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"I take the hard view that science involves the creation of testable hypotheses" - Michael Crichton I'm not trying to be a troll. Really, I promise. But I real

by viggity 15y ago

"I take the hard view that science involves the creation of testable hypotheses" - Michael Crichton I'm not trying to be a troll. Really, I promise. But I really hope that the next field they do this in, is in Climate Science, specifically articles on climate change. It seems like bulk of their work is based on computer models and I just don't know how you're supposed to replicate any of that. How do you isolate the millions of variables to show cause and effect with a closed source computer model. That is my biggest problem with climate science.

roc 15y ago
> "It seems like bulk of their work is based on computer models" Then it seems that you are confused. Climate science is about gathering data, putting forth a testable hypothesis and seeing how future data fits the prediction. Yes, they use computer models. In the same way that you or I might gather data from a wind tunnel test and make a computer model of wind flow from that data to extrapolate a theory and create new testable hypotheses of a more-aerodynamic shape. But so long as new data is used to test those hypotheses, the use of a computer model is irrelevant. Science is being done. Testable hypotheses are being created and new data is being compared to those predictions. As long as we aren't running around half-cocked, believing the predictions of hypotheses that have not yet been tested, there's no concern. And the core hypotheses under the umbrella of Climate science have been tested. Some disproved by data, leading to changes in thinking, further research and new testable theories. Some supported by data. None of the 'alternate' hypotheses can say the same. (No, it's not the solar cycle. No, it's not distorted temperature readings from data stations in urban areas.) The very reason that there is a general consensus around the so called 'tent-pole' theories in Climate Science is precisely because they have been tested and have been shown to make accurate predictions and continue to do so. Some of them, for decades now.
- stfu 15y ago
  Somehow I find that thought uncomfortable that the complexity of factors impacting something as complex as climate is getting reduced to a wind tunnel test. One is a highly controlled scenario where all(most all) the externalities can be controlled. The other some extremely complex modeling, which will, at least in my view, always depend on some consensus among the participants which factors are more important than others. I am far from a climate change skeptic, but the best example for the fundamental failure of grasping complex scenario with some factor-based prediction systems has been demonstrated with the complete failure of economics in predicting something as "simple" as the financial crisis. But then again, I am coming from a social science perspective assuming that as soon as humans are involved data and data analysis will always be subjective.
  - trevelyan 15y ago
    You are not "far from a climate change skeptic". You are a climate change skeptic. At best, your post is the vague claim that complex systems cannot be modeled or tested empirically, and is empirically wrong in its claim that no-one predicted the financial crisis.
    - ThomBot 15y ago
      Based on the second claim of stfu’s post, “as soon as humans are involved data and data analysis will always be subjective”, I think he is really trying to highlight the unpredictability of a model that must generalize human choices using statistics. Since even conservative scientists will agree that climate change has some anthropogenic dimension, we should understand the limitations of modeling it. Being skeptical of the model, however, does not prohibit you from accepting what the model is suggesting. Historical data and scientific opinion can be enough to convince us that climate change is occurring. But no model can predict how our reaction to that knowledge will affect climate change in the future.
    - Produce 15y ago
      Call me a skeptic too in that case. Chaotic systems are inherently unpredictable to us, though they are ofcourse deterministic. The climate is chaotic (http://www.mendeley.com/research/nonlinearities-feedbacks-and-critical-thresholds-within-the-earths-climate-system/ http://www.mendeley.com/research/nonlinearities-feedbacks-an...). Chaotic systems have a horizon of predictability (http://www.britannica.com/EBchecked/media/3227/Sensitivity-of-a-chaotic-number-sequence-to-initial-value-illustrating http://www.britannica.com/EBchecked/media/3227/Sensitivity-o...), so climate models are still useful to an extent. They will tell us, with some degree of accuracy, roughly what will happen in the near future. The long term remains a mystery and there's little that can be done about that.
      - scarmig 15y ago
        It goes much too far to say that the climate is chaotic and therefore totally unpredictable in the long run. After all, if you buy that whole hog, you're also led to say that if you moved the Earth to Mercury's orbit it would be impossible to predict that the Earth would get hotter, in the long term. This results from the flaw of confusing weather (which is indeed chaotic) with statistics about weather (i.e. climate). A butterfly flapping its wings can cause a hurricane. But it can also prevent a hurricane. All those perturbations don't change the fact that, within an order of magnitude, we can predict how many hurricanes will occur in a given year. Alternatively, think about the classical three body problem: even though it's the preeminent example of a chaotic system, you can still make broad predictions about it. Center of mass, average speed of the bodies, average collision time. This isn't some obscure controversial field, either: in physics, these emergent statistical properties form the basis of statistical mechanics and therefore thermodynamics as a whole. Chaos doesn't mean you have to throw your hands up and give up on making any long term predictions at all about a system.
bjaress 15y ago
I think computer models just mean you do replication the other way around. Of course anyone who runs the same program gets the same results, so ordinary replication is pointless--instead you answer the same question with a totally different program and see if your answer is close. And then, of course, you wait and see if the predictions of the models come true. You can't reset the world and re-test it, but you can re-run the models and ask for more prediction in the future and wait some more. Climate scientists do both of those things all the time because they're in one of the most heavily scrutinized fields. Isolating variables just means you compare two setups with everything the same except one. That's actually one of the things the models are for. You can't re-run the world without humans, but you can re-run the model with humans turned off. Then someone else can do the same with their totally different model. And if both of your answers match reality with humans on and each other with humans off, well maybe the difference between humans on and humans off is the impact of humans. Or maybe not. But adding more different models helps. In short: climate science generates testable hypotheses, does replication, and isolates variables. It's possible they're wrong (and publishing source code is a good idea) but they don't have a methodology problem. And they're probably right. Also, Michael Crichton basically wrote Hollywood scripts in novel form. He's not a good source on anything.
- ArbitraryLimits 15y ago
  > Of course anyone who runs the same program gets the same results, so ordinary replication is pointless That would be true, if anyone actually distributed their actual code. Pick a journal article at random in any field that describes results from a computational model, and 99% of the paper will describe the results and not the model. The paper will never contain the complete code (which is fair enough, since it would be too long); 1 paper out of 100 will have excerpts of the code, and another 10/100 will have a URL that claims to have the code. If you actually follow that link, you'll find that 2-3 times out of 10 the code won't actually compile or run, and 9 times out of 10, the figures in the paper were generated by tweeking some parameters not defined in the paper whose particular values the author never recorded, and so even the author couldn't reproduce what he actually published, even if he wanted to. Some people are trying to make institutional change here, see http://www-stat.stanford.edu/~wavelab/Wavelab_850/wavelab.pdf http://www-stat.stanford.edu/~wavelab/Wavelab_850/wavelab.pd... But really it's a pretty sad state of affairs.
scarmig 15y ago
There's an interesting issue in climate science, and I say this as someone who thinks that dealing with climate change is probably the most important task of our generation. The (small subset of) professional statisticians I've spoken to are both similarly suspicious of climate models (not climate change itself), though for more technical reasons than you mention. At the same time, the physics dictate that the general sign and order of magnitude of CO2 forcing in climate models is correct, as surely as doubling solar output would increase mean surface temperatures. The physics also don't preclude the effects being even more severe than the models predict. But there's considerable uncertainty involved in both directions, and when people hear "well, things might end up better than scientists think is the average case, and at no cost to us!" they jump for that option and ignore the average prediction, let alone the worst case scenario that's within plausibility. Coupled with an extremely well-funded group of fossil fuel industrialists putting hundreds of millions of dollars into the outright shutting down of climate research, good scientists and especially not-at-all-scientific activists end up on the defensive, overemphasizing the finality of the models and using them as solid predictions instead of tools to vindicate the general thrust of the physics. As far as your particular point, think of the the models in climate journals as tools to understand the issue instead of the final word. It is somewhere between very difficult and impossible to come up with a climate model where CO2 forcing doesn't cause significant warming, but individual parts of those models need to be and often are tested. Indeed, those are the main points of dispute in the legitimate research and end up being thoroughly vetted.
- deleted 15y ago
  [deleted]
- dudeguy999 15y ago
  There are a billion dollars worth of research money for group-think infested alarmist journals for every million dollars available from the fossil fuels industry. Your life as a climate scientist is MUCH easier if you shut up and find a hockey stick than if you take Exxon funding.
  - danielharan 15y ago
    You have got to be fucking kidding. Scientists have billions, and Exxon has millions for this fight? Hell of an extraordinary claim. Got any proof?
MaysonL 15y ago
Go read James Hansen's 1981 predictions, and its match with current reality, and weep. Climate change is real, and is probably going to be disastrously significant in the lives of many now alive. http://www.theatlantic.com/technology/archive/2012/04/now-this-is-interesting-a-climate-prediction-from-1981/255658/ http://www.theatlantic.com/technology/archive/2012/04/now-th...
- nkurz 15y ago
  I think we see this graph very differently. I see a linear rise in measured temperature, and a prediction that shows an inflection point at the year 2000. If I were trying to match the actual to the prediction, without knowing the labels, I'd probably match it to 2c. This turns out to be the hypothetical coal phaseout in 2000. http://www.realclimate.org/index.php/archives/2012/04/evaluating-a-1981-temperature-projection/ http://www.realclimate.org/index.php/archives/2012/04/evalua... After looking for a bit, my questioning side kicks in: How did they choose the zero point for the overlay? Since it was published 1981, shouldn't the measured match up with the prediction until then? If not, why not? For that matter, what exactly is the overlay? Is the pink line a time smoothed average of the red or a pencil? Would it create a different impression if extended to 2012? In what way is a prediction that is 30% off a good prediction? Has it been long enough that we should have seen the change in slope? If anything it seems like it levels off. I don't think that I ask these questions because I'm a "climate skeptic", but because I'm "generally skeptical". If you tell me a graph tells me something, my first instinct is to doubt you, and then see if the evidence supports your position. This one feels more fuzzy to me than terrifying, and there are lots of things about the direction of the world that terrify me. What about it makes you weep more than the rest of the news?
  - MaysonL 15y ago
    I agree with you about the rest of the news. This (and the whole climate denial[not skepticism]) is just one more piece of ongoing tragedy, which is going to get quite a bit worse before it gets better (if it does).
guelo 15y ago
Climate science is much closer to the "hard sciences" than psychology, and thus much less prone to shenanigans.
lukifer 15y ago
As someone who accepts global warming (and is uncertain how much alarmism is warranted), I completely agree with you. The best way to debunk (or validate) the climate skeptics is to attack the theory as vigorously as possible, and to see whether is holds up or not. Of course, I still think in the meantime we should be building nuclear plants, investing in solar tech, etc, but there are many reasons to wean ourselves off of oil and coal rather than just climate change.
- AngrySkillzz 15y ago
  You are very right. Things like rising cancer rates, alarming increases in extinction, massive destruction of natural habitats, destabilization of entire ecosystems, etc. Some may attack anthropogenic climate change despite strong evidence, rightly or ignorantly, but it's an absurd (and tragically common) the degree to which actual environmental damage that is happening right now is ignored. Some of it is likely due to global warming, but there are a lot of other externalities that are really dangerous for our planet and even our species.

by viggity 15y ago

roc 15y ago

> "It seems like bulk of their work is based on computer models" Then it seems that you are confused. Climate science is about gathering data, putting forth a testable hypothesis and seeing how future data fits the prediction. Yes, they use computer models. In the same way that you or I might gather data from a wind tunnel test and make a computer model of wind flow from that data to extrapolate a theory and create new testable hypotheses of a more-aerodynamic shape. But so long as new data is used to test those hypotheses, the use of a computer model is irrelevant. Science is being done. Testable hypotheses are being created and new data is being compared to those predictions. As long as we aren't running around half-cocked, believing the predictions of hypotheses that have not yet been tested, there's no concern. And the core hypotheses under the umbrella of Climate science have been tested. Some disproved by data, leading to changes in thinking, further research and new testable theories. Some supported by data. None of the 'alternate' hypotheses can say the same. (No, it's not the solar cycle. No, it's not distorted temperature readings from data stations in urban areas.) The very reason that there is a general consensus around the so called 'tent-pole' theories in Climate Science is precisely because they have been tested and have been shown to make accurate predictions and continue to do so. Some of them, for decades now.

stfu 15y ago
Somehow I find that thought uncomfortable that the complexity of factors impacting something as complex as climate is getting reduced to a wind tunnel test. One is a highly controlled scenario where all(most all) the externalities can be controlled. The other some extremely complex modeling, which will, at least in my view, always depend on some consensus among the participants which factors are more important than others. I am far from a climate change skeptic, but the best example for the fundamental failure of grasping complex scenario with some factor-based prediction systems has been demonstrated with the complete failure of economics in predicting something as "simple" as the financial crisis. But then again, I am coming from a social science perspective assuming that as soon as humans are involved data and data analysis will always be subjective.
- trevelyan 15y ago
  You are not "far from a climate change skeptic". You are a climate change skeptic. At best, your post is the vague claim that complex systems cannot be modeled or tested empirically, and is empirically wrong in its claim that no-one predicted the financial crisis.
  - ThomBot 15y ago
    Based on the second claim of stfu’s post, “as soon as humans are involved data and data analysis will always be subjective”, I think he is really trying to highlight the unpredictability of a model that must generalize human choices using statistics. Since even conservative scientists will agree that climate change has some anthropogenic dimension, we should understand the limitations of modeling it. Being skeptical of the model, however, does not prohibit you from accepting what the model is suggesting. Historical data and scientific opinion can be enough to convince us that climate change is occurring. But no model can predict how our reaction to that knowledge will affect climate change in the future.
  - Produce 15y ago
    Call me a skeptic too in that case. Chaotic systems are inherently unpredictable to us, though they are ofcourse deterministic. The climate is chaotic (http://www.mendeley.com/research/nonlinearities-feedbacks-and-critical-thresholds-within-the-earths-climate-system/ http://www.mendeley.com/research/nonlinearities-feedbacks-an...). Chaotic systems have a horizon of predictability (http://www.britannica.com/EBchecked/media/3227/Sensitivity-of-a-chaotic-number-sequence-to-initial-value-illustrating http://www.britannica.com/EBchecked/media/3227/Sensitivity-o...), so climate models are still useful to an extent. They will tell us, with some degree of accuracy, roughly what will happen in the near future. The long term remains a mystery and there's little that can be done about that.
    - scarmig 15y ago
      It goes much too far to say that the climate is chaotic and therefore totally unpredictable in the long run. After all, if you buy that whole hog, you're also led to say that if you moved the Earth to Mercury's orbit it would be impossible to predict that the Earth would get hotter, in the long term. This results from the flaw of confusing weather (which is indeed chaotic) with statistics about weather (i.e. climate). A butterfly flapping its wings can cause a hurricane. But it can also prevent a hurricane. All those perturbations don't change the fact that, within an order of magnitude, we can predict how many hurricanes will occur in a given year. Alternatively, think about the classical three body problem: even though it's the preeminent example of a chaotic system, you can still make broad predictions about it. Center of mass, average speed of the bodies, average collision time. This isn't some obscure controversial field, either: in physics, these emergent statistical properties form the basis of statistical mechanics and therefore thermodynamics as a whole. Chaos doesn't mean you have to throw your hands up and give up on making any long term predictions at all about a system.

bjaress 15y ago

I think computer models just mean you do replication the other way around. Of course anyone who runs the same program gets the same results, so ordinary replication is pointless--instead you answer the same question with a totally different program and see if your answer is close. And then, of course, you wait and see if the predictions of the models come true. You can't reset the world and re-test it, but you can re-run the models and ask for more prediction in the future and wait some more. Climate scientists do both of those things all the time because they're in one of the most heavily scrutinized fields. Isolating variables just means you compare two setups with everything the same except one. That's actually one of the things the models are for. You can't re-run the world without humans, but you can re-run the model with humans turned off. Then someone else can do the same with their totally different model. And if both of your answers match reality with humans on and each other with humans off, well maybe the difference between humans on and humans off is the impact of humans. Or maybe not. But adding more different models helps. In short: climate science generates testable hypotheses, does replication, and isolates variables. It's possible they're wrong (and publishing source code is a good idea) but they don't have a methodology problem. And they're probably right. Also, Michael Crichton basically wrote Hollywood scripts in novel form. He's not a good source on anything.

ArbitraryLimits 15y ago
> Of course anyone who runs the same program gets the same results, so ordinary replication is pointless That would be true, if anyone actually distributed their actual code. Pick a journal article at random in any field that describes results from a computational model, and 99% of the paper will describe the results and not the model. The paper will never contain the complete code (which is fair enough, since it would be too long); 1 paper out of 100 will have excerpts of the code, and another 10/100 will have a URL that claims to have the code. If you actually follow that link, you'll find that 2-3 times out of 10 the code won't actually compile or run, and 9 times out of 10, the figures in the paper were generated by tweeking some parameters not defined in the paper whose particular values the author never recorded, and so even the author couldn't reproduce what he actually published, even if he wanted to. Some people are trying to make institutional change here, see http://www-stat.stanford.edu/~wavelab/Wavelab_850/wavelab.pdf http://www-stat.stanford.edu/~wavelab/Wavelab_850/wavelab.pd... But really it's a pretty sad state of affairs.

scarmig 15y ago

There's an interesting issue in climate science, and I say this as someone who thinks that dealing with climate change is probably the most important task of our generation. The (small subset of) professional statisticians I've spoken to are both similarly suspicious of climate models (not climate change itself), though for more technical reasons than you mention. At the same time, the physics dictate that the general sign and order of magnitude of CO2 forcing in climate models is correct, as surely as doubling solar output would increase mean surface temperatures. The physics also don't preclude the effects being even more severe than the models predict. But there's considerable uncertainty involved in both directions, and when people hear "well, things might end up better than scientists think is the average case, and at no cost to us!" they jump for that option and ignore the average prediction, let alone the worst case scenario that's within plausibility. Coupled with an extremely well-funded group of fossil fuel industrialists putting hundreds of millions of dollars into the outright shutting down of climate research, good scientists and especially not-at-all-scientific activists end up on the defensive, overemphasizing the finality of the models and using them as solid predictions instead of tools to vindicate the general thrust of the physics. As far as your particular point, think of the the models in climate journals as tools to understand the issue instead of the final word. It is somewhere between very difficult and impossible to come up with a climate model where CO2 forcing doesn't cause significant warming, but individual parts of those models need to be and often are tested. Indeed, those are the main points of dispute in the legitimate research and end up being thoroughly vetted.

deleted 15y ago
[deleted]
dudeguy999 15y ago
There are a billion dollars worth of research money for group-think infested alarmist journals for every million dollars available from the fossil fuels industry. Your life as a climate scientist is MUCH easier if you shut up and find a hockey stick than if you take Exxon funding.
- danielharan 15y ago
  You have got to be fucking kidding. Scientists have billions, and Exxon has millions for this fight? Hell of an extraordinary claim. Got any proof?

MaysonL 15y ago

Go read James Hansen's 1981 predictions, and its match with current reality, and weep. Climate change is real, and is probably going to be disastrously significant in the lives of many now alive. http://www.theatlantic.com/technology/archive/2012/04/now-this-is-interesting-a-climate-prediction-from-1981/255658/ http://www.theatlantic.com/technology/archive/2012/04/now-th...

nkurz 15y ago
I think we see this graph very differently. I see a linear rise in measured temperature, and a prediction that shows an inflection point at the year 2000. If I were trying to match the actual to the prediction, without knowing the labels, I'd probably match it to 2c. This turns out to be the hypothetical coal phaseout in 2000. http://www.realclimate.org/index.php/archives/2012/04/evaluating-a-1981-temperature-projection/ http://www.realclimate.org/index.php/archives/2012/04/evalua... After looking for a bit, my questioning side kicks in: How did they choose the zero point for the overlay? Since it was published 1981, shouldn't the measured match up with the prediction until then? If not, why not? For that matter, what exactly is the overlay? Is the pink line a time smoothed average of the red or a pencil? Would it create a different impression if extended to 2012? In what way is a prediction that is 30% off a good prediction? Has it been long enough that we should have seen the change in slope? If anything it seems like it levels off. I don't think that I ask these questions because I'm a "climate skeptic", but because I'm "generally skeptical". If you tell me a graph tells me something, my first instinct is to doubt you, and then see if the evidence supports your position. This one feels more fuzzy to me than terrifying, and there are lots of things about the direction of the world that terrify me. What about it makes you weep more than the rest of the news?
- MaysonL 15y ago
  I agree with you about the rest of the news. This (and the whole climate denial[not skepticism]) is just one more piece of ongoing tragedy, which is going to get quite a bit worse before it gets better (if it does).

guelo 15y ago

Climate science is much closer to the "hard sciences" than psychology, and thus much less prone to shenanigans.

lukifer 15y ago

As someone who accepts global warming (and is uncertain how much alarmism is warranted), I completely agree with you. The best way to debunk (or validate) the climate skeptics is to attack the theory as vigorously as possible, and to see whether is holds up or not. Of course, I still think in the meantime we should be building nuclear plants, investing in solar tech, etc, but there are many reasons to wean ourselves off of oil and coal rather than just climate change.

AngrySkillzz 15y ago
You are very right. Things like rising cancer rates, alarming increases in extinction, massive destruction of natural habitats, destabilization of entire ecosystems, etc. Some may attack anthropogenic climate change despite strong evidence, rightly or ignorantly, but it's an absurd (and tragically common) the degree to which actual environmental damage that is happening right now is ignored. Some of it is likely due to global warming, but there are a lot of other externalities that are really dangerous for our planet and even our species.