The world has never seen such freezing heat

[Dinner]

Originally posted by snoopy369


That doesn't parse logically... more ice melts in the summer so there is more ice in the winter? We're not talking more ice FORMING, but more ice TOTAL, as far as I can tell...

I think we're learning simply that weather is a chaotic mess and trying to predict anything substantial over a long period of time is ... difficult.

The area refreezing is larger because the area melting is larger. Areas which would have remained frozen year round are now melting in summer and then refreezing in winter so "the growth of ice" is larger even if the total area frozen in winter is unchanged or decreases slightly.

In any event this gets back to weather vs climate where as weather is individual events and climate is long term average conditions.

[Felch]

Originally posted by Unimatrix11
Well, sure it´s hard to model global climate - but what´s the alternative ? Try it out on the real thing ? When you cant do an experiement, you have to make a model.

Here's an alternative: Don't Panic.

Computer models should not be the basis of our domestic policies.

[KrazyHorse]

Originally posted by snoopy369


That doesn't parse logically... more ice melts in the summer so there is more ice in the winter? We're not talking more ice FORMING, but more ice TOTAL, as far as I can tell...

I think we're learning simply that weather is a chaotic mess and trying to predict anything substantial over a long period of time is ... difficult.

No. It means that predicting over long periods is easier than predicting over short periods. Which anybody who knows anything about statistics knows.

[KrazyHorse]

Originally posted by Felch
Computer models should not be the basis of our domestic policies.

They're a lot better than what most domestic policies are based off of (total ignorance).

[Unimatrix11]

They should be taken into consideration, though. After all, they represent the ´best guess´ of what is (going to) happen, that mankind can come up with in this case. Actually it is the same reason, which makes experiments impossible, that should make us concerned about the topic - we will have had one try if we mess it up. The fact we cannot predict the climate 100% correctly doesnt mean, that we shouldnt care about it. Not knowing of effects will not not make them happen. As a dynamic system, the climate might feature threshold after which positive feedback loops set in, which could prevent the system from going back to status quo, after the cause for the change has been removed. Things like that make it reasonable to be very concerned about the topic and research, how inefficient (it´s effectiveness being a matter of its results being accepted) it may be, to be pushed. There might be dangers we are not even aware of.

But that CO2 emissions warm up the climate in principle, taken as an isolated factor, is a well known fact. If we dont want it to heat, it is a good idea to reduce CO2 emissions. You dont need computer models for that, and domestic policy should take this fact into account. If a decicion to reduce CO2 in a society is very hurtful, that usually shows all the more, that this society needs to cut down on it anyways. For example (and this is not to pun anyone), it is the US (among the ´west´ at least), who participates the least to international agreements and such, just because it is the one who should change the most. To change something could mean, that enviromental issues would make the ´basis of our domestic policies´, while in other countries, most anti-CO2-laws just go with the daily business. The amount of change needed relates to the conveiced ´basisisness´ of the concept that needs implementation. In fact global warming is part of the basis of domestic policies in almost every country. To accept a problem to be real should imply you act on it - it doesnt mean, that you have to go all overboard with it and stop caring about everything else.

[Felch]

Originally posted by KrazyHorse
No. It means that predicting over long periods is easier than predicting over short periods. Which anybody who knows anything about statistics knows.

I was under the impression that these models weren't simple things like counting cards at black jack. These are full of unknown, interacting variables. They are trying to anticipate the effect of phenomena that we have no experience in dealing with. In other words, I have serious doubts about these models. I just don't trust people to accurately predict things that have never happened before.

[snoopy369]

Originally posted by KrazyHorse


No. It means that predicting over long periods is easier than predicting over short periods. Which anybody who knows anything about statistics knows.

Sorry, I probably wrote that in a way that a brilliant physicist such as yourself would misunderstand it.

Predicting something in the far future is harder than predicting something in the near future, and particularly so when the something is very chaotic.

[KrazyHorse]

The climate models, such as they are, only need to model a few variables well to get fairly robust results. Included are:

0) Radiative forcing from greenhouse gases (there is no doubt about this part; it's 19th century physics)
1) Ice cover (from increased temp)
2) Cloud cover (from increased amount of water vapour)
3) Convection (from increased temp)

Decreased ice cover leads to lower albedo which leads to more heat absorbed
Increased cloud cover leads to higher albedo which leads to less heat absorbed
Increased convection leads to quicker heat transfer out

As I understand the state of the science, 1 strongly outweighs 2 and 3 in all believable models.

[KrazyHorse]

Originally posted by snoopy369


Sorry, I probably wrote that in a way that a brilliant physicist such as yourself would misunderstand it.

Predicting something in the far future is harder than predicting something in the near future, and particularly so when the something is very chaotic.

Again, this is blatantly wrong.

I can't predict the weather 2 weeks from now. But I can predict global average temperatures for the decade of 2030-2040 pretty easily.

[KrazyHorse]

I love it when non-scientists try to criticize science they don't even come close to having the analytic tools to understand.

[KrazyHorse]

If there were political implications to high energy physics I'm sure one of you would attempt to lecture me on the suitability of the factorization model of particle collisions.

[Naked Gents Rut]

The climate models, such as they are, only need to model a few variables well to get fairly robust results. Included are:

0) Radiative forcing from greenhouse gases (there is no doubt about this part; it's 19th century physics)
1) Ice cover (from increased temp)
2) Cloud cover (from increased amount of water vapour)
3) Convection (from increased temp)

Do the models include cloud cover now?

[Unimatrix11]

Well, KH, in 0) there is no doubt about the effect itself, but there is debate about quantities emmited, their future ammounts (both often parametered for scenarios), the Greenhouse potential of various gases (about ten years ago N2O was listed as 117 CO2-equivalents, but now this number is way beyond 200), absorbation of CO2 by the oceans and various biomes, their capacity, change of maritme life due to warming, deforestation, speed and effect of which and so forth.

That alone makes it very complicated, but what really makes it huge is that it also tries to give local predictions, going beyond things like ´mean temp worldwide will be +2°C approximately in 50 years´, but rather saying ´due to changed rain-patterns, the sahara desert will be green again´ (good examples of early records there btw). Computing these local effects is actually, what the most powerful computers yet devised are needed for. Of course, being aware that the whole system has chaos in it, the scientists dont run a scenario once and present the outcome to the public, but many times, using the same parameters, and then come up with the most likely result, according to the series.

[Unimatrix11]

NGR - yes they do. Sim Earth did.

[Felch]

Originally posted by KrazyHorse
If there were political implications to high energy physics I'm sure one of you would attempt to lecture me on the suitability of the factorization model of particle collisions.

Well, yeah. There are political implications to history, and all sorts of amateurs refuse to shut up. People have a right to try to determine their destiny.