The process that terrestrial plants use to absorb carbon dioxide is called photosynthesis. During photosynthesis, plants convert carbon dioxide and water into glucose and oxygen, using sunlight as an energy source. This process primarily takes place in the leaves within chloroplasts, which contain the green pigment chlorophyll necessary for capturing light energy. Photosynthesis not only provides energy for the plant itself but also produces oxygen, which is vital for the survival of aerobic organisms. By sequestering carbon dioxide from the atmosphere, plants play a critical role in regulating the Earth's climate and carbon cycle.