The contribution and modeling the Green House Gases (GHG) from transport sector in total pollution into the atmosphere air in Azerbaijan has been evaluated. As a result of conducted surveys, it is ascertained that car wastes are the main pollution sources of worsening air quality. Thus, over 80% (1 mln ton) the total emissions has been exhausted by vehicles. In the frame of survey, COPERT 4 software evaluation program has been applied to calculate Carbon-dioxide (CO2), nitrous oxides (N2O) and methane (CH4) which is one of main source of Global Warming and Climate Changes. The methodology has been based on IPCC/CORINAIR air pollutant emissions inventory guidebook. The key results of the study show that calculating vehicles emission using the COPERT-4 methodology can improve the estimation methods and could help to modeling the pollution for next years. The method based on fuel consumption, average emission factors, road infrastructure, motion of vehicles at different condition included in the guidelines of İPCC. Methodology require the collection of all the considered activity data by using the respective guidelines, calculate the total emissions from each source and pollutants of interest. Currently, gradual growth at fuel consumption is irrational for economical and air quality aspects Using the methodology proposed in this work is able to start from certification data to define modal emission rates of fuel consumption and NOx emission according to COPERT-4 software. This data and methodology can be further used in any other driving cycle, using the correspondent vehicle time distribution, to estimate and modeling fuel use and emission outcome in a given vehicle ore fleet of vehicles.