Geoscience Reference
In-Depth Information
continents in their tracks. But the Earth is a powerful and stubborn force. She limits our resources, and
her geological will is extremely hard to check.
If distant descendants of the human lineage can't stop the Snowball, can they weather it? That's
hard to imagine, too. Getting a few simple marine creatures through the ice is one thing, but the com-
plex creatures that inhabit our planet today would be another matter. Antarctica is the most hostile
place on Earth. Unless you take your own life-support system of food and fuel and shelter there with
you, you will die. And in a Snowball, Antarctica takes over the world. For any truly complex creatures,
the result would surely be disastrous. Norse mythology has a word for it. After the catastrophe of Fim-
bulwinter comes Ragnarok, the end of the world.
But a new Snowball wouldn't be the end for
all
life on Earth, any more than the previous ones
were. The destructive power of the last Snowball was followed by an extraordinary new beginning.
Who knows what direction a post-Snowball Earth might encourage its living things to take?
Our planet is, after all, a master of invention. Through geological time, Earth has constantly sought
out new forms and taken on remarkable new identities. Plumes of hot rock ascending from the interi-
or drive continual reshaping of the continental surface. A mountain range rises; another falls. Oceans
open here and close there. Earthquakes and eruptions and tidal waves that seem so catastrophic to us
are all just part of Earth's irresistible transforming urge. Even the flimsy atmosphere plays its part in
adapting, then reinforcing, our planet's shifting moods. Change doesn't alarm the Earth; it is a funda-
mental part of its nature. We humans, and the other creatures that share our geological slice of life, are
the fragile ones.