The Dividing Line Between Nuisance and Catastrophe: Feedback

I have written for quite a while that the most important issue in evaluating catastrophic global warming forecasts is feedback.  Specifically, is the climate dominated by positive feedbacks, such that small CO2-induced changes in temperatures are multiplied many times, or even hit a tipping point where temperatures run away?  Or is the long-term stable system of climate more likely dominated by flat to negative feedback, as are most natural physical systems?  My view has always been that the earth will warm at most a degree for a doubling of CO2 over the next century, and may warm less if feedbacks turn out to be negative.

I am optimistic that this feedback issue may finally be seeing the light of day.  Here is Professor William Happer of Princeton in US Senate testimony:

There is little argument in the scientific community that a direct effect of doubling the CO2 concentration will be a small increase of the earth’s temperature — on the order of one degree. Additional increments of CO2 will cause relatively less direct warming because we already have so much CO2 in the atmosphere that it has blocked most of the infrared radiation that it can. It is like putting an additional ski hat on your head when you already have a nice warm one below it, but your are only wearing a windbreaker. To really get warmer, you need to add a warmer jacket. The IPCC thinks that this extra jacket is water vapor and clouds.

Since most of the greenhouse effect for the earth is due to water vapor and clouds, added CO2 must substantially increase water’s contribution to lead to the frightening scenarios that are bandied about. The buzz word here is that there is “positive feedback.” With each passing year, experimental observations further undermine the claim of a large positive feedback from water. In fact, observations suggest that the feedback is close to zero and may even be negative. That is, water vapor and clouds may actually diminish the already small global warming expected from CO2, not amplify it. The evidence here comes from satellite measurements of infrared radiation escaping from the earth into outer space, from measurements of sunlight reflected from clouds and from measurements of the temperature the earth’s surface or of the troposphere, the roughly 10 km thick layer of the atmosphere above the earth’s surface that is filled with churning air and clouds, heated from below at the earth’s surface, and cooled at the top by radiation into space.

When the IPCC gets to a forecast of 3-5C warming over the next century (in which CO2 concentrations are expected to roughly double), it is in two parts.  As professor Happer relates, only about 1C of this is directly from the first order effects of more Co2.  This assumption of 1C warming for a doubling of Co2 is relatively stable across both scientists and time, except that the IPCC actually reduced this number a bit between their 3rd and 4th reports.

They get from 1C to 3C-5C with feedback.  Here is how feedback works.

Lets say the world warms 1 degree.  Lets also assume that the only feedback is melting ice and albedo, and that for every degree of warming, the lower albedo from melted ice reflecting less sunlight back into space adds another 0.1 degree of warming.  But this 0.1 degree extra warming would in turn melt a bit more ice, which would result in 0.01 degree 3rd order warming.  So the warming from an initial 1 degree with such 10% feedback would be 1+0.1+0.01+0.001 …. etc.   This infinite series can be calculated as   dT * (1/(1-g))  where dT is the initial first order temperature change (in this case 1C) and g is the percentage that is fed back (in this case 10%).  So a 10% feedback results in a gain or multiplier of the initial temperature effect of 1.11 (more here).

So how do we get a multiplier of 3-5 in order to back into the IPCC forecasts?  Well, using our feedback formula backwards and solving for g, we get feedback percents of 67% for a 3 multiplier and 80% for a 5 multiplier.  These are VERY high feedbacks for any natural physical system short of nuclear fission, and this issue is the main (but by no means only) reason many of us are skeptical of catastrophic forecasts.

[By the way, to answer past criticisms, I know that the models do not use this simplistic feedback methodology in their algorithms.  But no matter how complex the details are modeled, the bottom line is that somewhere in the assumptions underlying these models, a feedback percent of 67-80% is implicit]

For those paying attention, there is no reason that feedback should apply in the future but not in the past.  Since the pre-industrial times, it is thought we have increased atmospheric Co2 by 43%.  So, we should have seen, in the past, 43% of the temperature rise from a doubling, or 43% of 3-5C, which is 1.3C-2.2C.  In fact, this underestimates what we should have seen historically since we just did a linear interpolation.  But Co2 to temperature is a logarithmic diminishing return relationship, meaning we should see faster warming with earlier increases than with later increases.  Never-the-less, despite heroic attempts to posit some offsetting cooling effect which is masking this warming, few people believe we have seen any such historic warming, and the measured warming is more like 0.6C.  And some of this is likely due to the fact that the solar activity was at a peak in the late 20th century, rather than just Co2.

I have a video discussing these topics in more depth:

This is the bait and switch of climate alarmism.  When pushed into the corner, they quickly yell “this is all settled science,”  when in fact the only part that is fairly well agreed upon is the 1C of first order warming from a doubling.  The majority of the warming, the amount that converts the forecast from nuisance to catastrophe, comes from feedback which is very poorly understood and not at all subject to any sort of consensus.

  • Hunter

    Reed Coray – it did look for a while like you were interested in science, but your point #8 is risible and pathetic and it now seems obvious that you have decided what you want to believe and will not let science trouble you. That was also hinted at by your quoting of the risible and patheric Chilingar paper, which undergraduates and even schoolchildren can easily spot the flaws in.

    But let’s ignore those, and just for the record talk about your other points. You seem to take Richard Courtney (someone who has never published a peer-reviewed climate-related paper) as a reliable source, and believe him when he says that temperatures now are the same as those in 1940. If you’d only check the data you could see that’s not true. For example, http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

    As for the connection between CO2 and warming, try eyeballing the two graphs here and see if you can’t spot it.

    You bring up the legendary tropical tropospheric hotspot. Firstly, it is a predicted response to any forcing, not just anthropogenic forcings, and secondly it is clearly detected.

    Your eight points:

    (1) atmospheric CO2 is NOT a pollutant–on the contrary, it is a blessing

    Largely a meaningless statement, as you don’t define your terms. How about you breathe pure carbon dioxide for a few minutes and then repeat this statement?

    (2) an increase in atmospheric CO2 will likely cause an increase in atmospheric temperature

    There’s no likely about it. It already has, and it will continue to do so.

    (3) man’s contribution to atmospheric CO2 levels is small compared to nature’s contribution

    No. 40% of the CO2 in the atmosphere today is there only because of human beings burning fossil fuels.

    (4) CO2-induced “feedback theories” that predict temperature increases by a factor of from 2 to 4 over what CO2 by itself would produce are at best problemantic and more likely nonsensical

    Feedbacks in the climate system are observational facts, not abstract theories.

    (5) the concept of “CO2-induced climate tipping points” is almost completely unfounded and is being used solely to promote “calls to immediate action”

    Sudden dramatic changes in the state of the climate system are the defining feature of the geological climate record.

    (6) some global warming (a few degrees centigrade) on balance will likely be beneficial to mankind

    A few degrees centigrade is pretty much the worst case scenario and would make our way of life unrecognisably different. A temperature rise of this magnitude has been linked to the severest mass extinction in the history of the planet at the end of the Permian period.

    (7) drastic cutbacks in fossil fuel energy production are likely to have a significant and detrimental impact to mankind

    Drastic cutbacks are inevitable; had you forgotten that fossil fuel reserves are finite?

    (8)

    Like I say, risible.

    “the scientific argument for AGW has three legs: (1) Over the past 400,000 years or so, the Vostok ice core data shows a good correlation between Antarctic atmospheric CO2 levels and Antarctic atmospheric temperatures; (2) the Mann Hockey Stick, which shows an abrupt upswing in temperature at about 1850–the time man’s use of fossil fuels took off; and (3) Global Circulation Models (GCMs) run on increasingly sophisticated computers”

    Quite wrong. The foundations for understanding that humanity is affecting the climate are two simple observations – first, the infrared absorption properties, and hence climate-affecting properties, of CO2, discovered 150 years ago by Tyndall, and second, the rising concentrations of CO2 due to human activity, discovered by Keeling about 50 years ago. As a consequence of these two observations, it is impossible that humankind is not affecting the climate.

    You should be ashamed of yourself for taking a view on something based only on the fact that somehow you’ve got the idea that ‘liberals’ are ‘pushing’ it. Admitting such a stance openly makes you look like a complete idiot.

  • Reed Coray

    Will

    I pretty much agree with what you say. As a physics student, it was drummed into my head that like football coaches, theories of how nature works fall into one of two categories: those that have been proven wrong, and those that are going to be. That statement (which is a theory in itself) may or may not be true, but it made sense to me in that I believe we will never stop learning about nature.

    The correlation between Antarctic atmospheric CO2 levels and Antarctic atmospheric temperatures as seen in the Vostok ice core data does exist; and yes, I also believe that many people (I’m one of them) are upset about the issue because of the way Al Gore misrepresented that data. It’s also true that the observation that I and others are upset is irrelevant to the technical argument. I do, however, think it’s a little strong to say “But that [CO2 has not been a driver of climate in the past] doesn’t necessarily say anything about the present.” Past behavior may not be proof of present behavior, but it is indicative.

    Dr. Jeffrey Glassman argues that the “under-appreciated solubility pump” (the millennium-long thermohaline circulation of sea water that moves CO2 from cold waters to warm waters) coupled with the Vostok temperature history can explain all of the observed CO2 behavior–(see “THE ACQUITTAL OF CARBON DIOXIDE”, URL: http://www.rocketscientistsjournal.com/2006/10/co2_acquittal.html). Specifically, he writes: “Throughout the past 420 millennia, comprising four interglacial periods, the Vostok record of atmospheric carbon dioxide concentration is imprinted with, and fully characterized by, the physics of the solubility of CO2 in water, along with the lag in the deep ocean circulation. Notwithstanding that carbon dioxide is a greenhouse gas, atmospheric carbon dioxide has neither caused nor amplified global temperature increases. Increased carbon dioxide has been an effect of global warming, not a cause. Technically, carbon dioxide is a lagging proxy for ocean temperatures. When global temperature, and along with it, ocean temperature rises, the physics of solubility causes atmospheric CO2 to increase. If increases in carbon dioxide, or any other greenhouse gas, could have in turn raised global temperatures, the positive feedback would have been catastrophic. While the conditions for such a catastrophe were present in the Vostok record from natural causes, the runaway event did not occur. Carbon dioxide does not accumulate in the atmosphere.”

    In his paper, Dr. Glassman plots CO2 concentration versus temperature. He notes that from the perspective of mathematics, the choice of which quantity (CO2 concentration, temperature) is the independent variable and which quantity is the dependent variable is arbitrary. However, from the perspective of physics, he argues that temperature is the independent variable because when temperature is treated as the independent variable, the physics of CO2 solubility in sea water can be used to explain the behavior of CO2 concentration; whereas when CO2 is treated as the independent variable, (a) the source of the CO2 is difficult to explain, and (b) the physics that explains the resulting temperature rise is weak. His arguments may not be proof that CO2 played a minor role in previous ice ages, but they sure tip the scales in that direction.

    Although I completely agree with you that “only time will tell” if there is any validity to GCMs, my money is on “not likely” or “very little”. ,-)

    Thank you

  • BillBodell

    Reed,

    I agree with Will.

    It’s really important to focus the debate.

    My suggestions are:

    Concede that the Earth has warmed over the last 100 years, that CO2 is (in large part) responsible and that the majority of the increase is due to human activity. Concede these points as early as possible in the debate. Although there may be quibbles, this is, indeed, the scientific consensus. Not stipulating these points will focus your entire opponent’s arguments on these. Don’t give him any easy points.

    Follow up by stating that, while past and future warming is likely, it’s the MAGNITUDE of warming that is in question. Note (as this site does), the relatively minor warming that has occurred over the last 100 years (0.6 C), despite a 43% increase in CO2.

    When dealing with the temperature trend since 1998, don’t claim that this means that there is no more AGW, just that this is an example of how natural fluctuations in climate can cancel out any increase due to AGW. Therefore, AGW is likely to result in only modest warming.

    The three pillars of AGW alarmism are:

    1) This is the warmest the world has been in 2,000 years. This can be effectively countered by reading http://www.ClimateAudit.org.

    2) It is warming now. Yes, but not by as much as anticipated. This has resulted in alarmists countering with sulfates and “lag-time”. It’s relatively straight forward to win points on these topics.

    3) Computer models tell us we’re going to fry. Until computer models can accurately predict the future, they aren’t anything but tools to assist in understanding climate. To see how well GCM’s are doing at predicting the future, check out http://rankexploits.com/musings/.

    Argue that we need to get a better handle on the degree of warming to be expected before committing billions of dollars to CO2 mitigation.

    Suggest that only scientific studies that have made their data and methods available and have been successfully replicated can be used for formulating public policy (that will remove about 98% of peer-reviewed climate studies from consideration).

    Urban Heat Island (UHI) effects probably account for up to half of past warming. Use this only when debating the magnitude of warming. See Ross McKitrick.

    Don’t mention ANY possible motives on the part of AGW alarmists. I pretty much agree with you, but it’s pointless. The science should be right or wrong independent of political motives. It might be interesting to study the motivations, but people’s motivations have nothing to do with whether AGW is real or not.

    Stay away from proposing other possible causes of GW. If you are trying to create doubt regarding AGW, suggesting other alternatives that have even less “consensus” behind them isn’t going to help your cause.

    Make the point that if CO2 needs to be restricted, that a carbon tax is better than “cap and trade”. A carbon tax is more effective and doesn’t allow the room for bureaucratic corruption, favor seeking and ineptitude.

    Energy independence may be a worthwhile goal, but policies to support this goal should be addressed on their own merits, not intertwined with AGW.

    Many skeptics here say it’s all about being “right”.

    I think it’s all about what the majority thinks is “right”. You may be “right”, but that’s not going to do much good if we allow the AG

  • BillBodell

    Reed,

    I agree with Will.

    It’s really important to focus the debate.

    My suggestions are:

    Concede that the Earth has warmed over the last 100 years, that CO2 is (in large part) responsible and that the majority of the increase is due to human activity. Concede these points as early as possible in the debate. Although there may be quibbles, this is, indeed, the scientific consensus. Not stipulating these points will focus your entire opponent’s arguments on these. Don’t give him any easy points.

    Follow up by stating that, while past and future warming is likely, it’s the MAGNITUDE of warming that is in question. Note (as this site does), the relatively minor warming that has occurred over the last 100 years (0.6 C), despite a 43% increase in CO2.

    When dealing with the temperature trend since 1998, don’t claim that this means that there is no more AGW, just that this is an example of how natural fluctuations in climate can cancel out any increase due to AGW. Therefore, AGW is likely to result in only modest warming.

    The three pillars of AGW alarmism are:

    1) This is the warmest the world has been in 2,000 years. This can be effectively countered by reading http://www.ClimateAudit.org.

    2) It is warming now. Yes, but not by as much as anticipated. This has resulted in alarmists countering with sulfates and “lag-time”. It’s relatively straight forward to win points on these topics.

    3) Computer models tell us we’re going to fry. Until computer models can accurately predict the future, they aren’t anything but tools to assist in understanding climate. To see how well GCM’s are doing at predicting the future, check out http://rankexploits.com/musings/.

    Argue that we need to get a better handle on the degree of warming to be expected before committing billions of dollars to CO2 mitigation.

    Suggest that only scientific studies that have made their data and methods available and have been successfully replicated can be used for formulating public policy (that will remove about 98% of peer-reviewed climate studies from consideration).

    Urban Heat Island (UHI) effects probably account for up to half of past warming. Use this only when debating the magnitude of warming. See Ross McKitrick.

    Don’t mention ANY possible motives on the part of AGW alarmists. I pretty much agree with you, but it’s pointless. The science should be right or wrong independent of political motives. It might be interesting to study the motivations, but people’s motivations have nothing to do with whether AGW is real or not.

    Stay away from proposing other possible causes of GW. If you are trying to create doubt regarding AGW, suggesting other alternatives that have even less “consensus” behind them isn’t going to help your cause.

    Make the point that if CO2 needs to be restricted, that a carbon tax is better than “cap and trade”. A carbon tax is more effective and doesn’t allow the room for bureaucratic corruption, favor seeking and ineptitude.

    Energy independence may be a worthwhile goal, but policies to support this goal should be addressed on their own merits, not intertwined with AGW.

    Many skeptics here say it’s all about being “right”.

    I think it’s all about what the majority thinks is “right”. You may be “right”, but that’s not going to do much good if we allow the AGW alarmists to trash the world economy.

  • Hunter

    This will be a post in several parts…

    Reed Coray – it did look for a while like you were interested in science, but your point #8 is risible and pathetic and it now seems obvious that you have decided what you want to believe and will not let science trouble you. That was also hinted at by your quoting of the risible and pathetic Chilingar paper, which undergraduates and even schoolchildren can easily spot the flaws in.

    But let’s ignore those, and just for the record talk about your other points. You seem to take Richard Courtney (someone who has never published a peer-reviewed climate-related paper) as a reliable source, and believe him when he says that temperatures now are the same as those in 1940. If you’d only check the data you could see that’s not true. For example, http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

    As for the connection between CO2 and warming, try eyeballing the two graphs here and see if you can’t spot it.

  • Hunter

    You bring up the legendary tropical tropospheric hotspot. Firstly, it is a predicted response to any forcing, not just anthropogenic forcings, and secondly it
    is clearly detected.

    Your eight points:

    (1) atmospheric CO2 is NOT a pollutant–on the contrary, it is a blessing

    Largely a meaningless statement, as you don’t define your terms. How about you breathe pure carbon dioxide for a few minutes and then repeat this statement?

    (2) an increase in atmospheric CO2 will likely cause an increase in atmospheric
    temperature

    There’s no likely about it. It already has, and it will continue to do so.

    (3) man’s contribution to atmospheric CO2 levels is small compared to nature’s contribution

    No. 40% of the CO2 in the atmosphere today is there only because of human beings burning fossil fuels.

    (4) CO2-induced “feedback theories” that predict temperature increases by a factor of from 2 to 4 over what CO2 by itself would produce are at best problemantic and more likely nonsensical

    Feedbacks in the climate system are observational facts, not abstract theories.

  • Hunter

    (5) the concept of “CO2-induced climate tipping points” is almost completely unfounded and is being used solely to promote “calls to immediate action”

    Sudden dramatic changes in the state of the climate system are the defining feature of the geological climate record.

    (6) some global warming (a few degrees centigrade) on balance will likely be beneficial to mankind

    A few degrees centigrade is pretty much the worst case scenario and would make our way of life unrecognisably different. A temperature rise of this magnitude has been linked to the severest mass extinction in the history of the planet at the end of the Permian period.

    (7) drastic cutbacks in fossil fuel energy production are likely to have a significant and detrimental impact to mankind

    Drastic cutbacks are inevitable; had you forgotten that fossil fuel reserves are finite?

    (8)

    Like I say, risible.

  • Hunter

    “the scientific argument for AGW has three legs: (1) Over the past 400,000 years or so, the Vostok ice core data shows a good correlation between Antarctic atmospheric CO2 levels and Antarctic atmospheric temperatures; (2) the Mann Hockey Stick, which shows an abrupt upswing in temperature at about 1850–the time man’s use of fossil fuels took off; and (3) Global Circulation Models (GCMs) run on increasingly sophisticated computers”

    Quite wrong. The foundations for understanding that humanity is affecting the climate are two simple observations – first, the infrared absorption properties, and hence climate-affecting properties, of CO2, discovered 150 years ago by Tyndall, and second, the rising concentrations of CO2 due to human activity, discovered by Keeling about 50 years ago. As a consequence of these two observations, it is impossible that humankind is not affecting the climate.

    You should be ashamed of yourself for taking a view on something based only on the fact that somehow you’ve got the idea that ‘liberals’ are ‘pushing’ it. Admitting such a stance openly makes you look like a complete idiot.

  • hunter

    And here’s the first part of my post that didn’t appear before:

    Reed Coray – it did look for a while like you were interested in science, but your point #8 is risible and pathetic and it now seems obvious that you have decided what you want to believe and will not let science trouble you. That was also hinted at by your quoting of the risible and patheric Chilingar paper, which undergraduates and even schoolchildren can easily spot the flaws in.

    But let’s ignore those, and just for the record talk about your other points. You seem to take Richard Courtney (someone who has never published a peer-reviewed climate-related paper) as a reliable source, and believe him when he says that temperatures now are the same as those in 1940. If you’d only check the data you could see that’s not true. For example, http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

  • Hunter

    As for the connection between CO2 and warming, try eyeballing the two graphs here and see if you can’t spot it.

  • Reed Coray

    Hunter (various above). I call my statement regarding “liberals” and “pushing it” truth in advertising in that those are my beliefs; and as foreign as this may sound to someone who doesn’t “belong to any camp”, in my interchange with Will Nitschke, I wanted to let him know where I was coming from. Finally, since you’ve resorted to name calling (a trait common to pro-AGW bloggers), I guess we’ll have to terminate our discussion without my getting an answer to that most perplexing question: How did someone with your intelligence stoop to conversing with a “complete idiot”? Ah, the mysteries of the universe.

  • Hunter

    Well, Reed Coray, if at any point you decide to start from evidence to develop an opinion, rather than deciding what you think and then working backwards to decide what evidence to believe, you’ll find what I’ve posted here useful.

  • “Alarmist Hunter” – can’t even think of your own comments and now have to repeat mine like a 12 year old?

    How about using your real name, and not pretend to be someone else? What about the “missing heat” problem you declared was “paranoid” and something I was making up. Anyone can just google “missing heat” to see how full of shit you are. 🙂

    And weren’t you the guy who accused people of being paedophiles because they disagreed with your point of view?

    Sure, there are climate cranks everywhere on the net, but you are a fine example of an extreme lunatic so typical of the other side of the debate.

  • Hi Reed,

    Sorry for interruption while I was addressing the troll…

    “I do, however, think it’s a little strong to say “But that [CO2 has not been a driver of climate in the past] doesn’t necessarily say anything about the present.” Past behavior may not be proof of present behavior, but it is indicative.”

    I’m just framing the counter-argument here. Not necessarily saying I agree with it…

    “Notwithstanding that carbon dioxide is a greenhouse gas, atmospheric carbon dioxide has neither caused nor amplified global temperature increases. Increased carbon dioxide has been an effect of global warming, not a cause. Technically, carbon dioxide is a lagging proxy for ocean temperatures. When global temperature, and along with it, ocean temperature rises, the physics of solubility causes atmospheric CO2 to increase.”

    I don’t think anyone (sceptic or believer) is disputing the general gist of what you’ve quoted above, although there is always room to quibble over the exact details.

    “If increases in carbon dioxide, or any other greenhouse gas, could have in turn raised global temperatures, the positive feedback would have been catastrophic. While the conditions for such a catastrophe were present in the Vostok record from natural causes, the runaway event did not occur. Carbon dioxide does not accumulate in the atmosphere.”

    I think this criticism is addressing perhaps some of the theories of James Hansen–tipping points and stuff. It might be worth observing here that is probably a position held by a fringe group in the AGW camp. I don’t see much mention of imminent tipping points leading to global catastrophe in the IPCC reports. Although that scenario is not entirely outside of their range of possibilities. Some climate models do predict this behaviour (the ones doing worst against empirical observations at the moment) and the IPCC has forecast up to 6C in the worst case over the next 100 years. Given the last decade of static temperatures and ever accelerating CO2 ppm in the atmosphere, we can probably rule those extreme scenarios out as even remotely likely, even with the data we have now.

    I think in a nutshell nobody is arguing that *something* causes warming (i.e., orbital change), which releases CO2 from the atmosphere. This is why temperature change and CO2 correlate well. Based on accepted physical principles, the extra CO2 should contribute to at least a small amount of additional warming. A “feedback loop.”. Again, no one except the nutcases at either end of the debate dispute this. What is not understood is how powerful this feedback loop is. The science behind understanding it is very sketchy and controversial at present. I don’t seem much evidence for alarm just yet. We probably need another 10 years of global temperature data in order to nail this one down further, and at least rule out if there is any possibility of it being harmless, costly and inconvenient, or dangerous.

  • Reed Coray

    Will Nitschke (12 march 2009, 7:52 pm). Based on our discussion to date, I am of the opinion that although we probably don’t agree on everything, basically you and I think alike. I appreciate your comments. Finally, I have to admit you were right when you said my mentioning “a one-world government” would be a negative. It was.

    Thank you

  • Hunter

    Ah, Will Nitschke, once you’ve got an idea into your tiny mind it’s very hard to dislodge it, isn’t it? Anyone who thinks googling gives definitive answers to science questions has shit for brains. You demonstrate here again and again that you’ve got shit for brains.

  • rickM

    I don’t like using wikipedia as a citation, but deep ocean circulation is very slow, and is not a player as portrayed by many.

    http://en.wikipedia.org/wiki/Thermohaline_circulation and http://www.atmosphere.mpg.de/enid/1vc.html

    Placing your faith in climate models is misplaced faith. Our unerstanding is paper thin.

    I do appreciate the civil tone and dispassionate debate in some of the comments posted here. They would never be allowed in RC, do nothing to shape anyone’s opinion on the issue except casue a hardening of them. Bravo, bravo…

  • Reed,

    Yeah, there is the “political” debate which is primarily a propaganda war between people of different temperaments and then there is the “scientific” debate, which I find somewhat more disturbing because you see academics who should know better, cherry picking data to support a viewpoint in a very self interested way right now. There is a lot of potential to do damage to the credibility of science in the minds of the public. I hope that doesn’t happen. Of course, there are conspiracy theory cranks and AGW loonies, such as the kid above pretending to be “Hunter”, who just make repeated fools of themselves and can only be laughed at. But they are marginal to the debate at best.

  • Ben

    Just a note for the author… The link to Prof. Happer’s Senate testimony actually takes you to an e-magazine or something. Wouldn’t it be better to link directly to the source on the Senate’s website?

    http://epw.senate.gov/public/index.cfm?FuseAction=Files.View&FileStore_id=84462e2d-6bff-4983-a574-31f5ae8e8a42

  • Stevo

    “Historically, the earth’s climate ranges between much too cold (ice ages), and a little too cold (interglacials). Warmer is better.”

    That’s an interesting claim, Alec Rawls. So you’re saying that human beings have evolved to be suited to a climate they’ve never actually experienced. How did they do that, exactly?