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0 pointsSymmetry7y ago0 comments

Ok, I finally watched the video and I don't think it was worth my time at all. It was nice that they were polite to each other but really we have understood the basics of how increased C02 causes global warming for about a century. Current detailed climate models are kind of crap, Nate Silver went into why in some detail in his book on modeling, The Signal and the Noise, which I recommend but that doesn't change the anything I said in the above post - climate models are as likely to undershoot the dangers of warming as they are to overshoot them. Christy basically seemed to be arguing that there's uncertainty so he was permitted to believe what he wanted to. That's not a rational way to approach problems, especially given how he exaggerated the nature of the uncertainty.

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vladimirralev7y ago· 2 in thread

I think you need to watch it again, because your summary sounds just wrong. Both scientists agreed completely that humans caused CO2 raise and it caused warming. All the actual arguments are way way past those basic facts that are agreed upon.

Did you listen when they agreed that proposed measures will not stop ocean water levels from rising? Did you listen to the cost-benefit analysis and socio-economic impact? Why are you ignoring this point? You don't think it's important?

If climate models are as likely to undershoot then how do you explain that ALL the best models in consideration overshot the last 30 years and not a single model undershot? If it was just as likely shouldn't we be seeing some models undershooting?

SymmetryOP7y ago

No, obviously ocean waters can't be stopped from rising. The question is all about how much they're going to rise. It really annoys me when people treat global warming as an all or nothing quantitative affair.

Yes, every climate model overshot air warming leading up to 2014. But they also all undershot ocean warming. That's because, for some reason nobody understands, from 1998 to 2014 all the extra thermal energy caused by CO2 forcing went into the ocean. But since 2014 air temperatures have shot up very rapily and now we're back on the trend-line predicted by models.[1] But really, you could just as easily have argued that models were undershooting because they all predicted cooler oceans than we got. And Ocean warming is the important part for determining sea levels. Christy was dishonestly cherry picking stats to make it look like errors only go in one direction when really they go in both.

If all you know about the global warming debate is what was in that video I can see how you found it convincing but it's actually a very shallow treatment of the whole topic. It's really hard to get into depth in a video, that why so many of us are reluctant to watch them when someone links to one.

[1]https://en.wikipedia.org/wiki/Global_temperature_record#/med...

EDIT: And in the future, can you try summarizing things from a video like this you found persuasive rather than just telling people to watch the video? If you had mentioned the "Overshot for the last 30 years" thing it should have been immediately obvious to people who follow climate science what was happening and how you'd been mislead. Then I wouldn't have had to wade through an hour long video trying to figure out what you found persuasive in it. I'm generally reluctant to watch videos linked off of Hacker News because they usually aren't worth it and after this I think people are going to find it even harder to persuade me to do so without better evidence.

vladimirralev7y ago

I am sorry but this is ridiculous, ignorant and condescending. Every single thing you said was addressed in the video already and all facts are agreed upon by both parties. You keep bringing up things that are well agreed upon by both scientists. You keep ignoring the socio-economic topic which is the central idea here.

You can't just say Christy was dishonestly cherry-picking, because those data points are what was represented in the IPCC reports as concerning. They are the important data points that dictate the policy, not the undershooting data points. IPCC already cherry-picked these data points with the overshoot to raise the alarm.

Things I found persuasive? You are suggesting the the video represents only one side. This is a debate and both sides raised valid questions. You are exactly what they talked about when asked if they feel embarrassed by the tribal behaviour on either side.

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