Simple Question About AGW

[Round Robin]

Excellent summary

Thank you, TS.

Regarding this whole Hansen thing, I think that we have all found primary source documents that allow us to be reasonably confident in claiming the following:

• Hansen considered the CO2 component of the Scenario A predictions to be "business as usual" (and BAU CO2 is what occurred)
• Hansen believed that Scenario B was the most plausible combination of all components of the A/B/C predictions (and none of the scenarios occurred in total)

Can we all agree that is fair?

My inference, because I have found no written proof of this, is that Hansen, therefore, did not believe it was likely for CO2 emissions to be worse than "business as usual" in the coming decades, so it was sensible to use BAU as a component of the Scenario A (worst case) forcing predictions. Any question as to the accuracy of the models, the sensitivity assumptions, etc., I am not qualified to comment on as I have not studied that yet. (heck; even if I did study those things I'm not sure I'd be qualified to comment! )

I'm not here to dispute whether or not he is a far-left radical; I have no position on that yet, as I have not studied him beyond the three or so source documents we've been discussing. I merely propose that the above summary of the whole Scenario A/B/C question is reasonable and balanced. Can't we all just get along?

 

[TrueSceptic]

Thank you, TS.

Regarding this whole Hansen thing, I think that we have all found primary source documents that allow us to be reasonably confident in claiming the following:

• Hansen considered the CO2 component of the Scenario A predictions to be "business as usual" (and BAU CO2 is what occurred)
• Hansen believed that Scenario B was the most plausible combination of all components of the A/B/C predictions (and none of the predictions occurred in total)

Can we all agree that is fair?

I think so. GCMs require huge amounts of computing power and this was very limited then (and still is relative to the complexity of the models). Ideally Hansen would have run a very large number of scenarios with different combinations of factors. He used just 3 to represent the many. It would be strange for the middle of the 3 not to be considered most likely, even if A was labelled BAU.

Had Michaels been honest in 1998, he would have shown all 3 scenarios and argued that B, although closest to what had actually happened in terms of temperature rise, was based on factors that didn't develop exactly as the model assumed, and that the model was therefore weak. He didn't.

My inference, because I have found no written proof of this, is that Hansen, therefore, did not believe it was likely for CO2 emissions to be worse than "business as usual" in the coming decades, so it was sensible to use BAU as a component of the Scenario A (worst case) forcing predictions. Any question as to the accuracy of the models, the sensitivity assumptions, etc., I am not qualified to comment on as I have not studied that yet. (heck; even if I did study those things I'm not sure I'd be qualified to comment! )

We always seem to end up arguing about the credibility of the scientists, and when that fails, move on to the reliability of the data, so actual science rarely enters into it.

I'm not here to dispute whether or not he is a far-left radical; I have no position on that yet, as I have not studied him beyond the three or so source documents we've been discussing. I merely propose that the above summary of the whole Scenario A/B/C question is reasonable and balanced. Can't we all just get along?

Agreed.

I think that Hansen cares passionately about the future of the biosphere; I don't think this necessarily indicates a left/right position.

If you see myself or others being abusive, you will rarely see that it is unprovoked. You might also understand that it is hard to remain polite after seeing the same disreputable tactics and outright garbage being repeated over and over. I'm impressed that you are still as polite as you are.

 

[Round Robin]

Had Michaels been honest in 1998, he would have shown all 3 scenarios and argued that B, although closest to what had actually happened in terms of temperature rise, was based on factors that didn't develop exactly as the model assumed, and that the model was therefore weak. He didn't.

That seems like a fair compromise; it neatly incorporates everyone's views, in my opinion.

 

[Bluefire]

That seems like a fair compromise; it neatly incorporates everyone's views, in my opinion.

Depends on what is supposed to be judged.

If we are to judge how good the science behind the model is, and the performance of the climate-modeling, then it is very much reasonable to say that the differing factor between A,B and C developed in accordance with A, and that as such, A is the relevant prediction to judge against the resulting temperature trend.

If we are to judge how well Hansen can predict political actions, sure , then B was the "most probable" from him. But that isn't really relevant to most discussions.

 

[Round Robin]

Depends on what is supposed to be judged.

If we are to judge how good the science behind the model is, and the performance of the climate-modeling, then it is very much reasonable to say that the differing factor between A,B and C developed in accordance with A, and that as such, A is the relevant prediction to judge against the resulting temperature trend.

If we are to judge how well Hansen can predict political actions, sure , then B was the "most probable" from him. But that isn't really relevant to most discussions.

Well, when I say "everyone's views", I meant the handful of people debating this point over the last few days. Still you make a fair point: it is presumptuous of me to assume that all views (even of the few of us debating) were incorporated. Now that I think of it, they probably weren't.

 

[Slimething]

Did you really mean to say that?

Yup. Are you arguing that my statement is self-contradictory? In your mind is elting ice = poles warming faster than the tropics?

 

[Slimething]

Science is the study of nature. Anthropology is the study of humanity. Unless you want to claim that humanity is not part of nature, you are simply wrong.

Amazing logic here. The study of anything that is natural is therefore science. Suddenly, I realize that religion, economics, politics and so on are sciences.

Why do I get the impression that you are either very young or not at all trained in science?

 

[Slimething]

Completely incorrect. Computer models are simulations of natural physical processes. Of course they are subject to error because of the simplifications inherent in them as well as (normally) the incomplete understanding of the physical process that the model is simulating.

Let me get this straight. You believe that computer models self-generate in computers and are incorrect only because the code over-simplifies nature? So, at no time is a scientist with a hypothesis and a software engineer involved in creating said model? Do you realize that you've just stated that something can come from nothing?

Polar regions are much more sensitive to changes than tropical regions because of the reflective properties of snow and ice. Snow and ice reflect more than 80 percent of the insolation back into space. Therefore, a decrease in snow and ice extent will lead to an decrease in the amount of insolation reflected and thus an increase in the amount of insolation absorbed. This will amplify the warming.

You may be late to the show here. I'm not asking whether or not the poles warm. I'm asking why the tropics aren't.

Tropical regions are also proficient at exporting heat. The rest of the Earth would be cooler if local temperature was solely a function of local processes.

To export heat, the heat must first be present. Why isn't it? The atmosphere in the tropics apparently is showing no tendency towards heating although one would expect that region to be most vulnerable to AGW. That's all I'm asking right now.

 

[TrueSceptic]

That seems like a fair compromise; it neatly incorporates everyone's views, in my opinion.

I don't see it as a compromise. More of an accurate view (IMO!).

 

[Slimething]

CO2 trapping photons and heating up Earth's surface??? Where did you get that idea from? That is not an accurate summation of the AGW theory. Do you understand this topic?

I think you need to read up on the physical basis for the GHG AGW hypothesis. It's been covered in other threads. AUP can point you to a very good on-line textbook on the subject.

Ummm, the tropics are hotter than the poles. And no GW theory is predicting that this will change.

Ummm, you need to read the thread.

 

[TrueSceptic]

Amazing logic here. The study of anything that is natural is therefore science. Suddenly, I realize that religion, economics, politics and so on are sciences.

Why do I get the impression that you are either very young or not at all trained in science?

Where do I get the impression that you are a dogmatic, narrow-minded ignoramus? Oh, I know: from what you post!

 

[Round Robin]

I don't see it as a compromise. More of an accurate view (IMO!).

Yeah, I already came to the conclusion that I have no right to speak for anyone else by declaring this a compromise. Apologies to all involved for my presumptuousness.

 

[Alric]

I'm asking why the tropics aren't.

Besides another thread, do you have a reference for this statement?

I believe the tropics are.

But seriously, do you have a references for the tropics not warming?

 

[Slimething]

Greenhouse gases don't absorb light, they're transparent to it. They absorb infra-red radiation. Surfaces absorb (or reflect) light, and emit infra-red. Absorbed light is the energy-income, and infra-red the energy outgoings, of the global energy budget. (That's from radiative physics, which is founded on observations.)

Since I'm a scientist, I use the word "light" to refer to the entire EM spectrum. Your milage varies. In either case, that's how GHG AGW is supposed to work, absorbance of light by CO2 and efficient reradiation.

The greenhouse effect is a local (the Earth's surface) phaenomenon in which the Sun plays no part. It is just as effective at the poles as it is at the equator (or anywhere else), and its effect is to reduce outgoings. Since the poles import heat from the tropics (thermodynamics) their energy-balance is going to increase faster than the equatorial region (which exports heat by other than radiative means). Other things being equal, such as a flat Earth.

You are wrong. You make the distinction between magnitude of warming and rate of warmng. Both phenomena are directly proportional to the concentration of CO2 (Beer's Law) and the intensity of sunlight (first-order thermodynamics and Beer's Law). Any statement that GHG warming is the same all over the planet means that light is not part of the equation and the theory of AGW falls apart. You really need to study up on the physics here. Your hand waving is getting obvious.

From your increasingly garbled responses I can see how you might be scared of me (there's a hint of panic in there) but I don't set out to frighten anybody.

I was only pointing out that the only reason anyone would pay attention to someone like you on a scientific topic is your clammor that we are all in peril from AGW. Otherwise, why would anyone listen to the likes of you or know-nothing politicians?

 

[Slimething]

Besides another thread, do you have a reference for this statement?

I believe the tropics are.

But seriously, do you have a references for the tropics not warming?

I am referring to the lack of an atmospheric hotspot at the tropics. mhaze posted that there was a lack of it and CD confirmed that any warming would necessitate such a hotspot. So, as most of us agree that warming is or has occurred, I'm asking why no hot-spot.

My purpose is not to disprove AGW, as I don't think it can be. It's practically unfalsifiable. I want people to realize what the models are and that they are imperfect at the moment. Some cling to them as if they were theory, though.

 

[Alric]

Since I'm a scientist, I use the word "light" to refer to the entire EM spectrum.

Well you shouldn't. The entire EM spectrum is the entire EM spectrum. Light, is that small portion of the EM spectrum that can interact with photoreceptors in animal eyes.

 

[Alric]

mhaze posted....

I mean a reliable primary reference...

 

[Slimething]

Where do I get the impression that you are a dogmatic, narrow-minded ignoramus? Oh, I know: from what you post!

That's OK. No need to apologize for your mischaracterization of science. Indeed, that takes a lot of honesty and integrity to admit an error.

Be well.

 

[TrueSceptic]

Yup. Are you arguing that my statement is self-contradictory? In your mind is elting ice = poles warming faster than the tropics?

You said

I followed your link and found text telling me that ice in the poles was melting but nothing about predictions that the poles should get warmer than the tropics.

Try it again. Perhaps Mhaze will let you borrow his famous "grammer tense" ?

 

[TrueSceptic]

Let me get this straight. You believe that computer models self-generate in computers and are incorrect only because the code over-simplifies nature? So, at no time is a scientist with a hypothesis and a software engineer involved in creating said model? Do you realize that you've just stated that something can come from nothing?

That must be an all-time great straw man!