2026 ASEE Annual Conference & Exposition

*** Category: This is a proposal for a 5-minute Lightning Talk. ***

The more I learn about sustainability and how to teach it, the more I am convinced of the need to learn and teach the basics of earth systems, biogeochemical cycles, and planetary boundaries. The direct reason is to establish the baseline conditions of the Holocene that then allow a proper understanding of how human behavior has impacted the environment and climate, leading to the Anthropocene. More generally, earth systems science simultaneously provides an excellent opportunity to introduce systems thinking and to develop scientific literacy (such as the need to think across different scales).

Meanwhile, I regularly use active learning techniques, including inductive learning and concept-based pedagogy. A particular technique is to pose leading questions at the outset of a topic, when the students are not expected to know the result, providing students with an opportunity to engage with a misconception and to reflect on their own intuition as the topic unfolds.

With this in mind, I will present an approach that I have recently developed to introduce the topic of earth systems science as part of an introductory course on sustainability fundamentals. Three questions are posed that are designed to reveal some surprising results and motivate curiosity to understand some essential facts about earth systems:

Question 1. All of the matter used in modern life was present on earth when it was formed approximately 4.5 billion years ago.

a. True
b, False

This question anticipates the notion that Earth is essentially a closed system with respect to matter, and leads to the broader realization that all matter is recycled.

Question 2. When a plant grows, most of its mass is derived from …

a. the atmosphere
b. the soil
c. groundwater

This question anticipates the discussion of photosynthesis and its central importance to life. Photosynthesis and the opposite process of respiration also introduce the question of how CO2 is cycled. As a parallel benefit, this discussion helps students improve their insights to chemistry.

Question 3. Where is most of the world’s oxygen stored?

a. The atmosphere
b. The crust and mantle
c. The oceans

This question anticipates the discussion of the Gaia Hypothesis, which is the (surprisingly recent) understanding that Earth’s climate system is regulated by an interplay between living (biotic) and nonliving (abiotic) entities. This leads to a more detailed discussion of the relatively fast cycling of matter between the atmosphere and surface due to the presence of living organisms, versus the relatively slow cycling of matter due to geological processes between the surface and solid earth.

I developed these questions because they reflect key waypoints where my own intuition conflicted with reality (“expectation failure”) along my recent journey to learn this topic well enough to teach it in a coherent, responsible, and hopefully engaging manner. My ultimate goal is to help students draw a picture of how earth materials cycling and climate were in relative balance during the Holocene, and how human activities have disproportionately upset these cycles, leading to what we now refer to as the Anthropocene, which includes climate change. I will present limited data to summarize student responses and their progress in learning about earth systems.