Is extinction of animals occuring at a faster rate today than it was in the 1900's?
Scientists agree that the extinction rate is currently much higher than the normal, or background, rate would dictate. Estimates of how much faster extinction is proceeding vary, from ten times to more than a thousand times more rapidly than it was in 1900.
In the Earth's past there have been events know as mass extinctions, which are believed to have been caused by global catastrophic events such as the Earth being struck by a large meteorite; one of these events removed an estimated 50% of all living species in a relatively short time frame. Some scientists warn that human activities are crowding species and altering habitat and climate so dramatically that we may well be the cause of the next mass extinction.