The Human bottleneck

http://candobetter.org/node/509
May 15th, 2008 by marco <http://candobetter.org/user/73>

Perhaps the most urgent near-term issue for environmentalists is one
that few yet talk about. It is what I call "the human bottleneck". This
is a time when most species may disappear. Mark O'Connor has designed a
graph to evoke this scenario.


Perhaps the most urgent near-term issue for environmentalists is one
that few yet talk about. It is what I call "the human bottleneck".

Just as the genus /homo/ itself went through a bottleneck when all but
one of its species vanished, and just as even that one survivor, /homo
sapiens/, seems to have fallen at one point to less than 10,000 breeding
pairs, so all other species on Earth will soon have to pass through a
bottleneck as humans pass through what we hope will be a maximum
population of about 9 billion, later this century. This will leave so
little land and food for other species that many, perhaps most of them,
will perish.

Note that the narrowest part of the bottleneck for other species will
not necessarily come when the human population peaks. At that stage
many, or even most humans will still be living in poverty but aspiring
to affluence. Hence the squeeze on all other species will actually
continue to get worse, and perhaps very much worse, after the human
population peaks.

The assumption that world population could peak at approximately 9
billion is taken from
http://www.census.gov/ipc/www/idb/worldpopinfo.html

For the assumption that much of that population will still be pursuing
increased consumption, and thus intensifying rather than relaxing the
squeeze on other species, the author relies on his perception of common
experience of human nature and of social inequalities.

You'll notice that the graph has such a small scale on the X axis (which
covers 200,000 years) that one cannot read fine detail from it about
values on the Y axis over the next 50 years (which would be speculative
in any case) or the last 50. This suits, because the figures would vary
according to what measures are used.

e.g. it is commonly said that humans now use some 40% of the Earth's
primary production (i.e. plant food created from sunlight). But it does
not follow that 60% of Earth's surface is freely available for other
species, and I presume less than 20% is in virgin state. It also depends
whether one includes the oceans. Virtually no part of the ocean surface
is not harvested by fishermen, so this might put us as at present
intensively harvesting the production of 80% of the planet rather than 40%.

Fortunately, as I say, the graph does not permit of reading its values
in such fine detail over short periods --which is another way of saying
that the overall shape remains the same pretty much regardless of what
measure one uses for human domination.

Mark O'Connor CMC,
home page: www.australianpoet.com

Mark O'Connor is the author of This Tired Brown Land, Duffy and
Snelgrove, NSW, 1994. He was Australia's Olympic poet for the year of
the olympics in Sydney. He has published many books of poetry, much of
it on ecological subjects.



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