Geothermal energy is theoretically more than adequate to supply humanity's energy needs, but currently only a small fraction may be profitably exploited. This is mostly because technology is not quite up to par, and its not cost effective to setup plants for it right now. As it is its been historically limited to areas near tectonic plate boundaries, but may be reachable in more areas cost effectively in the future with advancements in technology.
As many clean options as we have should be used to combat climate change. It goes to reason that certain areas of the world will benefit more from different types of clean energy. For instance you wouldn't see solar panels in Alaska being of much use but windmills might. Geothermal is something I can see working in a wide variety of places.