[Prev][Next][Index][Thread]
Re: Human vs. natural influences on the environment
charliew wrote:
>
> In article <50i1bb$c1b@spool.cs.wisc.edu>,
> tobis@skool.ssec.wisc.edu (Michael Tobis) wrote:
> >jw (jwas@ix.netcom.com) wrote:
> >: In <504hmm$pdp@spool.cs.wisc.edu>
> tobis@scram.ssec.wisc.edu (Michael
> >: Tobis) writes:
> >: >What we should be concerned about isn't how much the
> >: >temperature increases (we're pretty confident at this
> point that
> >: >it's nonzero and positive) but what that means to the
> general
> >: >circulation.
> >
> >: We cannot be confident of this in the least - *even*
> assuming,
> >: for the sake of the argument only,
> >: that the greenhouse effect and all the chain of
> >: its indirect consequences (some of which may
> >: well have opposite signs) is somehow modelled
> >: perfectly.
> >
> >I see you confuse "confident" and "certain" when it suits
> your purposes.
> >Since this is the case, I will state that I am certain that
> all else
> >being equal, increasing greenhouse gases warms a planet
> reliably and
> >effectively.
>
> I agree with this statement 100%. However, how do I know
> that "all else" is actually "equal"? There are some hidden
> assumptions here that should be validated by observation.
> Unfortunately, many see the consequences as so "dire" that
> they do not want to gather the observations necessary to
> validate the underlying theories! What consequences can be
> so dire that we don't have the time to follow the scientific
> method?
First let me point out that in public affairs, significant changes are
made without any scientific basis at all. To give two examples, the
supply side argument that lowering taxes would raise revenues had not
been proved correct by economic analysis at the time it was put into
effect. By observation, it certainly appears that this public policy
did not have the desired effects. (I know there are all sorts of
excuses about why they didn't or that despite the evidence they really
did, but I don't find them very convincing.) Simiarly, we have just
engaged in a radical change in welfare policy with no scientific
evidence that it will have the predicted effects. The politician who
has studied the matter in greatest detail and even has professional
qualifications in the area, Senator Moynihan, is appalled by the
legislation passed by Congress and signed by the President. He had the
perverse experience of calling for years for welfare reform and warning
about the problems and then finding the Yahoos rolling over him on hte
issue he was most identified with.
With respect to climate change, we know the following for sure.
Greenhouse gases, other factors being equal, will lead to an increase,
even a significant increase in average global temperature and also
significant climate change. We also know that according to a business
as usual scenario, the atmospheric concentrations of these gases will
grow exponentially (or close to exponentially) in the next century,
and there is no reason to think they will stop then. We also know
that there are long lag times, so that if we wait until climate change
is so obvious that no one will doubt the need to reduce emissions,
it will take decades for any reductions to have any effect. Indeed
things will get worse for a long time before they get better.
What we don't know is how a host of other factors will interact with
the postive forcing of grennhouse gases. Other possible factors are
the effect of aerosols, the effect of clouds, long term climate cycles,
water vapor feedback (although this is very likely a positive feedback),
solar variability.,etc. However, betting that everything else will
work out so as to almost completely cancel the enhanced greenhouse
forcing does not seem like a good bet.
On the other hand, economic and social changes produced by concerted
effort of society at large tends to be oppposed by various segments of
society. Some of them like any sort of limitations of freedom to drive
anywhere at any time---which is a myth anyway, as you will clearly be
aware of the next time you are caught in a traffic jam on a major
highway---are likely to be opposed by almost all Americans. So
although our societies and economies undergo vast changes brought on by
forces other than government, government at this period in history,
at least in most of the major industrial countries, seems quite limited
in what it can do. That means that we probably can't make radical
changes in how we use fossil fuels now, but we can at least begin to
make small changes. In particular, some changes make a lot of sense
anyway. Perhaps people have defeated the mandated fuel efficiency
standards, introduced during the oil shocks of the 70s, by buying vans
and small trucks. But I see no reason why people would object to more
efficient engines in such trucks, which are not now covered by the fuel
efficiency standards. American manufacturers have had the gall to
argue that this would be a bad idea since it would give Japanese
manufacturers an advantage because they already know how to do it and
American manufactuers who have faught such standards aren't ready to.
So as many of us have suggested before, the scientific case is strong
enough to justify actions which make sense in their own right.
Of course those who oppose any governmental action (or usually just
those that interfere with their sacred cows), will never be willing to
admit that any level of certainty has been reached. However, if the
public becomes aware of the potential problems which could face their
children and grandchildren, they may be more supportive of some changes.
Then the debate could switch to how most effectively to accomplish such
changes. The answers to that question are not at all obvious. There
have been times in the past when our nation could act to attain
desirable aims. Recent history has produced cynicism about and even
hatred of government and enormous deficits have made it very difficult
to spend money to solve pressing problems. But with a clear view of
the problems, we may be able to begin to make some progress, if not
directly through government as in the past, perhaps by other means.
Leonard Evens len@math.nwu.edu 491-5537
Department of Mathematics, Norwthwestern University
Evanston Illinois
Follow-Ups:
References: