I wonder if because of all these forest fires in California the people living there have a huge co2 footprint? Since it's electric lines causing the fire, it can be seen as human made for sure.
Your carbon footprint is determined by how much carbon you're adding (e.g. burning gas that was previously sequestered deep underground) to the carbon cycle.
I suppose if a bunch of plastic got burned in the forest fire, that would technically be adding a carbon footprint, but it's likely negligible.