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

["John Clement" <clement@hal-pc.org>]

Of course the situation is frustrating.  This is a problem which is far more
complicated than most physicists have to deal with.  It is more complicated
than most medical problems.  It is probably even more complicated than
educational research.  The basic ideas are fairly simple.  We can measure
the increase in CO2, and we know it is ratcheting up.  We can measure how
CO2 acts to hold in thermal energy.  We know from historical data that we
should be going into an ice age soon by geological time measurement, but the
opposite is happening.  We also know that all glaciers except for the very
high Himalayas show significant melting.  The main ice to be concerned about
is Greenland and Antarctica both of which are melting.

As physicists we do understand that data with a lot of statistical noise can
look very different in the short term than in the long term.  Here is where
the public is easily fooled.  The detractors look at a single hard winter
and use that as evidence, but that is just the random noise on the overall
trend.

Then you have all kinds of other distractions.  Some have predicted that we
are going into a Mauder minimum in the sun spot cycle, which may decrease
the incoming energy.  There is evidence that such a minimum happened during
the little ice age.  But recent evidence shows that there was some large
volcanic activity which may have triggered the little ice age.  Or possibly
both effects may have contributed.

One reason for predictions of large disruptions is that the climate system
has positive feedback.  Increased ice increses the albedo so you get
feedback which drives the ice age.  But the opposite can drive a runaway
warming trend.  That type of idea is not really understood by many people.
So of course you have people with no qualifications in hard science making
all kinds of predictions, and others listen to them.  There also are some
negative feedback mechanisms, but they may only come into play once a new
dramatically different temperature has been established.  We all know how
growth curves do eventually level off.

It is one thing to be a skeptic and come up with some evidence for why the
models are wrong, and it a different thing to be a denier.  The following
web site shows the political distribution of deniers:
http://publicreligion.org/research/2011/09/climate-change-evolution-2012/
One can be convinced either way but be open to evidence.

John M. Clement
Houston, TX

> The reason why the skeptics can get away with their nonsense is  
> precisely because the effects are small and the correct explanations  
> are complicated.  As a physicist, I find this situation extremely  
> frustrating.