Carbon dioxide estimation at Lampung University based on vehicle volume

Of all activities related to carbon dioxide generation in Lampung University, vehicle exhaust is a main source of anthropogenic carbon dioxide (CO2). Carbon dioxide (CO2) may trap the earth’s heat which worsens the climate change. As For the physical condition of humans, high concentration of CO2 exposure may cause death, unconsciousness, convulsions and fetus damage. Even in lower concentration, CO2 exposure can cause hyperventilation, vision damage, lung congestion, central nervous system injury, and other health problems. A case survey was conducted to measure CO2 emission based on two type of vehicles; private car and motorcycle to obtain the number of vehicle entry per gate. A mathematical model was also used to estimate CO2 production. Several factors such as fuel consumption, emission factor, and number of running per day (distance) were used as inputs. CO2 emission in the next five years was also estimated using the same method by previously extrapolated the earliest 5 years population data of Lampung University. The result shows that motorcycles are responsible for 1.636 ton of CO2 emission or approximately 55% of the total CO2 emission in Lampung University. Meanwhile, cars contribute to 1.34 ton of CO2 emission or approximately 45% of the total CO2 emission. It was also estimated that Lampung University would have an increase in vehicle number by 7.81%.


Introduction
It is an undeniable fact that transportation sector has become one of the biggest contributors of greenhouse gas (GHG) emissions around the world [1]. Report from IPCC in 2007 stated that more than a quarter of carbon dioxide (CO2), shares of methane (CH4), and nitrous oxide (N2O) around the world was caused by transportation [2].
Based on the stated above fact, countries around the world has started to formulate strategies to tackle the challenge of GHG. Bali Climate Declaration in 2007 is one of the committed ways that emphasized joint efforts of developed and developing countries on climate change [3]. Green Campus concept is one of committed actions taken by Indonesian government to tackle the climate change issue in a small platform, in this case, university level.
Lampung University, is one of several campuses in Indonesia that has committed to provide a long term environmental improvement within the campus community, proved by its participation in UI GreenMetric along with other universities around the world. The aim of this program is to trigger participating universities to: a) provide more green space as well as the development of sustainable energy by 15%, b) increase the effort for energy efficiency in their buildings by 21%, c) establish programs related to waste treatments by 18%, d) decrease water usage by 10%, while at the same time, increase conservation program, e) limit the number of motor vehicles in campus by 18%, and f) raise By early 2018, Lampung University has a 70 Ha of area with 29,462 number of people including students, lecturers, and academic staffs. This number triggers high and active movement from one building to another with 82.5% of it includes vehicles. Therefore, a high consumption of fossil fuel is to be expected along with the CO2 emission as the result of vehicle exhaust. Estimation of current CO2 concentration from vehicle exhaust is essentially needed in order to build an efficient countermeasure.
Conducting this research, some objectives were set. Those are: (a) to estimate CO2 concentration from vehicle exhaust in Lampung University, (b) setting futute planning for countermeasures of CO2 emision in Lampung University.

Research Methods
The estimation of CO2 in the Lampung University was based on the vehicle volume. In which the estimation was focused by the consumption of fuel from vehicle movement. Some data collection were needed. The estimation of CO2 was performed by the simple mathematical model based on the fuel consumption

Subject and study area
This research was performed on two types of vehicle: cars and motorcycles; within the area of Lampung University in 2018 with a case survey study using random sampling method. Eight (8) faculties were chosen to become control points, as they generate most vehicle movements, with three main entrances: Gate 1, Gate 2, and Gate 3; as starting points as seen in Figure 2

Data collection
There are two types of data used in this study: secondary and primary data. Secondary data such as volume of vehicle was obtained from previous inventory study owned by Lampung University. Meanwhile, primary data: distance between gates and faculties and the number of vehicle entry per gate were obtained from the survey using random sampling method. A time series of population number in Lampung University was also needed. The population data was used to predict the number of population within the next five years, by extrapolation. The plotting of population number in the next five years, helped to predict the vehicle population that may exist in Lampung University and its CO2 emision.

Formula and equation
CO2 emission concentration was estimated by calculating the number of vehicle movements in several faculty buildings with road segments connected to the entrance gates of Lampung University.   Table 2.

Trip distance
Economics and Bussinees Faculty (FE) , (7) Law Faculty (FH). Trip distance was calculated with origin of trip were the three gates in Lampung University. The trip distance will influence how much the fuel was consume for the purpose of movement within Lampung University.
The longest distances from trips into those eight faculties were the trips from Gate 1. And the lowest distance were from Gate 3. The trip distance from Gate 1 were around 1 km until 1.3 km. While from Gate 3, the trips were around 0.4 km to 0.9 km.

Number of Vehicles in Lampung University
The number of vehicles in Lampung University is shown in Table 3 below. Based on the table, the vehicles in Lampung University was dominated by motorcyles with number of 20964 (86%) while private car was 3334 (14%).

CO2 Emision Estimation
Calculation of CO 2 Emision was performed based on Eq.1 and Eq.2 was shown in Table 4 and Table  5. It is estimated that motorcycles contribute to at least 1.636 ton/day of CO2 emission or pproximately 55% of the total CO2 emission in Lampung University. Meanwhile, cars contribute to at least 1.34 ton/day of CO2 emission or approximately 45% of the total CO2 emission as shown in Figure 2.  It also estimated that by 2023, Lampung University would sustain an increase in number of students. Thus, an increase of vehicle number shall be expected. Using linear extrapolation and the same calculation method that is based on the earliest 5 years data, it was estimated that Lampung University would an increase in vehicle number by 7.81%. Early countermeasure shall be efficiently planned and practiced in order to achieve a greener campus. Figure 3. shows the result of CO2 emission estimation in present time and the next 5 years.    Based on this result, an immediate future planning is needed to reduce the concentration of CO2 emission. Centralized parking system for student's motorcycle can be a technical solution for this problem as it might reduce the running distance of vehicle. Hence, a decrease in CO2 emission by is also to be expected. Figure 4. shows where the centralized parking system shall be located.

Conclusion
The vehicle movement in Lampung University was dominated by motorcyle with its number was around 20964. For private car, it was around 3334. By considering petrol as vehicle's fuel, CO2 estimation finding showed that motorcycles contributed about 55% or 1,636 ton/day while cars created about 45% or 1,34 ton/day. The projection for the next five years shown that there will be 7.81% of vehicle increament with CO2 emision were 1,764 ton/day for motorcyles and 1,443 ton/day for cars. Centralized parking system for student's motorcycle can be a technical solution for this problem as it might reduce the running distance of vehicle. Hence, a decrease in CO2 emission by is also to be expected.