Social cost of CO2 emissions in Tehran waste management scenarios and using life cycle assessment to select the scenario with the least impact on global warming

Climate change includes global warming driven by human-induced emissions of greenhouse gases and the resulting large-scale shifts in weather patterns. Tehran, Iran, has a population of 13 million (2017) and produces about 13,000 tons of municipal solid waste per day and 4.7 million tons annually. This study used the life cycle assessment (LCA) method to calculate all the emissions in different scenarios for Tehran's waste management. The IWM model was used for Phase II of the LCA. The results of the proposed scenarios showed that the highest emission was from greenhouse gases (GHG), which were9.6, 3.2, and 2.7 million tons in the first, second, and third scenarios, respectively. The IPCC reports and the results from the life cycle inventories were used to calculate the social cost analysis for the scenarios based on the CO2 equivalents. The third scenario caused a 71.8% and 17.2% reduction in terms of social costs compared to the first and second scenarios, respectively. Thus, according to the importance of greenhouse gases in global warming, employing a third scenario in the waste management system could effectively reduce greenhouse gases in Tehran.