Talk-Polywell.org

For the latest IPCC report the climate models did 5 runs each (I have only read about a few but they all report the 5 runs number).

The problem with that is computer generated chaos and the "initial conditions" problem. And the chaos of climate/weather itself.

You need to do 20 runs per given model at least to get a handle on that.

Averaging models doesn't help with that problem because it doesn't uncover the chaos in a particular model.

And if we understand climate so well why are there so many models? Isn't one the correct number of models for a process that is understood?

No, they're not outsourced.

Schneibster wrote:No, they're not outsourced.

You mean the IPCC does the models? First I've heard of that.

And of course you haven't come to grips with why there are so many models.

I'll give you a hint. There are a plethora of modes because NO ONE understands climate very well. And why is that? The biggest hole is the greenhouse gas H2O. Poorly measured and very poorly understood. And the models are worse than our measurements and understanding because of parametrization and large grid cells.

GIGO.

MSimon wrote:

Schneibster wrote:No, they're not outsourced.

You mean the IPCC does the models? First I've heard of that.

The IPCC doesn't do science. The models are done by the physicists doing the research, not third parties. And the best models are done by national research organizations. GISS and Hadley come immediately to mind.

MSimon wrote:And of course you haven't come to grips with why there are so many models.

LOL

If I was that interested I'd be doing one of my own too.

It's not that hard dude. This isn't database or web programming, or interactive applications, or anything complex like that. It's just equations; grab your Fortran book and get to work. Most of the base-level physics are long well-known. The spectra of everything, both theoretical and empirical. Well-tested longstanding models of convection and circulation, simulating N-S equations. Measurements of CO2 from multiple sources, such as ice cores, mud cores, tree ring variations, δO¹⁸ readings from fossilized vegetable matter for temperature, and about eight or ten other methods that tell us the CO2 concentrations and temperatures in the atmosphere back well before the Cambrian.

Almanacs for coal consumption. Seriously. This is a matter of being smart enough to be able to count. Really.

MSimon wrote:I'll give you a hint. There are a plethora of modes because NO ONE understands climate very well. And why is that? The biggest hole is the greenhouse gas H2O. Poorly measured and very poorly understood. And the models are worse than our measurements and understanding because of parametrization and large grid cells.

But see, the problem is, we have satellite measurements, and they tell us how much goes in and how much comes out. And they're different.

That tells us
1. We're not in temperature equilibrium.
2. It's going to get hotter.

There just isn't anywhere to hide any more.

MSimon wrote:GIGO.

Yep. And the garbage is, "butttheresnoglobalwarming."