The increase in regional demographics certainly affects the use of energy for transportation and households which will ultimately have implications for greenhouse gas (CO2) emissions in the region. This study focuses on the planning of green open space in the Mamuju Urban Area in order to minimize the effects of greenhouse gases so that the quality of space in the area is maintained. This research is a type of quantitative descriptive research that explores the condition of green open space in the Mamuju Urban Area and takes into account the existing emission potential. The data analysis used is AHP (scoring and weighting) to determine the value and influence of each thematic, image digitization and field observations to determine the existing green open space in the Mamuju Urban Area, and overlay using the ArcGIS 10.8 application to combine maps that be a research indicator. The results obtained from this study are that the Mamuju Urban Area continues to grow from time to time, the distribution of existing green open space continues to decrease along with land use changes that continue to occur, and from the analysis of potential emissions, the largest green open space planning directive is private green open space planning with an area of 354, 14 Ha.