to free
ne
8. Read the passage. Summarize the central idea of the passage.
"Sustainability is the hot buzzword among scientists and environmentalists right now. But what,
exactly, does it mean? Sustainability is the capacity of the earth's
natural systems to adapt and
survive in changing environmental conditions. Earth has an
extraordinary ability to maintain a
healthy balance in its temperature, energy, and food chains. Although
humans have only existed
on earth for a fraction of the planet's existence, there
is increasing evidence that humans have
seriously affected earth's ecosystems in ways that may
compromise its ability to sustain itself. For
example, humans are using renewable resources, like trees, faster
than the earth can replace
them. If humans do not adopt sustainable practices,
the damage may be irreversible. Sustainable
ensure that businesses and individuals consume fewer
resources and in a way that does
practices
not damage
the earth's ecosystems."