Catastrophe Denied: The Science of the Skeptic’s Position

I have repaired the overscan issues in the DVD files and am re-posting the links, which are all good now.

Once upon a time, Al Gore had a PowerPoint deck.  Several years ago, I came to the conclusion that Gore’s presentation was deeply flawed, so I made my own PowerPoint deck in response, and have been updating it ever since.  Here is the most recent version

Powerpoint presentation with notes pages (.ppt)

Adobe Acrobat .pdf file

Then, Al Gore made a movie from his PowerPoint deck.  He won an Oscar and a Nobel prize for his movie.  Those are a bit out of my reach, so I will have to settle for actually being right.  My previous movie showed my PowerPoint deck presented to a live audience, and can still be found online here.  I felt the sound quality could be improved and the narration could be tighter, so I went into the “studio” to create a tighter version.  The product of this is what I believe to be my best effort yet at explaining, in a comprehensive but simple manner, the science of the skeptic’s position to laymen.

I have become a big fan of Vimeo because I don’t have to break videos up into 10-minute chunks as on YouTube.  The Vimeo version is here and is embedded below:

Other Viewing Options

When I get the time to break this into 9(!) parts, I will post a link here to YouTube.

You can download the 212MB .wmv file here (link on the lower right).  Alternatively, it can also be found here.  The .wmv is also available via BitTorrent:  You can find its page at Pirate Bay or the torrent directly here.

Download the .iso file (DVD disk image) to make you own playable DVD here (beware:  1.6GB).  A free tool to burn the DVD from the image is ImgBurn

The .iso file is also available via BitTorrent: you can find its page at Pirate Bay with the torrent here.

Finally, you can buy the DVD at cost, here, for $7.50 plus shipping.

71 thoughts on “Catastrophe Denied: The Science of the Skeptic’s Position

  1. Henry C

    Warren, I really enjoyed the content of your presentation and talking fast just kept me on my toes. It seems that some people just don’t get it, man’s contribution to CO2 in the atmosphere is small and that rising CO2 in the atmosphere, natural or man made is causing little if no threat to our climate. In fact there is evidence that the earth has gotten greener, probably due to more nutrition from CO2 for the plants. If CO2 were a pollutant why do commercial greenhouse operators add CO2 to the air to increase the concentration to around 700 PPM. Could it be they found out that plants grow bigger and stronger and produce more food? If the climate alarmists think that there is a consensus among scientists they should go to the US Senate web site and read the report from more than 700 scientists from around the world sent to the senate in 2007, updated in 2008 and again in 2009. It is a good place to send alarmists to open their eyes. Go to , then to the Minority site, then down on the left click on: Hundreds of Scientists dispute the Global Warming Alarmism.

  2. E -

    Looks to be an error in this slide -

    james hansen’s 1988 forecast to congress was grossly exaggerated

    Comments on slide say 1998…looks like it should be 1988 -

    Thanks -

    E -

  3. Ron Feltman

    Super presentation that should be distributed to all interested persons. Telling it as it is with facts rather than fiction is a welcome change. I hope Gore gets to see this just to show how ignorent he shows himself to be. The IPCC should be required to apologize to the world for its obvious scam.

  4. Ron Feltman


    What are we going to do about H.R. 2454 which uses the work of the IPCC as justification for this bill?

  5. Grant Smith

    Excellent video. I for one say you speak at a normal pace. Had you gone at ‘Who wants to be a millionaire?’ speed we would have only answered 5 trivia questions in those 90 minutes! Time for the general public to have a coffee and start listening faster! Jeesh!

  6. Mari Warcwm

    Excellent! I have been reading a great deal about AGW and you are everywhere bang on target. Thank you. I will distribute it to the deluded and hope that they listen and learn.

  7. John Campbell

    Excellent presentation on all fronts. Very well done and very informative. I would highly recommend this presentation to everyone of an adult age.

    On another note, in addition to what you have already developed, would it be possible to create a separate presentation as a sort of “how to” on combating problems with people who are so sold on the man made global warming issue that they simply will refuse to recognize the fallacy? Might I suggest using their own charts and graphs more closely as a one on one to illustrate that the argument the man made global warming devotional attempts to make with one graph or chart on one argument runs counter to the very graph or chart they attempt to use for another argumentative point? You seemed to have touched on this during the presentation, but illustrating such in a closer analysis for a short presentation could possibly be more effective in pointing this out to the masses of those who the UN and global warming pervayors have managed to garner and exploit as a cadre. I also think this method could be used as a teaser to draw more attention to your larger presentation.

    Also, is there any point, possibly several points, that the graphs end at today can easily dovetail into historical past trends that would show the cyclical event if linked?

    Nonetheless, well done.

  8. hamlock

    this is why the warmers wont debate their sience it simpley doesnt stack up. if only the broarder public could view your doco i feel the warmers would be under alot more pressure to improve their transparancey. GREAT WORK KEEP IT UP

  9. peter brown

    Very good indeed…..Would be nice if one of the larger European news organizations could actually summon the guts to bring this work to the attention of the general public.

  10. Tim

    hunter calls Warren a”Dopey fucking cunt.”
    Can you say “ad hominem attack!” When you can’t fight them with facts,
    you demonize the person– a typical AGW proponent strategy!

  11. John Beare

    Just tuned-in to this web site and looking forward to watching your PowerPoint presentation. One minor quibble about the reference to Al Gore’s “PowerPoint deck”. His presentation was not made with PowerPoint. As a long-time Macintosh user I am ashamed to say that Gore’s presentation of 35 convenient untruths and exaggerations was made with Keynote, the Mac equivalent to PowerPoint.

  12. Tom

    I thought that the video was an excellent effort for an amateur.
    More important was the content. Your explanations were clear (some would same ‘fair and balanced’)and your arguments compelling.
    While some of the audience have short attention spans, the topic requires detailed analysis.
    Very nice job!

    PS. I split my time between Toronto and Fort Myers FL. Toronto’s average temp is 3 degrees warmer so far this 2009-10 winter and Fort Myers’ is 3 degrees cooler which proves, eh, nothing.

  13. Dave

    Great presentation. When I discuss my own position on climate change with friends — I’m not sure who to believe, really — I’m always attacked with the consensus. “There’s a scientific consensus,” I’m told. “They all agree that climate change is happening. Why would all the scientists lie?” It may be nice if this were addressed in your piece. I don’t disagree with your facts, but a great many scientists would. Why?

  14. HarryDinPT

    Dave….Simply ask what consensus they are referring to?
    I think Warren made this point very well.
    If it is the consensus that: CO2 is a greenhouse gas; our society has been emitting CO2 at a rapid clip over the last 60 years; temperatures have risen over the last 150 years; and, at equilibrium, a doubling of CO2 from current concentrations would result in a temperature rise of a little over 1 degree C, then say they are correct. But, this does not lead to the catastrophic predictions we all hear about.

    This piece by Richard Lindzen in the Wall Street Journal sums up the whole argument very well:

    And if you have the time….about an hour and a half….Lindzen speaking at Fermilab:

    You need RealPlayer installed to watch the above.

  15. Glenn

    I loved the preso. I’m a non-scientist and barely numerate, so the science tends to get mind-numbing very quickly on scientific sites. I have a couple of questions which I really hope folks smarter than me on this site can answer.

    1. Given your statement that there has been no warming in the past 15 yrs, how do I square the recent public pronouncements that the last decade was the warmest on record and that ’09 was the warmest year on record?
    2. This is more philosophical. I necessarily give more weight to climate scientists and have read what Michaels, Spenscer, Lindzen and others have to say with interest. But they seem to be opposed by large numbers of scientists – Lindzen is opposed by others within MIT, for example. Other skeptics like yourself, McIntyre, the Wattsupwiththat, Monckton and others are not scientists, so with respect, I don’t give your’s or their opinions nearly as much weight as say Gavin Schmidt or Phil Jones. As well, the skeptical critcism seems all over the place, and some are inconclusive. Lindzen recently submitted and then withdrew a scientific paper he authored with Choi that was supposed to be a silver bullet because of very serious methodological challenges from climate alarmists and skeptics alike. The hypotheses about sun spots has yet to be proven, etc. As a layman, I’m forced to put my trust somewhere and I tell you, I don’t trust anyone at this point. I add to this the ‘asymmetric’ nature of the threat described by alarmists and, like everyone else, I would hate for us to be wrong in being skeptical. My question (and thanks for being patient) is, how do we resolve this conflict in opinion, given such serious impacts are at stake for acting, or potentially by not acting? I don’t think a ‘precautionary’ stance is adequate. We will either be responding insufficiently or unnecessarily if we pursue that course. What I can’t understand is why we can’t unify and resolve the science? I mean, if the holes you have found are valid, why haven’t scientific papers been submitted to prove your contentions resulting in a shift in the scientific communities point of view? It seems to me that we need to get definitive about the science here. How can we do that in a way that average guys like me and policy makers can trust?

    Thanks for the great work – it helps me understand much about this complex topic.

  16. Mike Aucott


    First off, let me start by saying that I earned a Ph.D. in environmental science at large cost to myself, including going to a lot of night school classes, so that I could understand scientific literature and learn enough to let me get into the nuts and bolts of some of these important issues. I believe I can read and understand the arguments pro and con pretty well.

    I agree with a couple points you make in Catastrophe Denied presentation, that a carbon tax is a much better approach than cap and trade, and that subsidizing ethanol production is a bad idea. If only we could agree on these points and move on.

    However, the rest of your presentation about the current state of the science on global warming doesn’t hold up to scrutiny, and contains many misinterpretations and statements that are virtually certainly wrong.

    The first 7 slides are OK. You agree with the basics. But, in my view, you start to veer off on slide 8, where you imply that because “CO2 has a diminishing effect as its ability to absorb radiation becomes saturated in certain frequency bands” that further increases aren’t of much concern. That it has a diminishing effect is well known. That’s why climate scientists talk of the effects of a doubling of CO2. A doubling of the pre-industrial level will very likely lead to 3 degrees C of warming, another doubling (which is a bigger absolute increase) would to lead to 6 degrees of warming, etc.

    Next you talk about how small an amount 385 ppm is. Yes. But small amounts can present big problems, for example if the small amount happens to be a poison. CO2 isn’t a poison, but it has a big effect on the radiative balance of the earth. You seem to be implying that CO2 couldn’t be a problem because it’s concentration is so tiny. This seems to be a misleading detour.

    Your discussion about positive and negative feedback and tipping points is good. But it seems to me you go awry after that. First of all, Gore was not at all talking about “feedbacks so high that they go to infinity” Feedbacks of the order of factors or two or three times the basic warming are what climate scientists are talking about insofar as CO2 is concerned. Some feedbacks are poorly understood, and are clearly positive, e.g. melting of arctic sea ice (an ice-free ocean is much darker and absorbs more radiation from the sun, leading to further warming). Climate models aren’t “built from the assumption” that there are tremendous positive feedbacks lurking out there. In fact, most of the climate models seem to have underestimated not only the temperature increase so far, but also sea level rise and the rate of arctic ice melt. The suspicion is that the models haven’t in fact done a very good job of accounting for non-linear positive feedbacks – i.e., things that kick in much more strongly than you’d predict from assuming a 1:1 relationship. Also, the understanding of the sensitivity of the climate to a doubling of CO2 relies more on the paleoclimate record than it does on models. Ice core data going back over 600,000 years now show that when CO2 has doubled, the temperature has gone up by about 3 degrees C. through several glacial cycles. Why should the earth behave any differently now?

    In slide #20 you claim that CO2 is a “very weak” greenhouse gas. You are correct that water vapor is stronger, and so is methane. (And so are exotic chemicals like sulfur hexaflouride). But this is not the point. It’s virtually certain that CO2 is the key driver of glacial and inter-glacial cycles, and earlier periods of warming and cooling. It seems to me that you are missing the point that the secondary effects that rising CO2 levels trigger are big, even though in the immediately previous slides you went through a discussion about secondary effects and positive feedback.

    In slides 24 through 32 you spend a lot of time trying to debunk the hockey stick graph, claiming that the ocean isn’t warming, the earth’s temperature has been “flat” for the past 10 or so years, etc. etc. You are just wrong about all of this. The leaked email thing is really irrelevant to the earth’s temperature record; it has been blown out of all proportion and doesn’t change any of the science or the data. The hockey stick graph, showing proxy temperatures going back 1200 years has been hashed and rehashed, and it is stronger than ever. For more info on this, see and

    Your information about the urban heat island effect is presented as if it’s something new. This is old hat. There definitely is an urban heat island effect. But it’s been thoroughly dismissed through numerous studies as being a significant factor in the measurement of the recent heating of the planet. The ocean chart you show is too short in terms of time. If it were longer it would clearly show the warming trend over the last 50 years. There are all sorts of fluctuations in the ocean and the atmosphere due to the chaotic effects of weather, but the long-term records of the ocean and that atmosphere and the earth, and glaciers, and time of snow melt, river thaw, changing ranges of species, and more all show the same picture. The earth is warming, virtually certainly more than at any time during the past 1200 years. 2009 was a cool summer for much of the U.S. But the U.S. represents 1.5% of the surface of the entire planet. Globally, 2009 was the second warmest year since thermometer-based records began to be kept in 1880. The last three years have seen more arctic ice melting than at any time since records started in 1979. See for some data on this. Sea level rise is in fact accelerating, and it’s probably the most robust measure of global warming.

    In slide 36, you make a point about the time lag between the onset of temperature rise and the increase of CO2. This is also old hat. Contrary to your assertion, it doesn’t present a causality problem. It’s widely accepted that wobbles in the earth’s orbit bring on the warming, because these changes expose northern hemisphere areas that are important to glaciation or the lack of it to more solar energy. When the earth starts to warm slightly due to these orbital changes, it causes CO2 to come out of solution in the oceans, and the CO2 then contributes to more warming, which then kicks in some of the other feedbacks (e.g. more water vapor, more methane, ice cap melting) which amplify the warming. You mention this at the end of your discussion on slide 36, but don’t connect the dots.

    There’s a lot more discussion up to and including slide 45 in which you talk about “upside down” data, etc. etc. It’s all trying to make the case that there’s no warming. It doesn’t fly. These critiques of the hockey stick chart, etc. have been gone over and over and found to be without merit. Again, see the web sites that discuss Michael Mann’s data, etc. noted above, and see the actual data on the warming from NASA or NOAA, e.g. website on the arctic above.

    I’m not sure where you are trying to go with slides 46 and 47. The chart in slide 47 is a good one. It shows that indeed, without human forcings (i.e. emissions of greenhouse gases and land use change such as deforestation in the tropics) the climate would have likely cooled over the last 50 years. With human forcings, the climate has warmed. In other words, only the emissions of greenhouse gases, etc. can explain the recent warming. Changes in the luminosity of the sun, volcanoes, and other natural happenings can’t explain it. In fact, the models nail the actual temperature record when they include all that they should. This is not the result of “tweaking”. I fear you do not get the implications of this. It means that there’s no other explanation for the recent warming. And it also means that the models are very likely correct in the projections, which are that the earth will warm considerably unless we drastically cut emissions of CO2 and other greenhouse gases soon.

    In slides 47 thru 51 there is more criticism of the models which seems to include some confusions. The flat period after WW II is actually quite well explained by the models as being due to aerosols from what was mostly uncontrolled coal combustion at the time, which released sulfates that exert a cooling effect. Also, there’s ample evidence that human emissions of greenhouse gases actually were quite significant as far back as the 1800s and earlier; in those earlier times it was probably mostly caused by methane from rice paddies, which expanded greatly as human population grew.

    In slide 52 you say it’s “frankly hilarious watching climate alarmists try to deny the sun has anything to do with climate variability.” You have evidently read very little of what has actually been written about this. It’s widely agreed that the sun has an effect. It’s been well-measured for the past 50 years or so. It’s not a big enough effect to account for more than a small fraction of the warming.

    In slides 53 to 55 you even get into the modeling act yourself with a combo of a “linear increase” that you attribute to “the rebound from the little ice age” and a sine wave factor that you hypothesize resembles ocean cycles. There’s no evidence offered why either of these factors are based on anything factual and therefore worthy of inclusion into a model, and this part of his presentation just seems silly.

    The next few slides are mostly rehashing things you’ve already said. Slide 59 however is interesting. Thanks for including references on this page (and throughout!) I was able to track down the Paltridge paper. It is interesting. But this humidity issue is not at all settled. As Paltridge himself notes, measuring humidity at altitude is not simple, and is potentially fraught with inaccuracies. Also, it should be pointed out that a drop in relative humidity by itself doesn’t mean that water doesn’t still exert a positive feedback effect. But such a drop might mean that the positive feedback isn’t as strong. Let’s hope that’s the case! But it would be unwise to count on it. Again, the paleoclimate data very strongly argues that the sensitivity to a doubling of CO2 is on the order of 3 degrees C, which means water almost certainly plays a role.

    Slide 60 again shows misunderstanding. It’s definitely true that methane seems to be leveling off. This is probably because sources of it, which include cows, rice paddies, landfills, are being better controlled and/or not increasing as fast as they once did, and methane has a short lifetime in the atmosphere, which means that its concentrations will stabilize because it will reach steady state. But this doesn’t negate methane as a contributor to positive feedback. The big positive feedback from methane that is worrisome wouldn’t kick in unless arctic permafrost starts to melt significantly or methane hydrates start to decompose. If the latter happens we’d see dramatically positive feedback.

    Slides from there up to 84 repeat and rehash previous incorrect statements about there being no warming, sea level not increasing, etc. You make a big deal about a prediction Hansen evidently made in 1988 that hasn’t materialized. Other predictions made around then predicting warming have pretty much come true. Take a look in James Lovelock’s book The Revenge of Gaia for a chart showing 1988 predictions by climate models. The warming we’ve seen so far is on the high side of many predictions of that time.

    I agree with you in slides 86 and 87! Carbon tax is a much better idea than cap and trade – as long as it is revenue neutral. I also agree with what you say about ethanol in slide 88! Subsidizing its production seems quite foolish.

    But we part company again with the rest of what you conclude. Sure, there are other environmental problems. But in my view, global warming is THE environmental issue we face if we want to see our grandchildren’s children have anything like the life we’ve enjoyed. The chief impacts of the warming for most people will probably be sea level rise and drying of the centers of the continents. Going back millions of years, the earth was much warmer than today during several periods. And the sea level was much higher, as much as 250 feet higher. It’s also clear from the geological record that sea level can change rapidly. It is easy to become very upset by these predictions, and I think that’s why some people are starting to argue so loudly that global warming cannot be. Denial is kicking into high gear.

    Thanks for reading through all of this. I hate to criticize anything that obviously represents a lot of sincere work. I just am virtually certain that you are off base on a lot of what you say. I recommend to you and anyone else who wants to better understand the current science on global warming a book that recently came out. It’s called The Long Thaw, by David Archer.


  17. toby

    No, I didn’t get it.

    I found the narration too fast for my comfort, so I looked at the pdf.

    Pretty much a rehash of discredited arguments. For example, the assertions that “there has been no warming for 15 years”. First of all, we know that 15 years is not long enough to capture a statistically significant trend at the rate it is increasing, however if you go back to about 1979, there is a statistically significant upward trend. When Professor Jones of UEA tried to explain this to the press, his words were “spun” to reverse his intended meaning (as if he said there was no global warming at all).

    On sea level rise go here to see that the rate of sea level has changed from 1.7mm/ yr to 3.32 mm/year. YOur presentation does not explain the more rapid recent rise, while AGW does.

    I could go on. The so-called urban heat effects (as you tired to demonstrate in Tucson) have been shown to be false.

    Like yourself, I am an amateur in climate science with a technical background (statistics). Unlike you, I think the professional climate scientists are doing a great job, as is Al Gore, in trying to prepare people to hear some very unpleasant news. I make it my business to explore every sceptic argument, and I find them all to be capably refuted.
    For example, at

    I also think the scientists have stepped upon a hornet’s nest of people who fear that the need to take collective action will upset the economic balance demanded by free market ideology. These people command far more media attention than climate scientists, so they are allowed may any kind of wild claims of fraud, conspriracy etc without challenge. Unfortunately, you are one of the gullible who have climbed on this bandwagon.

    I perfectly recognise your right to free speech and your own opinions. In the words of Cromwell “I beseech thee,think that you may be mistaken”. There is a lot hanging on it.

  18. Milo Wolff

    Understanding the Earth by calculating the “Carbon Cycle”.

    This calculation recognizes that all the energy for life on Earth
    comes from Sun energy that is processed, initially, by vegetable life
    forms. The Sun energy falls onto green leaves and algae that contain chlorophyll
    that converts CO2 in the atmosphere into carbohydrates during the day,
    and emits O2 during the night. This is the origin of the O2 and CO2
    that we breathe.
    Energy for animal life (including us) arises and grows from eating the
    carbohydrates of the leaves, fruit, the wood, and all vegetables of
    every kind. All these then die. Dead matter,vegetable or animal, decays
    and restores the CO2 of the atmosphere, completing the carbon cycle.
    It becomes obvious that CO2 is essential to life. Without CO2 we are
    all dead!
    This calculation can also show that the Solar energy input to all
    the various life forms (land and sea), far exceeds the energy of human
    activities and industry (hundreds of times).
    It demonstrates that billions of years ago, CO2 and H2O density were zero on an original dry barren Earth planet. The CO2 density then increased steadily along with N2, H20 and O2, making possible the growth of life on Earth
    over billions of years. The slow growth of CO2, – as well as H2O – an
    equally essential ingredient of life, parallels the formation of various life forms.
    This calculation makes it obvious that the current fads of “Global
    Warming”, “Evils of Carbon dioxide”, “Greenhouse emissions”, etc. are
    popular delusions and politics. See the famous book, published by Mackay
    150 years ago: “Popular Delusions and the Madness of Crowds”.
    History repeats itself.

    Contributed by; Milo.Wolff,MIT retired, APS member of 50 years.

  19. Edison

    I just finished watching the video and I really enjoyed it. I took AP Environmental Class in highschool, so we talked about “Global Warming” or “Climate Change”. I think I’ll be sending a link of this to my old teacher. Just one thing bothered me about the presentation, I feel increases in crop production can also be largely contributed to better farming practices, irrigation, crop rotation, fertilization. We can protect and grow our crops in places we couldn’t handle before. Otherwise I agree on most of the speaking points you made.

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