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ever since I read this article titled "Clouds May Be the Key to a Climate Modeling Mystery"[0], I've come to understand that all climate models are basically us

ever since I read this article titled "Clouds May Be the Key to a Climate Modeling Mystery"[0], I've come to understand that all climate models are basically useless for predicting anything. anyone who claims such-and-such will happen as a result of climate change, because a model said so, is speaking nonsense. the planet is massive and its climate is an infinitely fractally complex system. if we can't even model clouds with anything remotely resembling accuracy, then why do we put any stock in predictive climate models at all? basically everyone agrees that the climate is changing, has always changed, and will always change. there is debate over how much of climate change is anthropogenic, but this is irrelevant to the point that predictive climate models are functionally useless, due to the complexity of the thing it's modeling. [0] https://www.scientificamerican.com/article/clouds-may-be-the-key-to-a-climate-modeling-mystery/ https://www.scientificamerican.com/article/clouds-may-be-the... downvoters: I would appreciate an explanation as to how my understanding of this situation is inaccurate. my views are never set in stone, I'm always open to learn new things. I just don't see how, short of a complete holistic Matrix-style simulation of the planet, one can obtain meaningful predictions from a data-driven climate model. I'm wrong about a lot of stuff all the time and I'd like to know where my understanding of this situation is incomplete or inaccurate.

vegetablepotpie 5y ago
> climate models are basically useless for predicting anything That is false. Although you’re correct that climate is very complex and it is impossible to model every detail. The notion that you cannot make valid conclusions from modeling because a set of observations do not match models is fallacious because it discounts the correct conclusions that climate models have achieved. For example, the first climate models from the 1960s predicted that the mesosphere will contract and cool as a result of increasing co2 concentrations, and this conclusion has been backed by empirical observations. Furthermore, modeling from the 1970s by scientists at Exxon Mobile found that by 2020, net warming would reach an average of 1 degree centigrade, which we’ve since exceeded.
- adamrezich 5y ago
  how is this different than a broken clock being correct twice a day? by this I mean to say, just because some predictions made using some models turned out to be correct, why does this validate those or all climate models as accurate predictors of the future? the system is so complex, poorly-understood, infinitely fractal, with endless variables depending upon each other in ways that we mostly don't understand... the models are so varied, based on different data sources, some omitting entire classes of data entirely... I would be more surprised if some predictions some models made didn't end up being true after several years. but that doesn't mean they're useful at predicting things going forward, by any means.
  - vegetablepotpie 5y ago
    It’s not the results that make models valid/invalid. It’s how well the model approximates the underlying processes that lead to the results, which make it valid. A clock that is stuck is a poor model of time because it does not model the progression of time, even though it is still correct twice a day. We can make a very simplistic climate model that would be valid. We have a sphere of radius 6,357km, which is illuminated by electro-magnetic radiation centered at wavelengths of 0.6um. When the light hits the surface, it is absorbed and is re-emitted as black body radiation with a wavelength centered at 10um. It has an atmosphere, which contains a gas, which blocks the escape of wavelengths at 4um and 15um. This reflects some of the black body radiation back to the sphere, causing it to warm. In 2009 for the earth, this lead to a net accumulation of 0.6 W/m^2 of energy absorption [1]. If accumulated over the entire area of the sphere and accumulated over time, this would lead to an increase in temperature. Although the model does not take into account land formations, ocean currents, air currents, seasons, etc, it still models the underlying process of the earth’s energy balance and can answer the question of whether the planet will warm and can provide estimates at how quickly this will occur. I think you’re hinting at systems being so complex that they can vary based on minute changes in initial conditions, you’d be correct to say that climate is chaotic. Not all chaotic systems are the same though. A double pendulum will swing in eccentric motions, but if you look at something like the stock market, there’s a lot of short term variability with long term certainty. I cannot tell you what my stocks will do next week. But markets generally converge on a doubling of money in 10 years. In fact that’s reliable enough that I’m willing to have a 401k. With the pendulum, I can tell you with a lot of certainty that if it’s damped, it will settle to its lowest energy state and stay there permanently. A climate model will not predict the weather. But in the same way that I can tell you that winter will be cold, I can also tell you that Arctic amplification and Hadley cell expansion will lead to very different weather patterns that civilization has not seen before, such as much more extreme swings in temperature and weather. [1] https://en.m.wikipedia.org/wiki/Earth's_energy_budget#/media/File%3AThe-NASA-Earth's-Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg https://en.m.wikipedia.org/wiki/Earth's_energy_budget#/media...
ximeng 5y ago
Based on reading an article about detailed work on making a model more accurate you’ve concluded that models are useless? Just because models aren’t infinitely perfect doesn’t mean they don’t have some predictive power. Yes you might drop a ball and it gets destroyed by a nuclear explosion before hitting the floor but it doesn’t mean a model that says it will likely hit the floor is useless! At large scale climate change isn’t that complicated - sun hits earth, heats it up, some energy escapes. We can get a pretty good picture from models and the details just add to that.
- adamrezich 5y ago
  > Based on reading an article about detailed work on making a model more accurate you’ve concluded that models are useless? no—I, knowing basically nothing about climate science and having been taught to more or less blindly trust climate models as accurate predictors of the future, read an article that said we have no idea how to model clouds with anything resembling accuracy, because clouds by themselves are crazy complex things. this led me to realize that this should have been intuitive knowledge without even reading the article, which led me to truly consider the scope of the climate system w.r.t. how it could possibly be modeled by computers, which led me to realize that the idea that it's possible for a data-driven computer model to predict anything about the future with any kind of reliability is pretty silly to begin with.
  - ximeng 5y ago
    This just seems like a ridiculous position to hold: data-driven computer models can’t predict anything with any reliability?! Pretty much all predictions about the future rely on data-driven models! Yes models are not perfect, but the answer’s not to close your eyes and hope!
  - lukifer 5y ago
    The right way to think about models at this scale is complexity isn't "Accurate" vs. "Inaccurate"; it's to use probabilistic/Bayesian reasoning. No map is a perfect representation of the territory, and no model can encapsulate the entirety of the earth. That doesn't mean maps and models are useless. A couple counterpoints from former climate skeptics: - Richard Mueller is a prominent physicist who founded an institute to debunk anthropogenic climate change, only to change his mind after thorough examination of the data. https://youtu.be/Sme8WQ4Wb5w https://youtu.be/Sme8WQ4Wb5w - Jerry Taylor is a libertarian and former climate debunker for the Cato Institute; a noteworthy pivot moment was speaking to a risk analyst for a financial institution, whose job it is to make bets on complex systemic risks in the context of uncertainty. He claimed that from a financial lens, AGW was a slam-dunk case for mitigation, not because of the certainty of any one model, but of the full probability distribution in aggregate. https://www.reckonings.show/episodes/17 https://www.reckonings.show/episodes/17
moistly 5y ago
> I've come to understand that all climate models are basically useless for predicting anything I am under the impression that the worst-case scenarios in most models have pretty much all come to pass, often earlier than expected. Seems to me that they’ve been very predictive. It would have been nice had the media more accurately delivered those predictions; perhaps it would have prompted some early action.
- adamrezich 5y ago
  "most models"???
  - moistly 5y ago
    Yes, most models plotted a range of outcomes over time, depending on how much we reined in CO2 production. Our current CO2 levels, ocean temperature & acidity, glacier melt, and global temperature are in excess of all “good case” predictions. We failed to rein in CO2 production and now we’re pretty much living the worst-case scenarios… as predicted.

vegetablepotpie 5y ago

> climate models are basically useless for predicting anything That is false. Although you’re correct that climate is very complex and it is impossible to model every detail. The notion that you cannot make valid conclusions from modeling because a set of observations do not match models is fallacious because it discounts the correct conclusions that climate models have achieved. For example, the first climate models from the 1960s predicted that the mesosphere will contract and cool as a result of increasing co2 concentrations, and this conclusion has been backed by empirical observations. Furthermore, modeling from the 1970s by scientists at Exxon Mobile found that by 2020, net warming would reach an average of 1 degree centigrade, which we’ve since exceeded.

adamrezich 5y ago
how is this different than a broken clock being correct twice a day? by this I mean to say, just because some predictions made using some models turned out to be correct, why does this validate those or all climate models as accurate predictors of the future? the system is so complex, poorly-understood, infinitely fractal, with endless variables depending upon each other in ways that we mostly don't understand... the models are so varied, based on different data sources, some omitting entire classes of data entirely... I would be more surprised if some predictions some models made didn't end up being true after several years. but that doesn't mean they're useful at predicting things going forward, by any means.
- vegetablepotpie 5y ago
  It’s not the results that make models valid/invalid. It’s how well the model approximates the underlying processes that lead to the results, which make it valid. A clock that is stuck is a poor model of time because it does not model the progression of time, even though it is still correct twice a day. We can make a very simplistic climate model that would be valid. We have a sphere of radius 6,357km, which is illuminated by electro-magnetic radiation centered at wavelengths of 0.6um. When the light hits the surface, it is absorbed and is re-emitted as black body radiation with a wavelength centered at 10um. It has an atmosphere, which contains a gas, which blocks the escape of wavelengths at 4um and 15um. This reflects some of the black body radiation back to the sphere, causing it to warm. In 2009 for the earth, this lead to a net accumulation of 0.6 W/m^2 of energy absorption [1]. If accumulated over the entire area of the sphere and accumulated over time, this would lead to an increase in temperature. Although the model does not take into account land formations, ocean currents, air currents, seasons, etc, it still models the underlying process of the earth’s energy balance and can answer the question of whether the planet will warm and can provide estimates at how quickly this will occur. I think you’re hinting at systems being so complex that they can vary based on minute changes in initial conditions, you’d be correct to say that climate is chaotic. Not all chaotic systems are the same though. A double pendulum will swing in eccentric motions, but if you look at something like the stock market, there’s a lot of short term variability with long term certainty. I cannot tell you what my stocks will do next week. But markets generally converge on a doubling of money in 10 years. In fact that’s reliable enough that I’m willing to have a 401k. With the pendulum, I can tell you with a lot of certainty that if it’s damped, it will settle to its lowest energy state and stay there permanently. A climate model will not predict the weather. But in the same way that I can tell you that winter will be cold, I can also tell you that Arctic amplification and Hadley cell expansion will lead to very different weather patterns that civilization has not seen before, such as much more extreme swings in temperature and weather. [1] https://en.m.wikipedia.org/wiki/Earth's_energy_budget#/media/File%3AThe-NASA-Earth's-Energy-Budget-Poster-Radiant-Energy-System-satellite-infrared-radiation-fluxes.jpg https://en.m.wikipedia.org/wiki/Earth's_energy_budget#/media...

ximeng 5y ago

Based on reading an article about detailed work on making a model more accurate you’ve concluded that models are useless? Just because models aren’t infinitely perfect doesn’t mean they don’t have some predictive power. Yes you might drop a ball and it gets destroyed by a nuclear explosion before hitting the floor but it doesn’t mean a model that says it will likely hit the floor is useless! At large scale climate change isn’t that complicated - sun hits earth, heats it up, some energy escapes. We can get a pretty good picture from models and the details just add to that.

adamrezich 5y ago
> Based on reading an article about detailed work on making a model more accurate you’ve concluded that models are useless? no—I, knowing basically nothing about climate science and having been taught to more or less blindly trust climate models as accurate predictors of the future, read an article that said we have no idea how to model clouds with anything resembling accuracy, because clouds by themselves are crazy complex things. this led me to realize that this should have been intuitive knowledge without even reading the article, which led me to truly consider the scope of the climate system w.r.t. how it could possibly be modeled by computers, which led me to realize that the idea that it's possible for a data-driven computer model to predict anything about the future with any kind of reliability is pretty silly to begin with.
- ximeng 5y ago
  This just seems like a ridiculous position to hold: data-driven computer models can’t predict anything with any reliability?! Pretty much all predictions about the future rely on data-driven models! Yes models are not perfect, but the answer’s not to close your eyes and hope!
- lukifer 5y ago
  The right way to think about models at this scale is complexity isn't "Accurate" vs. "Inaccurate"; it's to use probabilistic/Bayesian reasoning. No map is a perfect representation of the territory, and no model can encapsulate the entirety of the earth. That doesn't mean maps and models are useless. A couple counterpoints from former climate skeptics: - Richard Mueller is a prominent physicist who founded an institute to debunk anthropogenic climate change, only to change his mind after thorough examination of the data. https://youtu.be/Sme8WQ4Wb5w https://youtu.be/Sme8WQ4Wb5w - Jerry Taylor is a libertarian and former climate debunker for the Cato Institute; a noteworthy pivot moment was speaking to a risk analyst for a financial institution, whose job it is to make bets on complex systemic risks in the context of uncertainty. He claimed that from a financial lens, AGW was a slam-dunk case for mitigation, not because of the certainty of any one model, but of the full probability distribution in aggregate. https://www.reckonings.show/episodes/17 https://www.reckonings.show/episodes/17

moistly 5y ago

> I've come to understand that all climate models are basically useless for predicting anything I am under the impression that the worst-case scenarios in most models have pretty much all come to pass, often earlier than expected. Seems to me that they’ve been very predictive. It would have been nice had the media more accurately delivered those predictions; perhaps it would have prompted some early action.

adamrezich 5y ago
"most models"???
- moistly 5y ago
  Yes, most models plotted a range of outcomes over time, depending on how much we reined in CO2 production. Our current CO2 levels, ocean temperature & acidity, glacier melt, and global temperature are in excess of all “good case” predictions. We failed to rein in CO2 production and now we’re pretty much living the worst-case scenarios… as predicted.