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95% of climate models agree: the observations must be wrong

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Re: 95% of climate models agree: the observations must be wrong

#101

Post by jkrems »

retrogradeorbit wrote: post #68
cjensen wrote: post #2

Thou shalt not make a graph without error bars. In that respect, the error here belongs entirely to whoever made that graph in the first place. They plotted all those models together to try to convince the reader that all models point to doom. But in doing so without error bars, they implied a level of confidence for specific years that was entirely absent from the models.

How do you measure the uncertainty in predictive models? From my physics I remember that measurements have uncertainty. And then you propagate the uncertainty into derived values with differential equations. But how do you ascertain the uncertainty in a computer model? Did the original graphs actually have error bars?

Yes, see the debunk links in here. Those models normally all have ranges. Since he's in expert, it's a reasonable assumption that he either intentionally choose a graph without errors or he intentionally removed the error bars. Don't know which one would be worse.

Re: 95% of climate models agree: the observations must be wrong

#102

Post by shadowmint »

ramblerman wrote: post #93
beloch wrote: post #89

Climate change models are based on data. Old data, but real data. The concept wouldn't have even occurred to us had real, physical phenomena not suggested it. The deviation of recent data from predictive models does not indicate that nothing is going on an everything is tickety-boo. It merely indicates we don't fully understand what's going on and our models still don't have much predictive power. So, if we don't ful…

You can flag what you want, but I'm unconvinced by your arguments. You concede that he makes a point and we have no predicitive power when it comes to the climate. After that you don't really win me back.

http://ycombinator.com/newsguidelines.html

    Please don't submit comments complaining that a submission is inappropriate for the site. 
    If you think something is spam or offtopic, flag it by going to its page and clicking on
    the "flag" link. (Not all users will see this; there is a karma threshold.) If you flag
    something, please don't also comment that you did.

Re: 95% of climate models agree: the observations must be wrong

#104

Post by theraccoundude »

jellicle wrote: post #75

I wish that climate-deniers and flat earthers were flagged off the front page of HN as fast as any discussion of sexism in the tech community is.

And I wish religious zealots would be banned in the comments section as well.

Re: 95% of climate models agree: the observations must be wrong

#105

Post by TheEzEzz »

yummyfajitas wrote: post #94
TheEzEzz wrote: post #85

Earlier quoted context omitted.

These are very different. There is evidence for the possibility of future catastrophic climate change. There is no evidence for the existence of hell. There are also arguments against Pascal's wager that do not apply to climate change. For example, you can postulate an anti-Christianity Hell, where only non-Christians are spared. This poses a new Pascal wager. There's no reason to think this wager has any different o…

Sure there is some evidence - the existence of a guy claiming to be god's son, a bunch of people claiming miracles occurred, etc. These things are weak evidence in favor of christianity - similarly, there is weak evidence in favor of islam, mormonism, etc. Given that there is no similar evidence for the Anti-Christianity you postulate, the odds don't cancel. Another interesting result of this line of thinking: a rati…

> These things are weak evidence in favor of christianity

I'm not convinced this is true. Certainly the story of Jesus is evidence, but it's not clear which direction the evidence should push us. Someone making a claim does not always mean our posterior estimate on the claim should increase.

Here's a simple example:

I hand you a small bottle filled with medical-looking pills and a nice label. I ask you, "What's the chance these pills cure malignant melanoma cancer?" You think for a moment, then answer, "Very small. There may be a cure eventually, but I've never seen evidence. I'm not on the cutting edge of research though, so perhaps this is a new breakthrough I haven't heard of. Plausible, but unlikely."

I then say, "Well, let me reassure you by showing you the website I ordered the pills from."

I bring up the website, which shows testimonial after testimonial of people claiming the pills cure malignant melanoma cancer. You then respond (correctly), "I've decreased my estimate. There is still a chance, of course, that the pills work, but I now know these pills are not from a legitimate medical breakthrough I hadn't heard of yet. In fact, this website pattern matches as a scam, so I'm decreasing my posterior to an estimate even lower than my completely uninformed prior."

P(Pills work | testimonials) Of course, the testimonials would be positive evidence if the pills had passed clinical trials.

Now, which is bigger:

P(Jesus is the son of God | Jesus said he is the son of God)

or

P(Jesus is was just a guy | Jesus said he is the son of God) ?

Honestly, this is not clear to me at all. But I think once we start taking in all the other evidence related to (but not necessarily in favor of) Christianity things become more clear. Just like the pill's website pattern matched for a scammy website, it seems to me that the evidence related to Christianity pattern matches to the evidence related to other man made religions. So I conclude:

P(Christianity is man-made | evidence) > P(Christianity is correct | evidence)

Hence P(Christianity is correct | evidence) may very well be less than the uniform prior that a particular god exists.

Edit: The above symbols aren't right, as yummy points out below, but the argument and analogy is sound. What we care about is the change in probability of each possibility. If

P(Christianity is man-made | evidence) > P(Christianity is man-made)

then we can conclude that Christianity is less likely due to the evidence.

Re: 95% of climate models agree: the observations must be wrong

#106

Post by glenra »

nl wrote: post #16

Let's just link to the debunking and move on. https://www.skepticalscience.com/global-warming-stopped-in-1... https://www.skepticalscience.com/The-Oceans-Warmed-up-Sharpl... https://www.skepticalscience.com/climate-models.htm https://www.skepticalscience.com/skeptic_Roy_Spencer.htm

Why do you consider any of those links to constitute "debunking" of the original linked post? Most of the points therein seem entirely compatible with the current claim

Most notably, the link on "climate models" says "Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean." and goes on to discuss hindcasting. But the argument here is about forecasting - how well the models did after predictions based on them were first published. How successfully do they turn out to reproduce temperatures since 2000? Not nearly as well as since 1900. Bringing up 1900 in this context seems like a red herring.

Further note: There's a difference between disagreeing and debunking. It can be assumed that skepticalscience will disagree with this sort of sentiment, but that doesn't make them correct to do so.

Re: 95% of climate models agree: the observations must be wrong

#107

Post by glenra »

vehementi wrote: post #50
001sky wrote: post #26

Earlier quoted context omitted.

It matters precisely in a moral sense. Because of the (in)effectuality of the action. Resources are scarce, and you are taking food from a baby...somewhere in the world. Of course none of this matters if you are having "first-world" pyschological problems about guilt...or you are trying to secure some money or presige for your first-world cushy lifestyle.

Scarce resources aren't the cause of starving babies

> Scarce resources aren't the cause of starving babies

They aren't? Wait, let's make the claim more specific. Biofuel mandates that had been justified in part based on CO2 concerns have driven up the cost of corn and other grains - crops and farmland is being needlessly diverted from food to fuel. Making grains more expensive has indeed been a cause of starvation in the third world.

Um, here:

http://www.foreignaffairs.com/articles/62609/c-ford-runge-an...

Re: 95% of climate models agree: the observations must be wrong

#108

Post by x0054 »

waps wrote: post #98
beloch wrote: post #89

Climate change models are based on data. Old data, but real data. The concept wouldn't have even occurred to us had real, physical phenomena not suggested it. The deviation of recent data from predictive models does not indicate that nothing is going on an everything is tickety-boo. It merely indicates we don't fully understand what's going on and our models still don't have much predictive power. So, if we don't ful…

The problem is exacerbated by the fact that we have no idea what effect the policies have. They could be good, BUT they can also have bad results. I mean bad beyond just the economic implications. Since the climate system has been working a certain way for ~10000 years, I'd say the default position should be that nothing is going to change. What's missing from your reply is an answer to the data he's showing. A long…

Climate engineering scares the shit out of me. I think this article is right, we do not fully understand global warming. We know something is happening, we do NOT know exactly what OR why. But we have the fucking hubris to assume that we can make it better (through climate engineering)!? Without even fully understanding the problem.

That said, we can still work on improving the world and cutting down CO2 emissions AND pollution. Global warming or not, no one can argue with the fact that air quality in large cities in US, India, and China is atrocious. Global warming may or may not kill us, but pollution is killing people, now, today. And that pollution is 100% man made, no argument about that.

I personally think we should work on innovation of power production, not conservation of said power. Better battery technology and better solar photovoltaic technology is the future, in my personal opinion.

UPDATE: updated for clarity.

Re: 95% of climate models agree: the observations must be wrong

#110

Post by Steko »

waps wrote: post #98
beloch wrote: post #89

Climate change models are based on data. Old data, but real data. The concept wouldn't have even occurred to us had real, physical phenomena not suggested it. The deviation of recent data from predictive models does not indicate that nothing is going on an everything is tickety-boo. It merely indicates we don't fully understand what's going on and our models still don't have much predictive power. So, if we don't ful…

The problem is exacerbated by the fact that we have no idea what effect the policies have. They could be good, BUT they can also have bad results. I mean bad beyond just the economic implications. Since the climate system has been working a certain way for ~10000 years, I'd say the default position should be that nothing is going to change. What's missing from your reply is an answer to the data he's showing. A long…

Speaking of piles of crap:

"The IPCC's 95% certainty bands it gave for 5 years out have been violated EVERY single time"

Alternatively, you could tell the truth that they've been accurate:

http://www.skepticalscience.com/ipcc-overestimate-global-war...

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