If trees will be removed from the forest, the effect will be a decreased rate of atmospheric CO2. The importance of CO2 for plants is used in photosynthesis because it is needed for them to produce their own food. The increase of carbon dioxide due to pollution will need more plants to use it but in this situation, logging will decrease the rate of used CO2 for plants leading to more CO2 that is circulating to the atmosphere which can also lead to global warming.
