“Curious, stubborn, argumentative – at times,” is how climate change researcher Dr Sarah Perkins-Kirkpatrick, research fellow at UNSW’s Climate Change Research Centre (CCRC), describes herself. Qualities which, combined with her passion for science, have seen her awarded an Australian Research Council Discovery Early Career Researcher Award (DECRA).
The award recognises the importance of her work on the influence of anthropogenic climate change on extreme weather events, and is supporting her research into a particular event that receives less attention than storms, floods or droughts, but potentially has more impact on human health and the environment.
“My research explores how heatwaves have changed, why they change, and how they will change in the future,” explains Perkins-Kirkpatrick, “as well as looking at how we measure them, and how to detect the human contribution from climate change that is affecting them.”
Heatwaves are prolonged periods of unusually hot weather and, according to the website Scorcher (developed by Perkins-Kirkpatrick), they kill more people annually than any other natural disaster. They can also damage infrastructure such as power supplies, which can become overloaded during peak air-conditioner use, and rail networks, where prolonged periods of intense heat can buckle train lines.
“Heatwaves are highly regional and very complex events, and are driven by changes in background temperatures due to climate change, but also things like weather systems, soil moisture, and long-term variability like the El Nino/Southern Oscillation,” explains Perkins-Kirkpatrick.
“Measuring them is not an easy task, as good quality daily temperature data are needed. Fortunately, there are good datasets available in Australia so we have a good picture of how they are changing here. Unfortunately, this is not the case for many parts of the world, such as South America, Africa and India.”
The subject matter sounds exciting but, according to Perkins-Kirkpatrick, she spends much of her time in front of a computer screen number-crunching.
“On a day-to-day basis, I’m processing big data from observations collected from all over Australia as well as those that are done globally. We’re not meteorologists, so we don’t go out and release weather balloons. For people like me, it’s very much about processing data,” says Perkins-Kirkpatrick.
The ability to analyse, interpret and discern trends in large datasets suggests Perkins-Kirkpatrick’s maths abilities are well honed. She admits, however, that a bad decision in high school has meant playing catch-up on her maths.
“Something that I didn’t do was keep up with my maths. I was pretty good at it in school, but I just never understood why I was learning differential equations, integrals … I just didn’t see the point. Lo and behold, I hit my career now, and I’m, ‘OK, whoops’,” she says.
Perkins-Kirkpatrick partly blames her older sister for this, who advised her not to take higher maths at school: “You’ll never need it,” her sister told her. So Perkins-Kirkpatrick’s advice to her younger self would be: “Don’t listen to your older sister, she doesn’t always know best.”
Although heatwaves are synonymous with summer, they can also develop in winter. They may not pack the punch of the sweltering temperatures experienced during summer, but they can have a disastrous effect on crops such as fruit trees, by interfering with their reproductive systems and inhibiting growth.
So how has climate change influenced heatwaves in the recent past, and what does the future hold?
“We can say with a high degree of certainty that heatwaves have increased since at least the 1950s,”explains Perkins-Kirkpatrick, “and that’s the case for pretty much everywhere on the globe where we’ve got good enough measurements.”
“Canberra over the last 50 years, for example, has seen a doubling in the number of heatwave days. Melbourne hasn’t seen much of a change in the number of heatwaves, but they have become hotter over the last 60 years. And Sydney has seen the heatwave season starting up to two or three weeks earlier.”
And the future looks anything but encouraging. According to Perkins-Kirkpatrick, the frequency, intensity and magnitude of heatwaves are all increasing, with frequency increasing fastest; and what is particularly concerning, these trends are also accelerating, meaning the rate of change is increasing too.
As with other areas of climate change research, Perkins-Kirkpatrick is attempting to make predictions; so it’s hardly surprising her favourite film reflects this.
“Back to the Future is pretty much my favourite movie trilogy of all time,” she says, recalling her childhood. “I recently gave a talk on how, in climate change, we look into the future, and managed to slip in a reference to Back to the Future.”
– Carl Williams