This paper contains an overview of legislative framework related to the problem of climate change, especially the segment important for development of methodology of carbon dioxide emissions calculation. The role of methodology of carbon dioxide emissions calculation in reduction of total emissions as part of the Kyoto Protocol is also defined. One of the responsibilities of the Kyoto Protocol parties is to establish national greenhouse gas inventories which consist of annual calculations of carbon dioxide emissions on a defined area. The principle of carbon dioxide emissions calculation is listed according to the instructions of the Intergovernmental Panel on Climate Change (IPCC) from 2006. The calculation encompasses those emissions which are consequences of anthropogenic activities and are not subject of The Montreal Protocol on Substances that Deplete the Ozone Layer. Those substances are: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), hydrofluorocarbons and perfluorocarbons (HFCs and PFCs), sulphur hexafluoride (SF6) and indirect greenhouse gases: carbon monoxide (CO), nitrous oxides (NOx), non-methane volatile organic compounds (NMVOCs) and sulphur dioxide (SO2). The methodology covers areas of energetics and industrial processes, use of solvents, agriculture, land use, land-use changes, forestry, and waste management. The methodology of carbon dioxide emissions calculation in the field of energetics in Croatia is elaborated in detail. The analysis of movement of carbon dioxide emissions in the field of energetics considering the main social and economic parameters has been made. The analysis includes movements in the past, as well as estimates of carbon dioxide emissions in the near future.