July: Future Of: Investigating Climate

Reconstructing the climate history of Australia

Associate Professor Tim Cohen is a geomorphologist and Quaternary scientist in the School of Earth, Atmospheric and Life Sciences (SEALS) at UOW. He researches landscapes, their evolution and past climates. He is the Theme leader for Climate in the ARC Centre of Excellence for Australian Biodiversity and Heritage (CABAH), and the recipient of an ARC Future Fellowship.


1.  What are you researching or working on in 2019/2020?

I am a Quaternary scientist and a geomorphologist, so I study landscapes and I use landscapes to investigate climate change over deep time and over shorter timescales. So, in 2019/2020 I am continuing my research using lakes all across the continent. These lakes and the sediment that are contained within, tell us something about Australia’s climate, such as periods of extreme wet and also periods of extreme dry. In its most simple description, my research is reconstructing the climate history of Australia, using lakes and I use everything from small lakes through to Australia's largest lake; Kati-Thanda Lake Eyre. Our group (including research fellows, PhD and Masters students) work on lakes everywhere from eastern Indonesia to SW WA to SE Australia. 

Our work involves digging holes, taking cores, and analysing the sediments within them. Those sediments are more, or less layered like a cake and the internal structure of the cake tells us a story about the history of the climate for that region. We then piece that information together across multiple regions and work towards understanding things like the frequency of extremes. We want to ascertain if we should expect to see more extreme climate conditions in the future. For example extensive and extreme wet seasons vs multi-year droughts. That way we can use the past as an analogue for the future.  

2. In regards to your field of study or expertise what are some of the most innovative or exciting things emerging over the next few years?

One of the things that CABAH (The ARC Centre for Excellence for Australian Biodiversity and Heritage) is doing is  integrating research-collaboration across a range of different disciplines. This means we're not just approaching climate change from a purely physical sciences angle. Rather we’re working with traditional owners to have them engage and actively participate in the research whilst also approaching the question from a range of angles.

We are working with ecologists, geneticists, and archaeologists, so the research and I'm doing with CABAH is pretty unique and more or less innovative in the sense that for the first time, in probably a very long time where we’re really trying to understand the history of the continent or a specific region from many different disciplinary perspectives.

That actually allows us to answer some very broad and important questions about humanity- everything from not just whether the climate is getting warmer and wetter [or drier, which is my interest as a climate scientist], but to understand how people have responded to that, and how Aboriginal and Torres Strait Islanders have managed those landscapes and responded to these climate fluctuations over time.

I think that's a novel component to what CABAH is doing with its multidisciplinary approach. For me its innovative, because I, like many people often approach their discipline in a pretty isolated bubble. CABAH’s work is a great example of where the bubble has been broadened and we are now being asked to engage in other bubbles. I think it's interesting because you learn many different aspects about the story, beyond what you thought was important.

Then with my ARC Future Fellowship, I’m concentrating on the last 1000 to 2000 years. One of the innovative aspects to this work is that I have been given  the opportunity to go into areas and sample key parts of Australian landscapes and at a resolution, something we haven't really done before. We aim to understand the frequency of droughts and the extreme wet phases, and assess if the frequency and intensity of those in recent years really is unprecedented. We need time and resources to answer these questions and strangely enough in many parts of Australia this simply has never been done.   

3. What are some of the things readers should be cautious of over the next few years, in this area of research?

In regards to climate science and obtaining the facts, it is easy for people to be attracted to half information, half-truths, or deep fakes. I think people often get attracted to quick, bite sized bits of news and often the places that deliver information in this fashion, aren’t always doing the best at providing good coverage of that particular issue.

The deep fakes of science are plentiful, and readily available online. I encourage people to read broadly and to look at reputable websites or information regarding climate change or temperature change, or CO2 predictions.

Climate change is a really relevant issue for every person and they should be looking at it, and learning about it, so they can understand the depth of the argument and not just the often polarised debates that we are often presented. 

4. Where do you believe major opportunities lie for people thinking about future career options?

Earth and environmental scientists will play an ever increasingly role in making sure Australia’s natural resources are managed in a sustainable way. One could be a pessimist about the way national and global politics are impacting large areas of the Earth’s environment. But the global reality really underpins the role for individuals in this sphere of Earth and environmental science. Since I left university as an undergraduate 25 years ago the number of jobs in the environmental sector has only grown. So for people thinking about future careers in this sector, there are many jobs for good scientists and we really need good scientists working in all tiers of government and working in the consulting world.

I actually think there will be some amazing job opportunities for scientists as we experience a transformation in what technology will allow us to investigate [and monitor]. Education in the STEM disciplines (science, technology, engineering and maths) will only become more valuable at a primary through to a tertiary level. This is an area government is rightly focused on trying to improve, due to a need to get more people into STEM to increase our technical capabilities as a nation. There are probably jobs within this field that don’t even exist yet. 

5. In regards to your field of study or expertise, what is the best piece of advice you could offer to our readers? 

The best piece of advice I could offer is to and get out and look at landscapes and at what the local region has to offer. Getting out and participating in landscapes around them and taking advantage of what are is being done in places such as Wollongong, and at places like CABAH.

There are some fantastic resources that are being developed and delivered face-to-face, free to people here on campus and also online. For example CABAH has a really good website where people can sign up for newsletters and information feeds, and they often run free seminars and information sessions that people shouldn’t be afraid to take a look at.

Most people understand the world based on their own experience and that experience might be multigenerational. These are often views from parents and grandparents and their anecdotes and modern history all inform us on a day-to-day basis.  I guess the thing I would advise people who are yet to expose themselves to the wonderful world of deep time is to appreciate that Earth and environmental scientists often use timescales that span- centuries, thousands, millions even billions of years. I think the past is a great way of understanding the context and depth of change. People who haven't thought about the deep past really should give themselves the opportunity. I think it's a great way of getting outside of the generational or modern historical bubble, which everyone uses as their personal reference point. Time is a very novel way of discovering the trajectory of both humanity and the planet. 

From a researcher perspective, it easy to put your head in the sand and projects and concentrate on what’s under your small patch of ground- your small area of focus, but its commonly said that some of the most novel contributions to research have come from interdisciplinary projects. That’s not just within science disciplines- that’s science and indigenous knowledge, science- arts, science- history, science education- all of those areas provide good opportunities for people to look beyond their own specific areas of interest. 

CABAH: ARC Centre of Excellence for Australian Biodiversity and Heritage

Tim Cohen: To find out more about Tim, visit his Scholars profile