In recent decades, active measures have begun to be taken to solve global problem due to the increase in the concentration of carbon dioxide in the atmosphere. The article presents a review of the literature over the past 30 years. It focuses on changes in natural and anthropogenic CO2 emissions over time. Forest fires are also included in a separate group. Annual natural CO2 emissions 550–848 billion tons (from 1990 to 2022). The main natural sources are the respiration of living organisms; soil respiration; processes occurring in the oceans; volcanic eruptions and the formation of minerals. The released carbon dioxide is absorbed by the oceans and photosynthesis of plants. The literature data confirm the fact that there is an imbalance in the natural cycle of carbon dioxide in relation to its emissions. One of the main factors influencing this is anthropogenic emissions. Their share increased from 2.9 to 5.3% of total carbon dioxide emissions between 1990 and 2022 (from 25 to 41 billion t/year). The main contribution to emissions is made by burning fossil fuels, agriculture, cement and concrete production, and deforestation. Up to 50% of anthropogenic gas is absorbed by natural ecosystems and involved in the carbonation of cement. The rest of the gas is trapped in the atmosphere. This led to a large accumulation of CO2 in the atmosphere over several decades. The carbon dioxide content increased by 20% (from 1990 to 2022). The share of total carbon dioxide emissions from forest fires is 0.9–1.3%.