With the current bushfires making their way through NSW at the moment, there has been a lot of public discussion on whether or not climate change is responsible for such a strong fire before summer has even hit. As environmental site assessment experts, we’ve had to deal with fire-damaged properties, so we thought we’d take a look at the correlation between climate change and increased bushfire intensity.
The McArthur Forest Fire Danger Index
The FFDI was created by Alan McArthur in the ‘60s and has undoubtedly saved many lives in its 50+-year tenure. The index utilises several elements such as temperature, wind speed, humidity and drought factor to determine how easy it would be to start a fire.
You may recognise the sign as it is often placed on the side of roads in rural areas of Australia – recognisable by its colourful semi-circle metre with a single hand pointing to what the danger rating is at the time.
There are six levels in the FFDI:
- Low-moderate – 0-11
- High – 12-24
- Very high – 25-49
- Severe – 50-74
- Extreme – 75-99
- Catastrophic (Code Red) – 100+
Because the 2009 Black Friday fires reached levels of around 150 – Catastrophic was added to the index. This was to indicate a level that was so critical that it posed an immediate danger to people’s lives and safety. NSW is currently set to code red.
“There is a very high likelihood that people in the path of the fire will die or be injured.”
– Australia’s revised arrangements for bushfire advice and alerts, catastrophic sample message.
El Nino events
When central and eastern tropical Pacific Ocean surface temperatures become much warmer than usual it can cause an atmospheric circulation shift. This is essentially what is known as an El Nino event. This means reduced rainfall and warmer temperatures across the majority of Australia’s south.
This is generally when the risk of bush fires is higher than usual. The 2019 El Nino event took place earlier in the year which is another indicator that even though there is no outside impact from an El Nino weather event, the catastrophic fires are still raging in NSW at the moment.
What’s the connection to climate change?
In 2018, the Bureau of Meteorology released a report stating that since 1910, Australia’s climate has warmed by just over 1 °C. The general consensus amongst scientific professionals is that our fire seasons are actually growing longer and more intense as a result of climate change.
Professor Glenda Wardle – an ecology and evolution professor at the University of Sydney – has said that “Much of NSW is also in drought and trees are dying and fuel loads are very dry, leading to dangerous conditions for fires to burn more intensely and spread fast.”
Droughts are poised to become longer and more frequent with climate change. Considering that droughts are one of the major contributors to bush fires, the link between the two begins to become clearer. Since the ‘50s, bush fire intensity and frequency have increased – indicating a long-term effect.
A lot of people are stating that this fire is an “unprecedented” event on account of its intensity and nature. The high evaporation and low moisture levels make it ideal for the fire to rage across the bushland unchecked. Fire authorities are also finding that the fire seasons are starting earlier and lasting longer than before.
“We propose that anthropogenic [human-led] climate change is the primary driver of the [upward trend in the fire danger index], through both higher mean temperatures and, potentially, through associated shifts in large-scale rainfall patterns.”
– Research found by Sarah Harris and Chris Lucas from the Victoria’s Country Fire Authority.
Do you need an environmental site assessment conducted?
Alpha Environmental is a premium environmental site assessment agency. We specialise in all three phases of an ESA and are able to complete each one comprehensively and efficiently. Our consultants are highly-thorough when researching and assessing sites – whether it be a new plot of land or fire-damaged property.
We also specialise in a variety of other services in addition to environmental site assessments, such as asbestos, mould, groundwater and soil testing as well as professional environmental advice and refurbishment/demolitions.
If you’d like to get in touch with us regarding an environmental site assessment, then please give us a call on 1300 039 181. Alternatively, you may also contact us by filling out the enquiry form found on our website.
