The media coverage of the devastating fires in Hawaii is particularly difficult to watch. The towering flames that lit up the night sky during the weekend have since revealed a mountain of ash from which there is little chance of finding survivors.
As the rising death toll hits home, so does the realisation that destructive wildfires are becoming increasingly common around the world, and we needn’t think it couldn’t happen here.
A look at the frost on the grass first thing in the morning is all we need to feel a long way from the weather conditions you might imagine would start a wildfire.
And you would be right. But as sure as night follows day, summer will inevitably roll around, bringing the environmental challenges we all associate with prolonged periods of high temperatures.
And, before you think back on the uncharacteristically wet 2022-23 summer … no, not that type of summer.
Rather, I refer to a new study which shows that parts of New Zealand may one day experience weather conditions similar to those that led to wildfires across the Tasman.
The study from the forestry research group Scion collected data through a climate model that covered the entire country in 5km by 5km grids.
According to Grant Pearce, a Scion scientist for fire research, a combination of increases in temperature, a decrease in rainfall in some areas, and increasing winds tended to lead to more frequent fire weather days.
Fire seasons were expected to become longer, starting earlier in spring and extending longer into autumn.
The research included four possible future scenarios spanning the next 75 years.
The first scenario mapped out the various outcomes should the world have removed carbon dioxide from the atmosphere.
Another two scenarios explored what might happen if CO2 emissions remained relatively stable, and a final scenario projected the likely level of fire danger in a world with high greenhouse gas emissions.
Somewhat soberingly, fire risk will increase, on average, both in the season length of fire weather conditions and in the intensity of fires that may take hold until mid-century, regardless of any effective climate mitigation efforts.
Those types of conclusions are not going to encourage anyone to try and reduce their carbon footprint, nor should they be ignored.
The study showed for the first time that conditions that led to the devastating 2019–20 Australian bushfire season, known as the Black Summer, would occur every three to 20 years in areas of the Mackenzie Country, Central Otago, and Marlborough.
Pearce says a broader understanding of all conditions that lead to fires was necessary to enhance preparedness. The Ohau, Hawaii fires in 2020 is now a prime example.
Those fires were at a time of year one would consider low risk. But there was a lot of dead grass from frost curing and strong winds. Frost, of all things.
The study uncovered a concerning trend in recent years – forests grown for carbon capture purposes were not managed like forests grown for timber was, with fire-controlling measures such as thinning of undergrowth not being a standard practice, for example.
Discussions in Wellington on managing carbon forestry are proceeding.
