This century, Australia has suffered more frequent and more severe bushfires. The Black Summer fires of 2019–20 were the worst on record for the area burned and property loss.
How much climate change has contributed to these increases is a hot topic. Bushfire risk is dialled up by four switches: fuel amount and condition, fire weather and ignition sources. Untangling these various influences is difficult, so the role played by the warming climate is heavily debated.
Fire-weather measures fire risk on a daily basis, while a fire-climate regime measures fire risk over seasonal and longer time scales. Our research shows almost everywhere in Australia is now in a different fire climate than it was just 20 years ago, with falling relative humidity a key factor. Previous research has also identified these sudden jumps in fire danger.
