Written by: Seamus Delaney

In 2018, at the International Conference on Chemical Education in Sydney, Andrew Eaton attended a plenary talk by Peter Mahaffy that addressed an ongoing challenge in high school chemistry teaching: how to help students connect core chemical processes with their wider environmental, economic, and societal implications. With more than two decades of experience, he had already been exploring ways to strengthen sustainability thinking in his classes. The plenary aligned with questions he had been considering for some time — and encouraged him to act.

A change to the New South Wales (Australia) curriculum created the opportunity. The newly mandated Depth Study required students to investigate a topic in greater depth, but the curriculum did not prescribe a particular approach. Although systems thinking was not explicitly mentioned in the state curriculum, not then nor now, Andrew recognised that the flexible structure of this Depth Study could allow him to integrate systems thinking meaningfully into senior high school chemistry.

Helping students see the bigger picture

Andrew developed a sequence of online, self-paced modules covering the chemistry of the Haber Process, the Solvay Process, biofuels, and ethylene–ethanol conversion. Alongside the chemistry, he introduced characteristics of systems thinking: identifying sources and uses of reactants and products, energy demands across a process, intended and unintended consequences, and connections to sustainability frameworks such as the United Nations Sustainable Development Goals (SDGs).

He modelled how a systems map works — how multiple nodes (connection points) show breadth, how cross-links reveal deeper relationships, and why factors like energy, catalysts, waste, and consumer use drive decisions. In Andrew’s lessons, he would demonstrate through examples “how multiple nodes … showed a broader understanding of the process,” and how links to other parts of the map demonstrated “a greater awareness of the relationships that are intertwined in all chemistry.”

Mapping, connecting, evaluating — and justifying

 Students then constructed their own systems maps. For each node, they identified SDG impacts and classified them as positive, negative, or neutral, colour-coding the map accordingly. Crucially, they also wrote a short paragraph justifying their decisions — drawing on chemical knowledge, sustainability concepts, and consumer uses. This shifted the task from descriptive to analytical. 

Students described the experience as demanding but rewarding. One explained:

“You actually have to really think about the broad impact of it … ‘where is the ethanol coming from? And how is that impacting everything?’"

Another valued the visual clarity of the map: “It gives a really good visual demonstration of its true benefits and negatives … so it’s definitely a broader focus on science in general, rather than just chemistry.”

A third highlighted how the evaluation and justification sharpened their thinking: “Writing down the positives and negatives … you find things that, oh, wow, that actually has a negative effect, even though I thought it was a quite positive thing.”

Assessment that made thinking visible

Andrew combined formative feedback with three summative tasks:

1. a short written comparing two chemical systems and their sustainability implications,

2. construction of a detailed systems map for a familiar chemical process taught in class and

3. evaluation of a teacher-created map of an additional chemical process students had not previously studied.

Maps were marked on their logic, breadth of connections, interrelationships across nodes, and the quality and justification of the SDG evaluations. Andrew designed a rubric that “worked well as a discriminating tool” and aligned with Andrew’s expectations.

Refining the approach over time

The first iteration required careful scaffolding. Andrew noticed that some students struggled to see the purpose of mapping until they understood what “good” systems thinking looked like. Each year he refined his explanations and examples, including introducing a strategy where students first list all possible SDGs before deciding on the weighting (-3 to +3) of each impact — a change that students found clearer and more manageable.

As the maps became more interconnected and the justifications more nuanced, Andrew observed a shift in student thinking. Systems thinking was no longer an add-on; it was a way of understanding chemistry in context. As he reflected, “This approach transforms simple chemical processes, usually represented by a chemical equation, into something greater, embedded in the global context.”

Why Andrew’s example matters

Andrew’s work shows that systems thinking can be embedded in senior high school chemistry without rewriting the curriculum, without losing content, and without requiring additional class time. Through the Depth Study, similar to other project-based assignments in other countries, he created a structure where students learned core chemistry and — simultaneously — developed the ability to evaluate complex, real-world implications.

 For educators considering whether systems thinking can fit into their own teaching, Andrew’s story offers a practical, classroom-tested pathway:

Start with one topic. Model the connections. Ask students to map, evaluate, and justify. The learning will follow.

 You can read more about Andrew’s story in these two articles.

Eaton, A. C.; Delaney, S. J.; Schultz, M. Situating Sustainable Development within Secondary Chemistry Education via Systems Thinking: A Depth Study Approach. J. Chem. Educ. 2019, 96, 2968–2974. https://doi.org/10.1021/acs.jchemed.9b00266

Schultz, M.; Chan, D.; Eaton, A.C.; Ferguson, J.P.; Houghton, R.; Ramdzan, A.; Taylor, O.; Vu, H.H.; Delaney, S. Using Systems Maps to Visualize Chemistry Processes: Practitioner and Student Insights. Educ. Sci. 2022, 12, 596. https://doi.org/10.3390/educsci12090596