Potentially dumb question: wouldn't the existence of a global magnetic field already imply the presence of a global electric field? Or is this discovery a separate unrelated electric field?
A permanent magnet produces magnetic field, but not electric field (unless it's electrically charged, but that's usually not the case), so no, magnetic field doesn't automatically imply electric field (charge).
Isn't electricity and magnetism the same force?
Not a physicist so this may not be related but AFAIU magnetic fields must change to produce current. Just having a magnetic field does not imply electrical current.
I think what GP meant is that (from one viewpoint) magnetism is an emergent property of the electric field and relativity.
I think OP is asking: if there's a static magnetic field but conductive stuff (say, the oceans) moves through it, doesn that not induce an electric field?
Varying electric and magnetic fields are coupled (to form electromagnetic radiation). Static electric and magnetic fields can exist separately.
per Faraday's law, a moving magnetic field implies an electric field