Published: 21 January 2013

Bronwyn Harch: using maths to solve the planet’s big issues

The Chief of CSIRO Mathematics, Informatics & Statistics, Dr Bronwyn Harch, talks to ECOS about her passion for using maths to study the environment, the challenges of her new role as CSIRO’s maths science leader, and her mission to inspire the next generation of multi-disciplinary scientists.

Dr Bronwyn Harch: ...<i>I want our staff not just to say ‘Hi, I’m a mathematician’ but ‘Hi, I’m working on global food security using maths’.</i>

Dr Bronwyn Harch: ...I want our staff not just to say ‘Hi, I’m a mathematician’ but ‘Hi, I’m working on global food security using maths’.

Credit: Kaylene Biggs

It was the 1980s, and environmental science was popular. Bronwyn Harch said to herself: ‘I need to get an edge – what is it?’ She had just completed a degree in environmental science (and teaching), and also enjoyed mathematics. She began to wonder: ‘Is there a career where I can combine the two?’. She realised the edge she was looking for was the interface between maths and the environment. It was the start of a fascinating career bringing the rigour of mathematics to ‘softer’ disciplines.

Even with your strong environmental background, you have made mathematical science a strong focus in your career. Can you describe the role that maths plays in research?

I consider mathematics to be a language of research that enables people from different disciplines to speak together. Whether they are environmental or agricultural scientists, they all need mathematical methods to look for patterns in their data and to come up with the required evidence to answer their questions.

Research is all about asking questions, and one of the major contributions from mathematics is generating and integrating data in a robust way, so you can come up with insights and make decisions.

After 17 years with CSIRO, you have taken on the role as Chief of CSIRO Mathematics, Informatics and Statistics (CMIS). What are some of your goals and aspirations for this division?

Within CMIS currently we have this mantra that I really believe in – we need to have the right people, doing the right science, achieving the right impacts. I want our division (CMIS) to be the ‘best in class’ in the way we apply maths and statistics in areas as diverse as biotechnology, finance, mineral processing, materials design, infrastructure, transport and of course the environment. Often the mathematical science applied in health research can be used for considering environmental issues, and likewise used when considering issues related to the mining or manufacturing sectors. We actually catalyse a lot of innovation because we can see the patterns across different sectors. Our innovation can be as simple as taking ideas from how we analyse things in one industry to another.

I am really keen to help Australian mathematicians and statisticians stand up and be proud of their contributions to multidisciplinary research. I want to make sure that people from the mathematical sciences are at the table when a team of scientists gather to first look at a challenge.

Most environmental science students don’t seem to focus on maths. How do you hope to get students to start thinking seriously about maths as a career option?

I think the current generation of students will probably end up having many different trajectories as they form their careers. So the challenge for them will be how to create forward moving trajectories and not continually needing to reinvent themselves.

Consequently people will need to look for opportunities that provide for ‘career lattices,’ rather than the traditional ‘career ladders.’ When people make a career choice, you want to be able to have the option to move sideways as well as up.

Through my experiences, I see that mathematical sciences give you opportunities to operate confidently through a career lattice, because underlying many of today’s challenges is the need to consider patterns and trends, whether its agriculture, health or the environment. In any one month I could be talking to the insurance industry about statistical analysis, and the next day I might be speaking to the health industries and governments about using their health information for enhanced system productivity. Then I might be talking to farmers about how they can use sensing information for real time decision making. I think it’s very natural for mathematical scientists to make the most of opportunities in a ‘career lattice’.

Are you finding much of an interest from the younger generation to move towards careers in mathematical science? And how do you hope to increase their awareness about the importance of mathematics in science?

We have found the CSIRO-managed Scientists in Schools and Mathematicians in Schools programs are a great connection to school students and we have multiple staff involved.

Likewise, our Graduate Fellow Program connects to students finishing their undergraduate degrees in maths. We want to try and capture them for mathematical research before they decide to go into industry specific roles (e.g. finance). The Graduate Fellows come into the division for two years and see what it is like to work in multidisciplinary research teams as a mathematician. This is a partnership with universities linking their undergraduates to us and then we can link them back if they want to undertake post graduate studies like a PhD.

Rather than just telling students to do maths or stats, you get current staff to inspire and mentor and let them make up their own minds from what they see. How do you train your staff to inspire students?

I think we need to be really good story-tellers and it’s important that we achieve a pull strategy – pulling students though to the particular challenge or application – rather than a push strategy, where only the math or stats angle is pushed at them. We have been doing things to try and relate to the younger generation like uploading videos to YouTube. Social media has been really important for us.

We also train our senior staff to tell stories and give ‘elevator pitches.’ For example, if you are in the elevator with the Prime Minister and you want to tell her the importance of mathematical science, what do you say? We put a great deal of emphasis on our communication networks and we get our communication staff to work with our scientists on this. I ask my leadership team every month to explain their achievements in words everyone can understand. Sometimes, I can be a bit cruel and ask them: who cares? I ask because I want them to think about what’s important about what they’re doing. I want our staff not just to say ‘Hi, I am a mathematician’ but ‘Hi, I’m working on global food security using maths.’

Dr Bronwyn Harch was in conversation with Ian McDonald. Follow Bronwyn on Twitter @BronwynHarch

Published: 17 January 2013

Crunch time for metals recycling?
Alex Serpo

With the world facing a rare-earth metals crisis, a paper published in the leading journal Science last year examined how far we are from cradle-to-cradle metal recycling, and identified future constraints and opportunities.

End-of-life recycling rates for commonly used metals such as iron, copper, zinc and lead are above 50 per cent. However, rare earths and other lesser known metals are seldom, if ever, recycled.
Credit: © rihardzz/istockphoto

In the paper, ‘Challenges in metal recycling’ written by US researcher, Barbara Reck, the author identifies a modern paradigm shift in metals use – today, humans exploit virtually every stable element in the periodic table.

In other words, we are now capitalising on every element’s unique physical and chemical properties, whereas for most of human history, we utilised only a handful of metals.

Another modern shift is that of recycling, a ubiquitous aspect of modern life. ‘The generation between 20 and 30 are now the first generation to have grown up with recycling bins as part of normal life,’ writes Reck from Yale University's Center for Industrial Ecology.

Reck adds, however, that the extent of modern metals recycling is well below potential.

'Metals are infinitely recyclable in principle. But in practice, recycling is often inefficient or essentially nonexistent because of limits imposed by social behaviour, product design, recycling technologies, and the thermodynamics of separation.'

She identifies two metrics that provide the most accurate measures of the rate of metals recycling – 'recycled content' and 'end-of-life recycling rate'.

Recycled content describes the share of scrap in metal production, which is important to get a sense of the magnitude of secondary supply. End-of-life recycling rate, on the other hand, is defined as the fraction of metal in discarded products that is reused in such a way as to retain its functional properties.

The paper makes reference to a United Nations’ panel that recently defined and quantified recycling rates for 60 elements. Two key trends are clear from this research.

The first is that end-of-life recycling rates for the commonly used base metals such as iron, copper, zinc and lead are above 50 per cent.

The second trend is that many trace elements are seldom, if ever, recycled. Most of these trace elements are increasingly used in small amounts for very precise technological purposes, such as red phosphors, high-strength magnets, thin-film solar cells, and computer chips.

In those applications, often involving highly comingled 'specialty metals', recovery can be so technologically and economically challenging that the attempt to recycle is seldom made.

'After millennia of products made almost entirely of a handful of metals, modern technology is today using almost every possible metal, but often only once. Few approaches could be more unsustainable,’ comments Reck.

Greater opportunities for collecting used metals have improved recycling rates over recent decades.
Credit: Bidgee under CC-BY-SA-3.0 via Wikimedia Commons

In her paper, Recki identifies lead as a notable exception : '...80 per cent of today’s lead use is for batteries in automobiles and for backup power supplies, and collection and pre-processing rates from these uses are estimated to be within 90–95 per cent as a result of stringent regulation worldwide. The result is a nearly closed-loop system for lead use in batteries.'

While improved product design and enhanced deployment of modern recycling methodology will both improve recycling rates, Reck identifies one activity that stands out as the key to increasing recovery.

'It seems mundane at first telling, but the activity with the greatest potential to improve metal recycling is collection,' she writes. 'Much improvement is possible, but limitations of many kinds – not all of them technological – will preclude complete closure of the materials cycle.'

Reck also identifies a perverse incentive when it comes to product design for recycling: the more advanced and highly engineered the product, the more difficult it is to recycle. This is particularly true for electronics products, but also applies to other goods like cars, aeroplanes and whitegoods.

Collectively, today’s high-tech products make use of almost every metal, in contrast to earlier products that used only a handful of the more common metals.
Credit: © Yutaka Tsutano under CC BY 2.0 licence via flickr

The paper identifies another paradox of modern materials recovery. 'It is not much of an exaggeration to say that we manufacture modern products with the best possible technologies we can devise, but generally recycle them with relatively basic approaches.

'It is unfortunate from a materials perspective that, for reasons of scale and economics, often only the more basic technologies (shredding, crushing, magnetic sorting) are routinely applied, whereas more advanced technologies (such as laser, near-infrared, or x-ray sorting) are limited to selected recyclate streams.'

The paper dismisses the common notions of infinite recyclability for bulk recycling of common metals.

'Markov chain modelling shows that a unit of the common metals iron, copper, or nickel is only reused two or three times before being lost, gainsaying the notion of metals being repeatedly recyclable.'

Reck’s concluding comments identify how materials substitution could help improve the sustainability of metals supplies.

'Sometimes, scarce metals can be replaced by more common metals with only modest loss of product performance. Examples are aluminum-doped zinc oxides substituting for indium tin oxides in liquid crystal.’

This is a lightly edited version of an article that first appeared in Business Environment Network (BEN) and is reproduced with permission.

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