Carbon-related processes including photosynthesis, biosynthesis, combustion, cellular respiration, and ecological carbon cycling, already play an important role in K-12 and college curricula, including the national standards documents.  The importance of understanding these processes has increased in recent years, as evidence has accumulated that they are key drivers of global climate change.  We suggest that current levels of public understanding provide a perilously thin basis for the kinds of large-scale changes in public reasoning and behavior that will be required during the lifetimes of young people who are students today.  All high school graduates should be able to understand, evaluate, and respond to discussions of global climate change at the level of An Inconvenient Truth.  People in policymaking positions—college graduates who majored in science or in other subjects—and science teachers should be able to understand and evaluate the IPCC (Intergovernmental Panel on Climate Change) reports and their implications for policy and action.  We are developing a learning progression (description of the successively more sophisticated ways of thinking about a topic) for carbon related processes using assessments of students (upper elementary through college).

Results/Conclusions

Our findings indicate that developing a sophisticated (college graduate-level) understanding of carbon-related processes is a hard-won accomplishment that involves the ability to use principled reasoning about tracing matter and energy through a hierarchy of systems and scale, the ability to quantify matter and energy, and an understanding of uncertainty and risk. While most students are aware of the laws of conservation of matter and energy and recognize that gases are matter, they have difficulty conserving gases during chemical and physical changes, and still confuse matter transformations with energy transformations. They may be able to describe systems changes in terms of materials, but their understanding of chemical identity of materials is limited. They may also have some familiarity with microscopic and atomic-molecular scale (cells, atoms) and large-scale (food chains, ecosystems), but cannot easily make connections between these scales (e.g., use a cellular process to explain visible phenomena of growth). The goals of the learning progression for carbon-related processes are to 1) clearly articulate what is essential knowledge for graduates, 2) describe how students can progress from naïve to sophisticated, and 3) to foster a dialogue between researchers and developers of curricula and standards.