An increase in the average level of carbon doixide in the atmosphere is most likely caused by and increase in what?

An increase in the average level of carbon dioxide in the atmosphere is most likely caused by an increase in the burning of fossil fuels, such as coal, oil, and natural gas, for energy and transportation. Deforestation also contributes to this rise, as trees that absorb CO2 are removed. Additionally, industrial processes and agricultural practices can release more carbon dioxide into the atmosphere. Together, these activities significantly elevate atmospheric CO2 levels, contributing to climate change.