"Human activity is so important in California because it causes about 90% of ignitions, versus much lower levels in other areas of the West, where lightning causes more fires," Solander said.

Source: https://phys.org/news/2023-01-re-burns-california-west.html

Hyundai and Kia cars are apparently too easy to steal so the attorney general of Minnesota, Keith Ellison, is demanding that the manufacturers do something about it; make those ignitions harder to jack.

Source: https://www.twincities.com/2023/03/11/soucheray-never-mind-the-thief-its-the-cars-fault/

Unplanned human ignitions typically occur near buildingstend to burn in grasses that dry out easily and burn quickly.

Source: https://kiowacountypress.net/content/western-wildfires-destroyed-246-more-homes-and-buildings-over-past-decade

While there is not necessarily a at this point even for this direction, Forest Service firing operations that expand wildfires cannot be considered to be using natural ignitions.

Source: https://www.counterpunch.org/2023/08/11/forest-service-wildfire-management-policy-run-amok/