• Author: Simon Brooks (Villanova University Sustainable Engineering)

    • Abstract:

    • This poster presents Carbon Calculus™—a novel integration of net present value (NPV) where the fundamental unit of measurement is CO 2 , not cash—as a critical approach for decarbonization decision-making. Across all large or small companies, federal or local governments, communities, families, and individuals, every action we take is fundamentally answering the decision-making question of how we should spend our limited time on Earth. The answer to this penultimate question will decide for how long humanity will thrive on pathways that sustain life on Earth equitably and justly for all people and all species of Earth’s biodiversity—today, and for all time. We are at a critical time in history that demands all decisions to be sustainable decisions, particularly decisions that have the potential to reduce our greenhouse gas (GHG) emissions. The science is clear: we need to stop emitting carbon dioxide (CO 2 ) and start removing the over-abundant CO 2 in our atmosphere. If you were asked to allocate $100 million to fund CO 2 reduction projects, how would you approach this decision? Making a sustainable decision requires comprehensive acknowledgement of the interconnectedness and complexity of our systems; all critical systems must be analyzed. This poster presents Carbon

      Calculus™ as a novel approach to quantify the net present value of carbon dioxide emission reductions (NPV CO2 ) and assist in more efficiently comparing the value of decarbonization actions—a variable presented as “effective decarbonization.” Any action with an expected positive effective decarbonization is presented as a “sustainability intervention.” An effective annual discount rate for CO 2 emissions was set at 3.355%, aligning with prior published work and the 100-year global warming potential (GWP) of CO 2 . It was determined that 1 ton of CO 2 permanently removed annually has an NPV CO2 of 30.8 tons of CO 2 permanently removed today.

      Case study examples are described to assist the decision-making process for implementing commonly discussed decarbonization projects, such as renewable electrification and direct air capture. Quantitative results are presented to align with the Science-Based Target Initiative (SBTi), and the United States Environmental Protection Agency (US EPA) social cost of carbon (SCC) valuation.