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Can you please explain why they are not other than just proclaiming they are not? I have never understood this reasoning other than proclamations that they are
by haltingproblem 6y ago
Can you please explain why they are not other than just proclaiming they are not? I have never understood this reasoning other than proclamations that they are not.
- Areading314 6y agohttps://www.noaa.gov/explainers/what-s-difference-between-climate-and-weather https://www.noaa.gov/explainers/what-s-difference-between-cl... Plenty of others if you care to look. Weather is a chaotic system whereas climate is not.
- laser 6y agoIt's a matter of scale. If I go outside and turn on a leaf-blower I can tell you with relatively high confidence the speed and direction of general air movement five feet out from the nose. On the other hand, if I tried to tell you the speed and direction of a dozen particles at X, Y, Z location in coordinate space, the effects of chaos (particles individually colliding, etc) would make this infeasible with current technology. Similarly, describing climate is like describing the general direction and speed of air moving out from the leaf blower, while weather is like trying to make the same prediction for small groups of particles within the system. They might sound like similar tasks, but due to chaos one is doable and the other is nearly impossible. All that being said, with regards to this particular study at the scale of 500 years it's likely our climate models nearly completely break down, as we've yet to successfully create one without significant divergence even a few decades out (although maybe that has changed as by definition the best ones we can test against only include those made before the year ~2000)
- haltingproblem 6y agoRight, I totally get the leaf blower and thank you for writing that. But the scientific boundary between climate and weather cannot be a analogy. It has to be more rigorous than that.
- dvdkhlng 6y agoDisclaimer: I'm not knowledgeable in that topic. But from a general physics PoV: - weather is mostly about complex local interactions between air pressure / surface temperature / air flow (convection) / humidity etc. these are described by differential equations with very chaotic behaviour (small changes in inputs may have extreme effects on the outputs the further you run the model) - climate is more about long-time effects of the energy input/output of the whole planetary surface and atmosphere. Mostly solar radiation (input) vs. black-body radiation (output). There are also some complex interactions and feedback cycles e.g. change of albedo (cloud cover), and changes of atmospheric composition (i.e. methane due to permafrost melting), but local weather patterns may cancel out when looking at the sum-total of surface thermal energy.
- Geminidog 6y agoClimate is also a more macro level view of a system. Think Entropy. Imagine Oxygen molecules in a box. The individual movements are complex and unpredictable but at a very high level macro view we can see all of these movements in aggregate as temperature. Temperature is not only much more stable then the chaotic movements of individual atoms but it is predictable and controllable. I can heat a kettle of water to a very specific temperature and I can accurately predict the rate in which it will cool down when I stop heating it. I cannot however control or predict the actions of specific molecules within the kettle. The lower level you go the more chaotic things become. The higher you go the more deterministic things appear to be.
- surfpel 6y agoWeather is the day to day fluctuations in atmospheric conditions. They are extremely sensitive to minor changes making it hard to predict. It’s even possible to actively change the weather by seeding clouds to start rain for example. Climate involves long term trends which are quite stable and predictable. It’s kinda like the stock market. There may be lots of fluctuations in a given day, but most traders are interested in long term trends which tend to be more stable and predictable.
- haltingproblem 6y agoI really like this definition because it is understandable. However we do not know long term where the stock market will be. There are countries that have been wiped out and their stock markets decimated (e.g. country that had a revolution). The US stock market is an exception in that distribution. Perhaps you mean macro vs. micro as in economics. Even there micro is far more predictable than macro. Macro is almost voodoo when it comes to prediction of any sort on any timescale.
- taneq 6y agoIf I pour water into a bucket at a set rate, I could not with all the computing power in the world tell you where a particular drop of water will end up in that bucket an hour from now, but I can tell you to the millimeter what the depth will be at any point in the future. Hopefully the analogy is clear.
- haltingproblem 6y agoI appreciate the analogy but this the difference between climate and weather can not be scientifically explained by analogy.
- woofie11 6y agoThat's an excellent analogy. Best I've heard. I'll make it a little bit more accurate. If I poor water into a bucket at a set rate, it takes incredible computing power to simulate the hydrodynamics and understand how the water is splashing, the patterns of ripples, and the turbulence in the water, but I can tell you that when I've poured in 2 gallon, the bucket will be full. I'll make it even better. I'm spraying water at my dog. Weather is predicting where the hose spray will fly, and how much make it on the dog at any moment. Climate is predicting how wet the dog will be in the end and what will get wet if dog goes in the house. My (blue) wife claims she can predict the exact amount of water on my dog, and says if I let the mutt in, 1.4 cups of mud will get on the stairs, and I shouldn't do it. I (red) correctly say that's nonsense, and that she can't predict that with any accuracy. I keep spraying the dog, and let the muddy dog in the house. Dog doesn't go for the stairs, but heads for the $5000 sofa, staining it to where it's a $100 Goodwill sofa, and shaking mud onto the AV system. Stairs are clean, though. TL;DR: We can't predict shit will get f-ed up to nearly the degree Democrats say they can. We know shit will get f-ed up, though, with pretty good certainty. (My own opinion is we've badly underestimated the impact of chemical effects, like ocean acidification, and overestimated the effects of temperature change; but the dog might go for the pantry instead)
- 6gvONxR4sf7o 6y agoIt's not a question of reasoning. It's a question of definitions. The most rigorous definition I've seen is that climate is a probability distribution over things like weather. Climate over a year in San Francisco will get you a distribution of temperatures, humidities, smoke, etc. Climate on Nov 13, spread out over many years is another distribution over weather. It's easier to deal with these distributions because you don't need to predict the next year of weather to predict what global temperature properties keep the earth in equilibrium with incoming solar energy, for example.
- haltingproblem 6y agoFantastic! A rigorous explanation (thank you). So you are saying that the mixtures of weather distributions are stable but the individual distributions can shift. I gotta think about that and dont know enough about weather distributions or probability to understand why climate (the mixtures) can be stable but individually weather cannot.
- jfengel 6y agoWeather is unstable because you need to know many factors (temperature, humidity, cloud cover, etc) over every single piece of land and water (over many different terrains). And those are unstable minute by minute. To report the weather, you need a moving weather map. By contrast climate is "simple" in that it can have fewer variables. The most basic climate model is literally zero-dimensional: it treats the earth as a homogeneous gas mixture and that's it. It can be reported in a single variable, the temperature. The zero-dimensional model won't tell you all of the things that happen: some places get more rain, some less, some even get cooler. There are more complicated models that do that, and to make specific policy recommendations you need those. But there is a crucial discussion that comes from that single number: yes, the world is getting warmer, because of humans turning carbon in the ground into CO2 in the atmosphere, and it's bad enough that action needs to be taken. The model is still unstable, but much more tightly constrained, to within a fraction of a degree C per year. That's because the atmosphere is so large, and the sheer mass of it means it has to change slowly, but predictably. Over very long scales (tens of thousands of years) additional factors create more instability, but they're not pressing problems the way highly predictable century-scale changes are.
- bausano_michael 6y agoNeil DeGrasse Tyson made following analogy: https://youtu.be/cBdxDFpDp_k https://youtu.be/cBdxDFpDp_k tldw: weather is like a dog on walk, running around, climate like the owner, bounding what weather is possible