Professor Patrick Baker, Professor of Silviculture and Forest Ecology at the University of Melbourne, explains how tree rings can tell us about a landscapes climate history, and prove a worrying trend towards more extreme weather events and bushfires as a result of climate change. His studies have shown that bushfires are becoming more widespread and hotter than ever before, not just scarring trees – but killing them.
We spent long periods shrouded in smoke due to the 2019-2020 bushfires that burned upwards of 12 million hectares. In addition to the tragic loss of life and devastation to ecosystems and infrastructure, there were significant levels of smoke exposure across Australia. The lives lost as a direct result are likely to number in the hundreds. Approximately 10 million people experienced elevated concentrations of fine particles on account of the recent fires, exposed to an air quality equivalent to smoking between 20 to 40 cigarettes. These ultrafine particles, less than 2.5 micrometres in diameter (a ninth of a grain of sand), are referred to as PM2.5 particles. Following the 2009 Black Saturday bushfires, the Victorian Bushfires Royal Commission recommended that 5% of public land should be burned annually to reduce the risk of catastrophic bushfires. While protective against large, uncontrollable bushfires, these prescribed burns produce smoke that can have a significant impact on health.