I'm increasingly less impressed by the claim that we can't predict weather across weeks, but we can somehow predict climate across decades. (I've never been overwhelmed by it, but it seems even less sensible over time.) And part of the reason why is that we can't seem to predict climate across years, and I'm really unconvinced we can't predict climate across years but we can predict it across decades.

Wrong predictions are wrong predictions; it is irrational to keep excusing wrong predictions over and over again and insisting they'll just get more right in the unknowable future.

If the models can't look into the future even a few months and see a high probability of the vortex detaching (and I'm fine with a probabilistic prediction, in fact I'm deeply suspicious of anything else), what use are they for predicting anything else? One wonders if the models are even capable of expressing that prediction (in the machine learning sense of the word "bias").

We've gotten much better at predicting weather a few days out[0], because not only has our understanding of the Earth's climate improved by leaps and bounds, but we've also had the chance to iterate thousands of times over the last couple decades to see how well our models perform and adjust them based on that evidence.

On the other hand, we've only had the chance to iterate a few times over the last couple decades in predicting longer-term trends several years out, and even though our understanding has increased here as well, we don't have the benefit of very many results to confirm if that understanding is anywhere near enough to predict well over these sorts of time spans. Apparently arctic sea ice has decreased faster than predicted, but average global temperatures are falling out of the "95%" ranges of most of the models of a decade or two ago[1]

[0]http://www.nytimes.com/2012/09/09/magazine/the-weatherman-is... [1]http://www.economist.com/news/science-and-technology/2157446...

Predictions aren't magic. They're based on looking at past data and using that to draw conclusions about future data.

Weather, being extremely variable even within a day, is a lot harder to predict than, say, "It will be colder in January than in August (in the northern hemisphere)." That one's a slam dunk.

Watching the warming trend, it seems more predictable than weekly weather. Even now, with this winder, the north pole is warmer than normal which is part of what's causing the weather systems we're experiencing in North America (as you referenced with the vortex).

Why on earth would the models have something like this vortex detaching built into them? We've never seen it before, or seen it so rarely that nobody built it into the model. That doesn't say we can't predict climate, it just says we didn't predict this particular consequence of climate change.

The idea is that there's a mostly random high frequency medium amplitude component (weather), a somewhat predictable medium frequency high amplitude component (seasons), and a low frequency low amplitude component (climate).

So if you observe for long enough, the higher frequency parts mostly average out to zero and you can get an idea of the low frequency component. Even without being able to predict the other components.

(See also, http://en.wikipedia.org/wiki/Fourier_transform )

That predicting behavior at larger scales is easier than predicting it at small scales is a principle you'll encounter repeatedly in the physical science and engineering disciplines. In the physical sciences, models are often top-down, as opposed to in computing where they are almost always bottom-up. In fluid dynamics, for example, the behavior air in a turbulent flow is chaotic at the small scale. Yet, we can still design airplane wings because we have pretty good approximate models for how such flows behave at larger scales. Or to use a physics example: it's easy to predict where a baseball will land, but very complicated to predict where an electron will be in a molecule.

The analogy I like to think of is a ping-pong ball in the ocean. At any given second, its location will be hard to predict, as at the second-granularity, its location will be dominated by local phenomenon. But, over the course of months and years, we can often accurately predict where it will generally end up in the world due to ocean currents.

I, too, am a bit skeptical, but this is boiling climate science down into too simple an exercise. We do, for instance, know that things are warming up, and we have many different models to predict what effect that will have on, say, weather trends over a longish period of time. It's kind of like the stock market -- I might think that the fundamentals of company ABC are good, and believe that they will be up over the next five years. Some people do make reasonably good predictions of this sort. Predicting the open and close of ABC's stock tomorrow, however, or the high and low over the next three weeks, is another story, and there's reason to believe that we do no better than random chance at this kind of prediction, in aggregate.

See NASA scientist, "the father of climate change," James Hansen's 2009 book entitled Storms of My Grandchildren. He's highly critical of models, though notes that they may be useful in certain specific scenarios. What he focuses more on is the geological record because models can only be as accurate as the information that goes into them.

I want to keep this brief, but I also want to quickly note that the cap and trade for greenhouse gases is business as usual for energy producers. Don't believe a word of it; the short story is that it worked poorly in preventing acid rain and won't work for combating climate change. We need a fee and dividend system that doesn't come back to us in tax breaks. I should note that Hansen comes across as very credible and apolitical; I don't trust anyone else when it comes to climate science.

His most recent work is available here:

http://www.columbia.edu/~jeh1/publications.shtml

It is harder to predict very unusual events.

Also, I am not sure what difference it makes? We want to predict climate to inform environmental policy. But a lack of certainty does negate the damage that pollution does.

There is an enormous difference in localized weather predictions, and whole globe climate predictions. That is, it is possible to predict, say, average temperature across the entire world, while being unable to reasonably predict average temperature in any one place.

It seems to me that people are misunderstanding looking backwards and looking forwards...

Well maybe if CERTAIN PEOPLE IN THE MEDIA (mostly) and in POLITICS (sometimes) didn't trot out lines to the effect of "Oh, it's summer! and it's hot today! This must be PROOF of global warming!" every summer when it got hot, then we wouldn't get this kind of blowback when it's unexpectedly cold out.

There is a problem in scientific reporting.

Scientists want to be honest and truthful. People interviewing scientists don't have much scientific understanding, and don't have time to listen to a full answer. And they'll often then turn to someone else providing an opposing viewpoint for "balance". This new person doesn't care about scientific integrity and they're happy to spew their purely opinion based opinion. (And this is ignoring the people paid to provide FUD who ised to work for the tobacco companies and who know use similar tactics to deny clomate change).

Considering I still hear "Global warming is fake; this is the coldest winter I can remember" on a near-constant basis, I'd have to say the common layperson knows very little.

I feel the same way when I hear "global warming is real, this is the hottest summer I can remember" from the other side of the argument.

I'd trust a layperson as much as a scientist. Which is to say, not at all.

Global Warming seems to be a political distraction, driven by some businesses looking to get special favors (carbon trading).

Let's just ignore the problems we face now, like pollution and resource depletion, dubious food quality, inhumane factory farming...

People will always seek to make money from a perceived opportunity. Whether the opportunity is the climate changing or people mistakenly afraid that the climate is changing does not in any way change whether or not the climate is actually changing.

In other words, an increase in umbrella salesmen does not any any way prevent the sky from falling.

Frankly, I don't know if global warming is true. Having examined some of the claims and by using my own intuition, I think it probably is. But its validity shouldn't matter to you if you truly care about the problems you listed.

For example, let's look at two of the other problems you listed that we are supposedly currently ignoring: pollution and resource depletion. Both of those problems are usually tied to the burning of fossil fuels, which just so happens to be the suggested cause of global warming. The suggested fix of global warming is typically burning less fossil fuels, which would in turn reduce pollution and lower our resource consumption. If you truly feel that those problems are what we should be focusing on, you should encourage people to believe global warming is a problem that needs fixed as it would further your goals.

Personally, I don't care if somebody makes a mint off solar power. I'd rather have money go that direction than the oil conglomerate. Even if both groups were equally "evil", I'd still vote for solar because I believe it's better for the ecosystem.

>you should encourage people to believe global warming is a problem that needs fixed as it would further your goals.<

Not sure if you missed a /sarc on that? Anyway, I think the root cause is clearly 9 billion humans on the planet, thus I got myself 'fixed' after having 2 kids (2.1 is the replacement rate), but I'm not going to lie to people about some warming to make my point... in fact, that would probably distract yet again from seeing the underlying problem.

It's quite depressing that people can't see three basic things:

1) exponential population growth is unsustainable (e.g. more than 2.1 kids)

2) resources per capita goes up when capita goes down (a good thing)

3) make a better world (technology, etc.) before increasing the population size... don't make it your kids' problem.

What has to do a climate scientist with "some businesses looking to get special favors (carbon trading)"

Are you saying that they are part of a conspiracy?

After spending a good deal of time reading about government funded nutritional 'science' over the last 50 years, in which high-carb hysteria took over (making many of us much less healthy, but making certain large businesses much richer, edit: and making food price inflation appear low), it's quite easy to make a case that research institutions dependent on government grants will absolutely not want to upset the status quo, and junk science is the result.

Let's also look at how many economists said "nobody could have seen the debt crisis coming". Clearly, skepticism that would harm the elites is not welcome in respectable academic institutions.

Let's say a democratic government does 99% of what rich or connected people want it to do. (Perhaps that's marginally better than a dictatorship) But the government wants to prove 'scientifically' it's doing the right thing. So it funds nutritional scientists and economists (and I will assume climate scientists) that see the 'right things' and give the policies legitimacy.

You say conspiracy, but the supreme court would disagree - this is just 'free speech' - corporations are people too! I'm sure you've heard "It is difficult to get a man to understand something when his salary depends upon his not understanding it."

No need to be deliberately obtuse--there are many people in industry and government who stand to benefit from carbon trading. There are also many scientists who research climate change. The two groups do not have to be intimately connected for them to benefit from each other.

Were all the loan originators at Countrywide part of a conspiracy to sell bad loans, or were they just "following the money"? Why would grant-seeking scientists be immune to the same incentives?

The OP has said that he doesn't trust scientists.

So, is he saying that scientists are part of a conspiracy.

And before calling others obtuses, read what the OP has said.

> Do people really know the difference between weather and climate?

In the UK, people worry about the climate and moan about the weather.