The Planck Response is defined as the warming you get with no feedbacks. There’s the Forcing and the Response, and also potentially Feedbacks to the Response that amplify or suppress it. The Planck Response to doubling CO2 is about 1.2 C. Larger responses come from a positive feedback and smaller ones from a negative feedback. The response is the warming and the Planck Response is a special case.
Comment on Week in review – science edition by Jim D
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Comment on Week in review – science edition by Jim D
Define a positive feedback then. That also is a case of warming which you would also call a negative feedback. The only thing you would call a positive feedback is runaway warming or maybe that is extremely negative in your terms because it is even more warming than the Planck Response. Think about it. You see what a mess your definition is.
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Comment on Week in review – science edition by Robert I. Ellison
“The Planck feedback is the most basic and universal climate feedback, and is present in every climate model. It is simply an expression of the fact that a warm planet radiates more to space than a cold planet.
As we will see, our estimate of λ0=−3.3 W m^−2 K^−1 is essentially the same as the Planck feedback diagnosed from complex GCMs. Unlike our simple zero-dimensional model, however, most other climate models (and the real climate system) have other radiative processes, such that λ≠λ0 .”
http://www.atmos.albany.edu/facstaff/brose/classes/ATM623_Spring2015/Notes/Lectures/Lecture03%20–%20Climate%20sensitivity%20and%20feedback.html
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Comment on Week in review – science edition by Robert I. Ellison
What utter nonsense.
The Planck response is not 1.2 C – it is -3.1 W.m^-2.K^-1
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Comment on Week in review – science edition by Geoff Sherrington
JimD,
Sorry the essay was beyond you.
You were invited to learn from it because your dogma is out of date.
Geoff.
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Comment on Week in review – science edition by Jim D
OK, so you don’t even define the response in terms of how much warming it goes with. This may be why you can’t define a positive feedback. For you any amount of warming is a negative feedback, the more warming the more negative. Opposite to common sense.
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Comment on Week in review – science edition by Jim D
That’s fine. Do you say anything different from other skeptics that would be worth looking at, or is it just a repackaged mash-up? I’ve seen it all before, and it is less than convincing.
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Comment on Week in review – science edition by Robert I. Ellison
Positive and negative feedbacks have +ve and -ve signs in front of them. It is explicit in the IPCC graphic. What’s your freakin point?
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Comment on Week in review – science edition by Jim D
The Planck response is -3.2 W/m2/K. If the actual response is -1 W/m2/K that is still a negative feedback to you, but a strong positive feedback in climate terms because it would be 3.7 K per doubling instead of 1.2. See how opposite to reality your definition is?
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Comment on Week in review – science edition by Robert I. Ellison
Using the 4 W/m2 for a doubling of CO2 and IPCC feedbacks – with the simple formula in the link I provided earlier – you get an ECS of 2.6 K – depending largely on clouds. LOL.
But that is really a quite pointless exercise. Much like this. You confuse the Planck response with the Planck feedback and piffle on with your usual snark. That is contrary to common sense.
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Comment on Week in review – science edition by Jim D
Is an ECS of 2.6 K a positive or negative feedback to you?
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Comment on Week in review – science edition by Robert I. Ellison
The Planck feedback is -3.2 m-2 K^-1. The Plaqnck response is 1.2 K. Confusing? Not really.
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Comment on Week in review – science edition by Jim D
So what is a positive feedback to you? Your definition has any warming at all as a negative feedback. The more warming the more negative. Doesn’t make sense.
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Comment on Week in review – science edition by Robert I. Ellison
Net feedbacks are always negative or the formula loses all physical meaning.
ΔTs = -(R/λ)
Plug in R for a CO2 doubling an net λ – in quadrature ideally to account for uncertainties.
How accurate or useful is any of it? Not very – especially if you murder the basics. . .
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Comment on Week in review – science edition by Jim D
You have your own definition then, because in climate, any sensitivity larger than 1.2 C per doubling signals a positive feedback, but a positive feedback is impossible under your definition just using a sign. You would be very confused by people talking about positive feedbacks if you really believe your definition of it.
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Comment on Special Report on Sea Level Rise by Andrew Bolt Misleading – Andrew's Blog
[…] (https://judithcurry.com/2018/11/27/special-report-on-sea-level-rise/) provides an independent research report on sea rise. It makes interesting reading, but is not […]
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Comment on Week in review – science edition by Robert I. Ellison
The less negative the net feedback – the more the warming. Makes perfect sense.
ΔTs=−(R/λ)
For doubling of CO2 – with only the Planck feedback.
ΔTs=−(4 W/m2 / -3.2 W m^2 K^-1) = 1.2 K
Everything you don’t know is here. Pay particular attention to the derivation if you can.
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Comment on Week in review – science edition by Jim D
That’s a confused definition. He defines the difference from the Planck Response as a positive or negative feedback, while also defining the Planck Response as a negative feedback itself when the difference from itself is zero implying zero feedback. Muddled. Two different contradictory negative feedback definitions. A mess you wouldn’t get into if you defined it as the Planck Response, not a feedback itself.
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Comment on Week in review – science edition by Robert I. Ellison
1.2 K is the response using only the Planck feedback – do you understand now why it is called the Planck response?
But there are positive feedbacks shown in the IPCC graphics. The sum is also shown – and clouds may be positive if uncertain.
The sum – is what you do with feedbacks – is less negative than the Planck feedback by itself and the response is greater.
Are you not capable of understanding the link provided? Or are you simply arguing nonsense now for climate partisan reasons?
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Comment on Week in review – science edition by Jim D
I am saying you have two different definitions of negative feedback in that article. Better to stick with sign of the difference from the Planck response, which is therefore the no-feedback response. See here, for example.
https://judithcurry.com/2010/12/14/co2-no-feedback-sensitivity-part-ii/
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