AMO Turns Negative(at least temporarily)

[FloridaJohn]

Climate models are atmospheric models. This statement is just plain wrong.

Let me just clarify what I meant since apparently I was being too subtle in my phrasing. I said "climate models are not the same as atmospheric models," and I meant exactly that. They are not the same. They are similar, the underlying physics are the same, but the models themselves are not the same. Otherwise, why wouldn't they just use the same model that is used for five day forecasts and just run it forward 50 or 100 years? So, like I said, they are not the same. I believe you have actually agreed with this when you said:

I already stated what the difference is between climate models and weather models

So even you understand there is a difference between the models, which is what I said.

Here is a chart from the article, which I'm still not sure you have read yet.

You can see it has a large atmospheric component, but that is not all. It also includes fast and slow feedbacks, as well as land use changes. Those additional components do not appear in standard weather models. That is all my point was, that they are not the same.

Climate models are not designed to, and not expected to, produce exact year-to-year variations in temperature. They are not "weather forecasts". Climate models are designed to show trends over decades-long time periods. So when you show a chart that shows current temperatures not matching exactly with a climate model result, you are being disingenuous on what that means. Climate models are run many times with different input conditions, and then the results are averaged together to produce the final line.

Due to this averaging step, there is no expectation that the model's lines will line up with year-to-year variations in global temperature. There is an expectation that long term trends (30 years) will be accurate.

[blizzard1024]

Let me just clarify what I meant since apparently I was being too subtle in my phrasing. I said "climate models are not the same as atmospheric models," and I meant exactly that. They are not the same. They are similar, the underlying physics are the same, but the models themselves are not the same. Otherwise, why wouldn't they just use the same model that is used for five day forecasts and just run it forward 50 or 100 years? So, like I said, they are not the same. I believe you have actually agreed with this when you said:

So even you understand there is a difference between the models, which is what I said.

Here is a chart from the article, which I'm still not sure you have read yet.

You can see it has a large atmospheric component, but that is not all. It also includes fast and slow feedbacks, as well as land use changes. Those additional components do not appear in standard weather models. That is all my point was, that they are not the same.

Climate models are not designed to, and not expected to, produce exact year-to-year variations in temperature. They are not "weather forecasts". Climate models are designed to show trends over decades-long time periods. So when you show a chart that shows current temperatures not matching exactly with a climate model result, you are being disingenuous on what that means. Climate models are run many times with different input conditions, and then the results are averaged together to produce the final line.

Due to this averaging step, there is no expectation that the model's lines will line up with year-to-year variations in global temperature. There is an expectation that long term trends (30 years) will be accurate.

 

Land ice cover which is snow appears in the weather models, SSTs do, land use does, sea ice does, in fact all these are in the weather models except they are not varied like they are in climate models. Plus the extra changing components in the climate models adds extra degrees of variability and error which feeds back to the actual atmospheric circulations. If anything they are even more complex than the models that are run for weather which makes them even more prone to error growth due to the non-linear feedback nature of the climate system. You can glean basic stuff from climate models...but to be so certain about feedbacks or use them to test sensitivity or attribution is going to have a lot of uncertainties. 

[sokolow]

The Tung et al paper (2013) was critical of the Foster/Rahmstorf (2011) paper on seperating the anthropogenic vs unforced warming trends and The recent Trenberth et al,

Had been meaning for a while to pop in and say I went and had a read of these and the surrounding blogosphere hullabaloo, and it was interesting. Thanks.