The municipal solid waste in Landfill is transformed into landfill gas during a biochemical conversion process called bio-degradation. Gas release from landfills has potentially different environmental effects; therefore, assessing and forecasting the rate of production and release of gas from landfill sites is important for designing these sites and for the successful exploitation of gases as energy sources. In this study, by using LandGEM model, in the span of 2018-2037, the amount of gases produced from the municipal landfill of Sirjan, Iran has been predicted. According to the results, the largest amount of landfill gas emission will be in 2038, a year following the last year of disposal of the waste to the landfill. The total amount of produced gas, carbon dioxide, methane, and NMOCs will be 1. 219E+05, 8. 932E+04, 3. 255E+04, and 1. 399E+03 tons per year in 2038 for Sirjan. In the next step, the LandGEM outputs were imported into OpenLCA software. The health and environmental effects of landfill gas emissions were evaluated by USEtox and traci method, respectively, in this software. According to the USEtox method, the value of total health effects was obtained as 0. 032496 CTUh; in addition, by using the traci method, the most environmental burden falls in the impact categories of global warming, photochemical ozone formation, ecotoxicity, acidification, respiratory effects. By making sound and suitable plans as of this 20-year period and implementing tube in this place, greenhouse gas emissions to the atmosphere can probably be prevented. It is also suggested that landfill gases be used to supply energy to the Sirjan recycling plant.