The paper is designed to present a method to estimate greenhouse gases (GHG) uptake or emissions in the absence of data for peat bog areas (GEST method). The paper presents the research results produced by a project on “Limiting CO2 emissions via the renaturalisation of peat bogs on the Eastern and Central European Plain”. The study area consisted of three peat bogs: Kluki, Ciemińskie Błota, and Wielkie Bagno (Słowiński National Park). The GEST method relies on the estimation of gas emissions on the basis of vegetation and water levels and greenhouse gas coefficients for each given habitat type provided in the research literature. The greenhouse gas balance was calculated for a baseline scenario assuming the lack of human impact and for a scenario taking into account human impact in the form of peat bog preservation. Initial research results indicate that there is a total of 41 GESTs in the studied bog areas and that a reduction in CO2 emissions of approximately 12% will occur following what is known as renaturalisation by raising the groundwater level, felling of trees across the bog, and making changes in habitats.