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Arthur T Knackerbracket has found the following story:
Last month, as much of the United States shivered in Arctic cold, weather models predicted a seemingly implausible surge of balmy, springlike warmth. A week later, that unlikely forecast came true—testimony to the remarkable march of such models. Since the 1980s, they’ve added a new day of predictive power with each new decade. Today, the best forecasts run out to 10 days with real skill, leading meteorologists to wonder just how much further they can push useful forecasts.
A new study suggests a humbling answer: another 4 or 5 days. In the regions of the world where most people live, the midlatitudes, “2 weeks is about right. It’s as close to be the ultimate limit as we can demonstrate,” says Fuqing Zhang, a meteorologist at Pennsylvania State University in State College who led the work, accepted for publication in the Journal of the Atmospheric Sciences.
Forecasters must contend with the atmosphere’s turbulent flows, which nest and build on each other as they create clouds, power storms, and push forward cold fronts. A tiny disruption in one layer of turbulence can quickly snowball, infecting the next with its error. A 1969 paper by Massachusetts Institute of Technology mathematician and meteorologist Edward Lorenz introduced this dynamic, later dubbed the “butterfly effect.” His research showed that two nearly identical atmospheric models can diverge widely after 2 weeks because of an initial disturbance as minute as a butterfly flapping its wings.
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(Score: 2, Insightful) by Anonymous Coward on Tuesday February 19 2019, @01:20PM (1 child)
Weather and climate are not the same, but not completely different either.
The weather models predict that it is likely to rain and generally where and when. This means predicting averages over the next few days. Not exactly when and where for each drop.
The article points out the Butterfly effect where random variation limits how far in the future a prediction can go. Given initial knowledge of the state of the system the models can only predict so far in the future.
That limit aside, there seem to be restoring forces in the weather which pull the random variations back to statistically measurable long term weather patterns.
Perhaps these long term weather patterns are the climate.
If they are predictable remains to be seen. In the last 50 years, the weather predictors have seen numerous 10 day weather cycles in detail. They have used these to tune their models to their current state. Still, the models are far from perfect in their ability to say if it will rain or not.
Climate prediction seems a similar problem, only the data set includes more things which are just constants to the weather models. The pattern cycles lengths are much longer. (It's been quite a while since the last ice age, but not so long since the last El Nino.) Mankind hasn't been around to see these cycles and can only glimpse at a few clues from the last one. (For example ice cores.) Given this, there seems no reason to expect a anything like the finely tuned weather model for the climate.
That said, one can still try. It is possible to gather more and more of the current state of the system. This includes especially the sea flows. It seems likely that we might not be able to predict, but will be able to better know the current state. For a climate scientist to call this prediction seems dishonest and discredits their field. This probably limits any response that these folks are hoping to see.
(Score: 2) by HiThere on Tuesday February 19 2019, @06:14PM
Of course, the problem is that as the climate warms, poles melt, etc. we are moving into a area where we don't have the relevant data. The models make predictions, but we have no idea how accurate they will be when the climate is, say 2 degrees warmer. All we know is that it will be hotter, and that water will evaporate more quickly. Moving into a modified Venus scenario is not impossible...though doing so quickly is, since that depends on a lot of photo-dissociation. Still, a large increase of water vapor in the exosphere is not desirable by any means. Etc.
The really dire scenarios are believe to be less likely than, say, a large meteor strike setting of another "Siberian Traps" chain of volcanoes and cooling everything back down again, but that's a guess. And the intermediately unpleasant scenarios which are deemed more likely are also guesses. My real guess is that we'll either have an AI Singularity or a nuclear war before the poles finish melting...which will cause global warming to cease to be a problem in one way or another.
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