Posted by Todd Zywicki:
Asking the Wrong Question on Global Climate Change:
http://volokh.com/archives/archive_2005_06_12-2005_06_18.shtml#1119104070
Ellen Goodman [1]writes today:
The climate is equally apparent in the struggle over what the Bush
administration calls "climate change" -- and everyone else calls
global warming. The only way to justify doing nothing about global
warming now is to deliberately muddle the science. It's not an
accident that Philip Cooney, the White House official caught
editing reports on greenhouse gases, left for Exxon Mobil, which
has indeed funded doubts.
Is it true that the only way to "justify doing nothing about global
warming now is to deliberatly muddle the science"? I think the answer
is quite plainly "no." Even if it is true that global warming is
occurring, this is only the first of many questions regarding whether
we can justify doing nothing about global warming.
Embedded in Goodman's assertion seems to be the implicit argument that
if the scientific evidence shows that the global climate is warming,
and if it is the result of human-induced factors, it follows that we
must do something to try to reverse (slow?) global warming. Leave
aside the scientific debate on the subject, and assume for a moment
that the scientific predicate is correct. (the world is warming
because of human influences). Even if this were true, the implicit
syllogism still seems incorrect to me on several levels.
First, assume that the Earth were warming for wholly natural causes,
and that the effect was as dire as the worst-case predictions under
the current scenario--the apocalyptic stories we read of famine,
pestilence, and natural disaster. Would the fact that this warming
were "natural" make any difference at all with respect to whether we
should do anything? The answer seems obviously no. We never stand by
and simply permit wholesale disaster simply because the cause of the
disaster is natural. Floods, hurricanes, cancer, smallpox, polio,
starvation, wild animals, influenza, AIDS, etc.--all of these things
are natural, yet that fact does not stand in our way of trying to
alter nature to prevent their harm to humans. So, if global climate
change is occurring, the quetion of whether we should do something
seems largely irrelevant whether it is caused by humans or
naturally-occurring.
So the real question to ask here is whether on net, the costs of doing
something about global climate change outweigh the benefits of doing
it. This is the same question we ask (or should ask) about every other
intervention into nature--should we kill the parasites in water so
that we can drink it, should we drain a mosquito-infested swamp to
eliminate the risk of malaria, should we provide a vaccine to kill
naturally-occurring smallpox. To imply that if the science shows we
are changing the climate we must do something about it is as
wrongheaded as it would be to say that if we are not contributing to
global warming we should not do anything about it.
On the question of whether global warming would be a net benefit or
detriment to the planet, the evidence I have seen to date suggests
that it is inconclusive. There will be impacts on crop yields, growing
locations, forests, energy consumption, etc., that cut in many
different directions. The question of whether the warming will occur
equally throughout the world, or whether it will occur more strongly
in the coldest parts of the world appears to also be unsettled, and
has powerful normative implications for policy. To get bogged down in
the science, and especially in causal questions, seems to me to be
largely beside the point.
Of course, this also shows why the "precautionary principle" is a
non-starter as an intellectual construct. As I understand it, if the
Earth was warming for natural causes and would nonetheless have the
same effect as anthropocentric global warming, then the precautionary
principle would tell us that we should not intervene to do anything
about it, regardless of whether it might destroy us all. How can that
possibly be an intellectually coherent position?
Moreover, note that like global climate change, economic growth is
path-dependent, so that if we make ourselves poorer today, we will be
forever poorer as a result, and as a result will have less of the good
things in life that we acquire through wealth (health, education,
medicine, safety, terrorism control). So some number of people will
die either way.
I think we need to remind ourselves that the questions of whether the
Earth is warming, and if so, why, are just the first question we need
to ask ourselves. The real question is, if so, what should we do about
it.
From what I can tell from reading the literature by Rob Mendelsohn and
others, it is quite possible that based on the best predictions of
global climate change over the next century at least, the net benefits
of global warming may very well turn out to exceed the costs. (Beyond
that time frame the predictions are largely irrelevant--recall that a
century ago there were no cars, for instance, which should give us
pause about the reliability of long-term models). But even if the
benefits exceed the costs, there will be substantial distributional
effects, primarily favoring wealthier countries that also tend to
reside in more temperate climates (in part, the two are related, as
the net beneficiaries of global warming also tend to have higher
levels of economic productivity).
If this is true, I want to suggest one way we can think about this is
the "Box 4" that is familiar to Property professors in teaching the
Coase Theorem (Spur Industries v. Del Webb). This would be to
recognize the right of the net "losers" of global warming as having
suffered a global nuisance from the net "winners," but to enforce it
with a liability rule that entitles them to compensation, rather than
a property rule that would entitle them to an injunction. The
transaction costs seem too high to give them a property rule. Forcing
the winners to pay compensation would also ensure that the net gains
from global warming to the winners do in fact outweigh the net losses
to the losers.
References
1.
http://www.washingtonpost.com/wp-dyn/content/article/2005/06/17/AR2005061701219.html
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