Plants give out carbon dioxide not only at night but during the day too. It happens because of the process of respiration in which plants take in oxygen and give out carbon dioxide. As soon as the sun rises another process called photosynthesis starts, in which carbon dioxide is taken in and oxygen is given out.
Plants use photosynthesis to capture carbon dioxide and then release half of it into the atmosphere through respiration. Plants also release oxygen into the atmosphere through photosynthesis
