A Study and Assessment of the Carbon Footprint of Tianjin University’s Weijin Road and Peiyangyuan Campuses, China

9 Background: A living University campus is like a model city; its energy and carbon 10 auditing can also model how energy and carbon can be studied and analyzed in a city. 11 China’s colleges and universities face grave problems, now and in the future - from 12 declining quality of campus environments to deteriorating building performance, 13 antiquated facilities, and inefficient energy and resources consumption. While research 14 and discussion exists on improving existing university buildings’ energy performance 15 and evaluation standards - much of that research focuses on energy savings, rather than 16 on greenhouse gas emissions reductions. Calculation of campus carbon emissions is the 17 first step for transforming and planning each existing university to carbon neutral 18 campus. Some researchers of campus carbon emissions in China have made 19 calculations, which, although as yet unpublished, create an initial framework for carbon- 20 neutral campus plan targets. The present research gives an overview of universities’ 21 drive towards sustainability in China and in other countries. The paper then details 22 carbon footprint accounting steps, quantifying major carbon emission sources and 23 carbon sequestration by vegetation inside the Tianjin University’s Weijin Road and 24 Peiyangyuan Campuses. Results from China’s universities are compared with 25 international results in the scientific literature. In this paper, based on this data, we 26 suggest strategies and show preliminary target settings for how to transform Weijin 27 Road into a carbon-neutral campus. 28 Results: Annual carbon emissions for 2019 of the Weijin Road campus were 58,172.68 29 tonnes, (2.60 tonnes per person), and Peiyangyuan campus, 55,213.75 tonnes (2.46 30 tonnes per person). The largest sources of the two campuses’ greenhouse gas emissions 31 were electricity and gas; Weijin Road campus; electricity = 61.42%, gas = 20.73%, and 32 Peiyangyuan campus electricity = 69.32%, gas = 11.60%. Carbon sequestered in the two 33 campuses by vegetation are 11,257.34 tonnes and 27,856.51 tonnes respectively. The 34 renewable energy contribution to carbon reduction in Peiyangyuan campus is 50.85 35 tonnes. 36 Conclusion: Per person carbon emissions of Tianjin University’s two campuses are 37 below the average for some US campuses, but are also greater than some in European 38 countries. Research may investigate methods used by successful campuses towards 39 becoming carbon neutral. 40

an unprecedented and sometimes irreversible way (McGrath, 2021). 67 China is now the world's in China were 9.57Gt (Gigatonnes) of CO2, which accounts for about 28% of total world 75 carbon emission (IEA, 2021). Most recent studies and news reports suggest that China's 76 GHG emission is critical to the world (Brown, 2021). With the growing attention to 77 Climate Change, in the 75 th UN meeting, China announced an ambitious 'Plan to 78 reducing GHG Emissions' and set a target for the country, known as the "30-60" target, 79 whereby 2030 will reach the peak value of the GHG emission and 2060 will reach 80 carbon-neutral country (China Plus, 2020).

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Climate Change is an important topic, and many organizations and universities 82 have realized the importance of mitigating their carbon footprint, and some have 83 completed their greenhouse gas inventories to determine their greenhouse potential, 84 which is the first step towards a planned carbon emission target (Roche et al., 2014). 85 Colleges and Universities are seen as an important part of society with the main 86 characteristic of a high density of population, and high energy consumption. Finding 87 how to reduce colleges and universities carbon emissions is now an important reference 88 and challenge for the whole of society. of "Green School" activities throughout the country (China, 1996). In 1999, the Ministry 122 published the 'National Environmental Education and Promotion Plan for 2001-2005', 123 which proclaimed the 'Green University' (China, 2001 The higher education sector in China has a higher population than that of any 152 country in the world. By the end of 2019, there were 2688 colleges and universities, 153 with over 30.31 million students enrolled in mainland China (Fig. 2). The education 154 system includes Bachelors, Masters and Doctoral degrees, as well as non-degree 155 programs, and is also open to foreign students. Carbon Neutrality of Chinese Colleges and Universities by 2050 (Development, 2021).  mobility of students and staff from outside the campus area where its impact is normally 265 lower than that of electricity (Helmers et al., 2021). The situation in China is not the 266 same and is impractical to calculate due to the very high number of students and staff.

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Students and staff at TJU travel from various parts of China, and they have various 268 modes of transport, making it difficult to predict or anticipate when and where mobility 269 occurred. Some studies have suggested questionnaire-based calculations for the mobility 270 of students and staff (Helmers et al., 2021), but due to the long distances covered and 271 the mobility situation in China, 'questionnaires' for the thousand (two campuses with 272 a combined population of approximately 45000 people in total) were beyond the scope 273 of this study -but an estimate would be sufficient rather than attaining precise and 274 reliable travel statistics from outside the campus.

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The carbon footprint of a university should be intrinsically focused on emissions 276 caused by activities within the campus, rather than the mobility of students and staff 277 occurring outside of the campus boundary which cannot be controlled by the university.

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It is also supported by Isiaka Adeyemi Abdul-Azeez, who pointed out in his research 279 that carbon emission assessment should be focused on the sources which a university 280 authority has control over where carbon emission strategies could be applied (Adeyemi,281 2018).

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In this regard, this research considers electricity, natural gas (heating and canteen 283 cooking), and mobility of cars within the campus, solid waste generation, tap water, and 284 human activity are each quantified for carbon emission accounting. Data was collected 285 to quantify the 'operational stage' of GHG emissions of the two campuses in 2019.  (Information, 2020), 'Provincial Guidelines for Greenhouse Gas Inventories(PGGGI)' 311 (Development, 2011), 'China's Regional State Grid Average Carbon Dioxide Emission 312 Factor for 2011-2012' (China, 2014) were used to select the coefficients and form 313 carbon accounting methods which are most suitable for Tianjin city regions of China. 314 Calculation of CO2 emissions, equal to the energy consumption and coefficient; Where E represents CO2 emission due to energy consumption. i represents the 317 corresponding energy coefficient, and E i is the emission factor.  inside the campus. Out of these emissions, food, waste and water could be controlled or 334 managed more effectively. The carbon emission from people breathing inside the 335 campus cannot be controlled, instead this could be replaced by carbon sequestration 336 using more plantations.

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In summary, the campus carbon emission inventory diagram can be used as a guide 338 for calculating both campuses' carbon emissions. In this study, we calculated carbon 339 emissions through their operational stage. In later sections of this paper we will examine 340 embodied carbon, and the operational platform which will monitor, review, estimate, 341 and most importantly, demonstrate -the carbon reduction paths for colleges and 342 universities.

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Distances were carefully plotted and the average of these distances were assimilated.

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Entry points and parking bays for the TJU Weijin Road Campus are shown in Fig. 8. 395 Weijin Road Campus has three main entry gates which are called East Gate, West Gate, 396 and North Gate. All vehicles are allowed to enter from these gates.

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The distance from each entry point to the most used parking bays is shown in 398  (China, 2020).

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The standard emission factor for diesel oil is given as =3.096kgCO2/kg, 420 one liter of diesel is 0.9kg on average (2021).     shrub-herb type, lawn type, and grassland.

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The arithmetic term of carbon sequestration amount is the following: Where is are green-lands with daily carbon sequestration (g·m -2 ·d -1 ) 503 and area green-lands area (m 2 ); D number of days for calculation, generally D=365. Therefore, the total avoided greenhouse gas emission due to using a solar water 542 heater system is 50.85 tonnes.   Fig. 10 shows that, at Tianjin 550 University's both campuses, electricity was the greatest source of emission, producing 551 65.27 % of total carbon emission followed by natural gas for heating, producing 16.28%, 552 human activity producing 12.34%, solid waste generation producing 5.19%, tap water 553 and transportation producing 0.66% and 0.26% respectively (Fig. 12).   University of Talca  Chile  2016  7869 98,000 32,869 (Yañez et al., 2020b) unfortunately, TJU carbon emissions are higher than many European Universities. proposal is a carbon reduction plan for every each year until the total emission is zero.   The author would like to acknowledge Chen Tian, who is the Chief of the Logistic Sector, 692 for his contribution in providing necessary information which was critical to this article. 693 We would also like to thank the following: Roger Hopkinson (