08-04-25 - City Council Work Session Agenda

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18. Greenhouse Gas (GHG) Emissions/Carbon Footprint a. GHG Quantification — For all proposed projects, provide quantification and discussion of project GHG emissions. Include additional rows in the tables as necessary to provide project -specific emission sources. Describe the methods used to quantify emissions. If calculation methods are not readily available to quantify GHG emissions for a source, describe the process used to cometo that conclusion and any GHG emission sources not included in the total calculation. About Greenhouse Gases (GHGs) Certain gases in the earth's atmosphere, classified as greenhouse gases (GHGs), play a critical role in determining the earth's surface temperature. Solar radiation enters the earth's atmosphere from space. A portion of the radiation is absorbed by the earth's surface and a smaller portion of this radiation is reflected back toward space. This absorbed radiation is then emitted from the earth as low -frequency infrared radiation. The frequencies at which bodies emit radiation are proportional to temperature. Because the earth has a much lower temperature than the sun, it emits lower -frequency radiation. Most solar radiation passes through GHGs; however, infrared radiation is absorbed by these gases. As a result, radiation that otherwise would have escaped back into space is instead "trapped," resulting in a warming of the atmosphere. This phenomenon, known as the greenhouse effect, is responsible for maintaining a habitable climate on earth. The primary GHGs contributing to the greenhouse effect are carbon dioxide (CO2), methane (CH4), and nitrous oxide (N20). Fluorinated gases also make up a small fraction of the GHGs that contribute to climate change. Examples of fluorinated gases include chlorofluorocarbons (CFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3); however, it is noted that these gases are not associated with typical land use development. Human -caused emissions of GHGs exceeding natural ambient concentrations are believed to be responsible for intensifying the greenhouse effect and leading to a trend of unnatural warming of the earth's climate, known as global climate change or global warming.31 Project Related GHG Emissions This section describes the GHG emissions from the existing buildings within the study area and include an estimated quantification of the following GHG emissions associated with the proposed scenarios: • Carbon dioxide (CO2) • Nitrous oxide (N20) • Methane (CHa) The projected GHG emissions are provided on an average annual basis using the CO2 equivalent (CO2e) and include the proposer's best estimate of average annual emissions over the proposed life/design service life of future development. The estimates include emissions from the construction and operating phases of the scenarios. Emissions were estimated using the US Environmental Protection Agency's Simplified GHG Emissions Calculator (SGEC) (Version 7 June 2021)32 and are summarized in Table 11 and Table 12 by project phase (i.e., construction and operations) and source type (e.g., combustion from mobile equipment, off -site electricity) (see Appendix C for tables). 31 Summarized from U.S. EPA, Overview of Greenhouse Gases: https://www.epa.gov/qhqemissions/overview- greenhouse-gases 32 Source: https://www.epa.gov/climateleadership/simplified-qhq-emissions-calculator Lino Lakes Main Street - AUAR 69 July 2025 Page 77 of 617