## 1 Introduction  
The global human population is increasing exponentially. According to the Population Reference Bureau [1], the global population is projected to increase from 7.7 billion in 2020 to 9.9 billion by 2050. This dramatic growth is clearly associated with inevitable urban growth. It is projected that the world will have 43 so-called megacities, with more than 10 million inhabitants, by 2030, most of which will be in developing regions [2]. Although cities have been the dominant driving force for economic growth and development, increasing population density in cities leads to risks and challenges for both humans and the environment. The rise of megacities in the global economy has boosted the demand for both primary and secondary raw materials. It can lead to greater pressures on land and other finite natural resources, including energy, food, and mineral resources. In terms of energy consumption, over two-thirds of the global primary energy consumption was attributable to cities. Furthermore, cities account for more than 75-80% of global greenhouse gas (GHG) emissions [3]. The International Energy Agency [4] estimated that energy-related GHGs in the urban areas accounted for about 71% of the total emissions in 2008 and this number is expected to rise to 76% by 2030. More specifically, energy consumed in the building sector accounts for as much as 30-40% of the global energy demand [5]. From a consumption-oriented point of view, approximately 80% of C40 cities,which is a network of global megacities committed to addressing climate change, contributed the largest share of consumption-based GHG emissions [3]. It should be noted that urban form and technological and economic factors were considered major determinants of citywide GHG emissions. [PERSON] and [PERSON] [6] estimated residential- and transport-related GHG emissions in the Toronto Census Metropolitan Area to define the impacts of urban form on emission-causing activities and found that GHGs from private auto use sources are on par with those from fuel use for building heating. [PERSON] [7] found that the 35 largest cities in China accounted for about 40% of the total energy usage and carbon emissions. By employing the input-output subsystem model, [PERSON] et al. [8] investigated the sectoral roles in GHG emissions in China and found that the three-largest CO\({}_{2}\) emitters were electricity and heat production and distribution; transportation, storage, postal services and telecommunications; and metal mining. In terms of the final sectoral demand, construction was considered the largest carbon emitter. Specifically, the service sectors generated more carbon emissions than the manufacturing and agricultural sectors. CO\({}_{2}\) was the largest component (99.45%) of the total emissions, followed by N\({}_{2}\)O (0.45%) and CH\({}_{4}\) (0.10%), respectively. Above all, it is often emphasized that cities are at the forefront of reducing total urban energy consumption and cutting carbon emissions. A study by [PERSON] et al. [9] revealed that citywide energy-related CO\({}_{2}\) emissions have gained increasing attention in recent years because citywide GHG inventories can promote energy efficiency and climate change mitigation policy, and thus help guide the direction of a city's emission reduction efforts. From a policy point of view, Thailand intends to cut its GHG emissions by 20% from the business-as-usual (BAU) level by 2030 as mentioned in its Intended Nationally Determined Contribution (INDC) [10]. Correspondingly, Thailand's INDC was formulated based on the National Economic and Social Development Plans, Climate Change Master Plan B.E. 2558-2593 (2015-2050), Power Development Plan B.E. 2558-2579 (2015-2036), Thailand Smart Grid Development Master Plan B.E. 2558-2579 (2015-2036), Energy Efficiency Development Plan (EEDP) B.E. 2558-2579 (2015-2036), Alternative Energy Development Plan (AEDP) B.E. 2558-2579 (2015-2036), Environmentally Sustainable Transport System Plan B.E.