By private transportation, we refer to staff and students driving their private cars to NUS. This is computed via the season parking passes that purchased through the Office of Estate and Development¹.

By using addresses of the parking passes applicants and their postal codes, they are divided into major districts according to the Singapore Post². The distance from each district to the two campuses is then calculated. It is assumed that people living in the same district takes the same distance to come to NUS by car. Driving on small roads from their houses to the expressway is not taken into account.

Using a petrol car’s default emission factor from the GHG Protocol, the relevant carbon emission for each vehicle is then calculated. A distinction is made between staff and student season pass holders because students only travel to campus during the academic period.

An improvement for AY09/10 has been made to make the calculations more accurate. This is achieved through requiring season pass applicants to specify vehicle engine size so that emission factor can be more specific to each category of engine size.

Another improvement was to change the “Address” field to “Residential Address”: In AY 0809, 11.57% of the KR staff season parking was addresses within NUS campus, but in AY0910 season parking, only 3.27% of the KR staff season parking (Semester period) addresses was NUS addresses.

As such, there was more accurate and complete accounting for GHG due to staff and student private car transport.

¹ http://www.nus.edu.sg/oed/services/transport/krcParking/index.htm
² http://www.ura.gov.sg/realEstateWeb/resources/misc/list_of_postal_districts.htm

Only public transport by students and staff to the Kent Ridge Campus is accounted for and the Bukit Timah Campus is excluded. This is because for Kent Ridge Campus, there are 2 SBS Transit bus services, 95 and 96, that are almost entirely dedicated to serve the NUS Kent Ridge Campus.

The frequency of the buses is derived from the SBS Transit website while the distance travelled is obtained using Google Maps. Using the distance based method in GHG Protocol, the amount of fuel consumed is determined from the distance travelled and fuel economy factor from GHG Protocol.

Staff Air travel is the second largest contributor to NUS carbon footprint, accounting for about 25% of NUS’ total carbon emissions. In calculating GHG due to air travel, NUS has only taken into consideration staff and faculty air travel; air travel by students for Student Exchange Program, Summer Programs, overseas internship and attachment programs or similar overseas programs are not included due to the complexity of gathering the data.

In calculating carbon emissions due to air travel, NUS has chosen to use Atmosfair for AY 07-09 which gives specific amounts of emissions for each location instead of just using generic conversion factors for short haul and long haul flights. In 2007, air travel data was collected from the 3 travel agents: Air Services, Diners World Travel and Safe2Travel. Information from Air Services were detailed enough to calculate the carbon emissions due to each flight route. Information provided by Diners World Travel and Safe2Travel were inadequate to generate emissions calculations, hence the carbon emissions due to flights booked from these 2 travel agents were calculated based on average from data analyzed from Air Services

With effect from September 2008, NUS changed its appointed travel agent to Pacific Arena Private Limited. Since then, NUS is able to obtain consolidated monthly reports indicating the class, destinations and number of tickets. This allows us to use Atmosfair for a more accurate estimation of carbon emissions due to staff air miles.

As part of the efforts to reduce NUS’ carbon emissions due to staff air travel, NUS senior management has initiated 20% cut in air budget for Financial Year 09 based on Financial Year 07 actual expenditure.

There are 7 shuttle bus services for the Kent Ridge Campus: A1, A2, B, C, D1, D2 and one Bukit Timah Campus service that plies between the Kent Ridge and Bukit Timah Campus.

Steps to calculate Carbon Emission Due to Internal Shuttle Bus are as follows:

1.		Distance of each service is multiplied with the fuel economy factor that is derived from the GHG Protocol to calculate the fuel used per trip
2.		The total number of trips per day is worked using the shuttle bus schedule found on OED Transport and Logistic webpage
3.		The total number of trips per year is then further calculated by multiplying trips per day with the total number of working days a year
4.		Number of working days per year is calculated using information from the Ministry of Manpower (See 2010 example here) and NUS Academic Calender
5.		The total amount of fuel used is then multiplied by the carbon dioxide fuel emission factor for diesel in the GHG Protocol to obtain the final carbon emissions due to NUS Internal Shuttle Bus Service