Prime Minister Morrison denies climate change because he wishes to support multinationals, to enable them to make money. Former US Vice president Dick Cheney preferred the term climate change to global warming because he thought it would be easier to defend against claims that it was caused by humans.
In some parts of Australia, lightning in the main source of bush fires.
Large fires can also create their own thunderstorms known as pyrocumulonimbus. They can cause erratic more intense and dangerous bushfire behaviour.
Inversions also have an influence on the smoke produced by a fire. In stable conditions, when an inversion is strong, smoke is trapped close to the ground causing issues with air quality and visibility. Once the inversion breaks, typically in the late morning, the smoke becomes more mixed with clear air and disperses through the atmosphere. New smoke produced by the fire forms a neat plume that moves downstream away from the fire.
Other sources of bushfires are:
Parking your hot police car on a dry grassy verge,
Dropping your cigarette but somewhere,
Mowing dry grass in a total fire ban (yes mowing is forbidden in a total fire ban),
Poorly maintained privatised electricity poles and wires sparking in high winds and the list goes on …
16 November 2019
Bureau of Meterology @ http://www.bom.gov.au/weather-services/fire-weather-centre/bushfire-weather/index.shtml