Geology: The big questions

[MarxSchmarx]

Are there any geology nerds here? What do you think are the biggest challenges facing the field of geology today? I guess I must admit that while it seems a ton of effort is put into "can we predict where such and such a resource will be found", or questions that intersect with paleontology or astrophysics, I'm curious about the old-school big questions of geology like "can we predict the earthquakes" and the sort.

So, if you had to make a list of 5 big challenging questions for geologists in the coming decades, what would they be?

[Lynx]

What are the mechanisms behind Earth's magnetic field?

[Ose]

What are the mechanisms behind Earth's magnetic field?
I think it's something to do with convection in the metallic component of the Earth's core. But as you can probably tell, I'm no geologist.

[occurin]

From what my textbook suggests, finding the exact nature of the convection currents in the mantle that help move tectonic plates. They don't really know if the mantle circulates all the way to the core, or if it only circulates to about 600km below the crust.