Emissions Trend Analysis

With the inventory completed, we calculated temporal trends in these metrics.  By combining these GHG emissions metrics with projected campus growth (specified in number of students) we established a business as usual projection of GHG emissions through 2050.  We have actual data for 1990 through 2006.  From 2007 onwards, we used the growth projections from the UC Berkeley Long Range Development Plan (1.14% annual increase in gross square footage and 0.609% annual increase in population).  Then, we mapped possible targets to assess what type of reductions would be feasible for UC Berkeley. 

The two largest emissions sources highlight the importance of choosing a utility provider that uses clean and renewable fuel sources:

• Steam - Steam usage is the single largest source of GHG emissions, representing roughly 40% of total emissions, followed by electricity, air travel and faculty and staff auto commute.

• Electricity - The increase in electricity emissions between 1998 and 2006 is due to the higher coal content in the power mix for the electricity generated by Arizona Public Services (38% coal for APS vs. 1% coal for PG&E).  In 2006, the main campus account (88% of the campus electricity) switched back to PG&E, which uses only 1% coal, 42% natural gas, 12% nuclear, 20% hydro and 12% renewable – a fuel mix that shows significant improvements in our emissions inventory for calendar year 2006.