
Why I decided not to enter the $100k global warming time-series challenge - aaronchall
http://andrewgelman.com/2015/12/09/why-i-decided-not-to-enter-the-100000-global-warming-time-series-challenge/
======
coherentpony
The first lesson in any experiment is to understand the question you're
answering. This is a great example of that.

------
threeseed
Those who believe in climate change should just reframe the argument in the
face of skeptics.

Just say, "you're right, we don't know the science is true but just like
people/companies take out insurance in situations of risk so should we."
Because when the problem is reframed as an exercise in risk mitigation then it
is very hard to argue against. Especially when said activities have not been
shown to have a measurable impact on the world's economic activity. In fact
huge benefits will come if we invent largely free energy.

~~~
tn13
I am against climate change people because they invariably suggest that the
governments should do something. Often this is a good opportunity for the
governments to grab more power and take away our freedoms. In my opinion this
can bring more misery to humanity than the climate change.

For example Indian government is pushing Solar power without must thought.
Billions of taxpayer money is being spend on solar panels which we are not
sure if they will work. Same amount of money could have produced more energy
through conventional means, supported more industry and helped few more
million people get out of poverty, I am not sure that by using Solar panels
Indian government has saved million people in future.

I think a small invention like a floppy disk might have saved more trees that
all government efforts put together. Environment might be changing but I would
bet on people like Elon Musk any day than the government.

~~~
Angostura
> I am against climate change people because they invariably suggest that the
> governments should do something.

I'm not sure that you are aware of just how ludicrous, this sounds. Do you
have the same complaint when someone's house is burning down and people
suggest that firefighters 'should do something'?

~~~
topynate
Is the purpose of a government to do something about climate change in the
same way that the purpose of a firefighter is to do something about a burning
house? Why?

~~~
Angostura
Citizens assign functions to governments that are impractical for individuals
or markets to handle. It doesn't make sense for everyone to buy a fire truck
and there isn't a good business to be made from putting out fires.

A classic case where individuals may band together to invoke government is is
where a 'tragedy of the commons' situation is threatened.

Left to its own devices, it is perfectly rational in the short term for an
individual or business to continue polluting, over-fishing, deforesting or
using the atmosphere/oceans as an infinite waste removal resource. In the
medium and long term it isn't such a good idea and governments provide the
least worst mechanism that we have for citizens to collectively enforce
actions that can protect people, society or the environment.

~~~
pbhjpbhj
>there isn't a good business to be made from putting out fires. //

This used to be how it worked, at least in the UK. It's probably quite a good
business; there I'd a question of mutual destruction for the rich if they just
let poor people's houses burn but also I feel there's a factor of social
morality at play too. It is socialism, at least in part, that has brought
democratised healthcare and schooling, firefighting and policing. Profit
motive thankfully isn't there only social driver.

------
zump
Andrew Gelman is a wizard

------
cossatot
I think that the best way to go about this would be to home in on the "random"
natural variation and really analyze the noise. Random noise should have very
different spectral characteristics than real temperature data, which may have
~decadal periodicity (from the Pacific Decadal Oscillation) or similar non
homogeneous frequency content. But with highly down sampled data like this a
lot could be lost.

That being said this is basically a Turing test with snippets of conversation
selected by an antagonistic mediator. As Gelman has shown, the expected ROI is
very low and any climate scientist worth her salt is better off using that
effort in the grant proposal contest instead; more money and better odds.

------
ksrm
Reminds me of
[http://www.patrickcraig.co.uk/other/compression.php](http://www.patrickcraig.co.uk/other/compression.php)

------
gus_massa
I'd like to see a graph of the histogram with the three Gaussians
superimposed. In this cases, sigma is bigger than the difference of mu, so the
overlap of the Gaussians would be big and the series in the middle would be
difficult to classify.

This is not as detailed as the analysis in the article, and it doesn´t provide
an estimation of the difficulty of the challenge, but it's a nice visual
representation of the problem.

------
jessaustin
_You could say that the above all demonstrates Keenan 's point, that you can't
identify a trend in a time series of this length._

You could, indeed.

~~~
allenlavoie
You could, but you would be wrong, as the remainder of the paragraph you
started quoting argues quite convincingly. Fiddle with the free parameters of
the contest and it "demonstrates" whatever you want it to.

~~~
jessaustin
That's a fair synopsis of the paragraph, but that understanding only supports
"Keenan's point". If "parameter fiddling" is out of bounds, we're back to the
drawing board for more climate models.

~~~
andrewprock
Conflating "climate model" with "parameter fiddling" seems like the more
significant logical failure.

~~~
jessaustin
The first link when one googles "climate model parameter":

[https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-1...](https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch8s8-1-3.html)

~~~
andrewprock
Nice non-sequitur.

------
andrewprock
It turns out the fellow who posted the challenge is a crank. Not surprising
that it is negative expected value.

~~~
jessaustin
_Non sequitur!_ Most lotteries and similar contests have negative expected
values. The house always wins!

------
zurn
What language is that in the code snippet?

~~~
capnrefsmmat
Most of them are R, with some Stan mixed in later.

~~~
zurn
Thanks. Stan looks interesting! Seems this guy is a major figure in its
development too.

Link: [http://mc-stan.org/](http://mc-stan.org/) ("Stan is a probabilistic
programming language implementing full Bayesian statistical inference ")

HN discussion:
[https://news.ycombinator.com/item?id=10244771](https://news.ycombinator.com/item?id=10244771)

