Merged Recent climate observations disagreement with projections

[Dancing David]

Don't we also have data showing that there has been an overall increase since the little ice age?

No because there is some debate over the extent of the LIA. Or at least the interpretations vary.

 

[macdoc]

Poptech doesn't like the critters opinion of his nonsense either......

Ample evidence Florida's feeling effects of climate change

By GEORGIA TASKER
Miami Herald
Saturday, March 28, 2009

Maybe the fish are on to something. Don Hammond, who catches, tags and releases dolphin-fish (also known as mahi-mahi), says those Florida natives are being hooked in some unusual places.

Like Massachusetts and Canada.

continues...
http://www.palmbeachpost.com/localnews/content/state/epaper/2009/03/28/0328climate.html

Yum I like maha mahi - last caught one in Dominican Republic.....maybe a Cape Breton catch is order now....

and he has yet to provide an alternative for the warming - which he grudgingly acknowledged - that fits with known physics and also explains why established GHG mechanisms have ceased to function......

 

[Wangler]

No because there is some debate over the extent of the LIA. Or at least the interpretations vary.

So if no increase, are we still in the LIA?

Can anyone point me to sources that describe how the start-stop of things like the LIA, or Maunder Minimum are determined?

 

[bokonon]

Scientists generally understand the difference between raw empirical data, and models.[/B] Just like they know the difference between data and theory. And the difference between observations and explanations.

It would be a stupid, irresponsible scientist to claim that models meet the stringent standards of actual data sampling. Thankfully, climatologists only use models... as models... to help inform them of what could happen... and NOT as the be-all-end-all ultimate truth of what's definately going to happen.

When I look at the raw empirical data charting carbon dioxide levels and global temperature stretching back over the past several hundred thousand years, I don't see the temperature rising and falling in lockstep with the CO₂ levels. Consequently, I'm inclined to doubt a team of experts with their black-box models telling me that's what's happening now, and we need drastic, immediate action to reverse it.

We do seem to be in a long-term warming trend right now. The raw empirical data tells us this.

What it doesn't tell us, and what only the models tell us, is how much this trend is influenced by human activities.

I'm inclined to agree with PopTech, that models of something as complex and poorly understood as climate are probably not worth basing policy on right now. Every technical trader on Wall Street has a "computer model" that he can back-test against decades of price data, and even in a system like that, with only two real variables (price and volume), their back-tested fitting doesn't enable them to accurately predict the future. Why would anyone assume that it will be any different with something like climate, which is more complex by orders of magnitude?

But I do have one real question. How many of these climate models are open source or public domain? Are the code and design documents available for public scrutiny anywhere? When Nature or Science publishes the conclusions or projections of such models, I haven't seen listings accompanying the articles. Are they available somewhere?

 

[technoextreme]

When I look at the raw empirical data charting carbon dioxide levels and global temperature stretching back over the past several hundred thousand years, I don't see the temperature rising and falling in lockstep with the CO₂ levels. Consequently, I'm inclined to doubt a team of experts with their black-box models telling me that's what's happening now, and we need drastic, immediate action to reverse it.

Well that is a Poptech level screw up you have here. There is plenty of stuff you can't see by just looking at the raw data in science.

Every technical trader on Wall Street has a "computer model" that he can back-test against decades of price data, and even in a system like that, with only two real variables (price and volume), their back-tested fitting doesn't enable them to accurately predict the future. Why would anyone assume that it will be any different with something like climate, which is more complex by orders of magnitude?

Another Poptech level screw up of basic science. Someone back me up here but economic models are chaotic as opposed to climate models. You just compared an apple to an orange.

 

[BenBurch]

Well that is a Poptech level screw up you have here. There is plenty of stuff you can't see by just looking at the raw data in science.

Another Poptech level screw up of basic science. Someone back me up here but economic models are chaotic as opposed to climate models. You just compared an apple to an orange.

Indeed. Spot on.

 

[Wangler]

Someone back me up here but economic models are chaotic as opposed to climate models. You just compared an apple to an orange.

So your contention is that climate models are simpler than stock priced models with two DOF?

Care to elaborate?

 

[technoextreme]

Indeed. Spot on.

Thanks. As I have said before I am not really debating whether or not global warming exists. I just want to make sure that everyone's science assumptions are ok. Just to reiterate clarify chaotic systems differ from other systems in that in the slightest change in a single variable will completely change the output. Another example includes the double pendulum. The slightest change in position drastically effects its behavior.

So your contention is that climate models are simpler than stock priced models with two DOF?

Care to elaborate?

Not really simpler persay but that one is much more sensitive to initial conditions than the other. And Im sure I just dragged this conservation into a realm that I know is going to be brought up now.

 

[Wowbagger]

What it doesn't tell us, and what only the models tell us, is how much this trend is influenced by human activities.

There are some lines of empirical evidence for that, too. Such as an increase in carbon isotope signatures from artificial burning sources, found in ice cores.

But, the models can put it all together, better than anything else we got, right now.

I'm inclined to agree with PopTech, that models of something as complex and poorly understood as climate are probably not worth basing policy on right now.

I agree with the point that policy can not be based solely on climate models.

But, I think PopTech and I seem to disagree on another point: He thinks they should be tossed out and ignored, entirely, as the "useless" buggers they are. I am willing to acknowledge that they provide a valuable tool for helping shape our understanding of climate, and how it can change over time.

(snip) Why would anyone assume that it will be any different with something like climate, which is more complex by orders of magnitude?

Beats me. I know the vast majority of policy makers don't.

But I do have one real question. How many of these climate models are open source or public domain? Are the code and design documents available for public scrutiny anywhere? When Nature or Science publishes the conclusions or projections of such models, I haven't seen listings accompanying the articles. Are they available somewhere?

That I can not answer so easily. I suspect a lot more university work is available than privately developed work.

But, as important as examining the source code might be, you still get a lot of value reading the deascriptions of how the models work, and the formulas they utilize. Most of your assessment of the model can be developed from that. The actual source code would probably be more useful, if you suspect an error in the actual implementation of code.

 

[BenBurch]

Stock price models have psychology at their basis. Not likely to be modeled right at any time in the foreseeable future. Would be simpler if everybody acted exactly as Ayn Rand says they ought to, but human beings are just not like her conception of them.

 

[Wangler]

Thanks. As I have said before I am not really debating whether or not global warming exists.

Smart move. I don't think that there are too many people who would argue that global warming doesn't exist.

 

[bokonon]

But, I think PopTech and I seem to disagree on another point: He thinks they should be tossed out and ignored, entirely, as the "useless" buggers they are. I am willing to acknowledge that they provide a valuable tool for helping shape our understanding of climate, and how it can change over time.

I agree that they're probably useful in testing how well we understand the forces which shape the climate, so I'm not saying they should be abandoned altogether. But I do think it's premature to implement a policy like "cap and trade" based on what the models say.

But, as important as examining the source code might be, you still get a lot of value reading the deascriptions of how the models work, and the formulas they utilize. Most of your assessment of the model can be developed from that. The actual source code would probably be more useful, if you suspect an error in the actual implementation of code.

That sounds reasonable. Are these descriptions and formulas available in the articles, and are there any you would specifically recommend for someone who hasn't really been engaged in AGW debates up to now?

 

[macdoc]

Here you go - get these understood before tacking the underlying formulas

http://www.realclimate.org/index.php/archives/2008/11/faq-on-climate-models/

http://www.realclimate.org/index.php/archives/2009/01/faq-on-climate-models-part-ii/

•••

But I do think it's premature to implement a policy like "cap and trade" based on what the models say.

You are focused on GHG and temperature...only ....there is sufficient reason in ocean acidification alone to move quickly to carbon neutral.....
Models only confirm observations.

Monaco declaration
http://news.bbc.co.uk/2/hi/science/nature/7860350.stm

Just as S02 was tackled successfully it's time for C02 as well to be controlled....long overdue.

 

[bokonon]

Someone back me up here but economic models are chaotic as opposed to climate models. You just compared an apple to an orange.

What makes you think that climate models are not chaotic?

 

[Herzblut]

Are these descriptions and formulas available in the articles, and are there any you would specifically recommend for someone who hasn't really been engaged in AGW debates up to now?

I'd recommend to have a look at:

Considering the Human Influence on Climate
by Dr. Roger A. Pielke, Sr.

http://www.marshall.org/article.php?id=656

Check out the very balanced and reasonable PDF article.

 

[Wowbagger]

I agree that they're probably useful in testing how well we understand the forces which shape the climate, so I'm not saying they should be abandoned altogether. But I do think it's premature to implement a policy like "cap and trade" based on what the models say.

I don't think anyone is implementing "cap and trade" based solely on what models say, either.

I don't think there is anyone of any significance using models as the sole basis for anything important. That would be an abuse of models.

If there is such abuse around, I would like to see some examples.

Are these descriptions and formulas available in the articles, and are there any you would specifically recommend for someone who hasn't really been engaged in AGW debates up to now?

I will see if I can dig up some good, specific examples later.

For now, this Wikipedia entry is a good starting point: http://en.wikipedia.org/wiki/Climate_model

 

[mhaze]

I was only trying to demonstrate that the IPCC does not solely rely on computer models.

The papers I linked to are full of empirical assessment.

What they prove or not is another debate.

My point is that the IPCC takes a comprehensive approach, that examines a mix of computer models and other things. That is all....

Skirting the issue. What the IPCC "examines" is not relevant to your assertion except when they address the subject of your assertion.

I've indicated how you could draw some data from the IPCC to support your assertion (and then I would shred it of course).

You've tried to claim some things helped your case that were unrelated, and you've been invited to do better.

 

[Wowbagger]

Skirting the issue.

I was addressing PopTech's specific claim that IPCC was basing their policies solely on models. I was not addressing any of your claims with those links.

Here is the claim:

Then why is the IPCC's conclusions all based on computer models

I demonstrated that they are not.

 

[aleCcowaN]

I've indicated how you could draw some data from the IPCC to support your assertion (and then I would shred it of course).

How do you know you will shred them? You will shred them no matter how, you will shred them no matter what cat fighting technique you have to resort to, that's what you meant, did you?

 

[lomiller]

Another Poptech level screw up of basic science. Someone back me up here but economic models are chaotic as opposed to climate models. You just compared an apple to an orange.

Climate models are physical, while economics models are statistical. In an economic model you find a pattern in the existing data and hope it continues as new data comes in. There are two serious problems with this:

First there are too many degrees of freedom. You can always find a pattern in any data.

Second the underlying driver is human behavior. I any model becomes to good people follow it and this changes the behavior of the system being modeled.

With a climate model on the other hand, you simulate the underlying physics. This constraint reduces the degrees of freedom and makes the model a lot more reliable.