Re: OT: is the AGW bubble about to burst?

On Aug 23, 8:21 pm, bill.slo...@xxxxxxxx wrote:
On Aug 23, 5:32 am, James Arthur <dagmargoodb...@xxxxxxxxx> wrote:



On Aug 22, 4:31 pm, bill.slo...@xxxxxxxx wrote:

On Aug 22, 8:37 pm, James Arthur <dagmargoodb...@xxxxxxxxx> wrote:

On Aug 20, 10:31 am, z <gzuck...@xxxxxxxxxxxxxx> wrote:

On Aug 17, 3:01 pm, James Arthur <dagmargoodb...@xxxxxxxxx> wrote:

For example, "IF cloud feedback is strongly positive..." That one
statement alone--the outcome is contingent on a critical factor which
is unknown--undoes the thing.

Kind of a stretch there. Although the IPCC is honest enough to admit
what things we do not know, in the sadly mistaken belief that critics
will be equally honest, it is not saying that we are totally in the
dark. A cloudy day does not plunge the earth into an ice age locally.
The spread of estimates of net cloud cover forcing is from -1 W/m^2 to
+3 W/M^2 for a doubling of CO2.http://www.grida.no/climate/ipcc_tar/wg1/275.htm
Fig. 7.2 The current estimate for the total radiative forcing due to a
doubling of CO2 is 3.7 W/m^2 So. even if the estimates for maximal
negative feedback of cloud cover were correct, there would be net
warming. And if the middle of the pack estimates were correct, as they
usually are with uncertain things, then the net feedback is positive.

My confusion is as to how this drivel can be seriously proffered as
anything other than mathematical masturbation.

Well, you actually have to do the math, as they say.

Okay, except you can't. The equations are dubious, with coefficients
even more elusive, and the knowledge of initial state is lacking.

Knowing that the earth started off as a ball of more or less molten
rock gives you an intial state, not that it is particularly useful.

You misunderstand. To predict the future of the system, it's
essential to know the initial state: temperatures, compositions,
directions, and flows throughout the oceans, ice caps, and atmosphere,
as well as cloud cover, and surface temperatures of the earth. You
have to know where the heat is, any inputs and outputs, and where it's
all going.

Consider the question "At what angle must I weld my rudder to in New
York in order to arrive at Bristol?" Knowledge of all the initial
rates and flows and how they'll change over time is clearly essential
to predicting the ship's actual course, of course. Change to question
to Liverpool or Manchester and the effect of initial state is even
more evident!

So, you need an accurate snapshot of initial conditions. Those, in
turn, must be input to a sufficiently accurate model in order for the
model to predict the future.

Likewise for climate. For example, how can we have ice in the world
when it's so hot in the Sahara?

Currents move heat. You can't predict where a current will wind up
unless you can predict the other currents it will interact with. To
predict those you need to know their initial state.

If you can't predict the heat flows, you can't predict the climate.

We know that you can't predict the weather that way, let alone the
climate.

Incorrect. Weather *is* predicted that way: intial conditions input
into a finite element analysis (FEA) modelling program.

The results are surprisingly good these days, but the farther you
project the results, the greater the model diverges from reality. The
divergence point is getting farther and farther out as the dataset
gets more detailed, and the FEA resolution is improved with faster
computers.

The equations you have to solve to do detailed predictions are too
sensitive to intial conditions for it to be possible to predict the
weather more than four or five days in advance.

AIUI, weather can be predicted decently well as much as two weeks(?)
in advance by the above method. The chief limitations, it was
explained to me, are the resolution and accuracy of the initial
conditions input to the model, and compute power.


In order to predict the climate, you have to lose the fine detail and
set up lumped approximations that capture the average behaviour of the
system - it isn't precise or exact, but it does give you a better
understanding of the system than does throwing your hands up in the
air and denying that any kind of prediction is possible.

That would be kind of useless, wouldn't it? How do you propose to
know the climate without knowing the course and temperature of the
Gulf Stream, that huge moderating influence to the U.K.'s (and
Europe's?) weather?

Surely we've not forgotten the large affect El Niño has on our
weather? Or the jet stream, for that matter. How can one make claims
about the future climate without knowing these?

And how can you project these surface effects without knowing the deep
ocean currents?

How can you intelligently project the influence and future of clouds--
enormously important to global warming/cooling--if you don't know
humidities and temperatures in the mountains / deserts / etc.?

The global climate *is* a heat transport problem--heat (sunlight) is
input at the equator, and circulated to the poles by various air and
ocean currents--and I believe (but can't swear) it's modelled that
way. That understanding is supported by this quote from Rich's link:

"The measurements also show that we have a flaw in some of our global
atmospheric circulation models. Now we can go back and improve those
models to better predict the temperatures in the middle and upper
atmospheres throughout both hemispheres."

I have the advantage of, through a friend, knowing one of THE
professionals who does this. I'll have to inquire next time I get the
chance.

Cheers,
James Arthur

.

Relevant Pages

  • Record Temps Expected
    ... Record breaking weather News.... ... Forecasters at the Met Office are predicting the highest July temperatures ...
    (uk.sci.weather)
  • Re: US water problems??
    ... The big difference between predicting the weather and predicting the ... climate is how soon people find out you were wrong. ... surface temperatures will have on the climate. ...
    (misc.rural)
  • Re: cap-and-trade
    ... Record low in Rochester, NY – Ties record set in 1926 - NATIONAL ... WEATHER SVC BUFFALO NY… THE TEMPERATURE AT THE ROCHESTER AIRPORT ... Temperatures in Concord, NH fell to 47-degress, the lowest ... INCHES OF SNOW... ...
    (alt.machines.cnc)
  • Re: OT: is the AGW bubble about to burst?
    ... and surface temperatures of the earth. ... We know that you can't predict the weather that way, ... forecasting will do poorly at forecasting where gets flooded or impacted ... ocean currents--and I believe it's modelled that ...
    (sci.electronics.design)
  • Re: How do you say Global Cooling in Swedish? NBC
    ... over 100 years this week as winter weather takes hold of the country, ... "It is far below average temperatures, ... With more snow on the way in from the Baltic Sea, ... Probably the same way you say Global Warming in Cleveland Ohio. ...
    (rec.music.artists.springsteen)