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Climate models are running red hot, and scientists don’t know why

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Re: Climate models are running red hot, and scientists don’t know why

#291

Post by imtringued »

LMYahooTFY wrote: post #179
cagenut wrote: post #150

Earlier quoted context omitted.

this is textbook middlebrow contrarianism. using some quote from some recognizable name to dismiss the incredible work of dozens of top of their field professionals doing their life's work. its a perfect example of the way hacker news "types" do climate change denial. via endless "well-actuallys" until you're lost and stuck in a level of analysis-paralysis that borders on an anxiety disorder. the problem with solving…

This reads as remarkably dismissive of a well thought out comment about the difficulty of dialing in metrics and manifesting social pressures. Your comment in no way addressed these topics, and instead moved the line, beyond which lie "outright-deniers" (i.e. deluded people), further up to include anyone who expresses skepticism, or apparently who doesn't accept the coordinated work of thousands of scientists whole-s…

No, the numbers don't matter anymore. Whether there will be 1.5°C warming or 4.5°C is simply no longer relevant. The steps needed to avoid either scenario are identical.

"patient" earth is sick. Will you cure him or not? That's the only important question.

Re: Climate models are running red hot, and scientists don’t know why

#292

Post by jschwartzi »

rayiner wrote: post #108
derg wrote: post #19

Earlier quoted context omitted.

Can you even imagine how a Total War economy/society based on transitioning to greener energies, cutting emissions and pollutants, and working on improvements to housing and urban planning would end up looking? Like ignoring the whole climate change thing for a moment (though we absolutely should not do that), just the quality of life improvements to our health and well being this kind of mobilization would bring wou…

> Total War economy/society > quality of life improvements to our health and well being this kind of mobilization would bring would be astonishing. The impact on quality of life and society would be "astonishing," but they won't be improvements. The Soviets and Chinese tried similar "mobilization[s]" for food production. The idea was to direct society's efforts to producing enough food for everybody. Tens of millions…

You’re referencing The Great Leap forward right? Because if so you’re completely ignoring the details in an attempt to use it to bolster your point. The reason tons of people died in The Great Leap Forward has nothing to do with food production per se. Rather, the Chinese government declared several animals to be pests and commanded everyone to eradicate them to protect the harvest. Among those animals were sparrows. Sparrows are minor agricultural pests, but they are fantastic at eating bugs. And so, having hunted sparrows nearly to extinction the Chinese were unpleasantly surprised when a huge plague of Locusts descended on their fields and ate nearly all of the harvest.

So the real lesson is not that command economies are bad but rather that unforeseen circumstances should be avoided. If they hadn’t killed the sparrows we would not now be hearing about how many died.

Re: Climate models are running red hot, and scientists don’t know why

#293

Post by imtringued »

admax88q wrote: post #201
shusson wrote: post #188

Earlier quoted context omitted.

I don't think the OP was suggesting we do nothing, but rather we should ground our fundamentals in the scientific method. We do not have another planet Earth to test climate change on. That doesn't mean we should do nothing, but we should also understand our limits in predicting a system like our planet Earth.

OP is arguing that the models are likely to overestimate warming/damage. The logical conclusion from there is that the damage isnt as bad as predicted and therefore less action needs to be taken.

That would only matter if you were taking any action at all. When you're doing nothing you simply don't care.

Re: Climate models are running red hot, and scientists don’t know why

#294

Post by SiempreViernes »

pepijndevos wrote: post #203
leifdenby wrote: post #47

There is a big observational campaign happening right now that is trying to get to the heart of this called EUREC4A (main website: http://eurec4a.eu and information sheet: http://eurec4a.eu/fileadmin/user_upload/eurec4a/2019/Press/E... ). The key uncertainty between different climate models is whether shallow clouds in the tropics (which in general cool the Earth through radiation) will disappear or not and make our…

How do these models address overfitting? I'm sure this is taken good care of, but from just reading the article it almost sounds like some details were added to make it fit recent changes better.

You don't really optimise parameters for large scale climate models, you put in your best guess at the initial values and then wait for weeks to months depending on your goal. With function evaluations that costly, I don't really see how you have time to overfit.

The big worry is bias, a lot of assumptions about how physics can be approximated are needed to make these models, but there isn't time to test every combination of them at the full scale. So you do small scale tests and hope nothing unexpected happens in the full run.

For scale, a performance basline paper from 2018 reports achiving 0.23 simulated years per wall clock day using 4900 GPU cores [1].

[1]: https://www.geosci-model-dev.net/11/1665/2018/gmd-11-1665-20...

Re: Climate models are running red hot, and scientists don’t know why

#295

Post by viburnum »

nharada wrote: post #178

It's disheartening to read some of the comments here. Scientists are basically saying "we're not sure if it's going to be a disaster or a catastrophe", and some folk's response seems to be "see! scientists don't know! why should we listen to them?"

Some people will do anything to change the subject when the subject makes them uncomfortable. Better to quibble about models than to confront the disaster.

Re: Climate models are running red hot, and scientists don’t know why

#296

Post by imtringued »

zaroth wrote: post #148
lucisferre wrote: post #87

Earlier quoted context omitted.

Yes it would be terribly foolhardy for us to stop polluting the atmosphere prematurely.

This isn’t really a helpful reply, because of course it’s not a question of magically reducing pollution. There are two basic modes of reducing pollution. Technological advancement, and conservation. In the case of technological advancement, you get less pollution per unit of output as the same or lower cost. As long as capital is fairly cheap, these advances tend to propagate quickly through a competitive market. In…

Why do governments fail to take advantage of this opportunity to inject money into their economy? Didn't Trump promise to bring the manufacturing jobs back? How is he going to achieve that if he's not going to rebuild the current power infrastructure or discourages companies from investing into the lucrative EV market?

I'm seriously wondering why there is any reason to oppose technological progress at all. What can they possibly gain by sticking to the old technology? Who's going to benefit from something so short sighted?

Re: Climate models are running red hot, and scientists don’t know why

#297

Post by [deleted] »

viburnum wrote: post #295
nharada wrote: post #178

It's disheartening to read some of the comments here. Scientists are basically saying "we're not sure if it's going to be a disaster or a catastrophe", and some folk's response seems to be "see! scientists don't know! why should we listen to them?"

Some people will do anything to change the subject when the subject makes them uncomfortable. Better to quibble about models than to confront the disaster.

[deleted]

Re: Climate models are running red hot, and scientists don’t know why

#298

Post by ilkan »

allovernow wrote: post #226

>The scientists went on to try 300 configurations of rain, pollution, and heat flows—something they can do as gods of their own digital earth—before matching the model to history. Having worked with complex geologic (not climate) models in the past, this is the part that gives me pause. The scientists have set out as a first principle to find warming and then are working backwards and, ostensibly, everything is legit…

As to your first point, I believe they are looking for the best fit to decades of data, not to a single point in time. As to your second argument, both historically and presently in science the tall nail gets hammered, it's a very conservative field. They look for a consensus (agreed minimum warming of x) rather than (an expected average warming of x).

Re: Climate models are running red hot, and scientists don’t know why

#299

Post by Accujack »

giarc wrote: post #125
Accujack wrote: post #81

Earlier quoted context omitted.

Not to rain on your parade, but programs like this from big power companies are essentially meant to allow customers to feel good while simultaneously not going through the work and cost of switching completely to renewable power. That's because the power companies want to keep people from developing competition to them... if enough individuals install solar plants with battery storage, eventually they power company…

Bullfrog Power isn't a power company. They invest in green energy projects. https://www.bullfrogpower.com/green-energy/projects-and-sour...

My bad, then. Carry on.

Re: Climate models are running red hot, and scientists don’t know why

#300

Post by SiempreViernes »

gbasin wrote: post #166
wbeckler wrote: post #154

Earlier quoted context omitted.

Here's a systematic comparison of climate model predictions vs reality, since the 1970s. It turns out that the models have done a great job of predicting reality. https://www.carbonbrief.org/analysis-how-well-have-climate-m... I'd be curious where your impression comes from, in terms of what sources of information you're receiving.

I was thinking of the same data, I guess it's not quite as clear as I thought, but the majority are overestimating the warming: https://www.carbonbrief.org/wp-content/uploads/2017/10/Scree...

If the idea is that the error in estimation is random around 0, you would expect about half to be overestimating.

I think 5 out of 8 is not a very strong difference from 4 out of 8, which is the comparison that makes sense in this context.

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