4.2. Comparison of GHG Emissions by Category
Comparisons between the CFs of different universities present considerable challenges due to the significant variations in their respective profiles, such as the distinction between teaching-oriented and research-oriented institutions, or those emphasizing science and engineering versus arts disciplines. Furthermore, comparisons are further complicated by the divergence in methodologies universities employ to estimate their carbon footprints, particularly regarding the activities considered within the Scope 3 category. Despite these inherent difficulties, comparisons across universities have nonetheless been undertaken because they provide valuable contextual understanding for the study. II UNAM [
11] and DMU [
36] had CFs per capita comparable to the CRGS results. Despite the similar CFs per capita, the distribution among scopes varied considerably. The most notable difference was observed for Scope 1 because the CRGS generates an insignificant amount of energy on site (0.1% of total GHG emissions). In contrast, DMU and II UNAM reported 6% and 5% of GHG emissions corresponding to Scope 1 owing to fuel consumption by their vehicle fleets and natural gas combustion for space heating, respectively. The CRGS does not have its own vehicle fleet and has minimal heating demand. Regarding GHG emissions from energy purchased (Scope 2), CRGS and II UNAM reported values of 0.33 and 0.68 t-CO
2e, respectively, for a difference of 50%. According to Güereca et al. [
11], the high energy consumption at II UNAM can be attributed to the type of activities carried out by the institute. Applied research at II UNAM makes use of laboratories and equipment that are energy intensive. Within Scope 3, the difference in GHG emissions can be attributed to business travel; the CRGS reported GHG emissions 2.5 times more than that of DMU and four times more than that of II UNAM, even though II UNAM made 24 more trips in America. For DMU [
36], the business travel category represented 7.9% of the total CF and mainly comprised student and business trips. This difference in results is mainly because 40% of the trips made by the CRGS community took place outside the continent. By population type, student trips represented 17.8%, 5.8%, and 0.5% of the total CF for the CRGS, DMU, and II UNAM, respectively. The CRGS and II UNAM had similar GHG emissions in the commuting category at 50% and 45%, respectively, of the total CF, but the contribution was only 21% for DMU. Although DMU reported 79% of its CF was in Scope 3 and CRGS reported 71%, the former considered GHG emissions from construction, product manufacturing, and food services, which were not considered in the present study.
CFs can be used to identify hotspots in supply chains [
18]. However, although the distribution by scope is useful for locating the main sources of GHG emissions, it is difficult to establish a comparison based on these percentages because each study accounted for different activities, especially in Scope 3. According to Lenzen and Treloar [
43], process analyses may not be comparable when the boundaries between systems are different. Larsen and Hertwich [
18] supported this argument by suggesting that a framework based on methodological coherence needs to be established to define the universal organizational limits to which universities must adhere.
4.3. Mitigation Scenarios
In support of the Race to Zero movement [
44], Mexican universities have committed to achieving net-zero GHG emissions before 2050, along with more than 550 universities worldwide. They have also committed to mobilizing resources for CC research and increasing the role of environmental education in study and outreach programs on campus. To contribute to this vision, three mitigation scenarios are proposed for reducing the CF of the CRGS in the short, medium, and long term, prioritizing those sources with greater potential for reducing GHG emissions.
Scenario 1: This scenario considers strategies for reducing GHG emissions in the energy purchase, commuting, and business travel categories.
Reduce the amount of energy purchased: The roof dimensions of the CRGS make it possible to install a photovoltaic system capable of supplying 27% of the electricity demand according to simulations carried out with System Advisory Model (SAM) software (version 2020.2.29) [
45].
Allow students to attend online classes 2 out of 5 days per week instead of going to the campus for a course distribution of 40% online and 60% face-to-face: Before the COVID-19 pandemic, most courses were face-to-face, so students traveled to the campus 4 days a week on average. Having experienced an entire semester online, students have found benefits in online classes, such as flexibility, convenience, cost reduction in transportation, and time for engaging in other activities. It is worth mentioning that not all courses offered at CRGS can be conducted online as they require students’ presence, such as practical studio art courses. However, a considerable number of classes can be taken in an online format. Migrating courses to a hybrid schedule of 30–79% online and face-to-face activities [
28] would reduce the total CF by 23%.
Reduce trips by administrative staff, collaborators, and teachers by 19%: According to the Wall Street Journal [
46], 19–36% of travel demand for administrative staff is expected to disappear post-COVID-19. In addition, an internal emission compensation program can be created to compensate for 100% of the GHG emissions generated by the air travel of collaborators that cannot be avoided. This aligns with the results of Geneidy et al. [
47], who studied the importance of organizational policies encouraging employees to choose greener means of transportation. Another step would be to apply a fee to each flight to offset 30% of the GHG emissions due to student travel, considering a cost of USD 18.50 to offset 1 t-CO
2 [
48]. According to Lu and Wang [
49], only 5% of those surveyed demonstrated an understanding of the environmental impacts of air travel, and young travelers between 21 and 30 years of age showed little willingness to change air travel habits, such as preferring land travel or video conferences. Only passengers over 50 years old were willing to participate in a project to offset GHG emissions from air travel. However, the willingness changed positively when travelers made trips once a year.
Scenario 2. This scenario considers additional strategies that are meant to be implemented after Scenario 1 is implemented.
In line with the national goal for 2024, purchase 35% of the energy demand in the BY from renewable energy sources [
50]: Although this percentage can be quite ambitious, it is possible to achieve based on precedent: UDEM bought 60% of its energy from low-carbon sources through cogeneration in 2015–2018.
Reduce in-person attendance by collaborators and replace it with home offices: Before the pandemic, employees attended the campus 5 days a week. A new normality is proposed where employees attend on average 3.5 days of face-to-face activities (3 days for collaborators with essential non-face-to-face activities and 4 days for collaborators with face-to-face activities). In a post-COVID-19 world, Sharfuddin [
51] and Geneidy et al. [
47] estimate that organizations will implement a hybrid scheme of 60% face-to-face activities and 40% virtual work (i.e., being present three out of five working days per week). This step will reduce the energy demand of the workspace, but more significantly, it will reduce the need to commute.
Reduce private car usage among students by up to 23% through the implementation of travel demand management (TDM) policies. Strategies such as increasing parking costs and promoting carpooling and vanpooling services can be effective. The revenue generated from increased parking fees can be allocated to fund sustainable transportation initiatives, including bike infrastructure improvements, subsidized transit or bus passes, discounted parking rates for shared vehicles, and carpooling programs. This percentage was obtained from data on using the vanpooling service and carpool parking spaces [
52]; it represents half of the students that use private cars and live near the stops of the vanpooling service or other students who can change their means of transportation. Barata et al. [
53] described how providing parking space in universities drives the use of private transportation. Increasing parking prices tends to deter the use of cars and increases the use of public transportation [
54,
55]. In places with limited public transportation services, charging for parking may incentivize carpooling [
56]. In contrast, Crotti et al. [
57] demonstrated that free parking permits increase the use of private cars and potentially carpooling options. Thus, parking costs should only be increased for solo drivers, while free parking should be provided for carpooling. Although UDEM already has an exclusive parking lot for carpooling, it is extremely limited. It has 105 parking spaces for a community of around 10,000 undergraduate and graduate students and collaborators and is 0.5 km from the CRGS. Hence, the CRGS can promote carpooling by reserving 130 parking spaces in the nearest parking lot for carpooling without charging. The university vanpooling service can be promoted by increasing awareness about the routes, stops, and environmental benefits. Promoting this service is important because only two people on average were transported by each van in the BY, despite a capacity of 20 seats.
Strengthen the voluntary emission compensation program for student trips to offset an extra 20% of the GHG emissions from travel: This can be achieved through institutional policy and promoting awareness because young people who are educated and aware of the environment are more willing to pay more to reduce their CF [
58].
Scenario 3. This scenario considers additional strategies that are meant to be implemented after Scenario 2 is implemented.
Increase the purchase of clean energy by an additional 8% to reach 43% of the demand in the base scenario: This is in line with the national goal for 2030 [
50]. Reduce the number of students using private cars for transportation by a further 23%: TDM policies can be promoted such as increasing parking costs [
59], which can serve as a subsidy for the promotion of carpooling and vanpooling services and the use of bicycles. Ensuring a bicycle-friendly environment on and around the campus may encourage students and collaborators to use this means of transportation [
57].
Apply a fee to every flight to offset 20% of the GHG emissions from travel: This will reach 90% compensation for student trips. Following the examples of Yale University [
60] and UCLA [
61], the emission compensation fund can be allocated to internal projects of the university to realize net-zero emissions, such as investment in more clean energy, sustainable mobility plans, and sustainability research.
As shown in
Figure 2, implementing these three scenarios through community participation would reduce the total CF of the CRGS by 63.5%. The three scenarios are meant for gradual implementation at a pace the CRGS community can accommodate. To increase the number of categories considered in the study, the following actions are proposed: in the upstream emissions category of purchased goods and services, it is suggested to differentiate products for each of the different schools of the university and measure the waste generation from green areas by CRGS to allocate the corresponding GHG emissions. Likewise, in the visitor travel category, it is proposed to implement a visitor registration form, collecting the routes and modes of transportation used by the invited collaborator. A monitoring committee should be established to ensure the correct execution of the strategies and measure their impact over the years.
According to Li et al. [
62], research on the carbon footprints of higher education institutions places decarbonization in a position to help solve climate issues [
9], encourage sustainable consumption patterns [
63], promote a low-carbon economy [
64], and develop low-carbon energy sources [
65]. Institutions of higher education are of utmost importance to achieve global net-zero. They help educate and raise awareness among future leaders about environmental impacts, create platforms for dialogue, and promote public and inclusive policies in sociopolitical and economic regimes. Their influence in other sectors is essential because CC is a challenge that requires global and immediate action to curb its effects. Creative and immediate solutions must be developed by institutes of higher education to offset the negative impact of GHG emissions on the environment [
66]. Over the years, universities have strengthened their efforts to document and evaluate their CFs, which can be used to generate and demonstrate tools for decarbonization [
67,
68,
69]. To be leaders in sustainability and drivers of change, universities must ensure that their students understand the need to guarantee resources for present and future generations and, more importantly, to act upon these problems and work to provide solutions. Collaborators focused on sustainable development will effectively educate students and generate a transition to sustainable social patterns through education and research, sustainable operation, engagement, and reporting [
70]. Due to the lack of economic availability, electric vehicles were not considered in these mitigation scenarios. In 2021, only one out of 1140 automobile buyers in Mexico opted for an electric vehicle (EV). EV sales accounted for over 4% of total vehicle sales in North America. Therefore, new car insertion remains lagging in Latin America. The lack of adoption of electric vehicles in Mexico is due primarily to high prices and limited availability [
71]. The majority of electric vehicles are priced above
$25,000 USD, making them affordable only for the upper middle class. As a result, the transition from internal combustion vehicles to EVs will proceed at a significantly slower pace [
72]. The mitigation scenarios mainly focus on cutting emissions from the electricity generation sector by 31% by 2030. The Mexican climate program does not foresee such a drastic drop in the transportation sector [
73]. Although adopting electric vehicles would decrease GHG emissions in Mexico, it would also require a stronger commitment to generating energy from renewable sources. Future research may include the evaluation of mitigation measures that encourage electric vehicles. The above is in line with the Electric Mobility Strategy, which seeks to reduce CO
2 emissions by 18% in the transport sector, conforming the national fleet with electric cars in 5% by 2030 and 100% by 2050 [
73].