An analysis of greenhouse gas emissions in urban areas: A case study of Tehran metropolis

Climate change is the result of human activities such as fossil fuel consumption and land use changes. While cities occupy only two percent of the Earth surface, they account for 71 to 76 percent of global carbon dioxide emissions. Since the pattern of production and consumption in the Iranian economy is based on fossil fuels, the concentration of population and activity in metropolises has increased the consumption of these fuels and the centralized emission of greenhouse gases. The purpose of the present study is to analyze and compare production-based and consumption-based approaches for measuring greenhouse gas emissions in urban areas and then implementing them in Tehran metropolis. The research method is descriptive-analytical, and the data are collected through documentary studies. The 1995 IPCC guidelines are used to measure greenhouse gas emissions. The statistical population of the study is Tehran metropolis and its fossil fuel consumption in a period of 11 years (2005 to 2016). Tehran has high per capita emissions of greenhouse gases, which is due to its pattern of production, distribution and consumption based on fossil fuels and associated lifestyles. This has turned the city into the largest emitter of these gases. The results of calculations with the IPCC (Production-Based Approach) show a per capita increase in the CO2 emissions of Tehran over a 10-year period (4.94 and 5.09 tons per citizen in 2006 and 2016). Also, using a consumption-based approach, the per capita carbon footprint of each citizen emerges to be 7.77 tons per year. Finally, the carbon dioxide emissions per capita of the city is compared with some other metropolises in the world. The results show that the per capita emissions in Tehran are higher than in other large metropolitan areas such as Rio de Janeiro, Seoul, Bangkok, Buenos Aires, Hong Kong and London.