What fuelled Australia’s “Black Summer” fires?

A photograph of a large tree, silhouetted against an orange sky and impending bushfire.
8 January 2021

Climate and bushfire experts have weighed in on links between human-generated climate change and last summer’s unprecedented, catastrophic bushfires that razed parts of Australia.

The paper, published in the Nature journal Communications Earth & Environment, highlights how climate variability and long-term trends combined to create the conditions that enabled the fires to burn out of control for months on end. 

These include hot, dry, windy weather often sparked by cold fronts, a build-up of prolonged, severe droughts, and forests comprised of fire-prone eucalyptus trees with accumulated expanses of vegetation, debris and dead wood. All that’s needed is a spark to ignite it – a risk factor compounded by dry lightning, which has increased over the past five decades.

Added to that, the team notes drops in rainfall during cool seasons in the south-eastern states, reaching a record low in 2019 compounded by an accumulated decline over the past 20 years. More broadly, they describe how factors such as greenhouse gas concentrations, ozone levels and atmospheric instability could fuse to increase fire risk.

Read the full article on the Cosmos website, featuring Prof Nerilie Abram