06 16 20 PWA_02_02 Exh2 - IS-MND

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L w FAIRVIEw BRIDGE REPLACEMENT AND STREET IMPROVEMENTS INITIAL STUDY/MITIGATED NEGATIVE DECLARATION J' (9TH STREET TO 16TH STREET) PROJECT MAY 2020 SANTA ANAL CALIFORNIA 3.8 GREENHOUSE GAS EMISSIONS Less Than Potentially Significant with Less Than Significant Mitigation Significant No Impact Incorporated Impact Impact Would the project: a. Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the ❑ ❑ ® ❑ environment? b. Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse ❑ ❑ ® ❑ eases? 3.8.1 Existing Conditions Global climate change (GCC) describes alterations in weather features (e.g., temperature, wind patterns, precipitation, and storms) that occur across the Earth as a whole. Global temperatures are modulated by naturally occurring components in the atmosphere (e.g., water vapor, carbon dioxide [CO21, methane [CH4], and nitrous dioxide [N201) that capture heat radiated from the Earth's surface, which in turn warms the atmosphere. This natural phenomenon is known as the "greenhouse effect." That said, excessive human -generated greenhouse gas (GHG)18 emissions can and are altering the global climate. The CEQA statutes, the Governor's Office of Planning and Research (OPR) guidelines, and the changes to the State CEQA Guidelines currently prescribe specific quantitative thresholds of significance or a particular methodology for conducting an impact analysis related to GHG effects on global climate. In contrast, as with most environmental topics, significance criteria are left to the judgment and discretion of the lead agency. Currently, there is no Statewide GHG emissions threshold that has been used to determine the potential GHG emissions impacts of a project. Thresholds and threshold methodology are still being developed and revised by air quality districts in the State. To provide guidance to local lead agencies on determining significance for GHG emissions in their CEQA documents, SCAQMD convened a GHG CEQA Significance Threshold Stakeholder Working Group. This Working Group proposed a tiered approach for evaluating GHG emissions for development projects where SCAQMD is not the lead agency. The applicable tier for the proposed Project is Tier 3; if GHG emissions are less than 3,000 metric tons (MT) of CO2 equivalent (CO2e) per year, Project -level and cumulative GHG emissions would be less than significant. Individual GHGs have varying global warming potentials and atmospheric lifetimes. Because it is not possible to tie specific GHG emissions to actual changes in climate, this evaluation focuses on the Project's emission of GHGs. CO2e is a consistent methodology for comparing GHG emissions because 18 The principal greenhouse gases (GHGs) of concern contributing to the greenhouse effect are carbon dioxide (CO2), methane (CH4), nitrous oxide (N20), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). Water vapor is the largest naturally occurring GHG; however, it is not identified as an anthropogenic constituent of concern. 3-44 R:\WKE1702\ISMND\Final ISMND\Fairview Street Bridge Final ISMND.docx (05/26/20)