Re: [Phys-l] Climate skeptic convinced by data. Was: Re: Mike Mann _The hockey

[John Denker <jsd@av8n.com>]

On 02/18/2012 01:59 PM, Anthony Lapinski wrote:
> Yes, we can't do anything about the Sun and its energy output. It affects
> the Earth much more than anything humans have ever done or will ever do.

That is just plain false.

1) There is no serious doubt that the recent increase in temperature is 
 unprecedented over the last 1000 or 2000 years.

2) There is no serious doubt that atmospheric CO2 has recently increased.

3) There is no serious doubt that the increase in CO2 is anthropogenic.
 The isotope signature gives it away.

4) There is no serious doubt that item (3) explains item (2). Since item (2)
 in turn explains item (1), this means that the warming is anthropogenic.

5) The rules of science require us to consider the competing hypotheses.
 The hypothesis that variation in solar output explains the variation in
 temperature is utterly untenable.  If you factor out the effect of the
 CO2, the models predict no warming.  If anything, they predict a small,
 insignificant cooling.

Let's be clear:  The sun explains the ballpark temperature, but it does not
explain the recent sudden warming.  We have explanations for both --- just
not the /same/ explanation for both.


On 02/18/2012 02:39 PM, fred bucheit wrote:
> > Do we really know all the various mechanisms involved in heating the atmosphere? 

Answer:  No.

We also don't know "all the various mechanisms involved" in cancer.  On the
other hand, we know smokers should stop smoking, and light-skinned people 
should wear sunscreen if they're going to spend a lot of time in the sun.

I'm sorry for belaboring the obvious, but it's the only way to answer the
question that was asked.  

Scientists, policymakers, and business executives -- just like everybody else -- 
make decisions on less-than-perfect information all the time.  When I fix 
dinner, I never know 'exactly' how many enchiladas to make ... but I don't 
let that paralyze me into inaction.  Sometimes an inexact number of enchiladas 
is better than no dinner at all.

There are systematic ways of making decisions on the basis of incomplete 
information.  There are fat books on the subject, but the basic idea is 
simple:  The idea is to consider all the plausible scenarios, evaluate the 
probability of each, and evaluate the gain or loss associated with each.

Among other things, you have to realize that the decision to do nothing is
a decision unto itself.  Sometimes it's the right decision, and sometimes
not.  Making that decision based on imperfect information is not _a priori_ 
better than any other decision.  You have to analyze *all* the plausible
scenarios.

These ideas are systematically taught in business schools, in engineering 
schools, in military academies, in the Boy Scouts, et cetera.