Question

Mounting evidence suggests that the average temperature of the planet is

Answer 1

About 50 years ago, mounting evidence was suggesting
that the temperature of Earth's surface has been sharply
increasing for the past couple of centuries.  Nowadays,
additional evidence no longer suggests it; it confirms it.

Today's mounting evidence suggests that human activity is
responsible for the increase, but that the increase eventually
spells curtains for much of human activity.