How can the political right and left look at the same scientific data
on environmental issues and come up with different explanations?

See this question: http://answers.google.com/answers/threadview?id=304458.
 It applies to this issue at least in part.  But the bigger part is
that you are mixing the political with the scientific.  This
inevitably leads to preconceptions and spin - from both sides. 
Further, the environment is such a complex web of interacting factors,
with enough missing data, that it is difficult to say what effect a
given change or factor will have with certainty.

Primarily because the scientific data contradicts itself, depending
upon which study you look at.

Kriswrite

The old saying "there are lies, damned lies, and statistics" seems
appropriate to this question. Environmental data are subject to so
much distortion and juggling by politicians that the "facts" can be
made to speak for almost any viewpoint.

hi,
   from what i've seen much of the data recieved from analysis and
experimentation is just data, and is open to interpretation. there is
so much of it (and probably more that is not publically known) that it
is hard to say overall. i don't think either side is flatly lying just
distorting or emphisizing different points that coincide with their
policies.
   its easy to see the motives and values a politician embraces based
on which scientific evidence that person embraces, but thats not
always the case. its more of an intellectual excersize i guess.
   i wish i knew which scientific data you were refering to, then i
could we see which argument is made and who benefits.
good luck,

mar

Perspective.

If fifty people witness an accident and the police interview each and
every one of them, no two reports will be the same.

Since you have specifically asked about environmental data, I think it
is more than just as simple as because they can.

Politicians are quite skilled in using available data to support their
own positions.  The right has an inherent interest in looking out for
corporate interests, while the left is more centrally focused on
social welfare.   I think those are the 1 sentence descriptions for
right and left, right?  Okay, so if you are interested mainly in
protecting the interests of Exxon-Mobile for example, when you look at
data showing a bunch of noise and an upward trend of temperatures over
the last 30 years, knowing that if the answer is going to hurt your
constituents if this is global warming, what are you going to do?  You
are going to be the harshest examiner of the data and look for
whatever flaws or uncertainties you possibly can to place doubt on
that conclusion.  To do otherwise would not serve your constituents.

The left on the other hand looks at the possibility of global warming
and says what is the worst case scenario.  That instantly becomes what
is going to happen, with absolutely no uncertainty, in their
arguments.  Why?  Because they view their constituents are any who are
unable to stand up for themselves, those who would be most affected by
climate change.  In this case, as in most, that is the lower classes. 
Oddly this logic is somewhat flawed in the case of climate change,
since the ones who will lose the most are the ones with the most to
lose, but that is clearly not perceived.

So, yes, politics is the use of persuasion to achieve your means and
that has little or nothing to do with accurate scientific analysis or
decision making.  We hope that good decisions are an outcome of the
political process, but it really is just an occasional byproduct, not
the primary goal.

A big part of the problem is that the environment is such a web of
interacting influences.  If you want to determine if a given policy or
action is good or bad, you have to weigh all the consequences of the
action, which is usually impossible due to the complexity and the
amount of unknown data.  As a very simplistic example, consider the
common question, "paper or plastic?".  We always used to think, "use
paper, it's recycleable".  But plastic bags can be recycled also.  The
question is how often are they?  I know people who use paper bags
because they can be recycled, but then throw them in the trash where
they go to a landfill.  Another consideration with this decision
though, is that to carry a given volume of groceries, the plastic
needed is much smaller in weight and bulk than the paper needed.  So
using paper requires more truckloads of bags to be delivered per year,
using more diesel fuel and creating more pollution.  How do you
balance these out?  And it becomes even more complex when you start
adding in non-environmental issues, such as jobs lost due to a policy
change or international relations strained by a policy decision.  If
we had all the data and enough computing power and could make the
decisions in a vacuum, i.e. unaffected by other political
considerations, then it would be easy.  Finally, all decisions have
included value judgements.  Everybody has their own beliefs on the
relative values of achieving different things.  If you believe that
saving domestic jobs is more important than maintaining good relations
with your neighbors, you will vote one way.  If you think preserving
the environment and protecting endangered species is more important
you will vote a different way.  That's the beauty of democracy - and
its curse.

llewellynwt-ga,

Scientific data by itself says nothing--it is only a collection of
information taken in context. This information is open to many
different interpretations, and can be "shaped" into different things
depending upon what one wishes to see.

omniscientbeing-ga

Dear llewellynwt,

I thought I would add my comments with the others.  The reason the
right and the left look at the same scientific data and come up with
different answers is because they are giving policital answers not
scientific ones.

It is true that science primarily collects data.  However, science
doesn't just present data, nor does the data contradict itself. 
Science presents data in a context of a theory and an explanation. 
While there are often minority opinions, most of the time the
scientific community has a relatively singular voice.  For example, it
is the opinion of the scientific community that evolution occurs and
can be measured.

There are, however, minority or even out-in-left-field opinions that
differ with this general idea.  Therefore, if you are a politician
wanting to find scientific opinions that voice what you want, you can
find it by looking at these minority voices.

Science is supposed to look at the data and come up with the best
explanation.  Politics comes up with the explanation and then looks
for the data to support it.

Peggy bill

I have been looking at such issues for many years. The truth is likely
close to the center on most of these topics. Earth's winters is likely
about one degree c = 1.8 degrees f warmer (average) than a century
ago. Most of this small amount of warming has probably occured in the
last 40 years. The area covered by glaciers in the Northern hemiphere
has decreased by about 1%. The average ocean level has not risen by a
measureable amount. The ozone layer near Antarctica has grown larger
by 1990, perhaps doubling the skin cancer risk for persons in southern
Austraia and southern New Zeeland. I have not heard any recent
reports, so the ozone hole may be closing. Likely these are all
natural cyclic events with humans contributing about 1% of the change.
Humans have however caused significant heath risks for ourselves and
other criters by releasing polutants into our biosphere = air and
water.
 Earth likely has more marginal crop land than a century ago, but we
are destroying good cropland faster than we creating good cropland.
The quality of our water supplies (almost everywhere) is decreasing
inspite of large expenditures to make it safer  Neil

That was suppose to read the hole in the ozone layer had grown   Neil