I’m waiting for May global land + ocean temperature data to be published from Hadley Climate Research Unit, at which time I’ll also show a comparison to GISS.
Since I did pretty well at guessing what RSS May data value would be, guessing 0.05 to -0.15°C, and having it end up at -.083°C, I’m going to put forth one for CRU.
My SWAG for HadCRUT is between +0.10 and +.0.17°C
Here is April 2008 from HadCRUT at 0.25°C
Click for a larger image
Reference: HadCRUT3 anomaly data which can be found here
description of the HadCRUT3 data file columns is here
Steve Stip:
True in what respect?
That the equations being used are incorrect or that Miskolczi re-derived the solution?
One of the tricks I learned long ago that helps when dealing with complex problems is “follow the energy.” There’s obviously something wrong with the “runaway GHG” scenario. Physical systems don’t usually do that — if only because it normally requires a release of internal energy. I can’t envision a scenario where an opaque gas could release internal energy without transforming itself chemically.
I say “obviously” because … well … it doesn’t happen. The temperature is stable. I don’t buy the “tipping point” logic for even a second. It’s not like the atmosphere is similar to a ball about to fall off the edge of a cliff where downward energy suddenly “appears” in the form of gravity. Nor is it like a chemical explosive that experiences sudden energy release after passing a threshold.
The dropping-off-a-cliff scenario is not completely out of the picture, though. It is possible that whatever negative feedback system that is currently operating to keep temperature in check could become overwhelmed. Still, the
handwavingpostulation of atmospheric “tipping point” is a guess. The proponents certainly can’t say what that feedback currently is let alone how much it can take before breakdown.OldJim,
Thanks, I wish I had paid more attention in differential equations.
In the days before computers, I reckon it made sense to simplify equations but with computers what need is there for that anymore?
If you want to read a simplified explanation (even I can understand most of it) this may help.
The subsequent 3 parts are also available as links within the comments
http://landshape.org/enm/modeling-global-warming/
Steve Stip (07:34:47) :
“In the days before computers, I reckon it made sense to simplify equations but with computers what need is there for that anymore?”
It’s not so much simplifying equations, but solving them. For example, if you know that acceleration is force / mass, then you can derive velocity and position given the initial values. One way is to derive the solution by integrating acceleration wrt time once for velocity and again for position. The other way is to let the computer do it with small steps in time. The differential equation is simple, a = f / m. The solution is more complex, s = s0 + (v0 x t) + (a x t^2)/2, where s0 and v0 are the initial position and velocity. (And things are more complex is acceleration isn’t constant.)
The advantage of the calculus solution is better understanding and having a new equation that can be readily applied. The disadvantage is that it doesn’t take much of a system that is described by a set of differential equations that cannot be solved. Then there’s really no choice these days other than letting the computer chew.
Checking one’s work, be it a suspension bridge or spacecraft heat shield or planet is never easy, but it is important.
While Miskolczi’s paper is very important, the feedback factor used in the models to try to handle the effect of more water vapor as the atmosphere warms appears to provide an even bigger error in the models.
Sidebar:
Any chaotic system doesn’t have a single equation that describes how it behaves. The best know and one of the first documented is the Lorenz attractor that takes three simple equations that describe atmospheric convection. I assume some variant of them are in weather prediction models, possibly not in climate models.
At any rate, no solutions, the best we can hope for are good answers. We have a ways to go.
http://en.wikipedia.org/wiki/Lorenz_attractor
DAV,
I meant, are the equations used false or not complete? What is the basis for the AGW claim if they use the wrong equations in their models?
Yes, predicting the past is easy, a neural net could learn to do that.
Also, the highest temperature I can imagine the earth reaching would be if it were painted black. How hot is that?
DAV,
My assertion about neural nets was rash. Still, in my experience, a simulation can be tweaked to give the “correct” results.
Ric Werme (08:51:41) :
Yes, you are speaking of the difference between the analytic approach and the iterative approach (made practical by computers). I always appreciate a math lesson though, particularly by a good teacher.
“At any rate, no solutions, the best we can hope for are good answers. We have a ways to go.” <—- humility, the secret of greatness
Thanks.
OldJim,
Thanks for the link. It looks good and something that might be at my level.
Hadcrut is now in for May:
2008/05 0.278 0.294 0.262 0.443 0.114 0.278 0.272 0.444 0.113 0.444 0.113
John M Reynolds