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This thread is relevant to my interests. On the subject of the "diamond" planet, I'm actually surprised to see the lead author of the paper in question referri

by hugh3 15y ago

This thread is relevant to my interests. On the subject of the "diamond" planet, I'm actually surprised to see the lead author of the paper in question referring to it as a "diamond planet". I thought that was just a media label. I read the paper when it came out, and all that was indicated was that an extremely large (Jupiter-mass) extremely dense (much smaller than Jupiter) body was detected orbiting a pulsar. The density was consistent with something reasonably close to diamond, but I would have thought that there always has to be some other elements in there... and in any case I wasn't convinced that the vast majority of the interior would be cool enough to be crystalline rather than liquid carbon. So while I'm very confident that there's some extremely massive, extremely dense planet orbiting that star, I'm yet to be one hundred percent convinced that "diamond" is the correct label for it. Which brings me neatly to the actual point of the article, on climate change. I'm somewhat out of my field here, but no more than the author is. The reason I'm skeptical about the hypothesis "burning fossil fuels is likely to cause significant and disastrous climate change in the future" is that it's all based on simulations which can't be tested against experiment. And I do simulations for a living, so I know enough about them to be very skeptical whenever confronted with simulations in the absence of experiment. Maybe it's true, and I wouldn't be surprised if it were, but I'm certainly not willing to talk about it as if it's as strongly supported as... well, the vast majority of other stuff that we mean when we talk about 'science'. The strength of a scientific theory is (and I'm still working on figuring out exactly how to phrase this) determined by the question of "If this turned out to be false, how much experimental data would suddenly be very difficult to explain?" If evolution were false, then pretty much all of biology is suddenly very difficult to explain. If the hypothesis "big dense planet thing orbiting PSR J1719−1438" turns out to be false, then there's a bunch of measurements which are very hard to explain. On the other hand if the hypothesis "diamond planet orbiting PSR J1719−1438" is false then it's not at all difficult to explain. And if the hypothesis of significant anthropogenic climate change turns out to be false, then this makes very little difference to our ability to explain existing experimental data.

pbreit 15y ago
I don't see how the man-mad warming camp can make-such-matter of fact assertions such as in http://daringfireball.net/linked/2011/09/07/krugman-shape-of-earth http://daringfireball.net/linked/2011/09/07/krugman-shape-of... when the evidence does not seem to be conclusive. It's even more alarming that the other side is belittled. Surely there must be something more compelling than "An Inconvenient Truth" on the matter?
- nl 15y ago
  http://www.skepticalscience.com/its-not-us-basic.htm http://www.skepticalscience.com/its-not-us-basic.htm is what you are after. See also http://www.skepticalscience.com/its-not-us-intermediate.htm http://www.skepticalscience.com/its-not-us-intermediate.htm and http://www.skepticalscience.com/its-not-us-advanced.htm http://www.skepticalscience.com/its-not-us-advanced.htm depending on the level of discussion you like. How do human CO2 emissions compare to natural CO2 emissions? http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions-intermediate.htm http://www.skepticalscience.com/human-co2-smaller-than-natur... is also related The whole site is rather good. You can pull up your objection and erad the discussion: http://www.skepticalscience.com/argument.php http://www.skepticalscience.com/argument.php
  - hartror 15y ago
    John Cook is my hero I've referenced his site in so many arguments with people on friend's facebook statuses[1]. [1] This is a hobby of mine, many friends of friends seem to work in the coal mining industry and therefore need the cognitive dissonance of climate change denial (not skepticism you will note, denial) in order to operate.
  - hugh3 15y ago
    That's a fairly good site, actually. However, when the position taken up by one side is "There is no room for skepticism about what my model predicts will happen in the future!" and the position taken up by the other side is "There is some room for skepticism about what that model says will happen in the future" then the no-skepticism side has already lost. If only these folks would phrase it as a balance-of-probabilities issue rather than an absolute-certainty issue then they'd have me on their side. But as it is, I'm forced to side with the skeptical side. Nothing could be worse for science than to try to make "skepticism" a dirty word.
    - epistasis 15y ago
      >"There is no room for skepticism about what my model predicts will happen in the future!" Can you show me an instance of someone espousing this position?
epistasis 15y ago
>The reason I'm skeptical about the hypothesis "burning fossil fuels is likely to cause significant and disastrous climate change in the future" is that it's all based on simulations which can't be tested against experiment I'm skeptical that this is your true reason. Many, if not most, fields of science are built in areas where it's hard to run a true physical simulation of the model. For example, take machine learning, where nearly every method is developed without novel collection of new data, but is run entirely on data that has previously been collected and been analyzed over and over again. If you run simulations, you should already know ways to test them without collecting new raw data, particularly if you have a large corpus of data from the real system. What's your true reason? Is it that you just think that humans can't impact the climate?
- hugh3 15y ago
  I'm skeptical that this is your true reason. What's your true reason? Is it that you just think that humans can't impact the climate? Feel free to correct me if I'm wrong, but please don't accuse me of lying about what I actually think.
  - epistasis 15y ago
    I don't think you're lying, but I do think that there's a different reason you are skeptical that is deeper and probably harder to express. "You can't rerun the climate" is a common enough sentiment, but when I hear that from technical people and probe them the same way, most will admit that it's not a logical reason to distrust scientific reasoning, and will come up with some other reason. Never tried it online though, so maybe I come across like too much of a jerk without vocal tones.
    - gavanwoolery 15y ago
      Skepticism is a good thing. Where would we be without it? The earth would still be flat. Why does he have to have some alternative motive for being skeptical? Skepticism is the basis of real science - trying to prove a hypothesis wrong to make sure that it is bullet proof. If it cannot be proven one way or the other, then it is not a fact, it is just a hypothesis.
ender7 15y ago
For one thing, the article is not suggesting that the climate change hypothesis is based on some random simulations that someone came up with (it's based on an incredibly rich amount of observational data, see final point below). He's talking about a hypothetical discovery, and he uses very careful words to describe it: "Let’s say we studied computer models of the influence of excessive greenhouse gases, verified them through observations, then had them peer-reviewed and published in Science." (my emphasis) Secondly, I don't find your counter-argument to climate change very convincing: - There is overwhelming evidence that the world is heating up dramatically and at an accelerating pace, whether or not you agree that the cause is man-made (cf. Gruber, http://daringfireball.net/linked/2011/09/07/krugman-shape-of-earth http://daringfireball.net/linked/2011/09/07/krugman-shape-of...). If it's due to some other cause, what is said cause? Why has no one suggested any credible alternative? - If you are of the "it's not us, it's something else" camp, this website does a great job laying out the reasons why so many scientists (~95%) believe that climate change is human-caused: http://www.skepticalscience.com/its-not-us-basic.htm http://www.skepticalscience.com/its-not-us-basic.htm (already linked somewhere in this thread).
- gavanwoolery 15y ago
  In science, a majority means very little. There have been many cases throughout history where one person was right and everyone else was wrong. The majority of people in China believe that eating shark fins prevents cancer - it does not mean they are right. I implore everybody to at least take a look at the arguments from the other side. Mind you, these are all very smart people, not just yahoos: http://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming http://en.wikipedia.org/wiki/List_of_scientists_opposing_the... Please, please, take at least a little bit of time to read some of their quotes. I'm not asking you to agree with me, I am asking you to form your own opinion on the matter.
  - bermanoid 15y ago
    In science, a majority means very little. There have been many cases throughout history where one person was right and everyone else was wrong. That is a plain old crap argument. Yes, there have been such cases, but they are far and away the exception rather than the rule. For every Einstein that was right when all of his peers were wrong, there are a thousand morons with websites that claim that Einstein was wrong, and they make plenty of noise and harass the hell out of scientists all over the place. The fact that Einstein's theories are now accepted is no reason to lend any more credibility to the "Einstein is wrong" theories, in fact, the ultimate acceptance of Einstein's theories is evidence that truth eventually wins out over fancy in science. For the most part, if you want to know what's true in a scientific field, you do accept the consensus opinion. There are brief periods where the consensus is wrong, but if there's actually enough evidence to prove it, these periods end rather quickly and the truth wins out. Scientists are not random people in China, they have actually spent their lives studying their fields, and truly care about finding truth. The bulk of a scientist's training is about methods of separating truth from fiction, and I would not be so quick to assume that people brought up with that ideal are willing to disregard it because - what? - it doesn't match their politics?
guelo 15y ago
So you admit that you're out of your field but then go on to opine about how the scientists that actually are in the field are doing something wrong, and denigrate the predictions they're making as "just simulations" without any experiments. According to you all those smart scientists working on climate change have never thought about the problem with computer models, have never run an experiment, have never thought about statistical confidence intervals for their predictions. I think you keep bringing up the nitpicky point about diamond to make this guy look dumb. But just like you can call out this guy on the diamond thing climate scientists call each other out in peer reviewed articles when they make weak assertions, that's the scientific method. Among the scientists that actually know what they're talking about a consensus has formed and they are trying to ring the alarm bell. It is dumb and arrogant to ignore them.
- gavanwoolery 15y ago
  I am a climate expert either, but I can easily identify a fallacy or bad experiment when I see one. I think hugh3 has written one of the most rational posts I have ever seen on HN. I think it is everybody else who is unclear on the scientific process. Being peer-reviewed DOES NOT constitute to the scientific process. Remember when every person and their peer believed that the earth was flat and it was the center of the universe? Guess what, it turns out popular assumptions are often wrong. Being peer-reviewed does very little when your peers are so eager to approve your work. The scientific process is as follows: 1. Ask a Question 2. Do Background Research 3. Construct a Hypothesis 4. Test Your Hypothesis by Doing an Experiment 5. Analyze Your Data and Draw a Conclusion <-- this is where people are messing up; insufficient data, jumping to conclusions, fallacies, etc. 6. Communicate Your Results
  - guelo 15y ago
    > I can easily identify a fallacy or bad experiment Please give an example of a bad experiment or logical fallacy by a climate scientist.
    - gavanwoolery 15y ago
demallien 15y ago
You seem a bit unclear about the scientific process as it applies to climate change. Firstly, here are the undisputable facts - facts that can be reproduced in a laboratory without relying on simulations. a) Sunlight bouncing off the Earth's surface is red-shifted. b) CO2 and other greenhouse gases absorb red light more than other forms of light, which they re-emit, often back towards the ground / lower atmosphere. c) The amount of greenhouse gases in our atmosphere are increasing, as directly measured d) this increase correlates with calculations associated with how much CO2 we are emittting through the burning of coal, oil and natural gas. Those are the facts. Looking at those facts, it seems pretty clear that the null hypothesis for climate change is that the temperature of the lower atmosphere should be increasing. We would expect the temperature to rise, unless there is some process that we don't know about that is affecting the numbers When we put the hypothesis to the test - is the temperature increasing? - we see that it is indeed increasing, which confirms the model. Now, about those simulations. Yes, they are not as reliable as the science I just when through above. We know that. But they all agree with the null hypothesis that the temperature will rise if we keep increasing the amount of CO2 in the atmosphere. If you want to throw that result into dispute, you need to show that there is some process going on that we didn't know about, and hence haven't been included in the models, or you need to show that the simulations themselves are actually wrong. What you can't do, if you want to be scientific about, is just state that you are skeptical about the simulations, and therefore we shouldn't act/create policy based on those simulations. I mean, sure, you can hold to that, but you have to admit that you are just being irrationally skeptical, and not scientific at all if that's the position you wish to hold.
- gavanwoolery 15y ago
  You seem a bit unclear about the scientific process as well. Take hugh3's example and throw out anthropogenic global warming. Do the facts still hold? The earth had dramatic warm and cool periods long before humans, and will continue to despite us. No one is questioning whether or not humans or CO2 have an impact - we all know that we do. The question is whether or not we have a SIGNIFICANT impact. That is, enough of an impact that we should actually give a damn, given we probably wont be using fossil fuels in 100 years anyway. If the case for anthropogenic global warming is so strong, why are scientists falsifying data like in ClimateGate? Much evidences suggests that we are headed into another "Little Ice Age" like in the 1700s. But few people talk about this for some reason.
alexdarlington 15y ago
I very much agree with your skepticism when it comes to believing the results of large scale simulations of complex systems. I personally think many people incorrectly transfer the certainty that we have of the underlying phenomena to the results of these complex simulations. No rational person disputes the direct effects that CO2 has on the absorption and re-emission of IR but once this is included into hugely complex simulations, I believe a very large degree of skepticism is warranted. However for almost exactly the same reasons I maintain some skepticism over the simulation results, I am personally very strongly in favor of minimizing man's impact on the environment. Precisely because it is a hugely complex system and I don't believe we can predict the effects of any changes we make to the environment. Depressingly, it seems that the chances of persuading America to really embrace a serious reduction in its CO2 emissions (especially if the Republicans get any more power) is extremely small. And even if America were on-board getting world-wide consensus would still be difficult in the extreme. It may very well be that the only option we have is deal with consequences of climate change as they arise. This will likely be more expensive than if we were investing in reducing our impact now but the way politics works the world over means that people are very reluctant to take short-term pain for long-term gain. And it should be remembered that even if the climate changes even faster than has been predicted, it will still be a gradual process, and countries will adapt to it the best way they can as and when it is required. By this I merely mean to dispel the idea that some people seem to have of utter catastrophe if action is not taken.
- lutorm 15y ago
  At its core, the CO2 argument is an energy balance argument and many of the details are unnecessary. To determine long-term, global temperature rise, you just need to know the energy in and energy out, which can be done in principle without knowing anything about climate. The problem is that some things that affect the radiation balance, chiefly changes in water vapor and clouds, are products of the local conditions, and it is to estimate the effects of those that you need simulations. The problem is that people seem to transfer their skepticism of the global climate simulations to the basic energy balance argument. Humans ARE affecting the climate, it's just that we may be affecting it in such a way that the net warming is hard to estimate because there are fairly large forcing terms that cancel.
wisty 15y ago
It's probably wrong to call climate scientists "scientists", just like it's wrong to call rocket scientists "scientists". They are probably more like engineers, but "engineer" is almost a protected title (except in software). No, they don't have a crystal ball. But just as nuclear weapons required a little forethought and co-ordination between nations, so does the ability to inflict colateral damage on the biosphere in a way that has never been done before. Unlike the last 5000 or so years of human history, we are making new and significant discoveries every year, and are able to roll them out across the whole world. The cost is we need to be a little cautious about them. Civilizations have collapsed before. New technology might be a factor - the ability to suddenly exploit a new resource can cause that a massive expansion, then a crash as the new resource becomes depleted. And more complex civilizations can be less able to survive a crash, as specialists are forced to become generalists in order to survive - doctors driving taxis or trapping gophers are much less productive. Sometimes scientists get worried for no good reason (Y2K?), and sometimes they have a good cause (radium), but there's no way to be sure. Not everyone should listen to all the doom and gloom (from reputable sources), but world leaders certainly should. And sadly, they only seem to listen when wide-eyed protestors shout slogans outside their offices. It's kind of depressing.
vacri 15y ago
<i>If evolution were false, then pretty much all of biology is suddenly very difficult to explain.</i> There are plenty of areas of biology that would survive evolution being 'cancelled'. Biology encompasses a lot more than heredity. Heredity is a very important section of biology, but you're moving the goalposts here - claiming biology is 'pretty much' totally dependent on evolution when it's not.
anigbrowl 15y ago
The reason I'm skeptical about the hypothesis "burning fossil fuels is likely to cause significant and disastrous climate change in the future" is that it's all based on simulations which can't be tested against experiment. There are also empirical observations - such as the facts that burning fossil fuels release measurable amounts of CO2, that CO2 behaves as a greenhouse gas, that CO2 content of the atmosphere observed over many years has been rising steadily, and that this correlates with the historical record of fuel consumption. Frankly I'm sick to the back teeth of 'let me explain what skepticism means' arguments. I've been interested in climate change for something like 15 years now, although I am not an activist of any kind. And all I ever hear from the 'skeptic' lobby is that they 'need more data,' but never any willingness to state what sort of confidence intervals they would find acceptable or why their models are any more reliable, or even any predictions of their own. About the climate that is. For some reason, almost all skeptics feel qualified to declare that climate mitigation efforts of any kind will be a huge economic disaster without presenting even the most rudimentary economic argument for why this should be so. This is how we end up with would-be presidential candidates who intone platitudes very similar to yours about falsifiability and standards of proof in between holding prayer meetings asking god to send more rain and revive the national spirit. And if the hypothesis of significant anthropogenic climate change turns out to be false, then this makes very little difference to our ability to explain existing experimental data. Fine, with so many alternatives it should be no trouble to make some clear and testable predictions that will blow the anthropogenic theory out of the water and settle the debate. We have plenty of satellites and observation platforms measuring solar output, cosmic rays and so on.

by hugh3 15y ago

pbreit 15y ago

I don't see how the man-mad warming camp can make-such-matter of fact assertions such as in http://daringfireball.net/linked/2011/09/07/krugman-shape-of-earth http://daringfireball.net/linked/2011/09/07/krugman-shape-of... when the evidence does not seem to be conclusive. It's even more alarming that the other side is belittled. Surely there must be something more compelling than "An Inconvenient Truth" on the matter?

nl 15y ago
http://www.skepticalscience.com/its-not-us-basic.htm http://www.skepticalscience.com/its-not-us-basic.htm is what you are after. See also http://www.skepticalscience.com/its-not-us-intermediate.htm http://www.skepticalscience.com/its-not-us-intermediate.htm and http://www.skepticalscience.com/its-not-us-advanced.htm http://www.skepticalscience.com/its-not-us-advanced.htm depending on the level of discussion you like. How do human CO2 emissions compare to natural CO2 emissions? http://www.skepticalscience.com/human-co2-smaller-than-natural-emissions-intermediate.htm http://www.skepticalscience.com/human-co2-smaller-than-natur... is also related The whole site is rather good. You can pull up your objection and erad the discussion: http://www.skepticalscience.com/argument.php http://www.skepticalscience.com/argument.php
- hartror 15y ago
  John Cook is my hero I've referenced his site in so many arguments with people on friend's facebook statuses[1]. [1] This is a hobby of mine, many friends of friends seem to work in the coal mining industry and therefore need the cognitive dissonance of climate change denial (not skepticism you will note, denial) in order to operate.
- hugh3 15y ago
  That's a fairly good site, actually. However, when the position taken up by one side is "There is no room for skepticism about what my model predicts will happen in the future!" and the position taken up by the other side is "There is some room for skepticism about what that model says will happen in the future" then the no-skepticism side has already lost. If only these folks would phrase it as a balance-of-probabilities issue rather than an absolute-certainty issue then they'd have me on their side. But as it is, I'm forced to side with the skeptical side. Nothing could be worse for science than to try to make "skepticism" a dirty word.
  - epistasis 15y ago
    >"There is no room for skepticism about what my model predicts will happen in the future!" Can you show me an instance of someone espousing this position?

epistasis 15y ago

>The reason I'm skeptical about the hypothesis "burning fossil fuels is likely to cause significant and disastrous climate change in the future" is that it's all based on simulations which can't be tested against experiment I'm skeptical that this is your true reason. Many, if not most, fields of science are built in areas where it's hard to run a true physical simulation of the model. For example, take machine learning, where nearly every method is developed without novel collection of new data, but is run entirely on data that has previously been collected and been analyzed over and over again. If you run simulations, you should already know ways to test them without collecting new raw data, particularly if you have a large corpus of data from the real system. What's your true reason? Is it that you just think that humans can't impact the climate?

hugh3 15y ago
I'm skeptical that this is your true reason. What's your true reason? Is it that you just think that humans can't impact the climate? Feel free to correct me if I'm wrong, but please don't accuse me of lying about what I actually think.
- epistasis 15y ago
  I don't think you're lying, but I do think that there's a different reason you are skeptical that is deeper and probably harder to express. "You can't rerun the climate" is a common enough sentiment, but when I hear that from technical people and probe them the same way, most will admit that it's not a logical reason to distrust scientific reasoning, and will come up with some other reason. Never tried it online though, so maybe I come across like too much of a jerk without vocal tones.
  - gavanwoolery 15y ago
    Skepticism is a good thing. Where would we be without it? The earth would still be flat. Why does he have to have some alternative motive for being skeptical? Skepticism is the basis of real science - trying to prove a hypothesis wrong to make sure that it is bullet proof. If it cannot be proven one way or the other, then it is not a fact, it is just a hypothesis.

ender7 15y ago

For one thing, the article is not suggesting that the climate change hypothesis is based on some random simulations that someone came up with (it's based on an incredibly rich amount of observational data, see final point below). He's talking about a hypothetical discovery, and he uses very careful words to describe it: "Let’s say we studied computer models of the influence of excessive greenhouse gases, verified them through observations, then had them peer-reviewed and published in Science." (my emphasis) Secondly, I don't find your counter-argument to climate change very convincing: - There is overwhelming evidence that the world is heating up dramatically and at an accelerating pace, whether or not you agree that the cause is man-made (cf. Gruber, http://daringfireball.net/linked/2011/09/07/krugman-shape-of-earth http://daringfireball.net/linked/2011/09/07/krugman-shape-of...). If it's due to some other cause, what is said cause? Why has no one suggested any credible alternative? - If you are of the "it's not us, it's something else" camp, this website does a great job laying out the reasons why so many scientists (~95%) believe that climate change is human-caused: http://www.skepticalscience.com/its-not-us-basic.htm http://www.skepticalscience.com/its-not-us-basic.htm (already linked somewhere in this thread).

gavanwoolery 15y ago
In science, a majority means very little. There have been many cases throughout history where one person was right and everyone else was wrong. The majority of people in China believe that eating shark fins prevents cancer - it does not mean they are right. I implore everybody to at least take a look at the arguments from the other side. Mind you, these are all very smart people, not just yahoos: http://en.wikipedia.org/wiki/List_of_scientists_opposing_the_mainstream_scientific_assessment_of_global_warming http://en.wikipedia.org/wiki/List_of_scientists_opposing_the... Please, please, take at least a little bit of time to read some of their quotes. I'm not asking you to agree with me, I am asking you to form your own opinion on the matter.
- bermanoid 15y ago
  In science, a majority means very little. There have been many cases throughout history where one person was right and everyone else was wrong. That is a plain old crap argument. Yes, there have been such cases, but they are far and away the exception rather than the rule. For every Einstein that was right when all of his peers were wrong, there are a thousand morons with websites that claim that Einstein was wrong, and they make plenty of noise and harass the hell out of scientists all over the place. The fact that Einstein's theories are now accepted is no reason to lend any more credibility to the "Einstein is wrong" theories, in fact, the ultimate acceptance of Einstein's theories is evidence that truth eventually wins out over fancy in science. For the most part, if you want to know what's true in a scientific field, you do accept the consensus opinion. There are brief periods where the consensus is wrong, but if there's actually enough evidence to prove it, these periods end rather quickly and the truth wins out. Scientists are not random people in China, they have actually spent their lives studying their fields, and truly care about finding truth. The bulk of a scientist's training is about methods of separating truth from fiction, and I would not be so quick to assume that people brought up with that ideal are willing to disregard it because - what? - it doesn't match their politics?

guelo 15y ago

So you admit that you're out of your field but then go on to opine about how the scientists that actually are in the field are doing something wrong, and denigrate the predictions they're making as "just simulations" without any experiments. According to you all those smart scientists working on climate change have never thought about the problem with computer models, have never run an experiment, have never thought about statistical confidence intervals for their predictions. I think you keep bringing up the nitpicky point about diamond to make this guy look dumb. But just like you can call out this guy on the diamond thing climate scientists call each other out in peer reviewed articles when they make weak assertions, that's the scientific method. Among the scientists that actually know what they're talking about a consensus has formed and they are trying to ring the alarm bell. It is dumb and arrogant to ignore them.

gavanwoolery 15y ago
I am a climate expert either, but I can easily identify a fallacy or bad experiment when I see one. I think hugh3 has written one of the most rational posts I have ever seen on HN. I think it is everybody else who is unclear on the scientific process. Being peer-reviewed DOES NOT constitute to the scientific process. Remember when every person and their peer believed that the earth was flat and it was the center of the universe? Guess what, it turns out popular assumptions are often wrong. Being peer-reviewed does very little when your peers are so eager to approve your work. The scientific process is as follows: 1. Ask a Question 2. Do Background Research 3. Construct a Hypothesis 4. Test Your Hypothesis by Doing an Experiment 5. Analyze Your Data and Draw a Conclusion <-- this is where people are messing up; insufficient data, jumping to conclusions, fallacies, etc. 6. Communicate Your Results
- guelo 15y ago
  > I can easily identify a fallacy or bad experiment Please give an example of a bad experiment or logical fallacy by a climate scientist.
  - gavanwoolery 15y ago

demallien 15y ago

You seem a bit unclear about the scientific process as it applies to climate change. Firstly, here are the undisputable facts - facts that can be reproduced in a laboratory without relying on simulations. a) Sunlight bouncing off the Earth's surface is red-shifted. b) CO2 and other greenhouse gases absorb red light more than other forms of light, which they re-emit, often back towards the ground / lower atmosphere. c) The amount of greenhouse gases in our atmosphere are increasing, as directly measured d) this increase correlates with calculations associated with how much CO2 we are emittting through the burning of coal, oil and natural gas. Those are the facts. Looking at those facts, it seems pretty clear that the null hypothesis for climate change is that the temperature of the lower atmosphere should be increasing. We would expect the temperature to rise, unless there is some process that we don't know about that is affecting the numbers When we put the hypothesis to the test - is the temperature increasing? - we see that it is indeed increasing, which confirms the model. Now, about those simulations. Yes, they are not as reliable as the science I just when through above. We know that. But they all agree with the null hypothesis that the temperature will rise if we keep increasing the amount of CO2 in the atmosphere. If you want to throw that result into dispute, you need to show that there is some process going on that we didn't know about, and hence haven't been included in the models, or you need to show that the simulations themselves are actually wrong. What you can't do, if you want to be scientific about, is just state that you are skeptical about the simulations, and therefore we shouldn't act/create policy based on those simulations. I mean, sure, you can hold to that, but you have to admit that you are just being irrationally skeptical, and not scientific at all if that's the position you wish to hold.

gavanwoolery 15y ago
You seem a bit unclear about the scientific process as well. Take hugh3's example and throw out anthropogenic global warming. Do the facts still hold? The earth had dramatic warm and cool periods long before humans, and will continue to despite us. No one is questioning whether or not humans or CO2 have an impact - we all know that we do. The question is whether or not we have a SIGNIFICANT impact. That is, enough of an impact that we should actually give a damn, given we probably wont be using fossil fuels in 100 years anyway. If the case for anthropogenic global warming is so strong, why are scientists falsifying data like in ClimateGate? Much evidences suggests that we are headed into another "Little Ice Age" like in the 1700s. But few people talk about this for some reason.

alexdarlington 15y ago

I very much agree with your skepticism when it comes to believing the results of large scale simulations of complex systems. I personally think many people incorrectly transfer the certainty that we have of the underlying phenomena to the results of these complex simulations. No rational person disputes the direct effects that CO2 has on the absorption and re-emission of IR but once this is included into hugely complex simulations, I believe a very large degree of skepticism is warranted. However for almost exactly the same reasons I maintain some skepticism over the simulation results, I am personally very strongly in favor of minimizing man's impact on the environment. Precisely because it is a hugely complex system and I don't believe we can predict the effects of any changes we make to the environment. Depressingly, it seems that the chances of persuading America to really embrace a serious reduction in its CO2 emissions (especially if the Republicans get any more power) is extremely small. And even if America were on-board getting world-wide consensus would still be difficult in the extreme. It may very well be that the only option we have is deal with consequences of climate change as they arise. This will likely be more expensive than if we were investing in reducing our impact now but the way politics works the world over means that people are very reluctant to take short-term pain for long-term gain. And it should be remembered that even if the climate changes even faster than has been predicted, it will still be a gradual process, and countries will adapt to it the best way they can as and when it is required. By this I merely mean to dispel the idea that some people seem to have of utter catastrophe if action is not taken.

lutorm 15y ago
At its core, the CO2 argument is an energy balance argument and many of the details are unnecessary. To determine long-term, global temperature rise, you just need to know the energy in and energy out, which can be done in principle without knowing anything about climate. The problem is that some things that affect the radiation balance, chiefly changes in water vapor and clouds, are products of the local conditions, and it is to estimate the effects of those that you need simulations. The problem is that people seem to transfer their skepticism of the global climate simulations to the basic energy balance argument. Humans ARE affecting the climate, it's just that we may be affecting it in such a way that the net warming is hard to estimate because there are fairly large forcing terms that cancel.

wisty 15y ago

It's probably wrong to call climate scientists "scientists", just like it's wrong to call rocket scientists "scientists". They are probably more like engineers, but "engineer" is almost a protected title (except in software). No, they don't have a crystal ball. But just as nuclear weapons required a little forethought and co-ordination between nations, so does the ability to inflict colateral damage on the biosphere in a way that has never been done before. Unlike the last 5000 or so years of human history, we are making new and significant discoveries every year, and are able to roll them out across the whole world. The cost is we need to be a little cautious about them. Civilizations have collapsed before. New technology might be a factor - the ability to suddenly exploit a new resource can cause that a massive expansion, then a crash as the new resource becomes depleted. And more complex civilizations can be less able to survive a crash, as specialists are forced to become generalists in order to survive - doctors driving taxis or trapping gophers are much less productive. Sometimes scientists get worried for no good reason (Y2K?), and sometimes they have a good cause (radium), but there's no way to be sure. Not everyone should listen to all the doom and gloom (from reputable sources), but world leaders certainly should. And sadly, they only seem to listen when wide-eyed protestors shout slogans outside their offices. It's kind of depressing.

vacri 15y ago

<i>If evolution were false, then pretty much all of biology is suddenly very difficult to explain.</i> There are plenty of areas of biology that would survive evolution being 'cancelled'. Biology encompasses a lot more than heredity. Heredity is a very important section of biology, but you're moving the goalposts here - claiming biology is 'pretty much' totally dependent on evolution when it's not.

anigbrowl 15y ago

The reason I'm skeptical about the hypothesis "burning fossil fuels is likely to cause significant and disastrous climate change in the future" is that it's all based on simulations which can't be tested against experiment. There are also empirical observations - such as the facts that burning fossil fuels release measurable amounts of CO2, that CO2 behaves as a greenhouse gas, that CO2 content of the atmosphere observed over many years has been rising steadily, and that this correlates with the historical record of fuel consumption. Frankly I'm sick to the back teeth of 'let me explain what skepticism means' arguments. I've been interested in climate change for something like 15 years now, although I am not an activist of any kind. And all I ever hear from the 'skeptic' lobby is that they 'need more data,' but never any willingness to state what sort of confidence intervals they would find acceptable or why their models are any more reliable, or even any predictions of their own. About the climate that is. For some reason, almost all skeptics feel qualified to declare that climate mitigation efforts of any kind will be a huge economic disaster without presenting even the most rudimentary economic argument for why this should be so. This is how we end up with would-be presidential candidates who intone platitudes very similar to yours about falsifiability and standards of proof in between holding prayer meetings asking god to send more rain and revive the national spirit. And if the hypothesis of significant anthropogenic climate change turns out to be false, then this makes very little difference to our ability to explain existing experimental data. Fine, with so many alternatives it should be no trouble to make some clear and testable predictions that will blow the anthropogenic theory out of the water and settle the debate. We have plenty of satellites and observation platforms measuring solar output, cosmic rays and so on.