Considering the serious threat caused by mobile phone use, the study dealt with the determination of how much carbon footprints from the use of mobile phones among the Science undergraduate students of a state university in Central Visayas, Philippines are emitted in the atmosphere. This study utilized the non-experimental quantitative research method, particularly the survey method, to gather data on the number of hours of mobile phone use, and on the conservation practices of the student respondents. The equivalent carbon footprint (CO2e) is obtained by converting the number of hours of phone use through the factor 57 g CO2e per minute use. Study findings revealed that the respondents spent the most in texting with an average of 17.95 kg CO2e per day. Application using, charging and calling contributed an average daily emission of 7.06 kg CO2e, 6.10 kg CO2e, and 1.78 kg CO2e, respectively. Bluetooth-using produced the least emission with 0.49 kg CO2e. These modes of use have implications in the educational setting, highlighting the need to adhere with significant educational theories and principles to maximize instructional time, rather than mobile use time. It was also found out that most students practiced conservation through reduction of mobile phone use, while 4% of them do not have mobile phones, and 9% do not have any conservation practices. Thus, the paper concluded that the students have affected the planet by contributing an annual emission of 84.71 tons kg CO2e, or less than a millionth of the total global emissions. In accordance with the Kyoto Protocol, the students should reduce their mobile phone utility by 25-31 minutes per day. Students are gaining advocay in environmentalism, and eventually towards sustainable development.