Russ's comments illustrate the differences between making science and making
policy. Ideally, science operates by patiently theorizing, experimenting,
and debating, untill one reachs a conclusion with a high level of certainty.
In experimental situations, one typically looks for effects that are
statistically significant at p=0.05 [or even better, p=0.01] (i.e., there is
a less than 5% [or 1%] chance of the observed effects being due to random
noise), and which can be replicated across multiple experiments. The
results are then used to modify, destroy, verify, or build a theory of how
that corner of the universe works.
>>>Seitz's problem is that it is the summary of the report which will affect
opinion, and not the report itself. For the summary contradicts the report.
.... The following quotations are provided by Seitz; they are from the
report, and contradict the summary:
>>>"None of the studies cited above has shown clear evidence that we can
attribute the observed [climate] changes to the specific cause of increases
in greenhouse gases."
Clear evidence, no. Evidence, yes? Does Seitz agree that there is murky
evidence?
>>>"No study to date has positively attributed all or part [of the climate
change observed to date] to anthropogenic [manmade] causes."
In my dictionary, "Positively" means "admitting of no doubt. Irrefutable".
>>>>"Any claims of positive detection of significant climate change are
likely to remain controversial until uncertainties in the total natural
variability of the climate system are reduced."
Again, "positive detection". Also, "likely to remain controversial". Even
if there was a positive detection & proof of human induced change, any
policy that requires changes in behavior will be controversial.
The large variability in weather-related data precludes reaching high levels
of precision as to the degree of climate change, the cause of climate
change, or even whether climate change can be distinguished from natural
effects. In short, we will never get to 99% (and probably not 95%)
certainty in this area.
Policy making, on the other hand, inevitably involves acting on lousy data.
There's a lot of noise in the data, there are few experiments, there are
many factors to consider, etc., etc.
The value of the IPCC summary is that it attempts to bridge the gap between
what we know we know (& the certainty level thereof), and a policy
recommendation. The data is lousy, the interactions are complex, but the
basic physics imply climate change due to man-made influences. Sure, there
can be other explainations, but we understand them much less well than the
man-made influences.
There are one of 3 outcomes of the climate change predictions:
Either the prediction will be accurate (the predictions are basically from
computer simulations, which do substantially match observed weather
patterns. Earlier simulations did predict larger than observed climate
warming, but the latest simulations, which are run on more powerfull
computers and incorporate more significant variables [such as cooling due to
sulfite aerosols in pollution] do substantially match observations).
Or the prediction will be high (if some poorly understood climate mechanism
works in our favor; or the observed global changes are due to high points in
the climate cycle and man made greenhouse gases somehow have no effect).
Or the prediction will be low (if some poorly understood climate mechanism
works against us; or the effect of man made greenhouse gases in observed
data have been obscured by low points in the climate cycle) .
Good policy would incorporate the three scenarios, the costs of various
actions, etc., and act to "hedge our bets". This gets into the fields of
risk analysis & decision theory--which is another e-mail all together.
>>>>Christians should be horrified at the violation of the Ninth Commandment
in reporting matters concerning the effect of man's activities on global
climate.
When you drive down a dark highway and you think that you're heading toward
a bridge abuttment, do you wait to change course until you are 95% sure that
it is indeed a bridge abuttment, rather than a parked truck? Is your spouse
violating the Ninth commandment when she tells you that you're heading
toward a pillar when she/he is only 60% certain? You, the policy maker,
will recognize that it is better to correct course now, when uncertain, than
later, when certain, because acting later will involve a much more drastic
swerve (which might not succeed).
consensus, it is a best guess given the evidence and the risks. I would
agree that signing on to the summary should be a separate issue from signing
on to the main study.
However, to characterize the summary as "false witness" because it does not
meet a 99% certainty criteria (however common that criteria is in laboratory
settings), is unrealistic.
Christians should be more horrified at the unambiguous cases of false
witness circulating in our circles--such as this typical example from a
popular christian book: "...the eruption of Mount St. Helens ...in 1980
dumped more than 910,000 metric tons of CO2 into the atmosphere, dwarfing
the output of all industrial sources." (This may be true if industrial
sources is narrowly defined--but CO2 from human activity [excluding
respiration] actually weighs in at 18 billion tons.)
Grace & peace,
Dennis Sweitzer