Wastewater treatment (WWT) is obligatory for the protection of ecosystems and human health but also produces the greenhouse gases (GHGs) nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2 ) along the process chain. According to the IPCC (2018) anthropogenic CO2 and carbon emissions must decline by 45% worldwide from 2010 levels by 2030 to keep temperatures from rising beyond 1.5 ° degrees. Currently the sector of WWT contributes about 0.11 % to the total carbon emissions in Germany and was responsible for about 5 % of global non-CO2 GHG emissions in 2005. N2O emissions in particular play the major role here. Aerobic granular sludge (AGS) for biological WWT has gained increasing interest mainly due to higher process efficiency compared to conventional activated sludge (CAS). Studies show a reduction potential of 20 – 25 % in operation costs, 23 – 40 % in electricity use and 50 –75 % in space requirements. AGS processes are implemented as sequencing batch reactor (SBR). SBRs with a small temporal and spatial variability for biological metabolism are likely to generate process conditions promoting N2O formation. A 1% increase in direct N2O emissions could already result in a 30 % increase of the carbon footprint of a WWTP. In this thesis direct GHG emissions from AGS treating domestic wastewater are studied. It was part of the project E-VENT where an AGS Nereda® pilot-plant has been operated at Stahnsdorf WWTP, Berlin (Germany). The reactor was fully-covered and GHG emissions have been monitored online over a 3 months period. A conservative approach for off-gas flow determination has been chosen to not over-estimate GHG loads. The plant was operated with domestic wastewater extracted after the primary clarifiers. At stable operating conditions maximum removal rates of 96 % chemical oxygen demand, 90 % nitrogen and 87 % phosphorous were achieved. Determined emission factors (EF) for N2O and CH4 over the complete measurement period were 2.86 % and 0.18 % respectively. Rising process temperatures from 13 – 20 °C showed a positive correlation with EFs and higher TN loads during the day lead to higher N2O complementing literature review on N2O EFs. The CO2 EFs showed that determined values for AGS are in accordance with 2.8 % ± 1.2 % found in a comparable study by Guimarães et al. (2017). Findings conclude that N2O contributes to about 95 % to total direct carbon emissions of the Nereda® plant and is a main factor for the climate impact of AGS.