ASU Carbon Summit: Food systems discussion and panel

By Kaeleb Kramer, Student Worker, Swette Center for Sustainable Food Systems

Just recently, the inaugural Carbon Summit was hosted at ASU's Rob and Melani Walton Center for Planetary Health on November 15th and 16th, 2023. This exciting event was led by Jason Marmon, an ASU graduate student in the College of Global Futures and management intern for University Sustainability Practices. It served as an informative showcase of sustainable solutions spanning five themes that were all on display through presentations and panels: food systems, energy transitions, circular economies, climate adaptation, and sustainability. By focusing on these topics, the Carbon Summit struck a balance between carbon and desert futures while addressing issues posed by climate change. I had the opportunity to attend the first keynote presentation and the following discussion on food systems. 

In the presentation “Finding the Value in Food Systems Waste” given by Dr. Bruce Rittman of the Swette Center for Environmental Biotechnology, the main points brought forward were society’s reliance on energy systems and how we can repurpose biomass waste in our food systems for current and future energy demands. For context, as of 2022, human activities and energy demand amount to about seventeen terawatts, which is almost enough power for ten billion, hundred-watt light bulbs [1] [3]. The majority of our energy sources are fossil fuels such as oil, coal, and natural gas. Biomass energy is an area of potential where we may divert crop residues, animal waste, food waste, and human waste by repurposing their molecular makeup through innovative processes. Dr. Rittman highlighted that for bioenergy sources to be viable, they must operate at larger scales. If all residual biomass from agricultural activities was used, this would meet over twenty-five percent of global energy needs.

In his presentation, Rittman examined anaerobic microbiological processes. Anaerobic digestion is the function by which microorganisms decompose organic matter (food or animal waste and wastewater biosolids) in the absence of oxygen. Reactors, which are sealed vessels specifically made for the site and feedstock circumstances, are where anaerobic digestion for the production of biogas occurs [2]. Methanogenesis, a form of anaerobic respiration that uses carbon as the terminal electron acceptor, resulting in the production of methane, is a more proven technology. It can be used to treat organic waste and produce useful compounds. It is the main pathway that breaks down organic matter in landfills, which can release significant quantities of methane into the atmosphere if unchecked. It is possible to gather and use biogenic methane as a sustainable substitute for fossil fuels. Secondly, Rittman proposed microbial electrochemical systems, a rapidly developing field of technology that uses microorganisms to extract chemical energy from bioorganic materials and turn it into electrical power. This is an actively developing technology, but he expressed optimism if more investments and adoption were made. Through proper implementation and management, digesters can offer better benefits like odor management and lower dangerous air emissions from manure because they absorb methane and other air pollutants. Utilizing digester biogas reduces emissions and fuel usage from non-renewable fossil fuels. As acknowledged by Rittman, for anaerobic digestion to be economically viable, it typically requires running on a large scale in order to produce biogas (as well as other kinds of energy products and technologies). Particularly for small operations, anaerobic digestion can be excessively costly and technically complicated. If manure is co-digested with non-farm wastes (such as food and green waste), the procedure may be less expensive.

Following the lecture was a discussion panel that sought to bring about respective individuals and their perspectives throughout all sectors of our local food systems. Jason Marmon served as the moderator, and speaking on the panel were Dr. Bruce Rittman, Michele Caporali, a professor at Scottsdale Community College, Charles Jones of DigestorDoc, a local company specializing in providing services related to anaerobic digesters, and Elora Bevacqua, a student worker with our very own Swette Center for Sustainable Food Systems. Several key prompts were brought forward that aimed to instigate thought-provoking discussions. One of the most important points raised was the concept of job succession in agriculture and how to engage with younger generations. Elora’s take was one that promoted optimism as she said that individuals should seek pathways through passions rather than out of fears such as climate anxiety and that through collective action, we may work towards obtainable goals. Charles Jones advocated for progressions in familiarity where all populations (consumers, producers, and everything in between) can go about learning more about the different interactions and processes that take place. Building off of that, the question of how we may face challenges in our education systems was poised, and Michele Caporali expressed that both educators and the learning populations at all levels can embrace change and look to bridge gaps through the creation of digestible information. 

Important lessons that I took away were the value of following one's passion and applying yourself, strengthening knowledge with various procedures and interactions, and tackling educational obstacles by producing clear and concise content. The potential of innovative food system practices to minimize the effects of climate change and create a more balanced carbon future was highlighted by the Carbon Summit as a whole.

A recording of the event is available to be viewed online here:


  1. Energy Institute. (n.d.). Home. Statistical Review of World Energy.
  2. Manure use for fertilizer and for energy: Report to Congress. (n.d.).
  3.  Ritchie, H. (2023, October 9). Energy production and consumption. Our World in Data.