Every time any animal breathe, you are producing CO2. During the nights even vegetables produce CO2. Anytime we burn gasoline, diesel, coal, wood, and any other type of fuel, we are producing CO2. During the day vegetables absorb CO2. read more
Yes carbon dioxide is present in air the quantity is about 0.04% Tress and Plants live on carbon dioxide as we humans on oxygen. read more
Carbon dioxide concentrations have varied widely over the Earth's 4.54 billion year history. Carbon dioxide is believed to have been present in Earth's first atmosphere, shortly after Earth's formation. read more
Carbon dioxide is present in the air because plants need carbon dioxide to make food and without carbon dioxide plants would die and eventually the rest of the food chain. read more