Fractionation of carbon isotopes in oxygenic photosynthesis characterization of food chains. Oxygenic photosynthesis is a metabolic pathway facilitated by autotrophs, including plants, algae, and cyanobacteria. This pathway converts inorganic carbon dioxide from the atmosphere or aquatic environment into carbohydrates, using water and energy from light, then releases molecular oxygen as a product. Organic carbon contains less of the stable isotope Carbon-13, or C, relative to the initial inorganic carbon from the atmosphere or water because photosynthetic carbon fixation involves several fractionating reactions with kinetic isotope effects. These reactions undergo a kinetic isotope effect because they are limited by overcoming an activation energy barrier. The lighter isotope has
Ocean storage of carbon dioxide Ocean storage of carbon dioxide Ocean storage of carbon dioxide (CO) is a method of carbon sequestration. The concept of storing carbon dioxide in the ocean was first proposed by Italian physicist Cesare Marchetti in his 1976 paper "On Geoengineering and the carbon dioxide Problem." Since then, the concept of sequestering atmospheric carbon dioxide in the world's oceans has been investigated by scientists, engineers, and environmental activists. 39,000 GtC currently reside in the oceans while only 750 GtC are in the atmosphere. Of the 1300 Gt carbon dioxide from anthropogenic emissions over the last 200 years, about 38% of that