Skip To Main Content

Through the completion of a local emissions study, or “greenhouse gas inventory,” the Earth Systems and Ecological Design classes of 2017-18 and 2018-19 have determined emissions levels for the school’s operations. Emissions include all sources for which HHS exercises direct operational control including building energy, waste generation, water consumption, and school bus fuel consumption. Emissions associated with vehicle trips by employees and students commuting to the school were also included in the inventory.


An important aspect of GHGs is the unit of measurement used to inventory and estimate emissions. While carbon dioxide (CO2) is the most prevalent and recognized GHG, there are other GHGs such as methane and nitrous oxide. To simplify the discussion and comparison of these emissions collectively, CAPs use a metric known as carbon dioxide equivalent (CO2e). The CO2e metric translates each GHG to an equivalent volume of CO2 by weighing its relative global warming potential. Methane and nitrous oxide are 25 and 310 times more potent, respectively, than CO2 in their abilities to trap heat in the atmosphere (DES 2009). Converting these GHG emissions into CO2e using global warming potential values allows us to consider all gases in comparable terms and makes it easier to communicate how various sources and types of GHG emissions contribute to climate change using a standard unit of measurement of the amount of GHG emissions produced and released into the atmosphere.