When Rachael Isphording was 12 years old, Hurricane Ivan passed through her hometown of Fairhope in Alabama, along with countless others along the south-eastern coast of the US.
It tore through communities in the Mobile Bay Area, uprooting homes – and lives – in a catastrophic event impacting US states and Caribbean nations.
Then, less than a year later, and while communities were still in recovery from that Category 5 hurricane, another massive cyclone blew through.
That was Hurricane Katrina, an event that remains the most expensive in US history having caused US$125 billion in damage. Nearly 2,000 deaths were directly attributed to Katrina, though more are likely to have died indirectly.
Some parts of the American south-east are still yet to rebuild. They may never do so.
In the aftermath, affected people were forced to queue for basics like water and military ready-to-eat meals.
Human displacement was also significant. With homes and infrastructure gone, many were forced to migrate interstate, some resettling permanently.
But for a young Isphording, that distressing event triggered what has become a lifelong interest in the planet’s atmospheric systems, and a career as a climate scientist on the other side of the world.
She’s now scientia PhD candidate in the Climate Change Research Centre at the University of New South Wales and the Australian Research Council Centre of Excellence for Climate Extremes.
Those experiences in Alabama have guided her studies both in the US and Australia, where she is now reliving the challenges presented by climate events through the lens of La Niña, and the flooding it has brought to her adopted home in 2021 and 2022.
“Ivan and Katrina were very impactful as a child,” Isphording tells Cosmos.
“I became quite obsessed with our local broadcast meteorologist and started really paying attention to his new segments! I always wanted to watch the weather.
“And he would always explain the science behind the forecasts and try to make it very accessible to all of us in small town, rural Alabama. So from an early age, I knew I wanted to pursue atmospheric science.”
Models and matchmaking
Climate models can be used to simulate rainfall patterns, and these are used by researchers like Isphording to understand the possibilities of short and long-term weather and how atmospheric changes influence the conditions that trigger major hazards like the floods driven by repeat La Niña cycles.
“I’m a matchmaker for models,” she says.
Isphording searches for complex computational models that can best explain future weather patterns and events, and how they will be influenced by a changing climate and human activity.
Like any matchmaker, she needs to identify which model might be most suitable for explaining the phenomenon being studied. Does one rainfall model work across a whole landmass, or does a specific one need to be used for a certain area? Will some models work at different times of year?
Through an interrogative approach, she can pair off models to situations and answer unique questions.
“There are so many different aspects of rainfall that could be important to different people, whether you’re more concerned with ground, or high intensity flood events, or the seasonality of rainfall,” she says.
Isphording recognises the burden of trying to anticipate how the weather systems will behave.
While it’s easy to fall into the trap of thinking weather and climate exists in the sky, the climate is a complex interaction between many different systems expanding across the planet’s atmosphere, landmasses, and oceans.
There’s also an important distinction between weather and climate. Although we can read weather predictions online or in a newspaper, climate refers to the long-term weather patterns for particular regions.
It’s now accepted that, as more carbon is released into systems that influence climate, this additional energy will serve to charge weather events in regions across the globe. Australia, it’s anticipated, will experience greater frequency and intensity of cyclonic activity, floods, droughts, wildfires and sea level rise as global average temperatures increase.
But while models can anticipate – with a high level of precision – what future climate patterns will unfold, they are not a crystal ball.
Pondering plausible futures
“Climate models actually aren’t predictions,” Isphording explains.
“We actually like to say they’re plausible futures… We’re really just using these computational tools to look at these possible futures and get a high-level, broad idea of what the climate will look like.
“For instance, will Sydney experience more linear rainfall events, or will the droughts be longer and more severe? Will they last 10 to 20 years, versus three to five years?
“Using all the different simulations, we can look at these different, plausible futures. But we don’t know which one is going to happen, which is why it’s also very important to acknowledge the limitations of the models.”
Are you interested in the energy industry and the technology and scientific developments that power it? Then our new email newsletter Energise, launching soon, is for you. Click here to become an inaugural subscriber.
One way to reduce the possible inaccuracy of simulating plausible futures, employed by leading reports such as those issued by the IPCC, is to effectively ‘layer’ predictions on top of each other, allowing researchers – and readers – to see how models stack up against each other.
Similarly, repeatedly running simulations enables greater precision by seeing how input variables influence modelled outcomes.
By building in these repeat ‘tests’, scientists are able to provide more robust information to decision-makers, be they governments, industries, or the public.
But gathering information on plausible futures is an important exercise for climate scientists, not just to inform planning, but to play their role to address the complex problems posed by climate change.
And like many leaders at this week’s Australian Meteorological and Oceanographic Society conference in Adelaide, she sees an opportunity for experts to further the impact of their work with everyday people.
Part of that opportunity, she says, is driven by the rare position these disciplines find themselves in Australia: what she describes as a “more nurturing and welcoming” environment than back home.
But even then, “Science”, she says “can only do so much.” Acknowledging that is important and emphasises the need for other stakeholders to come to the table when engaging with data and research.
“Climate is one of those wicked problems… It’s such a cross disciplinary problem, and it needs cross disciplinary input.”