Protection of the
Earth needs to take
several forms - protection from
internal dangers and
external dangers.
The external
danger that most of us worry about - if we worry about
anything - is the
threat of a
meteor or
comet hitting the Earth and causing an
Extinction Level Event. The reason we perhaps worry about this so much is
because it's been
popularised by
Holywood in such films as
Deep Impact and
Armageddon. How likely is an
extinction level
event? There's
strong evidence to suggest it's happened
before, and it will
certainly happen in the
future. The only question is
when, and that's something that's very hard to
predict.
Astronomers are apparently doing well at tracking
large objects in the solar system, but just the other week a meteor that could have destroyed a small city passed by
Earth at a
near miss, and the object hadn't been detected until it was really too late to do
anything about it.
The internal
dangers that most of us worry about are
pollution and
Global Warming. Some people may also
cite the
hole in the ozone layer, but that'll be gone in fifteen years
anyway.
Is Global Warming a
threat? It certainly looks like it,
although we must also
remember to take into account standard
climate variation that the
Earth undergoes anyway - the
planet's been put through a lot worse than our
hypothetical global warming scenario is/will putting/put it through without our help!
Another danger we think about a lot is the threat of
nuclear war. Unfortunatly, this
threat is totally in the hands of human beings. If I could think of anyone to give a
nuclear arsenal, it wouldn't be
human beings. Thankfully,
political tension seems to be decreasing
rapidly now, and with
disarment in process this threat should
dwindle. The possibility of us destroying ourselves in some other elaborate way will remain the same,
of course.