviewed but has conclusions that you disagree with automatically misinformation?"

    It isn't disagrement with the conclusions that makes something misinformation joeygoze. It is the use of cherry-picked data, logical fallacies and playing on the ignorance of your audience to falsely produce a 'conclusion' that can't be identified as spurious by your audience.

  36. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze #11 You might want to read this post about the Lu paper you reference.


    Misinformation? Dunno. Fairly sloppy work? Yep

  37. Coumou & Robinson on Extreme Heat: Choose Your Own Adventure

    Thanks for this summary of a fascinating study. It's worth pointing out the reason why there is a greater increase in 3 and 5 sigma events near the equator: because the natural temperature variation in those regions is considerably smaller than near the poles, so even a small rise in temperatures rapidly starts to become extreme on the distribution chart. Now, since these are the areas where there is already a lot of heat, then extra heat in these places can be particularly damaging to human and natural systems. Nonetheless, this statistical quirk (of smaller natural temperature variation near the equator) can serve to hide just how extreme the Arctic warming is projected to be. Since the Arctic naturally experiences much more year-to-year temperature variability, then even the effects of Arctic amplification (where more of the globe's extra heat ends up in the Arctic than anywhere else) don't show up clearly in Figure 2.

  38. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    ubrew12 @30, human senses are not good at recording "temperature".  Rather, they record heat flow, which can change with age.  Further, human memory is not crash hot either, and is unikely to register a change of 0.7 C in temperature between youth and current conditions.  I know that early each summer, temperatures feel hot which late in the summer I would consider cool because I am better adapted to the heat.  Given that, the idea that I could reliably register the difference in temperature now compared to that 45 years ago (when I was seven) is not plausible, even if I was in the same city (which I am not).

    Having said that, my mother accepts climate change implicitly because she has noticed that the Jacaranda's in Brisbane now bloom a month earlier than they did when she was studying teaching here.  Specific anecdotal evidence like that, or like the date cherries bloom in Japan, or ice forms on lakes in Canada can form significant evidence of a changing climate - and have been used in scientific studies for just that purpose.

  39. One Planet Only Forever at 14:53 PM on 21 August 2013
    2012: One of the 10 Warmest Years on Record

    The discussion of whether 2012 is the 8th, 9th 10th or 11th warmest annual global average surface temperature is intellectually engaging (and a bit of a waste of the engaged intellect), but a more significant point is that the warm years since 1998 have all occured without a transient bump comparable to the one that 1998 recieved from the signifcant El Nino that occured. As mentioned, 2012 was warmer because a weak La Nina ended.

    How much warmer the globe has become compared to 1998 can only really be commented on after an El Nino influence on the global average surface temperatures similar to the 1997-1998 El Nino occurs, and other transient or cyclical influences on the "annual average" are considered.

    The difference in global average between the 1982-83 El Nino event and the 1997-98 event may give an indication of how much warmer than 1998 the yet to come next major El Nino year will be.

    The rolling average of 30 years still climbs with every new month of temperature data.

  40. Coumou & Robinson on Extreme Heat: Choose Your Own Adventure

    One interesting point is the comparison between model and observations for 1 sigma events.  Clearly, from figure 3, obervations show lower percentages of the land area with 1 sigma events relative to the models from 2000 to 2012, but quite the opposite impression is made by figure 2, where it appears that observations overshoot the model projections.  I wonder if the discrepancy is due the the large extent of areas not observed in the African and South American tropics, areas which if they match their neighbouring regions, would have had a very high percentage of 1 sigma events.  Did Coumou and Robinson normalize figure three to compensate for this unobserved land area?  That is, does the percentage of land area shown represent the percentage of total land area?  Or the percentage of actually observed land area?

  41. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    unbrew12: I don't know about that method for increasing the number of people that accept the reality of human impact on climate. I'm a bit over 50 and I can't say I've seen a change in climate.  From what I understand, we are only now starting to see the impacts in some of the indicators. John Q Public living near the coast can't tell that sea level has risin since he was a kid. And even if he imagined he could see a difference he doesn't have to believe there is a large human caused influence.  You'd be better off surveying, say, those responsible for water supply planning that are familiar with historic reservoir fill data and runoff curves and such in areas that are starting to be impacted. There are lots of other examples that are probably valid as well. But I think the main thing is to somehow get the population to realize the reality that scientists are much more trustworthy source of information than the other purveyors of opinion such as thinktanks whose purpose is to market doubt.  It may (I hope not though) be the case that future generations will be able to say they've seen the climate change..."my dad used to have a farm but the droughts got more frequent and..." We don't want to get to that point.  As a population we need to accept the results of the work done by experts, have the basic literacy to comprehend the graphs, etc, and not be fooled by false skeptics.  That is what it will take.

     

  42. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    As an adjunct to John Cook's excellent polling of Climate Science papers since 1990, and Climate Scientists themselves, perhaps someone should just go out there and ask anyone over Age 50: has the climate changed or not?

    The deniers have convinced themselves, and an astonishing fraction of the population, that the ENTIRE Climate Science profession is being paid off by Mr. Gore himself, to lie about an aspect of nature they can access themselves by going out the front door and looking UP.  So why not enlist THEM, themselves, as the 'climate scientists'.  Have you, if you're over 50, seen a change in climate?  It could be useful.

  43. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    joeygoze,

    The 12,000 papers that were assessed were simply the set of all scientific papers published during the period of question that survived a set of easy-to-apply filters to make the manual task easier. They do not represent all papers that might be relevant to the question at hand, nor do they represent only papers that might be relevant to the question at hand. They are merely a (hopefully unbiased) sample to estimate the level of consensus in relation to the question at hand in the whole of the scientific literature.

    As such, any calculations of endorsement that involve all of the papers in the sample, rather than just those papers that were deemed to be relevant to the question at hand on manual inspection, are invalid. After all, with sufficient resources, it would be possible to assess every single scientific paper ever published, guaranteeing that all relevant papers were assessed, but also guaranteeing that the percentages of endorsement and rejection out of the whole sample would be approximately zero due to the large number of irrelevant papers involved. In spite of that, we have a fair degree of confidence that if all of the irrelevant papers were excluded from the calculation, the levels of endorsement and rejection should be quite similar to that found by Cook et al due to the scale of the survey conducted by Cook et al and there being no demonstration of bias that I've seen to date in the filtering algorithm used to narrow down the sample size.

    All of this has been discussed previously. If you feel you have some new insight to bring to the table then please do so, but it's annoying to have the exact same comment being made over and over again by an unending stream of different people who apparently think nobody else has considered this issue and can't be bothered reading up on it. But keep in mind two things:

    1. The classification of "relevant to the question at hand" was obviously very conservative, in that the author's own ratings of many papers that Cook et al classified as "No position" based on the abstracts were actually claimed to take a position by their authors based on the entire paper. This means that the true value of "papers out of the 12,000 that support the claim" is actually much higher than 33%.

    2. The authors' own ratings gave very similar results despite large numbers of "No position" papers being reclassified by their own authors — so even though significant numbers of papers were added to the pool of relevant papers, the ratio of endorse:reject barely changed.

  44. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    Oh my, someone's discovered the word 'cherry picking'! The nonsense is familiar but I haven't seen it mixed with 'cherry picking' before.

    In fact, of course, everyone but the very few denialists knows that AGW is a fact, so there's no point in expressing support for it, any more than articles on evolution need to point out that the earth is not 6000 years old. On the other hand, if you have evidence against AGW, that's new and important, and why in the world wouldn't you put it in your summary? If anything, dropping the 67% that didn't take a position underestimated the consensus.

    And if that weren't sufficient demolition, let's recall that scientists were invited to rate their own papers' support for AGW, and once again the consensus was over 97%.

  45. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    For evidence of extent to which FF companies fund US politicians, this link is pretty interesting.

  46. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    StealthAircraftSoftwareModeler,

    some thoughts I have on your comments in @26.

    You took exception to @1 mike roddy's comment about oil companies influence. You say you don't think big oil is buying votes or controlling congress. I would just say it doesn't take "control" to accomplish the goal of preventing action and appropriate leadersip for addressing climate change: it takes "monkey wrenches". This is the point  the comment @1 was making I think, and in my opinion this is what is happening. 

    And yes, exact prediction is impossible. The magnitude of the negative impacts of climate change can only be approximated.  But I'm convinced that these approximations are valid. To compare the best estimate of impacts from a concensus of the science will yeild an approximation of reality that is likely to resemble the actual reality. The majority climate science contrarians influencing public opinion, as far as I can tell, are not interested inhonestly bracketing the problems a warming planet might cause us, but instead have the goal downplaying the science to the point that those that most of the public is misinformed.

    And I'm not sure your example about the accuracy of weather predictions and climate models is a very good one. A better analogy might be a groundwater flow model where a basin scale model can answer the gross flux issues with good accuravy but modeling localized pumping interference effects is much more difficult.

    What can one person do? Not much. One person flying a private airplane full of sandwiches to Berlin in 1948 would not have helped.  One coal plant scrubbing emissions would not make dent in the acid rain problem.  Too bad all those Berliners were starved, and the acid rain problem has continued to worsen over the decades - wait that didn't happen.

    It takes good leadership, looking at the problems seriously, honest players without ulterior motives, and buy in from the public. Don't know a better way to put it than that an honest person could find much fault with news stories leaning towards "AGW will bring problems", but also find the "it's no problem"-bunch of contrarians to be happy to point the public in the oppisite direction of reality.

     

  47. Andrew Dessler on Why It's Stupid not to Act on Climate Change

    Stealth, perhaps you might like to look at the "Its too hard" argument. Frankly, your comments come across someone who is trying to rationalize doing nothing rather engaging with science. The evidence is that climate has a sensitivity between 2 and 4.5. Even at low end, mitigation is cheaper than adaptation. You think studies are making rediculous claims, so how about you cite a study you think is flawed, and give us some evidence as to why it is flawed (in an appropriate thread).

  48. StealthAircraftSoftwareModeler at 09:29 AM on 21 August 2013
    Andrew Dessler on Why It's Stupid not to Act on Climate Change

    This whole video is flawed because it a form of Pascal’s Wager. No one really knows the odds one way or another, so people do not see either choice as valid. Inaction is a typical response.

    @1 I don’t think big oil is buying votes or controlling congress. Democrats line up on environmental issues, and Republicans don’t (they line up behind corporations). No amount of money is going to change any of that, so no one is buying anything or any control.

    I think most people do not tend to believe the dire AGW forecasts or predictions for a couple of reasons:

    1) (-snip-).

    2) (-snip-).

    3) (-snip-).

    (-snip-). Reduce fossil fuels because it is a good thing to do. There is a finite amount of it, so we’re going to run out some day. But right now, it is cheap, cost effective, and very high energy density. Until something comes a long that is better, then things will not change. People will not change, or allow laws to change, if it costs a lot more or reduces capability. The majority rules, and the majority is cheap.

    (-snip-).

    Moderator Response:

    [DB] Sloganeering snipped.

  49. Andrew Dessler on Why It's Stupid not to Act on Climate Change
    Mark Bahner, the fundamental flaw in your logic is that there are no known >1-2km asteroids on a collision course with Earth, and it is highly unlikely such objects will be discovered over the next century or so, albeit the risk is non-zero. Therefore, despite >97% planetary scientists agreeing that such impacts are likely on geological timescale (indeed, near-certain), there is precious little that is "actionable" about an impact threat from an undiscovered object. You can't divert/destroy an object you have not found! We could launch some kind of defence system "just in case", but it would likely not need used.In contrast, >97% of climate scientists understand the hazard of global warming caused by very real, very present, and (contrary to what Tony Abbott thinks) very visible greenhouse gases, emitted by human activity. They are there, demonstrably casing the warming now. Reducing our emissions of those gases is very "actionable" indeed. We can actively mitigate this threat immediately - ie actively significantly lower the probability of significant damage, unlike with your undiscovered asteroid.
  50. Bulletin of the Atomic Scientists: Closing the Consensus Gap

    Billy Joe - no, you are making a non-argument by not acknowledging a problem in the study that out of a set of 12,000 papers that deal with climate change, only 33% support the claim of CO2 driving climate change.  You prefer to cherry pick data that out of the 33% that took a position, most support the concept that man made CO2 is driving climate change and that is where the 97% consensus comes from.

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