Greenhouse Gas Inventory

Greenhouse Gas (GHG) Emissions

Duke's Climate Action Plan is specifically targeted for the University, including the School of Medicine and School of Nursing. As of 2015, Duke has achieved a 19 percent reduction in emissions, based on a 2007 baseline.

2015 GHG

This reduction can be partially attributed to energy conservation measures and an elimination of coal usage on campus, as well as the implementation of other Climate Action Plan measures.  Additional factors, such as economic conditions, also impact the University's emissions.  The graph below compares Climate Action Plan (CAP) projections and 2015 actual emissions.  The graph demonstrates that University emissions reductions are on target with the goals outlined in the Climate Action Plan.

CAP projections

Duke University's carbon emitting activities can be grouped into three major categories:

  • Electricity, which is purchased from Duke Energy;
  • Stationary fuel, which includes the two campus steam plants used for heating and hot water; and 
  • Transportation, which includes employee commuting, air travel paid for by the University, and the campus fleet.

The graph below displays the breakdown of emissions of the University (including the School of Medicine and School of Nursing) based on carbon emitting activity in 2015.  The "Other" category includes waste, refrigerants and fertilizers.

2015 GHG

Transportation Footprint

Duke's transportation footprint is comprised of three major sources which contribute the following percentages to Duke's overall GHG footprint:

  • Commuter travel (13%), employees commuting from their home to work;
  • Air travel (20%), faculty/staff work travel, sports team travel, and school-related student travel; and
  • Fleet (1%), all bus and university vehicles operated for directly work-related purposes.
In total, transportation comprises about 34 percent of Duke's greenhouse gas inventory, as displayed in the pie chart above.

Successful transportation demand management programs have helped to decrease the number of commuters driving alone to campus from 85 percent in 2004 to 79 percent in 2015.  However, the percentage of commuters driving alone to Duke increased from 70 percent in 2014 to 79 percent in 2015. This reduction in use of alternative transportation options may be due in part to lower gasoline prices.

Energy Footprint 

Energy use at Duke has a significant impact on the environmental footprint of the University.  According to Duke's 2015 GHG inventory, energy comprises 64 percent of the University's GHG emissions. 

Formerly, on site energy emissions stemmed primarily from combustion of coal to produce steam in two campus steam plants.  As part of the Climate Action Plan, Duke has renovated both the East Campus steam plant and West Campus steam plant to burn natural gas instead of coal.  As of 2011, Duke eliminated coal use from campus completely.  Duke’s emissions from campus steam plants decreased 38 percent as of 2014 compared to a 2007 baseline.

As of 2015, Duke's overall energy emissions are down 33 percent compared to a 2007 baseline.

The 2015 GHG inventory indicates that emissions from purchased electricity off site through Duke Energy make up 42 percent of the total campus GHG emissions (including emissions from transportation).