Are there generally-understood "noisy" systems with underlying trends?

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  • Are there generally-understood "noisy" systems with underlying trends?


Answer #1 | 29/12 2013 14:56
I think MTRStudent gives a good answer. If the temperature at the beginning of April is higher than the temperature at the end, is that proof that summer will not follow spring? It would be to the denier mindset. Ottawa Mike claims "All noisy systems have underlying trends." I have no idea why he says that, but it is certainly not true, Then he posits that engineers have doubts about AGW because of their experience with noisy systems--when that would instead be evidence that they should discount any "pause" in warming. Kano once again claims "Once you get past 150ppm of CO2 it has little to no warming effect." even though he knows that is wrong. EDIT: Rio, I actually used to work on systems where the SNR for an individual experiment was much less than 1. Nevertheless the signal was quite real--we'd just run the experiment 10,000 times or so and add up the results and the signal would become clear. On the other hand, there is no guarantee that a noisy system will have any real signal in it, or "underlying trend". Sometimes noise is just noise.
Positive: 100 %
Answer #2 | 29/12 2013 09:32
So climate scientists are unable to model noisy systems then. Gotcha.
Answer #3 | 29/12 2013 10:04
All noisy systems have underlying trends (i.e. the signal). I think engineers are more likely skeptical of AGW based on the idea of signal to noise ratio. In systems where the noise is much larger than the signal, there is little to be gained. For example, the change in global temperature not only has short term noise (variations) but the signal is generally smaller than even the noise of the instruments used to measure it. Extracting a signal buried in noise is generally a very difficult problem in engineering. That's why engineers question the confidence of most climate data let alone future predictions of it.
Answer #4 | 31/12 2013 03:16
As fundamentalists, alarmist often get confused with long term system dynamics and short term weather statistics. It would be hugely gratifying, if they made up their minds. Anything greater than a SNR of 1:1 is considered a signal. Peg is so FOS. Edit: probably one of the better examples of how noise and signaling can be confused.

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