The Earth has never stood still. Change is built into the life
of the planet, whether physical changes to the surface of the
Earth through the slow action of erosion or glaciation or
biological changes to the species that populate it. We only have
to go back to the last ice age which peaked just 20,000 years
ago, a coffee break in geological time to see a climate that is
utterly different from the one human beings have thrived in for
the last few thousand years. Heraclitus had it right: the only
constant is change. So it's not the fact that the global
environment and the climate are changing that so worries many
scientists. It's the rate of change and whether or not human
beings, and everything else that lives on the Earth, can adapt.
Because the Earth, it turns out, is changing very, very fast.
This is the sobering conclusion of a study published in the
journal Nature earlier this month. Scientists from around the
world looked at past research on ecological change, and found
that the planet may be approachin