Tuesday, February 5, 2013

Air Travel and the University

Hintz Family Alumin Center, Penn State
In a recent post, I spoke about how air travel represents a huge chunk of the carbon footprint of an academic like me.  But what if instead we consider the carbon footprint of the university as a whole?

Energy use figures for the Penn State university system can be found on the web at the "Green PSU" site.   From this page we can infer the following annual consumption figures for the University Park campus:
  • 284 GWh of electricity from the grid
  • 36000 tonnes of coal
  • 900 million cu ft of natural gas
Using ballpark figures for CO2 intensity of these sources, the respective CO2 emissions from these are
  • 140,000 tonnes from electricity generation (assumed intensity: 500g/kWh)
  • 105,000 tonnes from coal burning (assumed 80% of coal is C, converted completely to CO2 by combustion)
  • 48,000 tonnes from natural gas (using 53.6 tonnes per million cubic feet).
The total of roughly 300,000 tonnes  per year is divided among roughly 45,000 students, 3,000 full-time faculty, and 9,000 full-time staff, giving about 5.1 tonnes/person annually for the campus-based emission figure.

Now, how much flying do these people do?  It is not easy to get direct information about this.  I already fessed up to an academic travel program that runs about 8 tonnes/year, but I am probably on the high side.  My undergraduate research assistant Kaley recently carried out a survey across several University Park departments and colleges.  67 faculty members completed the survey and the  data (I should stress very preliminary) suggest that an average academic travel program corresponds to about 3 tonnes/year emissions.  If we assume that all 3000 full-time faculty travel at this intensity, that produces a figure of 9,000 tonnes/year or about 3% of campus fixed emissions.  That may well be high because it is plausible that those who don't travel at all were disproportionately likely not to respond.  Even if you assume that everyone travels as much as I do, the percentage is still "only" 8%.

What to make of this figure? It makes a significant but not a huge dent in the total environmental impact of a place like the UP campus.  But on the other hand, the campus meets the needs of 45,000 students as well as the faculty and staff.  It would be equally "correct" to say that the average carbon dioxide emissions attributable to a faculty member's travel seem roughly two-thirds of  the fraction of the campus' fixed emissions attributable to him or her.

Which way of counting is most morally relevant?

(UPDATED 2/8 to correct an arithmetical error.)

Photo by Flickr user akrobat77, licensed under Creative Commons

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