Current is _generated_ in static lengths of wire.
At any point the voltage exceeds the design, it arcs.
Current passing through imperfect conductors are heating elements.
Both sparks from shorts and excess heating of conductors are possible ignition points.
Oh, so you mean it might just be power (or other metal) lines causing fires indirectly?
I'd be very surprised if anything naturally occurring in a forest would be long and/or conductive enough to be a problem even during very strong geomagnetic storms.
Both sparks from shorts and excess heating of conductors are possible ignition points.
n.b. I have not look at the paper.