Greenhouse Gas Inventory
Greenhouse Gas (GHG) Emissions
Duke's GHG inventory contains data back to 1990, but incorporates far more activity beginning in 2007. Also beginning in 2007, emissions are broken out by University (which includes the School of Medicine and School of Nursing) and Health System. In total, Duke has achieved an 11% reduction in University emissions as of 2011, based on a 2007 baseline. The graph below displays a reduction in overall emissions of the University and Health System since 2008.
Duke's Climate Action Plan is specifically targeted for the University (including the School of Medicine and School of Nursing). The graph below displays an 11 percent reduction in University emissions in 2011, based on a 2007 baseline. 
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 demonstrates that University emissions reductions are on target with the goals outlined in the Climate Action Plan.
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 2011.
Transportation Footprint
Duke's transportation footprint is comprised of three major sources:
- Commuter travel (10%), employees commuting from their home to work;
- Air travel (16%), 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.
Energy Footprint
Energy use at Duke has a significant impact on the environmental footprint of the University. According to Duke's 2011 GHG inventory, energy comprises 72 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. In 2009, as part of the Climate Action Plan, Duke opened a newly renovated baseload natural gas East Campus steam plant, which cut coal consumption by 70% on campus. In April 2011, Duke eliminated coal use from campus completely, and began renovations to its West Campus steam plant to convert it from a coal-burning plant to a natural gas facility like its sister plant on East Campus.
The 2011 GHG inventory indicates that emissions from purchased electricity off site through Duke Energy make up 48 percent of the total campus GHG emissions (including emissions from transportation).