Question

The natural resources used by society are limited by various factors. Why is coal considered a nonrenewable resource?
a.
Once coal is used up, it can never be replaced.
b.
Coal is a nonrenewable resource, because it comes from the impact of meteors with the Earth.
c.
Coal was a renewable resource, until it was mismanaged by humans.
d.
Coal is considered a nonrenewable resource, because it takes millions of years to form.

Answer 1

d. Coal is considered nonrenewable because it takes millions of years to form from buried plant matter under heat and pressure, so it cannot be replenished on a human timescale (much slower than we use it).