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Sea Level Rise Pt. 3

Re: Sea Level Rise Pt. 3

Unread postby Gmark » Fri 23 Jul 2021, 23:39:27

ROCKMAN wrote:Plant -As you point out models are difficult. Especially since there is no such thing as an UNBIASED model. Every complex model requires many dozens (if not hundreds) of assumptions built into the model. And those assumptions always run in a range. And often a very wide range. So the modeler has to chose those values. And all to often the modeler has an objective. Human nature being what it is assumptions are chosen leading to the goal. Which isn't to say they are incorrect. But also not to say they are correct. And typically those assumptions rarely have any absolute measure of validity.

Thus one is really saying they agree with the assumptions made when they agree with the model. Which is often just agreeing with the modeler's OPINIONS.


I agree with you that the built-in assumptions to every model really complicate things, and some of those built-in assumptions are pretty subtle.

One of the primary tools used in meteorology for forecasting weather, hurricanes etc., is the 'ensemble forecast', where you take a bunch of models, put them together, and see where they agree and disagree.

You can also run your model, change the initial conditions slightly, run it again, change the initial conditions again, run it again, etc. You wind up with a bunch of models each with slightly different starting conditions. When you put them together you can see where the slightly different initial conditions don't make much of a difference to the final output.

With meteorology and climatology this is important as so many factors are not linear, and a minor change in one initial parameter can mean major changes as you move forward in time.

The other problem is that even with supercomputers, this is very time consuming and there often isn't enough time to run too many models covering too big an area. This does work for hurricanes though and is common .

Some of the modeller's I know frequently do 'back forecasts' and 'model verification', checking this week to see how last weeks forecast conformed to reality, and where the model was wrong, try to figure out whether they screwed something up with the initial conditions, or if there were other factors that came into play that they didn't expect.

The best modeller's take it very seriously. But there are a lot of junk models out there.
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Re: Sea Level Rise Pt. 3

Unread postby Outcast_Searcher » Thu 29 Jul 2021, 11:31:56

Gmark wrote:
ROCKMAN wrote:Plant -As you point out models are difficult. Especially since there is no such thing as an UNBIASED model. Every complex model requires many dozens (if not hundreds) of assumptions built into the model. And those assumptions always run in a range. And often a very wide range. So the modeler has to chose those values. And all to often the modeler has an objective. Human nature being what it is assumptions are chosen leading to the goal. Which isn't to say they are incorrect. But also not to say they are correct. And typically those assumptions rarely have any absolute measure of validity.

Thus one is really saying they agree with the assumptions made when they agree with the model. Which is often just agreeing with the modeler's OPINIONS.


I agree with you that the built-in assumptions to every model really complicate things, and some of those built-in assumptions are pretty subtle.

One of the primary tools used in meteorology for forecasting weather, hurricanes etc., is the 'ensemble forecast', where you take a bunch of models, put them together, and see where they agree and disagree.

You can also run your model, change the initial conditions slightly, run it again, change the initial conditions again, run it again, etc. You wind up with a bunch of models each with slightly different starting conditions. When you put them together you can see where the slightly different initial conditions don't make much of a difference to the final output.

With meteorology and climatology this is important as so many factors are not linear, and a minor change in one initial parameter can mean major changes as you move forward in time.

The other problem is that even with supercomputers, this is very time consuming and there often isn't enough time to run too many models covering too big an area. This does work for hurricanes though and is common .

All valid points.

OTOH, weather forecasts (and many other things models do for us) are decent, as long as the expectations for the model aren't unrealistic. (For example, I pay attention to weather forecasts up to 48 hours out for things like rain and temps, but beyond a week they're basically useless re any accuracy.) And of course, as long as one doesn't have blind faith in the veracity of models, given how imperfect they are.

They're generally a useful tool, AFTER they've been subjected to enough scrutiny to EARN scientific veracity. But they're most definitely NOT the holy grail when it comes to anything approaching "absolute truth".

Math tells us, for example, that there are a hell of a lot of problems that are basically unsolvable. Models might help put some boundaries around some of the potential solutions to allow, say, a rough gauge of sizes of solutions, but they most certainly aren't going to "solve" such problems in any significant way.
Given the track record of the perma-doomer blogs, I wouldn't bet a fast crash doomer's money on their predictions.
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Re: Sea Level Rise Pt. 3

Unread postby JuanP » Sat 04 Sep 2021, 16:33:42

"Sea-level rise becoming a hazard for suburban South Florida neighborhoods far from ocean"
Sun Sentinel
https://www.msn.com/en-us/weather/topst ... np1taskbar

"Sea-level rise may appear to be a problem only for coastal residents, a hazard that comes with the awesome views and easy access to the beach.

But neighborhoods 20 miles inland are starting to feel the impact, as the Atlantic Ocean’s higher elevation makes it harder for drainage canals to keep them dry. The problem showed up last year in Tropical Storm Eta, when floodwater remained in southwest Broward neighborhoods for days, partly because the elevated ocean blocked canals from draining the region."

Our main farming location in Miami is a few miles inland from Biscayne Bay. The elevation in the area is 2 to 4 feet above sea level. Some of the streets in the area get flooded every time it rains, sometimes for up to a week.
"Only Americans can hurt America." Dwight D. Eisenhower
"We have met the enemy and he is us." Pogo
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Re: Sea Level Rise Pt. 3

Unread postby Newfie » Sat 04 Sep 2021, 20:12:34

Juan,

You ever consider relocating?
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