Collectively
we are a stunningly large species. A way of illustrating the global nature of
our species comes from calculations of our own ecological footprint; Invariably
we exceed the amount of productive land available to us. For example, the
population of the Chicago Metropolitan Statistical Area contains around 9
million people. The amount of land required to sustain each person (the
physical footprint of our buildings, land for agricultural productivity and so
forth) is about 20 acres. Collectively this is 180,000,000 acres (281,250
square miles). Illinois's land area is 55,593 square miles, making the
ecological footprint of Chicagoans five times larger than the state of
Illinois. In fact Chicagoans do not live in Illinois - they live wherever their
environmental shadow is cast. In turn, the US population is larger than the
country which contains us, and the global population footprint is now larger
than the globe. We can overshoot on the global scale only by drawing down on
global environmental capital. And the planet may prove to be a rather taciturn
banker when accounts come due.
The
resource gluttony that got us to this point has had extravagant consequences on
a global scale: despoliation of the biosphere, vast eutrophication of the
hydrosphere, depletion of soils, and atmospheric changes resulting in climate
disruption.
We
are in the seemingly paradoxical position of not knowing the number of species
on Earth to the nearest order of magnitude (are there 5 or 50 million?) but
knowing that we have accelerated species loss to rates comparable to that of a
mass extinction event. That extinction is the fate of all species is beside the
point, since ultimately the loss is measured in repercussions to us. Not the
least part of this is the implication for our ethical self-conception. Is it
good to be asteroid-like, comparable to the one that took out the dinosaurs?