Greenhouse Gas Report

The Orange County Transportation Authority (OCTA) reviews greenhouse gas (GHG) emissions from our fleet’s operations on an annual basis to understand our effect on Orange County’s vehicle air emission levels.  Additionally, we review how overall emissions levels are affected when drivers shift from private vehicles to public transit.  A reduction of congestion on our streets and freeways is expected when public transit is used. To quantify GHG emissions, the OCTA uses guidance from the American Public Transportation Association (APTA). APTA has set standards for Quantifying Greenhouse Gas Emissions From Transit. These standardized methodologies aid in calculating “displaced emissions” when people shift from cars to bus and rail.

In 2011, the OCTA produced 83,927 metric tons of CO2e (carbon dioxide equivalent for greenhouse gas emissions) from its day to day activities.  Comparatively, 140,562 metric tons of CO2e was displaced by transit activities in Orange County. Total GHG emission from the OCTA’s operations had a net-positive effect of -56,635 metric tons of CO2e.   These results are similar to OCTA’s GHG emissions in 2010 with no significant changes. In Orange County, public transportation directly results in significant reduction in overall GHG emissions. The OCTA is committed to reducing its own carbon footprint and encouraging the use of public transportation in Orange County.


Review 2005 - 2010 Greenhouse Gas Report
Review 2011 Greenhouse Gas Report