Transportation: Emissions Analysis
Air Travel
We estimate that in 2007 air travel related to Williams College activities accounted for nearly 70 % of the College’s transportation emissions and produced ~4,500 metric tons of CO2 from an estimated 16 million miles of air travel. These estimates are based on a 450 ticket sample (from the ~2200 plane tickets purchased for Faculty and Staff business travel) and information about destinations for these tickets. Estimated student travel to and from campus and flights for students who studied abroad (Table 1) are also included in the total.Table 1. Estimated air travel and CO2 emissions, FY 2007.
| Category | Approximate cost (dollars) | Number of round trips | Total distance (miles) | Emissions (metric tonnes eC02) |
| Students studying abroad | 239 | 2,297,769 | 644 | |
| Faculty and staff | $1,180,000 | >2000 | 9,565,445 | 2,683 |
| Students traveling to and from campus | 4,171,400 | 1,168 | ||
| Total | 16,034,614 | 4,496 |
At least some plane tickets purchased for grant-related travel are not included in our calculations and actual student travel is probably greater than values listed in Table 1, so our estimates for air travel are probably low. To put this figure in perspective, 4,500 metric tons of CO2 is equivalent to the annual greenhouse gas emissions from 823 passenger vehicles or the energy use of 397 homes for one year (ref.). In 2007 air travel alone accounted for nearly 17% of all campus greenhouse gas emissions.
Emissions for Fiscal Year 2007: Air Travel, Other Travel, and Total