TKO for AGW! (III)

Here are a series of e-mails that show how this work was being done. They all come from a single e-mail written 10 years ago--has anything changed since?: # 926947295.txt. Since these e-mails have several layers of replies, the earliest messages start at the bottom in the link. I will unravel them here and remove the ">" forwarding marks and clean up some paragraphing. The only thing I've changed is the removal of some phone numbers. All bolding is mine:

Here's the start of the e-mails, which is a correction to a previously-sent e-mail:

;
Mike MacCracken [Ann - this might be him ]
Date: Friday, May 14, 1999 8:12 PM
Subject: Re: CO2


Please disregard the previous message and replace with this message (1st
paragraph is unchanged).

On Fri, 14 May 1999, Benjamin Felzer wrote: [Ann - This might be him ]

> Going back to some of the original radiative forcing values, it would
> appear that the 1% increase is true of RADIATIVE FORCING, whether of CO2,
> CH4, etc, or the total (to an approximation). However, once we convert
> back to CO2 concentration (using the exponential relationship), the
> actual
> increase in concentration is more along the order of 0.7% (all
> compounded). Is it possible that the original 1% assumption was
> mistakenly applied to CO2 concentrations for the modelers when it was
> actually meant for radiative forcing??
>
> Therefore for the ecological models we should use Dave's original
> suggestion, because the models really did use a 1% increase in equivalent
> CO2, which approximates a 1% increase in CO2 alone. The point here is
> that this 1% increase is much higher than IS92a, but that might be because
> of the confusion between radiative forcing increase and concentration
> increase discussed above. In fact a 0.7% increase in equivalent CO2 might
> have been a more realistic assumption for IS92a, but the 1% increase in
> concentration is what was actually used in these earlier models. The CO2
> concentrations used in the ecological model should correspond to those
> used in the GCMs, not to what we think they should be.
>
>
> Any other thoughts?
>
> Ben
>

---------------------

And now the reply to that one. I've tried to clean up the paragraphing:

-----Original Message-----
From: franci [mailto:franci@xxxxxxxxx.xxx]
Sent: Saturday, May 15, 1999 3:58 PM
To: Benjamin Felzer
Cc: Mike Hulme [Ann - This is probably him ]; schimel@xxxxxxxxx.xxx; wigley@xxxxxxxxx.xxx; kittel@xxxxxxxxx.xxx;
sjagtap@xxxxxxxxx.xxx; nanr@xxxxxxxxx.xxx; Mike MacCracken
Subject: Re: CO2


dear ben,

You just showed that the Hadley transient run we are supposed to use for the national assessment is too high, forcing-wise, because it assumes an overall 1.2% increase in total forcing.

My question is then the following:

-why are we using a 1% annual increase in GHG [Ann—I assume this is Green House Gas] forcing (corresponding to the 1.2% increase) as a criteria for GCM simulations to then be used for the national assessment? Is it because of the possible confusion you refer to below? If so, that criteria needs to be revised.

I still have a problem with the real CO2 calculations, in connections to hadley or CCCM. It seems to me it is still arbitrary to use one or another CO2 curve.

However, in this arbitrariness, two easy solutions are possible ( i am just summarizing previous e-mails, at the cost of being highly repetitive and obvious):

-one is dave's, i.e, assume no change i GHG forcing mix from today, and apply 1% compounded increase to the 1990 actual levels. That gives a concentration of real CO2 in 2100 that is >1050 ppm. THAT'S 50% higher than projected by IS92a, and even 17 % higher than the worst emission case devised in IS92f.

-the second is tom's. Just use the co2 in IS92a, and assume that all other further changes necessary to get the hadley forcing (whatever they are) happen in GHG other than CO2.

I will repeat that I like the latter solution.

Whatever the consideration of self-consistency and physics are when you make this decision, I do not think we should carry out the national assessment by using "unrealistic" CO2 numbers. I thought the numbers that come out of our exercises (from the impact side of things) were supposed to serve as some basis to be used in the process of decision making at the national and regional level. Am i out of line here? There are dozens of people right now, out there, including our group at giss, who are gathering data, fine-tuning models, making connections among physical and socio-economic variables, etc., at a very low "effort spent/retribution received", and then we are going to run things at 1000 ppm in 2100? As far as my specific contribution is concerned, it surely might make a big difference in crop yield changes under climate change whether I use 700 ppm in 2100 (the IS92a) curve, or >1000 ppm (the 1% compounded increase).

The problem is the same for the 2040's (the other decade we have decided to simulate), although possibly not as bad as the 2090's case.

Either solution we opt for, we have to make clear to whomever will receive our results that the climate forcing scenario is on the "high" side of things.

Ah! It was so nice and easy when we were working with doubled-CO2 equilibrium runs!

cheers,

francesco

PS what about the CCCM scenario?

Questions:

1) "supposed to use" according to who? or according to what scientific evidence? In general, this isn't the way science is supposed to happen. You do literature searches to back up your choices. If you choose one method of analysis or one value over another, you need to back up that decision with previous research. You aren't supposed to pull numbers out of the ether just because those are the ones you are "supposed to use". If you're a scientist, back up your choices with proof!

2) "It seems to me it is still arbitrary to use one or another CO2 curve." No kidding. And isn't this the crux of the problem? An arbitrariness in the selection of data and analysis techniques. In other sciences, this isn't a question. You can make an arbitrary decision, as long as you back up the reasoning behind your selection. Whether or not that was done is the heart of this whole matter.

3) "Just use the co2 in IS92a, and assume that all other further changes necessary to get the hadley forcing (whatever they are) happen in GHG other than CO2." Just pick something (whatever it is), make lots of unsubstantiated assumptions, and enjoy!

4) "Whatever the consideration of self-consistency and physics are when you make this decision, I do not think we should carry out the national assessment by using "unrealistic" CO2 numbers." What a novel idea! Our assessments should be based on realistic data! Shocking! Astonishing! What a breakthrough in scientific reasoning!

Next e-mail in the chain (I snipped out the telephone numbers on this one, no need to pass those along.):

On Sun, 16
May 1999, Shrikant Jagtap [ Ann - This is probably him, unless there are two Shrikant Jagtaps at UFl ] wrote:

Friends,

I'm enjoying the current debate about CO2 levels. I feel that we are using the GCM scenarios, and we MUST use exactly those CO2 levels for crop model runs, so all data is consistent. So if we are wrong, we are uniformly wrong and adjust our explanations accordingly whenever we agree on things. Now to use different data will be hard to explain.


Shrikant

Dr. Shrikant Jagtap
104 Rogers Hall, Ag & Biol. Engineering
University Of Florida
Gainesville, FL 32611

This one gets a dramatic response:

Final e-mail:

From: Dave Schimel [Ann - this is probably him ]
To: Shrikant Jagtap
Subject: RE: CO2
Date: Mon, 17 May 1999 09:21:35 -0600 (MDT)
Cc: franci , Benjamin Felzer , Mike Hulme , schimel@xxxxxxxxx.xxx, wigley@xxxxxxxxx.xxx, kittel@xxxxxxxxx.xxx, nanr@xxxxxxxxx.xxx, Mike MacCracken

I want to make one thing really clear. We ARE NOT supposed to be working with the assumption that these scenarios are realistic. They are scenarios-internally consistent (or so we thought) what-if storylines. You are in fact out of line to assume that these are in some sense realistic-this is in direct contradiction to the guidance on scenarios provided by the synthesis team.

If you want to do 'realistic CO2 effects studies, you must do sensitivity analyses bracketing possible trajectories. We do not and cannot not and must not prejudge what realistic CO2 trajectories are, as they are ultimatley a political decision (except in the sense that reserves and resources provide an upper bound).

'Advice' will be based on a mix of different approaches that must reflect the fact that we do not have high coinfidence in GHG projections nor full confidence in climate ystem model projections of consequences.

Dave

That one seems to speak for itself. Read it a couple times, because it looks quite important: don't use realistic scenarios because that's a political decision. If you do use realistic scenarios you "are out of line." That last paragraph is a whopper too: "we do not have high confidence in GHG (again, I think that's green house gas) projections, nor full confidence in the system model projections.

In other words: we're talking out of our ass, so don't start doing realistic data analysis and screwing everything up! Keep it fake, keep it inline with what we need.

Again, this doesn't exactly look like science, does it?