2014-069 - Final Environmental Impact Report No. 2014-01

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HARBOR BLVD. MIXED USE TRANSIT CORRIDOR PLAN FINAL EIR CITY OF SANTA ANA 5. Environmental Analysis 5.5 GREENHOUSE GAS EMISSIONS This section of the Environmental Impact Report (EIR) evaluates the potential for the Harbor Boulevard Mixed Use Transit Corridor Plan project (proposed project) to cumulatively contribute to greenhouse gas (GHG) emissions. Because no single project is large enough to result in a measurable increase in global concentrations of GHG emissions, climate change impacts of a project are considered on a cumulative basis. The chapter evaluates consistency of the project with the strategies outlined in the California Air Resources Board's (CARB) Scoping Plan in accordance with the GHG reduction goals of Assembly Bill 32 (AB 32) and strategies proposed by the Southern California Association of Governments (SCAG) to reduce vehicle miles traveled (VM'I) in the region, in accordance with Senate Bill 375 (SB 375). 5.5.1 Environmental Setting Greenhouse Gases and Climate Change Scientists have concluded that human activities are contributing to global climate change by adding large amounts of beat trapping gases, known as GHG, to the atmosphere. Climate change is the variation of earth's climate over time, whether due to natural variability or as a result of human activities. The primary source of these GHG is fossil fuel use. The Intergovernmental Panel on Climate Change (IPCC) has identified four major GHG water vapor,' carbon (CO2), methane (CHa), and ozone (Oz) —that are the likely cause of an increase in global average temperatures observed within the 20th and 21st centuries. Other GHG identified by the IPCC that contribute to global warming to a lesser extent include nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons, perfluorocarbons, and chlorofluorocarbons (IPCC 2001).2 Table 5.5- 1 lists the GHG applicable to the proposed project and their relative global warming potentials (GWP) compared to CO2. The major GHGs are briefly described below. Carbon dioxide (CO2) enters the atmosphere through the burning of fossil fuels (oil, natural gas, and coal), solid waste, trees and wood products, and respiration, and also as a result of other chemical reactions (e.g., manufacture of cement). Carbon dioxide is removed from the atmosphere (sequestered) when it is absorbed by plants as part of the biological carbon cycle. I Water vapor (1120) is the strongest GHG and the most variable in its phases (vapor, cloud droplets, ice crystals). However, water vapor is not considered a pollutant 2 Black carbon contributes to climate change both directly, by absorbing sunligbt, and indirectly, by depositing on snow (making it melt faster) and by interacting with clouds and affecting cloud formation. Black carbon is the most strongly ligbt�xbsorbing component of particulate matter (PM) emitted from burning fuels such as coal, diesel, and biomass. Reducing black carbon emissions globally can have immediate economic, climate, and public bealth benefits. California has been an international leader in reducing emissions of black carbon, with close to 95 percent control expected by 2020 due to existing progouns that target reducing PM from diesel engines and burning activities (GARB 2013). October 2014 Page 5.5 -1