Climate Change

[Nefertiti2]

Is there a dedicated climate change thread- I couldn't find it?

This piece about climate change mass migration in the US seems as good a place to start.

[ursus arctos]

The closest one is ten years old, so a new one is clearly warranted.

[Fussbudget]

What about this one?

[ursus arctos]

Ah, good call

[Nefertiti2]

Thanks for that Fussbudget. I don't think it really matters what it's called. But it does seem to be undisputed that man made climate change is now here. I spoke to a glaciologist friend a few days ago just back from the Arctic who confirmed he thought there was no going back.

[Fussbudget]

No problem, I knew I remembered linus posting a ton of graphs somewhere about how everything is fine and we can all relax.

[ursus arctos]

Which makes the policies of the current US administration all the more rage-inducing.

[Moonlight Shadow]

No need to speak to a climatologist, any old chap in the Alps will do, they can see the changes for themselves...

[San Bernardhinault]

The opening piece is interesting, but it's depressingly focused on the US - if there's 6 feet of sea level rise, we might have problems with a few towns in Florida or Louisiana needing to relocate or spend a fortune on Dutch style sea defences. But if there's 6 feet of sea level rise, several hundred million poorer people on the planet are going to be much, much more fucked.

[San Bernardhinault]

A couple more things about the article.

One big criticism is that figure of "6 feet of sea level rise". That number is basically off the scale. The IPCC estimated figure (with - I think - an 85% confidence) is a range of 25-55cm 2100. I think it's generally very unhelpful when people create hype stories of upcoming disaster which are in the 99th percentile. 1 to 2 feet of sea level rise will fuck us up enough.

The second thing, not a criticism but just an observation, is that America is trying very hard to pretend that sea levels aren't even going to rise one or two feet. There is a massive disconnect between housebuilding - which is happening in flood plains - and property that should be insurable. I can't pretend to understand it, but there's some government insurance system that's covering all these newly built houses in places that should be utterly uninsurable. The market should basically stop anyone get a mortgage on these houses, but instead they're still getting built and sold. The great migration isn't happening yet. People are actually moving in their droves to places that are increasingly vulnerable.

[anton pulisov]

A couple more things about the article.

One big criticism is that figure of "6 feet of sea level rise". That number is basically off the scale. The IPCC estimated figure (with - I think - an 85% confidence) is a range of 25-55cm 2100. I think it's generally very unhelpful when people create hype stories of upcoming disaster which are in the 99th percentile. 1 to 2 feet of sea level rise will fuck us up enough.

The main problem with these predictions is that they are truncated at the year 2100. That's only 82 years from now. There are young children and babies alive today who will live beyond 2100.

So what happens after 2100? Even if all humans went extinct today and, therefore, ceased emitting CO2, sea level would continue to rise for a few hundred years. We are already pretty much locked in to a minimum 2 m change by the year 2200, due to the slow reaction of the ocean to perturbations in temperature. It will take a while for the heat currently in the top of the ocean to be transported to the isolated, deep parts of the ocean. When it does, it will cause thermal expansion of deep waters.

[Eggchaser]

The NHTSA have said there's no point fighting it so we may as well all drive rolling coal pick up trucks.

[San Bernardhinault]

The main problem with these predictions is that they are truncated at the year 2100. That's only 82 years from now. There are young children and babies alive today who will live beyond 2100.

So what happens after 2100? Even if all humans went extinct today and, therefore, ceased emitting CO2, sea level would continue to rise for a few hundred years. We are already pretty much locked in to a minimum 2 m change by the year 2200, due to the slow reaction of the ocean to perturbations in temperature. It will take a while for the heat currently in the top of the ocean to be transported to the isolated, deep parts of the ocean. When it does, it will cause thermal expansion of deep waters.

I think the assumption - not unreasonably - is that in such a complex system it's almost impossible to reliably model beyond 2100. And if you're making policy, you should be making it on data you're relatively confident about.

I'd also add (but I doubt this is the IPCC's position) that human ingenuity and the advance of technology is such that 80 years is a ridiculously long period of time and who knows what remedial technology we'll be bringing on stream, so again it's better to make policy aimed at the foreseeable long term future.

[anton pulisov]

That depends on what you mean by reliable. It is impossible to model precisely beyond 2100, but you can model accurately as long as all errors are included. And then, even in the best case scenario (at the bottom of the error bar), we are screwed at 2200.

[linus]

The main problem with these predictions is that they are truncated at the year 2100. That's only 82 years from now. There are young children and babies alive today who will live beyond 2100.

So what happens after 2100? Even if all humans went extinct today and, therefore, ceased emitting CO2, sea level would continue to rise for a few hundred years. We are already pretty much locked in to a minimum 2 m change by the year 2200, due to the slow reaction of the ocean to perturbations in temperature. It will take a while for the heat currently in the top of the ocean to be transported to the isolated, deep parts of the ocean. When it does, it will cause thermal expansion of deep waters.

Busy week at work, don't have time to delve into a lot of the issues here before the weekend, but this is a bit tenuous of a statement on its surface (pun intended) that is pretty easy to shoot down, because assuming your model is correct and that the oceans have warmed due to human CO2, the warm layer of ocean water at the surface will have already expanded. The heat being redistributed would not result in any net overall additional thermal expansion, because it is already in the system.

If you were to heat the edge of a cold metal bar, the warm bit at the end would expand, then contract again as the heat is redistributed across the bar, with the bulk of the cold bar expanding slightly, by a length roughly equal to the contraction of the edge as that part cools down.

If anything, I would expect lower expansion levels overall as the heat transits from the surface to the bottom, because the bottom of the ocean is subject to compressibility, the bulk modulus of water being far from negligible.

I guess you're assuming that more heat is getting trapped into the atmosphere and being injected into the ocean system, but you did claim above that sea levels would still rise even if CO2 levelled off purely based on the heat accumulated so far in the ocean surface, a notion which doesn't cut the mustard.

In any case this debate is moot because the data and observations do not support the IPCC and other alarmist models of a significant acceleration in sea level rise over the last century. The historic rise has been steady, of the order of ~6in inches per century, your prediction fo a 2m rise in 2200 is off by about 800%:

[Lang Spoon]

Hmmm.

[San Bernardhinault]

You do realise that metal doesn't circulate in your hypothetical metal bar, don't you, linus?

[anton pulisov]

Ah shit yeah, if only the IPCC had thought to look at past sea level change. Good call there Linus. Somebody send them the memo.

[linus]

The metal doesn't circulate, but the heat within that metal bar does, given that most metals are very effective heat conductors. So the metaphor is valid as an illustration of my point about thermal expansion in the ocean.

[linus]

Ah shit yeah, if only the IPCC had thought to look at past sea level change. Good call there Linus. Somebody send them the memo.

You're onto something here. The IPCC has many fundamental flaws, ignoring past data in favor of models that have consistently turned out to be too alarmist is one of them.

As an organization that was put together by people like Maurice Strong, it has a set agenda and a narrow scope. The IPCC's mandate marginalizes the influence of natural causes in climate change, by design. Judith Curry addressed some of these IPCC fundamental issues in this book review:

https://judithcurry.com/2011/10/19/l...e-on-the-ipcc/

[Lang Spoon]

https://rationalwiki.org/wiki/Judith_Curry

Yeah she seems cool

[linus]

Curry was the head of the School of Earth and Atmospheric Sciences at Georgia Tech, her technical competence is beyond reproach. As well, she started out in the mainstream and only later became skeptical on many issues surrounding CAGW. This cost her her job, as she was pushed away from academia.

The smear jobs from "rationalwiki", presenting her as a Koch brothers shill, are beyond pathetic, they're quite representative of the kind of personal harassment she's had to endure by going against the scientific establishment on this issue.

[Lang Spoon]

Has she taken cash from them Koch lads or their proxies?

[Lang Spoon]

Mmmm just seen a link to a James Delingpole article in a blog post by her contra Michael Mann. If that’s the kind of bastard you’re using to bolster yr arguments, your brain (Curry’s, not Linus) has cracked at best. At worst you’ve become a shill for bastards.

[anton pulisov]

This is why we can't have a climate change thread on this board.