From: userDHAL@mts.ucs.UAlberta.CA (David Halliwell)
Subject: Re: Lawyer's science vs. unbiased presentation of the facts
Organization: University Of Alberta, Edmonton Canada
Date: Wed, 29 Jul 1992 22:43:13 GMT

szabo@techbook.com (Nick Szabo) writes:

>In article <1992Jul24.184652.10374@meteor.wisc.edu> tobis@meteor.wisc.edu (Michael Tobis) writes:

>>My final word for a while. I promise.
>This is a weekly event.  :-)

>[ bickering deleted - DH ]
 
>>Volcanoes and El Nino are somewhat off the subject, as their impact is
>>brief in the first case and oscillatory in the second.

>No, for determining ecosystem impact they are quite _on_ the subject.
>Ecosystem impacts are caused by local, not global temperatures.

    The only thing that short term variations are relevant to is the
subject of short term changes. Global warming is not a short term change
and thus the impact of short term changes is not relevant. Nick has
not yet replied to my post discussing this last week. Since is was not
successfully crost-posted to sci.geo.meteorology or sci.skeptic, I will
repeat it here to see if Nick has anything to say in response. Part of
this will now seem a bit out of place, but them's the breaks.

<----- start of included text ------->

 
In article <1992Jul20.164701.8222@techbook.com> szabo@techbook.com (Nick Szabo) writes:
>In article <1992Jul17.204754.12012@meteor.wisc.edu> tobis@meteor.wisc.edu (Michael Tobis) writes:
> 
>>[claims credit for arguing against "PC science" earlier]
> 
>This is irrelevent.  We are supposed to be engaged in a search
>for the truth, not in a contest to see who is more PC than thou.
> 
>>Since Nick refuses to consider the evidence that I bring to bear on this
>>subject,
> 
>Hyperbole.  I have considered every piece of evidence you have
>presented.
> 
>>but insists on bringing up quibbles that are obviously either
>>fabricated or at best ill-informed,
> 
>Please name even _one_, for example?  I have brought up major questions
>about your interpretation of the data, which you have been unable
>or unwilling to answer. 
> 
 
   Well, Nick: I have been watching some of your posts, and have come
to the conclusion that you do not understand the significance of a number
of the points which have been made in response to you questions. Let us
take a few examples from this post:
 
> [various low-content bickering between Michael and Nick deleted - DH]
> [They finish off discussing atmospheric CO2 content]
> 
>>Current levels are abput 350 ppm, increasing
>>smoothly and exponentially by 0.5 % / yr. 
> 
>"Smoothly and exponentially" because somebody has fitted a curve.  The 
>anthropogenic CO2 sources vary due to many factors, including economic 
>cycles and technological change.  It is not the job of a climatologist 
>to project such trends, and they should not pretend to do so as you have 
>done here.
> 
 
    Future forecasts of atmospheric CO2 are *not* simple extrapolations
of past curves, as Nick suggests. They are based on extrapolations of
fossil fuel use and considerations of the global carbon cycle. Generally,
a number of economic/technological scenarios are considered, which will
affect the *time* at which we expect to reach 600ppm CO2. No scenario
I know of predicts *no* increase in CO2 concentrations. The most likely
scenarios (limited reductions in _growth_ of fossil fuel use) still lead
to a growth curve which is approximately exponential.
 
>>Doubled CO2 yields a forcing of 4.3 Watts/meter^2, on a time scale of
>>decades. The solar forcing change is known to be less than 1.3 W/m^2 on a time
>>scale of centuries. (Wigley & Kelly, _Transactions of the Royal Society_,
>>A330:547)
> 
>You're again back to the lawyers science of blithely talking about 
>"decades" instead of giving the actual number (c. 300 years). 
 
    However, the 300 year period includes a *very* small change over
the first couple of hundred, and puts a rather large amount of the
change in the last 50 years or so. This is "decades".
 
>                                                                  You 
>implied a comparison of measured forcing, instead you're again foisting 
>computer models off as experimental evidence.  Will you explain if this 
>4.3 W/m^2 includes possible side effects, such as increased reflection 
>from cloud cover, snow cover, etc. from increased evaporation?
> 
 
    Nick, Nick, Nick. Perhaps you should go back and review *something*
about systems. What is the difference between a *forcing* factor and
a system *response*? Michael's *forcing* factors look at a change in
the net radiation value between the earth/atmosphere system and space.
In an equilibrium climate situation, this net radiation equals zero: the
E/A system is neither gaining nor losing energy in its exchange with
space. If we upset this balance by X W/sq.m, the system will show a 
response, either heating or cooling (depending on the sign of the change).
Changes in cloud cover, snow cover, evaporation, etc. are then the
*response within the system* to the forced change. If CO2 has 3x greater
*forcing*, then we would generally expect to see a greater response.
The only "model" that is required in this comparison concerns the direct
radiative effects of adding CO2 to the atmosphere (a relatively simple
task), and *not* a model of how the system will respond to this change.
 
>>>>VERY LARGE. 
>>
>>Comparable to an ice age transition.
> 
>Larger in rate, but smaller in magnitude.  The rate suits your belief 
>so you avoid describing the magnitude (and avoid explaining your 
>reasonining behind VERY LARGE at all until called on it).  Here you are 
>again foisting lawyer's science, playing advocate while you accuse others 
>of being advocates.  If you want to appear unbiased and scientific, how 
>about stick to the facts and lose the meaningless nhyperbole?
> 
 
    Well, when the *rate* of change is the controlling factor in how
quickly the biosphere must respond, then the *rate* is the important
consideration, not the magnitude. Or would you argue that controlled
braking from 100 km/hr is more likely to injure you than hitting a
brick wall in your car going 50km/hr? After all, in the second case
the deceleration rate is larger, but the *magnitude* of the total
deceleration is less!
 
>>>  There are many known climate 
>>>changes that were more rapid than the IPCC mean global warming (2.5C in
>>>c. 100 years), and many that were of greater magnitude, and from our
>>>scant look at recent climate history at least one (Younger Dryas) that was 
>>>both.  But you would rather hyperbolize about how VERY LARGE it is.
>>
>>These changes may exist, but they are extremely rare, and have never
>>occurred since civilization began, and would be extremely disruptive.
> 
>ENSO is rare?  Ice age transitions are rare?  Pinatubo-sized volcanoes
>are rare?  Whoo boy.  You would also be hard pressed to demonstrate Younger 
>Dryas (greater than IPCC hypothesized global warming in both rate and 
>magnitude) is rare, since it is a newly discovered phenomenon of a kind 
>not yet looked for in other epochs (I hope they're looking now, though).
>Since the YD is quite recent, there could be dozens or thousands like
>it waiting to be found in the geological record.
> 
 
    And once again Nick shows that he fails to understand the difference
between weather and climate.
 
   Nick_logic (extended):
   - Observations:
     -  it is 15 degrees warmer this afternoon than it was last night.
     -  life on earth has survived with no noticable stress in response
        to this 15 degree change.
   - Conclusions:
     -  life will adapt to a global climatic warming of 15 degrees with
        no problems.
 
   Let me try again to point out the difference between weather and climate.
Weather relates to the immediate/current events and short periods afterwards
(e.g. hours to days) at specific locations on the earth's surface. Climate
relates to the likelihood over long periods of time (e.g. decades, centuries,
or millenia) of particular weather-related events. In between, we can't
really call it weather very well, but we are still dealing with transient
rather than long term events.
 
   A single ENSO event is *not* a climate change. The *climatology* of
ENSO events can be summarized as follows: ENSO events occur on an 
irregular cycle of 2-7 years, and last less than a year. This statement
says nothing about when the last one was, or when the next one will be.
Forecasting a specific ENSO event would be a *weather[ish]* forecast, 
not a climate prediction.
 
   As long as ENSO events occur with the same magnitude and frequency,
then the climate is not changing. However, if suddenly we began to see
ENSO events occuring every 2-3 years, and they lasted more than a year,
we *would* have a climate change, even though the weather events are
nothing new. And this climatic change *could* be important. 
 
   Let us take a hypothetical example: we have a particular vegetation
type that does well in a particular area during non-ENSO periods, but
is under considerable stress during ENSO events. If it can survive in 
its current area as long as ENSO conditions only come along (on average) 
no more than every 5 years, with 4 good years (on average) in between, 
it is going to be in big trouble if we switch to a climate in which
ENSO conditions predominate. To extrapolate its survivability for
infrequent ENSO events to the situation for frequent ENSO events is
silly.
 
   Likewise, a single volcanic event is not a climate change. A long
series of volcanic eruptions which significantly increased the amount 
of dust and sulpur compounds in the atmosphere for a sufficiently
long period *could* lead to climatic change. Just because a single
volcanic event is survivable does *not* mean that the climatic shift
caused by extensive volcanic activity would also be survivable.
 
   Ice age transitions (glacial/interglacial) are accompanied by
*extensive* changes in vegetation distribution. The rate at which
the climate changed (and thus the rate at which the vegetation had
to adapt or migrate) during ice age transitions is quite a bit
*slower* than the rate expected from CO2 increases.
 
>>I will grant that the Younger Dryas transition is as fast as the middle
>>range of the IPCC predictions, though not as fast as the upper range.
> 
>Again, you make a lawyer's claim instead of stating the facts!
>From the numbers I have, this claim is nonsense.  Younger Dryas was a 
>change of 7C over 40 years.  The worst case IPCC scenario is 5C in over 
>100 years (best case 1.5C, mean 2.5C).
> 
>N.B., the 100 years assumes no technological change that reduces CO2
>emissions -- something you always fail to mention; you imply to the layman
>that the CO2 projection is based on climatology just like the other
>projections.  Even the "best case" IPCC projection is a fantasy world
>where humans never learn how to conserve or become proficient in
>non-fossil electricty or biomass for fuels, etc.
> 
 
    As long as large numbers of people keep saying that the greenhouse
effect is a myth and that we should wait another 10 years (and repeat 
this every 10 years), then I don't think there is much chance for
conservation or replacement to have any effect.
 
>>You should also note that the absolute global temperature implied
>>by 2xCO2 warming, all else being equal, is unprecedented in the
>>last 3,000,000 years at the LOW range of the estimates. 
> 
>Ah, now you mention magnitude and ignore the rate.  Many volcanic 
>eruptions during this period have achieved a rate (both cooling
>and rebound) far greater than 0.05C/year for the worst-case global
>warming.  In fact, I would bet you are wrong even on magnitude;
>largest volcanoes were probably of greater global absolute temp
>change than 1.5C.
> 
 
    And if we had reason to expect that volcanic activity was going to
increase so that the *climate* was 1-2C cooler, then we would have to
plan for for a rather large adaptation as well.
 
 
>The comparison to Younger Dryas is valid, because ecosystems are impacted 
>by regional temperature changes. Younger Dryas had impact on ecosystems 
>from Newfoundland to Portugal, and we should be able to learn quite a bit 
>about worst-case climate impacts from it.
> 
>>From Crowley & North, _Paleoclimatology_, Oxford Press, 1991, p. 254:
>>
>>       "The CO2 perturbation therefore represents a major climate
>>       change, which will occur at a rate comparable to or exceeding
>>       any known to have occurred in earth history. 
> 
>Looks like C&N have a bit of hyperbole of their own.  This is only
>true in the very narrow sense of CO2 increases over 300 years (and
>even that being unprecedented is conjecture; there are millions
>of 300-year chunks we haven't looked at for CO2 levels).  Most rational 
>observers would rate asteroid strikes, major volcanos, and Younger Dryas as 
>more severe, and some would include ENSO and Pinatubo since the rate of 
>change is larger.
> 
 
   Discussion of single, short-term fluctuations is almost totally
irrelevant in the case of *climate* change. The only relevance is
if we expect changes in the magnitude or frequency of these events.
Then an impact will be felt.
 
 
    Ok, Nick. I have now attempted to illustrate the illogical nature
of your post. Counterpoint???
 
 
Dave Halliwell
Department of Geography
University of Alberta
Edmonton, Alberta