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Port Hills fire – Expert Reaction

Fire crews are responding to a large vegetation fire in the Port Hills near Christchurch.

Fire and Emergency New Zealand (FENZ) was alerted to the fire at 2.15pm on Wednesday 14 February.

The SMC asked experts to comment.

Dr Nathanael Melia, Director & Principal Scientist, Climate Prescience, comments:

“Seven years after ‘The Port Hills Fire’ in 2017, another widespread aggressive wildfire took hold on Valentine’s Day 2024. Fire and Emergency NZ (FENZ) have thrown everything at the fire, including an incredible 12 air assets yesterday; this has controlled some fire areas, although the main fire front remains uncontained. During the day, FENZ and the rural-urban interface community enacted many lessons from the 2017 blaze, which is great to see in action.

“In contrast to the stormy 2022/2023 summer, 2023/2024 is a big El Niño season, and the globe continues at record temperature levels. The 2024 local conditions in Canterbury in late summer are conducive to wildfire development. The meteorological conditions on Valentine’s afternoon in the Christchurch Port Hills area were ‘Very-high’ to ‘Extreme’ and only deteriorated post-ignition as the afternoon fight began.

“Ongoing drought conditions above extreme fire risk thresholds are the background, while yesterday’s culprit was the extremely dry and gusty winds causing the extreme fire spread rates. These conditions resulted in immense difficulty in containing the fire as it spread fast up the steep Port Hills and was often able to leapfrog ahead, starting new fires in a phenomenon known as ‘spotting’. This extreme fire behaviour makes fighting at the main fire front far too dangerous as ground crews can become rapidly surrounded.

“A full investigation into the Valentine’s Day fire will find the ignition point. Recent wildfire ignition sources include a camping stove, malfunctioning powerlines, and a metal landscaping blade sparking off rock. I renew my call to ban certain activities that may lead to ignition during extreme wildfire conditions, and I encourage relevant parties to investigate plans and legislation along these lines.”

Conflict of interest statement: “Nathanael is the Founding Director of the climate research firm Climate Prescience, which has previously received public and private funding to forecast the effect of climate change on wildfire risk.”


Shana Gross. Wildfire Scientist, Scion, comments:

“As wildfire researchers, we know that fire conditions are worsening and there are more and more extreme fire days each year. The changing climate is increasing the frequency and severity of wildfires, and escalating the risks, not just in rural areas like we saw last week in Lee Valley, but also where people feel more secure like the edges of cities. The Port Hills area is another example of this. Overseas this trend is even more advanced with fires burning well into established cities across the globe, including fires that burnt more than 15,000 homes in the cities of Valparaiso and Vina Del Mar in Chile.

“We always look to learn from rural fires and our controlled research burns to better predict and prevent wildfires as part of collaborative efforts to safeguard lives and property. As such, Scion conducts case studies of both historical wildfires as well as attending active wildfires like the one we’re seeing in Port Hills this week. Primarily, we are focused on gathering data and information. On Wednesday, Scion started collecting fuel samples and remained ready to support FENZ should they request that we directly participate by providing our prediction and modelling skills. This involves using tools, such as Prometheus, which is a computer program that estimates how a fire may spread on the landscape over time.

“Of course, where there’s fire there’s smoke and that can have a lot of implications as well. At Scion, we’ve developed a prototype for smoke forecast modelling that is available to the public and can be used to inform guidance from health authorities. The modelling identifies locations where smoke and fine particulate concentrations are predicted to drift.

“The automatic modelling is done using satellite detected fire hotspots and forecasted weather, which together are used to generate potential fire size and subsequent smoke emissions and downwind particulate concentrations. It is these small particles that can affect human health.

“But automatic modelling has some flaws including that satellites pass over in four-hour intervals and clouds affect satellite visibility, reducing the number of hotspots detected. In addition, automatic models are built on assumptions that may not be appropriate for all situations. So, Scion’s Fire and Atmospheric Team also runs the system manually upon request, usually from Fire and Emergency New Zealand.

“This modelling can inform Fire and Emergency New Zealand, health authorities and the public about potential smoke impacts. This could range from poor visibility over roads to adverse health effects for anyone with respiratory conditions. Health authorities could use this information to advise people on the best things to do, such as staying inside, shutting windows, or evacuating due to smoke.”

No conflict of interest declared.


Dr Nicola Day, Senior Lecturer, Plant and Fungal Ecologist, School of Biological Sciences, Te Herenga Waka – Victoria University of Wellington, comments:

“It is not surprising that the fire started on the Port Hills today. FENZ has been warning us all summer about tinder dry conditions that will fuel fires and the winds today have really helped the spread. February, the end of summer, is when the vegetation is at its driest so that’s providing good fuel for a wildfire.

“The effects on biodiversity and recovery of plants will depend on how the fire burns, how long it burns, and how hot it gets. The hotter the fire, the more likely there’ll be detrimental impacts on plants and it will make it harder for vegetation to recover. We might even see big changes in vegetation caused by fire and, possibly, invasion by weeds.

“I know that after the last fire on the Port Hills in 2017 the Christchurch City Council has been consulting with scientists, like Tim Curran from Lincoln University, about planting species that don’t burn very well so could hinder fire spread. This could reduce fire spread and its impacts on peoples’ homes and biodiversity. This event is a timely reminder of how we need to prepare for the combined effects of a warmer climate in conjunction with an El Niño year.”

No conflict of interest declared.