"Air conditioning made it [global warming] all possible. And now having
opened the door to southern pols and Dixie climes, it’s also planning to export
those hot summer winds all over the world by making the hole in the ozone
layer a reality."
Michael Moore, Stupid White Men, p130

Ozone depletion and global warming are not two wholly unrelated issues. Both,
for instance, can be seen as the product of mankind’s high levels of consumption
having detrimental effects on the environment. But they are not as closely related
as they are sometimes assumed to be.

Ozone depletion is mainly caused by chlorofluorocarbons (CFCs) and its main
effect is to raise the amount of harmful ultraviolet B (UV-B) radiation reaching
the earth’s surface. Global warming, on the other hand, is thought to be at
least in part the result of increased man-made emissions of carbon dioxide (CO2)
and its main effect is an increase in the Earth’s temperature.

Despite these clear differences, however, there have been various attempts
to link the two. Some of these are respectable and follow the general lines
of arguing that what contributes to one phenomenon can also contribute to the
other; or that the kind of human activity that causes one also causes the other.
But, at most, these accounts suggest some kind of specific overlap. They do
not make one phenomenon the flip side of the other.

This has not stopped many people, often environmental campaigners, deliberately
or otherwise, using this small area of overlap to blur the distinction between
the two. In Michael Moore’s polemic, for example, he just seems to have got
confused. It would only be possible to "export those hot summer winds all
over the world by making the hole in the ozone layer a reality" if ozone
depletion were a major cause of global warming. But no credible scientist seriously
believes it is.

What Moore has done, perhaps unwittingly, is to have blurred the boundary which
keeps the two issues distinct. For anyone committed to clarity, precision and
intellectual rigour this is bad in itself. To understand any issue clearly one
needs to understand all the important distinctions that enable one to give a
precise account of what is at stake. Blurring the boundaries of debates is clearly
the opposite of this kind of careful analysis.

So why do it? Sometimes it is just ignorance. We just mistakenly think, because
we haven’t paid enough attention to the facts, that two similar sounding issues
must be more or less the same. Human beings are by nature "cognitive misers".
As a result, we don’t like to think about two things when we can get away with
thinking about just one. So we have an instinctive impulse to simplify which
makes us all too ready to lump two similar-ish issues together instead of keeping
them apart.

This probably explains why too many people (although fewer by the day) have
thought of smoking cannabis and injecting heroin as basically the same kind
of activity. Legal drugs okay, illegal drugs bad is a simple rule to follow
and it is so much easier than looking at the wide range of different drugs available
and thinking about the similarities and differences between their effects, addictiveness,
relation to crime and so on. The real issues about drug use are complicated
and that provides an incentive for us to fool ourselves into thinking they are
simpler than they really are.

But sometimes the reasons for blurring the boundaries are more calculated.
Blurring issues can be a useful rhetorical or polemical device. In the case
of environmental campaigners, for instance, if ozone depletion and global warming
are connected in people’s minds, then they will perceive a single threat that
is larger than each of the two by themselves. It also means that doubts about
the science behind environmentalists’ claims can be more easily diffused. The
threat is too large, the risks too high for any doubts about the reliability
of evidence, which is only ever going to be about one or the other, to throw
the campaign off course.

This is also what is probably happening with the war on terror and the conflict
with Iraq. Any links between the two are indirect and probably more to do with
long-term strategic aims (cutting off support for and dampening down militant
Islam by instilling a western friendly, more or less secular regime in the heart
of the Gulf) than the tactical hunt for Bin Laden and his supporters. But while
it is true that there are some links between the two campaigns, it would help
the Americans and British enormously if people were to think of the campaign
against Iraq as a simple extension of the war on terror. Blurring the boundaries
is thus intended as a means of increasing public support for an attack on Iraq
(not that it seems to be having much success).

Whether intended for polemical purposes or the result of some form of ignorance,
blurring the boundaries can never be a good move when trying to understand any
issue properly. The inquiring mind needs to attend to the important distinctions
in a debate, not fudge them.